// SPDX-License-Identifier: GPL-3.0-or-later
/* Check calls to formatted I/O functions (-Wformat).
   Copyright (C) 1992-2019 Free Software Foundation, Inc.

   Extended for FRR's printfrr() with Linux kernel style extensions
   Copyright (C) 2019-2020  David Lamparter, for NetDEF, Inc.
 */

#include "gcc-common.h"

#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
//include "c-target.h"
#include "c-common.h"
#include "alloc-pool.h"
#include "stringpool.h"
#include "c-tree.h"
#include "c-objc.h"
#include "intl.h"
#include "langhooks.h"
#include "frr-format.h"
#include "diagnostic.h"
#include "substring-locations.h"
#include "selftest.h"
#include "selftest-diagnostic.h"
#ifndef FIRST_PSEUDO_REGISTER
#define FIRST_PSEUDO_REGISTER 0
#endif
#include "builtins.h"
#include "attribs.h"
#include "gcc-rich-location.h"
#include "c-pretty-print.h"
#include "c-pragma.h"

extern struct cpp_reader *parse_in;

#pragma GCC visibility push(hidden)

/* Handle attributes associated with format checking.  */

/* This must be in the same order as format_types, except for
   format_type_error.  Target-specific format types do not have
   matching enum values.  */
enum format_type { frr_printf_format_type,
		   format_type_error = -1};

struct function_format_info
{
  int format_type;			/* type of format (printf, scanf, etc.) */
  unsigned HOST_WIDE_INT format_num;	/* number of format argument */
  unsigned HOST_WIDE_INT first_arg_num;	/* number of first arg (zero for varargs) */
};

static GTY(()) tree local_uint64_t_node;
static GTY(()) tree local_int64_t_node;

static GTY(()) tree local_size_t_node;
static GTY(()) tree local_ssize_t_node;
static GTY(()) tree local_atomic_size_t_node;
static GTY(()) tree local_atomic_ssize_t_node;
static GTY(()) tree local_ptrdiff_t_node;

static GTY(()) tree local_pid_t_node;
static GTY(()) tree local_uid_t_node;
static GTY(()) tree local_gid_t_node;
static GTY(()) tree local_time_t_node;
static GTY(()) tree local_suseconds_t_node;
static GTY(()) tree local_suseconds64_t_node;

static GTY(()) tree local_socklen_t_node;
static GTY(()) tree local_in_addr_t_node;

static struct type_special {
  tree *match;
  tree *replace;
  tree *cousin;
} special_types[] = {
  { &local_atomic_size_t_node,	&local_size_t_node,	&local_ssize_t_node, },
  { &local_atomic_ssize_t_node,	&local_ssize_t_node,	&local_size_t_node, },
  { &local_size_t_node,		NULL,			&local_ssize_t_node, },
  { &local_ssize_t_node,	NULL,			&local_size_t_node, },
  { &local_uint64_t_node,	NULL,			&local_int64_t_node, },
  { &local_int64_t_node,	NULL,			&local_uint64_t_node, },
  { &local_pid_t_node,		NULL,			&local_pid_t_node, },
  { &local_uid_t_node,		NULL,			&local_uid_t_node, },
  { &local_gid_t_node,		NULL,			&local_gid_t_node, },
  { &local_time_t_node,		NULL,			&local_time_t_node, },
  { &local_suseconds_t_node,	NULL,			&local_suseconds_t_node, },
  { &local_suseconds64_t_node,	NULL,			&local_suseconds64_t_node, },
  { NULL,			NULL,			NULL, }
};

static bool decode_format_attr (tree, function_format_info *, int);
static int decode_format_type (const char *);

static bool check_format_string (tree argument,
				 unsigned HOST_WIDE_INT format_num,
				 int flags, bool *no_add_attrs,
				 int expected_format_type);
static bool get_constant (tree expr, unsigned HOST_WIDE_INT *value,
			  int validated_p);
static const char *convert_format_name_to_system_name (const char *attr_name);

static int first_target_format_type;
static const char *format_name (int format_num);
static int format_flags (int format_num);

/* Emit a warning as per format_warning_va, but construct the substring_loc
   for the character at offset (CHAR_IDX - 1) within a string constant
   FORMAT_STRING_CST at FMT_STRING_LOC.  */

ATTRIBUTE_GCC_DIAG (5,6)
static bool
format_warning_at_char (location_t fmt_string_loc, tree format_string_cst,
			int char_idx, int opt, const char *gmsgid, ...)
{
  va_list ap;
  va_start (ap, gmsgid);
  tree string_type = TREE_TYPE (format_string_cst);

  /* The callers are of the form:
       format_warning (format_string_loc, format_string_cst,
		       format_chars - orig_format_chars,
      where format_chars has already been incremented, so that
      CHAR_IDX is one character beyond where the warning should
      be emitted.  Fix it.  */
  char_idx -= 1;

  substring_loc fmt_loc (fmt_string_loc, string_type, char_idx, char_idx,
			 char_idx);
#if BUILDING_GCC_VERSION >= 9000
  format_string_diagnostic_t diag (fmt_loc, NULL, UNKNOWN_LOCATION, NULL,
				   NULL);
  bool warned = diag.emit_warning_va (opt, gmsgid, &ap);
#else
  bool warned = format_warning_va (fmt_loc, UNKNOWN_LOCATION, NULL,
				   opt, gmsgid, &ap);
#endif
  va_end (ap);

  return warned;
}

/* Check that we have a pointer to a string suitable for use as a format.
   The default is to check for a char type.
   For objective-c dialects, this is extended to include references to string
   objects validated by objc_string_ref_type_p ().  
   Targets may also provide a string object type that can be used within c and 
   c++ and shared with their respective objective-c dialects. In this case the
   reference to a format string is checked for validity via a hook.
   
   The function returns true if strref points to any string type valid for the 
   language dialect and target.  */

static bool
valid_stringptr_type_p (tree strref)
{
  return (strref != NULL
	  && TREE_CODE (strref) == POINTER_TYPE
	  && (TYPE_MAIN_VARIANT (TREE_TYPE (strref)) == char_type_node
	      || objc_string_ref_type_p (strref)));
//	      || (*targetcm.string_object_ref_type_p) ((const_tree) strref)));
}

/* Handle a "format_arg" attribute; arguments as in
   struct attribute_spec.handler.  */
tree
handle_frr_format_arg_attribute (tree *node, tree ARG_UNUSED (name),
			     tree args, int flags, bool *no_add_attrs)
{
  tree type = *node;
  tree format_num_expr = TREE_VALUE (args);
  unsigned HOST_WIDE_INT format_num = 0;

  if (!get_constant (format_num_expr, &format_num, 0))
    {
      error ("format string has invalid operand number");
      *no_add_attrs = true;
      return NULL_TREE;
    }

  if (prototype_p (type))
    {
      /* The format arg can be any string reference valid for the language and
	target.  We cannot be more specific in this case.  */
      if (!check_format_string (type, format_num, flags, no_add_attrs, -1))
	return NULL_TREE;
    }

  if (!valid_stringptr_type_p (TREE_TYPE (type)))
    {
      if (!(flags & (int) ATTR_FLAG_BUILT_IN))
	error ("function does not return string type");
      *no_add_attrs = true;
      return NULL_TREE;
    }

  return NULL_TREE;
}

/* Verify that the format_num argument is actually a string reference suitable,
   for the language dialect and target (in case the format attribute is in 
   error).  When we know the specific reference type expected, this is also 
   checked.  */
static bool
check_format_string (tree fntype, unsigned HOST_WIDE_INT format_num,
		     int flags, bool *no_add_attrs, int expected_format_type)
{
  unsigned HOST_WIDE_INT i;
  bool is_target_sref, is_char_ref;
  tree ref;
  int fmt_flags;
  function_args_iterator iter;

  i = 1;
  FOREACH_FUNCTION_ARGS (fntype, ref, iter)
    {
      if (i == format_num)
	break;
      i++;
    }

  if (!ref
      || !valid_stringptr_type_p (ref))
    {
      if (!(flags & (int) ATTR_FLAG_BUILT_IN))
	error ("format string argument is not a string type");
      *no_add_attrs = true;
      return false;
    }

  /* We only know that we want a suitable string reference.  */
  if (expected_format_type < 0)
    return true;

  /* Now check that the arg matches the expected type.  */
  is_char_ref = 
    (TYPE_MAIN_VARIANT (TREE_TYPE (ref)) == char_type_node);

  fmt_flags = format_flags (expected_format_type);
  is_target_sref = false;

  if (!(fmt_flags & FMT_FLAG_PARSE_ARG_CONVERT_EXTERNAL))
    {
      if (is_char_ref)
	return true; /* OK, we expected a char and found one.  */
      else
	{
	    error ("found a %qT but the format argument should be a string",
		   ref);
	  *no_add_attrs = true;
	  return false;
	}
    }

  /* We expect a string object type as the format arg.  */
  if (is_char_ref)
    {
      error ("format argument should be a %qs reference but a string was found", format_name (expected_format_type));
      *no_add_attrs = true;
      return false;
    }

  /* We will allow a target string ref to match only itself.  */
  if (first_target_format_type 
      && expected_format_type >= first_target_format_type
      && is_target_sref)
    return true;
  else
    {
      error ("format argument should be a %qs reference",
	      format_name (expected_format_type));
      *no_add_attrs = true;
      return false;
    }

  gcc_unreachable ();
}

/* Verify EXPR is a constant, and store its value.
   If validated_p is true there should be no errors.
   Returns true on success, false otherwise.  */
static bool
get_constant (tree expr, unsigned HOST_WIDE_INT *value, int validated_p)
{
  if (!tree_fits_uhwi_p (expr))
    {
      gcc_assert (!validated_p);
      return false;
    }

  *value = TREE_INT_CST_LOW (expr);

  return true;
}

/* Decode the arguments to a "format" attribute into a
   function_format_info structure.  It is already known that the list
   is of the right length.  If VALIDATED_P is true, then these
   attributes have already been validated and must not be erroneous;
   if false, it will give an error message.  Returns true if the
   attributes are successfully decoded, false otherwise.  */

static bool
decode_format_attr (tree args, function_format_info *info, int validated_p)
{
  tree format_type_id = TREE_VALUE (args);
  tree format_num_expr = TREE_VALUE (TREE_CHAIN (args));
  tree first_arg_num_expr
    = TREE_VALUE (TREE_CHAIN (TREE_CHAIN (args)));

  if (TREE_CODE (format_type_id) != STRING_CST)
    {
      gcc_assert (!validated_p);
      error ("unrecognized format specifier");
      return false;
    }
  else
    {
      const char *p = TREE_STRING_POINTER (format_type_id);

      p = convert_format_name_to_system_name (p);

      info->format_type = decode_format_type (p);

      if (info->format_type == format_type_error)
	{
	  gcc_assert (!validated_p);
	  warning (OPT_Wformat_, "%qE is an unrecognized format function type",
		   format_type_id);
	  return false;
	}
    }

  if (!get_constant (format_num_expr, &info->format_num, validated_p))
    {
      error ("format string has invalid operand number");
      return false;
    }

  if (!get_constant (first_arg_num_expr, &info->first_arg_num, validated_p))
    {
      error ("%<...%> has invalid operand number");
      return false;
    }

  if (info->first_arg_num != 0 && info->first_arg_num <= info->format_num)
    {
      gcc_assert (!validated_p);
      error ("format string argument follows the arguments to be formatted");
      return false;
    }

  return true;
}

/* Check a call to a format function against a parameter list.  */

/* The C standard version C++ is treated as equivalent to
   or inheriting from, for the purpose of format features supported.  */
#define CPLUSPLUS_STD_VER	(cxx_dialect < cxx11 ? STD_C94 : STD_C99)
/* The C standard version we are checking formats against when pedantic.  */
#define C_STD_VER		((int) (c_dialect_cxx ()		   \
				 ? CPLUSPLUS_STD_VER			   \
				 : (flag_isoc99				   \
				    ? STD_C99				   \
				    : (flag_isoc94 ? STD_C94 : STD_C89))))
/* The name to give to the standard version we are warning about when
   pedantic.  FEATURE_VER is the version in which the feature warned out
   appeared, which is higher than C_STD_VER.  */
#define C_STD_NAME(FEATURE_VER) (c_dialect_cxx ()		\
				 ? (cxx_dialect < cxx11 ? "ISO C++98" \
				    : "ISO C++11")		\
				 : ((FEATURE_VER) == STD_EXT	\
				    ? "ISO C"			\
				    : "ISO C90"))
/* Adjust a C standard version, which may be STD_C9L, to account for
   -Wno-long-long.  Returns other standard versions unchanged.  */
#define ADJ_STD(VER)		((int) ((VER) == STD_C9L		      \
				       ? (warn_long_long ? STD_C99 : STD_C89) \
				       : (VER)))

/* Enum describing the kind of specifiers present in the format and
   requiring an argument.  */
enum format_specifier_kind {
  CF_KIND_FORMAT,
  CF_KIND_FIELD_WIDTH,
  CF_KIND_FIELD_PRECISION
};

static const char *kind_descriptions[] = {
  N_("format"),
  N_("field width specifier"),
  N_("field precision specifier")
};

/* Structure describing details of a type expected in format checking,
   and the type to check against it.  */
struct format_wanted_type
{
  /* The type wanted.  */
  tree wanted_type;
  /* The name of this type to use in diagnostics.  */
  const char *wanted_type_name;
  /* Should be type checked just for scalar width identity.  */
  int scalar_identity_flag;
  /* The level of indirection through pointers at which this type occurs.  */
  int pointer_count;
  /* Whether, when pointer_count is 1, to allow any character type when
     pedantic, rather than just the character or void type specified.  */
  int char_lenient_flag;
  /* Whether the argument, dereferenced once, is written into and so the
     argument must not be a pointer to a const-qualified type.  */
  int writing_in_flag;
  /* Whether the argument, dereferenced once, is read from and so
     must not be a NULL pointer.  */
  int reading_from_flag;
  /* The kind of specifier that this type is used for.  */
  enum format_specifier_kind kind;
  /* The starting character of the specifier.  This never includes the
     initial percent sign.  */
  const char *format_start;
  /* The length of the specifier.  */
  int format_length;
  /* The actual parameter to check against the wanted type.  */
  tree param;
  /* The argument number of that parameter.  */
  int arg_num;
  /* The offset location of this argument with respect to the format
     string location.  */
  unsigned int offset_loc;
  /* The next type to check for this format conversion, or NULL if none.  */
  struct format_wanted_type *next;
};

/* Convenience macro for format_length_info meaning unused.  */
#define NO_FMT NULL, FMT_LEN_none, STD_C89

static const format_length_info printf_length_specs[] =
{
  { "h", FMT_LEN_h, STD_C89, "hh", FMT_LEN_hh, STD_C99, 0 },
  { "l", FMT_LEN_l, STD_C89, "ll", FMT_LEN_ll, STD_C9L, 0 },
  { "q", FMT_LEN_ll, STD_EXT, NO_FMT, 0 },
  { "L", FMT_LEN_L, STD_C89, NO_FMT, 0 },
  { "z", FMT_LEN_z, STD_C99, NO_FMT, 0 },
  { "Z", FMT_LEN_z, STD_EXT, NO_FMT, 0 },
  { "t", FMT_LEN_t, STD_C99, NO_FMT, 0 },
  { "j", FMT_LEN_j, STD_C99, NO_FMT, 0 },
  { "H", FMT_LEN_H, STD_EXT, NO_FMT, 0 },
  { "D", FMT_LEN_D, STD_EXT, "DD", FMT_LEN_DD, STD_EXT, 0 },
  { NO_FMT, NO_FMT, 0 }
};

static const format_flag_spec printf_flag_specs[] =
{
  { ' ',  0, 0, 0, N_("' ' flag"),        N_("the ' ' printf flag"),              STD_C89 },
  { '+',  0, 0, 0, N_("'+' flag"),        N_("the '+' printf flag"),              STD_C89 },
  { '#',  0, 0, 0, N_("'#' flag"),        N_("the '#' printf flag"),              STD_C89 },
  { '0',  0, 0, 0, N_("'0' flag"),        N_("the '0' printf flag"),              STD_C89 },
  { '-',  0, 0, 0, N_("'-' flag"),        N_("the '-' printf flag"),              STD_C89 },
  { '\'', 0, 0, 0, N_("''' flag"),        N_("the ''' printf flag"),              STD_EXT },
  { 'I',  0, 0, 0, N_("'I' flag"),        N_("the 'I' printf flag"),              STD_EXT },
  { 'w',  0, 0, 0, N_("field width"),     N_("field width in printf format"),     STD_C89 },
  { 'p',  0, 0, 0, N_("precision"),       N_("precision in printf format"),       STD_C89 },
  { 'L',  0, 0, 0, N_("length modifier"), N_("length modifier in printf format"), STD_C89 },
  { 0, 0, 0, 0, NULL, NULL, STD_C89 }
};


static const format_flag_pair printf_flag_pairs[] =
{
  { ' ', '+', 1, 0   },
  { '0', '-', 1, 0   },
  { '0', 'p', 1, 'i' },
  { 0, 0, 0, 0 }
};

#define ETAB_SZ 128
static kernel_ext_fmt ext_p[ETAB_SZ] = {
  { }
};
static kernel_ext_fmt ext_d[ETAB_SZ] = {
  { }
};

static const format_char_info print_char_table[] =
{
  /* C89 conversion specifiers.  */
                      /* none,    hh,      h,       l,       ll,      L,       z,       t,       j,       H,       D,       DD     */
  { "di",  0, STD_C89, { T89_I,   T99_SC,  T89_S,   T89_L,   T9L_LL,  TEX_S64, T99_SST, T99_PD,  T99_IM,  BADLEN,  BADLEN,  BADLEN },   "-wp0 +'I",  "i",  NULL, ext_d },
  { "oxXb",0, STD_C89, { T89_UI,  T99_UC,  T89_US,  T89_UL,  T9L_ULL, TEX_U64, T99_ST,  T99_UPD, T99_UIM, BADLEN,  BADLEN,  BADLEN },   "-wp0#",     "i",  NULL, NULL },
  { "u",   0, STD_C89, { T89_UI,  T99_UC,  T89_US,  T89_UL,  T9L_ULL, TEX_U64, T99_ST,  T99_UPD, T99_UIM, BADLEN,  BADLEN,  BADLEN },   "-wp0'I",    "i",  NULL, NULL },
  { "fgG", 0, STD_C89, { T89_D,   BADLEN,  BADLEN,  T99_D,   BADLEN,  T89_LD,  BADLEN,  BADLEN,  BADLEN,  TEX_D32, TEX_D64, TEX_D128 }, "-wp0 +#'I", "",   NULL, NULL },
  { "eE",  0, STD_C89, { T89_D,   BADLEN,  BADLEN,  T99_D,   BADLEN,  T89_LD,  BADLEN,  BADLEN,  BADLEN,  TEX_D32, TEX_D64, TEX_D128 }, "-wp0 +#I",  "",   NULL, NULL },
  { "c",   0, STD_C89, { T89_I,   BADLEN,  BADLEN,  T94_WI,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN },   "-w",        "",   NULL, NULL },
  { "s",   1, STD_C89, { T89_C,   BADLEN,  BADLEN,  T94_W,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN },   "-wp",       "cR", NULL, NULL },
  { "p",   1, STD_C89, { T89_V,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN },   "-wp",       "c",  NULL, ext_p },
  { "n",   1, STD_C89, { T89_I,   T99_SC,  T89_S,   T89_L,   T9L_LL,  BADLEN,  T99_SST, T99_PD,  T99_IM,  BADLEN,  BADLEN,  BADLEN },   "",          "W",  NULL, NULL },
  /* C99 conversion specifiers.  */
  { "F",   0, STD_C99, { T99_D,   BADLEN,  BADLEN,  T99_D,   BADLEN,  T99_LD,  BADLEN,  BADLEN,  BADLEN,  TEX_D32, TEX_D64, TEX_D128 }, "-wp0 +#'I", "",   NULL, NULL },
  { "aA",  0, STD_C99, { T99_D,   BADLEN,  BADLEN,  T99_D,   BADLEN,  T99_LD,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN },   "-wp0 +#",   "",   NULL, NULL },
  /* X/Open conversion specifiers.  */
  { "C",   0, STD_EXT, { TEX_WI,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN },   "-w",        "",   NULL, NULL },
  { "S",   1, STD_EXT, { TEX_W,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN },   "-wp",       "R",  NULL, NULL },
  /* GNU conversion specifiers.  */
  { "m",   0, STD_EXT, { T89_V,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN },   "-wp",       "",   NULL, NULL },
  { NULL,  0, STD_C89, NOLENGTHS, NULL, NULL, NULL, NULL }
};

/* This must be in the same order as enum format_type.  */
static const format_kind_info format_types_orig[] =
{
  { "frr_printf",   printf_length_specs,  print_char_table, " +#0-'I", NULL,
    printf_flag_specs, printf_flag_pairs,
    FMT_FLAG_ARG_CONVERT|FMT_FLAG_DOLLAR_MULTIPLE|FMT_FLAG_USE_DOLLAR|FMT_FLAG_EMPTY_PREC_OK,
    'w', 0, 'p', 0, 'L', 0,
    &integer_type_node, &integer_type_node
  },
};

/* This layer of indirection allows GCC to reassign format_types with
   new data if necessary, while still allowing the original data to be
   const.  */
static const format_kind_info *format_types = format_types_orig;

static int n_format_types = ARRAY_SIZE (format_types_orig);

/* Structure detailing the results of checking a format function call
   where the format expression may be a conditional expression with
   many leaves resulting from nested conditional expressions.  */
struct format_check_results
{
  /* Number of leaves of the format argument that could not be checked
     as they were not string literals.  */
  int number_non_literal;
  /* Number of leaves of the format argument that were null pointers or
     string literals, but had extra format arguments.  */
  int number_extra_args;
  location_t extra_arg_loc;
  /* Number of leaves of the format argument that were null pointers or
     string literals, but had extra format arguments and used $ operand
     numbers.  */
  int number_dollar_extra_args;
  /* Number of leaves of the format argument that were wide string
     literals.  */
  int number_wide;
  /* Number of leaves of the format argument that are not array of "char".  */
  int number_non_char;
  /* Number of leaves of the format argument that were empty strings.  */
  int number_empty;
  /* Number of leaves of the format argument that were unterminated
     strings.  */
  int number_unterminated;
  /* Number of leaves of the format argument that were not counted above.  */
  int number_other;
  /* Location of the format string.  */
  location_t format_string_loc;
};

struct format_check_context
{
  format_check_results *res;
  function_format_info *info;
  tree params;
  vec<location_t> *arglocs;
};

/* Return the format name (as specified in the original table) for the format
   type indicated by format_num.  */
static const char *
format_name (int format_num)
{
  if (format_num >= 0 && format_num < n_format_types)
    return format_types[format_num].name;
  gcc_unreachable ();
}

/* Return the format flags (as specified in the original table) for the format
   type indicated by format_num.  */
static int
format_flags (int format_num)
{
  if (format_num >= 0 && format_num < n_format_types)
    return format_types[format_num].flags;
  gcc_unreachable ();
}

static void check_format_info (function_format_info *, tree,
			       vec<location_t> *);
static void check_format_arg (void *, tree, unsigned HOST_WIDE_INT);
static void check_format_info_main (format_check_results *,
				    function_format_info *, const char *,
				    location_t, tree,
				    int, tree,
				    unsigned HOST_WIDE_INT,
				    object_allocator<format_wanted_type> &,
				    vec<location_t> *);

static void init_dollar_format_checking (int, tree);
static int maybe_read_dollar_number (const char **, int,
				     tree, tree *, const format_kind_info *);
static bool avoid_dollar_number (const char *);
static void finish_dollar_format_checking (format_check_results *, int);

static const format_flag_spec *get_flag_spec (const format_flag_spec *,
					      int, const char *);

static void check_format_types (const substring_loc &fmt_loc,
				format_wanted_type *,
				const format_kind_info *fki,
				int offset_to_type_start,
				char conversion_char,
				vec<location_t> *arglocs);
static void format_type_warning (const substring_loc &fmt_loc,
				 location_t param_loc,
				 format_wanted_type *, tree,
				 tree,
				 const format_kind_info *fki,
				 int offset_to_type_start,
				 char conversion_char,
				 const char *extra = NULL);

static bool check_kef_type (const substring_loc &fmt_loc,
		const struct kernel_ext_fmt *kef,
		unsigned arg_num,
		tree cur_param,
		tree wanted_type,
		const format_kind_info *fki,
		int offset_to_type_start,
		char conversion_char,
		vec<location_t> *arglocs);

/* Decode a format type from a string, returning the type, or
   format_type_error if not valid, in which case the caller should print an
   error message.  */
static int
decode_format_type (const char *s)
{
  int i;
  int slen;

  s = convert_format_name_to_system_name (s);
  slen = strlen (s);
  for (i = 0; i < n_format_types; i++)
    {
      int alen;
      if (!strcmp (s, format_types[i].name))
	return i;
      alen = strlen (format_types[i].name);
      if (slen == alen + 4 && s[0] == '_' && s[1] == '_'
	  && s[slen - 1] == '_' && s[slen - 2] == '_'
	  && !strncmp (s + 2, format_types[i].name, alen))
	return i;
    }
  return format_type_error;
}


/* Check the argument list of a call to printf, scanf, etc.
   ATTRS are the attributes on the function type.  There are NARGS argument
   values in the array ARGARRAY.
   Also, if -Wsuggest-attribute=format,
   warn for calls to vprintf or vscanf in functions with no such format
   attribute themselves.  */

void
check_function_format (tree attrs, int nargs, tree *argarray,
		       vec<location_t> *arglocs)
{
  tree a;

  /* See if this function has any format attributes.  */
  for (a = attrs; a; a = TREE_CHAIN (a))
    {
      if (is_attribute_p ("frr_format", TREE_PURPOSE (a)))
	{
	  /* Yup; check it.  */
	  function_format_info info;
	  decode_format_attr (TREE_VALUE (a), &info, /*validated=*/true);
	  if (warn_format)
	    {
	      /* FIXME: Rewrite all the internal functions in this file
		 to use the ARGARRAY directly instead of constructing this
		 temporary list.  */
	      tree params = NULL_TREE;
	      int i;
	      for (i = nargs - 1; i >= 0; i--)
		params = tree_cons (NULL_TREE, argarray[i], params);
	      check_format_info (&info, params, arglocs);
	    }

	  /* Attempt to detect whether the current function might benefit
	     from the format attribute if the called function is decorated
	     with it.  Avoid using calls with string literal formats for
	     guidance since those are unlikely to be viable candidates.  */
	  if (warn_suggest_attribute_format
	      && current_function_decl != NULL_TREE
	      && info.first_arg_num == 0
	      && (format_types[info.format_type].flags
		  & (int) FMT_FLAG_ARG_CONVERT)
	      /* c_strlen will fail for a function parameter but succeed
		 for a literal or constant array.  */
	      && !c_strlen (argarray[info.format_num - 1], 1))
	    {
	      tree c;
	      for (c = TYPE_ATTRIBUTES (TREE_TYPE (current_function_decl));
		   c;
		   c = TREE_CHAIN (c))
		if (is_attribute_p ("frr_format", TREE_PURPOSE (c))
		    && (decode_format_type (IDENTIFIER_POINTER
					    (TREE_VALUE (TREE_VALUE (c))))
			== info.format_type))
		  break;
	      if (c == NULL_TREE)
		{
		  /* Check if the current function has a parameter to which
		     the format attribute could be attached; if not, it
		     can't be a candidate for a format attribute, despite
		     the vprintf-like or vscanf-like call.  */
		  tree args;
		  for (args = DECL_ARGUMENTS (current_function_decl);
		       args != 0;
		       args = DECL_CHAIN (args))
		    {
		      if (TREE_CODE (TREE_TYPE (args)) == POINTER_TYPE
			  && (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (args)))
			      == char_type_node))
			break;
		    }
		  if (args != 0)
		    warning (OPT_Wsuggest_attribute_format,
			     "function %qD might be a candidate for %qs %<frr_format%> attribute",
			     current_function_decl,
			     format_types[info.format_type].name);
		}
	    }
	}
    }
}


/* Variables used by the checking of $ operand number formats.  */
static char *dollar_arguments_used = NULL;
static char *dollar_arguments_pointer_p = NULL;
static int dollar_arguments_alloc = 0;
static int dollar_arguments_count;
static int dollar_first_arg_num;
static int dollar_max_arg_used;
static int dollar_format_warned;

/* Initialize the checking for a format string that may contain $
   parameter number specifications; we will need to keep track of whether
   each parameter has been used.  FIRST_ARG_NUM is the number of the first
   argument that is a parameter to the format, or 0 for a vprintf-style
   function; PARAMS is the list of arguments starting at this argument.  */

static void
init_dollar_format_checking (int first_arg_num, tree params)
{
  tree oparams = params;

  dollar_first_arg_num = first_arg_num;
  dollar_arguments_count = 0;
  dollar_max_arg_used = 0;
  dollar_format_warned = 0;
  if (first_arg_num > 0)
    {
      while (params)
	{
	  dollar_arguments_count++;
	  params = TREE_CHAIN (params);
	}
    }
  if (dollar_arguments_alloc < dollar_arguments_count)
    {
      free (dollar_arguments_used);
      free (dollar_arguments_pointer_p);
      dollar_arguments_alloc = dollar_arguments_count;
      dollar_arguments_used = XNEWVEC (char, dollar_arguments_alloc);
      dollar_arguments_pointer_p = XNEWVEC (char, dollar_arguments_alloc);
    }
  if (dollar_arguments_alloc)
    {
      memset (dollar_arguments_used, 0, dollar_arguments_alloc);
      if (first_arg_num > 0)
	{
	  int i = 0;
	  params = oparams;
	  while (params)
	    {
	      dollar_arguments_pointer_p[i] = (TREE_CODE (TREE_TYPE (TREE_VALUE (params)))
					       == POINTER_TYPE);
	      params = TREE_CHAIN (params);
	      i++;
	    }
	}
    }
}


/* Look for a decimal number followed by a $ in *FORMAT.  If DOLLAR_NEEDED
   is set, it is an error if one is not found; otherwise, it is OK.  If
   such a number is found, check whether it is within range and mark that
   numbered operand as being used for later checking.  Returns the operand
   number if found and within range, zero if no such number was found and
   this is OK, or -1 on error.  PARAMS points to the first operand of the
   format; PARAM_PTR is made to point to the parameter referred to.  If
   a $ format is found, *FORMAT is updated to point just after it.  */

static int
maybe_read_dollar_number (const char **format,
			  int dollar_needed, tree params, tree *param_ptr,
			  const format_kind_info *fki)
{
  int argnum;
  int overflow_flag;
  const char *fcp = *format;
  if (!ISDIGIT (*fcp))
    {
      if (dollar_needed)
	{
	  warning (OPT_Wformat_, "missing $ operand number in format");
	  return -1;
	}
      else
	return 0;
    }
  argnum = 0;
  overflow_flag = 0;
  while (ISDIGIT (*fcp))
    {
      int nargnum;
      nargnum = 10 * argnum + (*fcp - '0');
      if (nargnum < 0 || nargnum / 10 != argnum)
	overflow_flag = 1;
      argnum = nargnum;
      fcp++;
    }
  if (*fcp != '$')
    {
      if (dollar_needed)
	{
	  warning (OPT_Wformat_, "missing $ operand number in format");
	  return -1;
	}
      else
	return 0;
    }
  *format = fcp + 1;
  if (pedantic && !dollar_format_warned)
    {
      warning (OPT_Wformat_, "%s does not support %%n$ operand number formats",
	       C_STD_NAME (STD_EXT));
      dollar_format_warned = 1;
    }
  if (overflow_flag || argnum == 0
      || (dollar_first_arg_num && argnum > dollar_arguments_count))
    {
      warning (OPT_Wformat_, "operand number out of range in format");
      return -1;
    }
  if (argnum > dollar_max_arg_used)
    dollar_max_arg_used = argnum;
  /* For vprintf-style functions we may need to allocate more memory to
     track which arguments are used.  */
  while (dollar_arguments_alloc < dollar_max_arg_used)
    {
      int nalloc;
      nalloc = 2 * dollar_arguments_alloc + 16;
      dollar_arguments_used = XRESIZEVEC (char, dollar_arguments_used,
					  nalloc);
      dollar_arguments_pointer_p = XRESIZEVEC (char, dollar_arguments_pointer_p,
					       nalloc);
      memset (dollar_arguments_used + dollar_arguments_alloc, 0,
	      nalloc - dollar_arguments_alloc);
      dollar_arguments_alloc = nalloc;
    }
  if (!(fki->flags & (int) FMT_FLAG_DOLLAR_MULTIPLE)
      && dollar_arguments_used[argnum - 1] == 1)
    {
      dollar_arguments_used[argnum - 1] = 2;
      warning (OPT_Wformat_, "format argument %d used more than once in %s format",
	       argnum, fki->name);
    }
  else
    dollar_arguments_used[argnum - 1] = 1;
  if (dollar_first_arg_num)
    {
      int i;
      *param_ptr = params;
      for (i = 1; i < argnum && *param_ptr != 0; i++)
	*param_ptr = TREE_CHAIN (*param_ptr);

      /* This case shouldn't be caught here.  */
      gcc_assert (*param_ptr);
    }
  else
    *param_ptr = 0;
  return argnum;
}

/* Ensure that FORMAT does not start with a decimal number followed by
   a $; give a diagnostic and return true if it does, false otherwise.  */

static bool
avoid_dollar_number (const char *format)
{
  if (!ISDIGIT (*format))
    return false;
  while (ISDIGIT (*format))
    format++;
  if (*format == '$')
    {
      warning (OPT_Wformat_, "%<$%> operand number used after format without operand number");
      return true;
    }
  return false;
}


/* Finish the checking for a format string that used $ operand number formats
   instead of non-$ formats.  We check for unused operands before used ones
   (a serious error, since the implementation of the format function
   can't know what types to pass to va_arg to find the later arguments).
   and for unused operands at the end of the format (if we know how many
   arguments the format had, so not for vprintf).  If there were operand
   numbers out of range on a non-vprintf-style format, we won't have reached
   here.  If POINTER_GAP_OK, unused arguments are OK if all arguments are
   pointers.  */

static void
finish_dollar_format_checking (format_check_results *res, int pointer_gap_ok)
{
  int i;
  bool found_pointer_gap = false;
  for (i = 0; i < dollar_max_arg_used; i++)
    {
      if (!dollar_arguments_used[i])
	{
	  if (pointer_gap_ok && (dollar_first_arg_num == 0
				 || dollar_arguments_pointer_p[i]))
	    found_pointer_gap = true;
	  else
	    warning_at (res->format_string_loc, OPT_Wformat_,
			"format argument %d unused before used argument %d in %<$%>-style format",
			i + 1, dollar_max_arg_used);
	}
    }
  if (found_pointer_gap
      || (dollar_first_arg_num
	  && dollar_max_arg_used < dollar_arguments_count))
    {
      res->number_other--;
      res->number_dollar_extra_args++;
    }
}


/* Retrieve the specification for a format flag.  SPEC contains the
   specifications for format flags for the applicable kind of format.
   FLAG is the flag in question.  If PREDICATES is NULL, the basic
   spec for that flag must be retrieved and must exist.  If
   PREDICATES is not NULL, it is a string listing possible predicates
   for the spec entry; if an entry predicated on any of these is
   found, it is returned, otherwise NULL is returned.  */

static const format_flag_spec *
get_flag_spec (const format_flag_spec *spec, int flag, const char *predicates)
{
  int i;
  for (i = 0; spec[i].flag_char != 0; i++)
    {
      if (spec[i].flag_char != flag)
	continue;
      if (predicates != NULL)
	{
	  if (spec[i].predicate != 0
	      && strchr (predicates, spec[i].predicate) != 0)
	    return &spec[i];
	}
      else if (spec[i].predicate == 0)
	return &spec[i];
    }
  gcc_assert (predicates);
  return NULL;
}


/* Check the argument list of a call to printf, scanf, etc.
   INFO points to the function_format_info structure.
   PARAMS is the list of argument values.  */

static void
check_format_info (function_format_info *info, tree params,
		   vec<location_t> *arglocs)
{
  format_check_context format_ctx;
  unsigned HOST_WIDE_INT arg_num;
  tree format_tree;
  format_check_results res;
  /* Skip to format argument.  If the argument isn't available, there's
     no work for us to do; prototype checking will catch the problem.  */
  for (arg_num = 1; ; ++arg_num)
    {
      if (params == 0)
	return;
      if (arg_num == info->format_num)
	break;
      params = TREE_CHAIN (params);
    }
  format_tree = TREE_VALUE (params);
  params = TREE_CHAIN (params);
  if (format_tree == 0)
    return;

  res.number_non_literal = 0;
  res.number_extra_args = 0;
  res.extra_arg_loc = UNKNOWN_LOCATION;
  res.number_dollar_extra_args = 0;
  res.number_wide = 0;
  res.number_non_char = 0;
  res.number_empty = 0;
  res.number_unterminated = 0;
  res.number_other = 0;
  res.format_string_loc = input_location;

  format_ctx.res = &res;
  format_ctx.info = info;
  format_ctx.params = params;
  format_ctx.arglocs = arglocs;

  check_function_arguments_recurse (check_format_arg, &format_ctx,
				    format_tree, arg_num, OPT_Wformat_);

  location_t loc = format_ctx.res->format_string_loc;

  if (res.number_non_literal > 0)
    {
      /* Functions taking a va_list normally pass a non-literal format
	 string.  These functions typically are declared with
	 first_arg_num == 0, so avoid warning in those cases.  */
      if (!(format_types[info->format_type].flags & (int) FMT_FLAG_ARG_CONVERT))
	{
	  /* For strftime-like formats, warn for not checking the format
	     string; but there are no arguments to check.  */
	  warning_at (loc, OPT_Wformat_nonliteral,
		      "format not a string literal, format string not checked");
	}
      else if (info->first_arg_num != 0)
	{
	  /* If there are no arguments for the format at all, we may have
	     printf (foo) which is likely to be a security hole.  */
	  while (arg_num + 1 < info->first_arg_num)
	    {
	      if (params == 0)
		break;
	      params = TREE_CHAIN (params);
	      ++arg_num;
	    }
	  if (params == 0 && warn_format_security)
	    warning_at (loc, OPT_Wformat_security,
			"format not a string literal and no format arguments");
	  else if (params == 0 && warn_format_nonliteral)
	    warning_at (loc, OPT_Wformat_nonliteral,
			"format not a string literal and no format arguments");
	  else
	    warning_at (loc, OPT_Wformat_nonliteral,
			"format not a string literal, argument types not checked");
	}
    }

  /* If there were extra arguments to the format, normally warn.  However,
     the standard does say extra arguments are ignored, so in the specific
     case where we have multiple leaves (conditional expressions or
     ngettext) allow extra arguments if at least one leaf didn't have extra
     arguments, but was otherwise OK (either non-literal or checked OK).
     If the format is an empty string, this should be counted similarly to the
     case of extra format arguments.  */
  if (res.number_extra_args > 0 && res.number_non_literal == 0
      && res.number_other == 0)
    {
      if (res.extra_arg_loc == UNKNOWN_LOCATION)
	res.extra_arg_loc = loc;
      warning_at (res.extra_arg_loc, OPT_Wformat_extra_args,
		  "too many arguments for format");
    }
  if (res.number_dollar_extra_args > 0 && res.number_non_literal == 0
      && res.number_other == 0)
    warning_at (loc, OPT_Wformat_extra_args, "unused arguments in %<$%>-style format");
  if (res.number_empty > 0 && res.number_non_literal == 0
      && res.number_other == 0)
    warning_at (loc, OPT_Wformat_zero_length, "zero-length %s format string",
	     format_types[info->format_type].name);

  if (res.number_wide > 0)
    warning_at (loc, OPT_Wformat_, "format is a wide character string");

  if (res.number_non_char > 0)
    warning_at (loc, OPT_Wformat_,
		"format string is not an array of type %qs", "char");

  if (res.number_unterminated > 0)
    warning_at (loc, OPT_Wformat_, "unterminated format string");
}

/* Callback from check_function_arguments_recurse to check a
   format string.  FORMAT_TREE is the format parameter.  ARG_NUM
   is the number of the format argument.  CTX points to a
   format_check_context.  */

static void
check_format_arg (void *ctx, tree format_tree,
		  unsigned HOST_WIDE_INT arg_num)
{
  format_check_context *format_ctx = (format_check_context *) ctx;
  format_check_results *res = format_ctx->res;
  function_format_info *info = format_ctx->info;
  tree params = format_ctx->params;
  vec<location_t> *arglocs = format_ctx->arglocs;

  int format_length;
  HOST_WIDE_INT offset;
  const char *format_chars;
  tree array_size = 0;
  tree array_init;

  location_t fmt_param_loc = EXPR_LOC_OR_LOC (format_tree, input_location);

  /* Pull out a constant value if the front end didn't, and handle location
     wrappers.  */
  format_tree = fold_for_warn (format_tree);
  STRIP_NOPS (format_tree);

  if (integer_zerop (format_tree))
    {
      /* Skip to first argument to check, so we can see if this format
	 has any arguments (it shouldn't).  */
      while (arg_num + 1 < info->first_arg_num)
	{
	  if (params == 0)
	    return;
	  params = TREE_CHAIN (params);
	  ++arg_num;
	}

      if (params == 0)
	res->number_other++;
      else 
	{
	  if (res->number_extra_args == 0)
	    res->extra_arg_loc = EXPR_LOC_OR_LOC (TREE_VALUE (params),
						  input_location);
	  res->number_extra_args++;
	}
      return;
    }

  offset = 0;
  if (TREE_CODE (format_tree) == POINTER_PLUS_EXPR)
    {
      tree arg0, arg1;

      arg0 = TREE_OPERAND (format_tree, 0);
      arg1 = TREE_OPERAND (format_tree, 1);
      STRIP_NOPS (arg0);
      STRIP_NOPS (arg1);
      if (TREE_CODE (arg1) == INTEGER_CST)
	format_tree = arg0;
      else
	{
	  res->number_non_literal++;
	  return;
	}
      /* POINTER_PLUS_EXPR offsets are to be interpreted signed.  */
      if (!cst_and_fits_in_hwi (arg1))
	{
	  res->number_non_literal++;
	  return;
	}
      offset = int_cst_value (arg1);
    }
  if (TREE_CODE (format_tree) != ADDR_EXPR)
    {
      res->number_non_literal++;
      return;
    }
  res->format_string_loc = EXPR_LOC_OR_LOC (format_tree, input_location);
  format_tree = TREE_OPERAND (format_tree, 0);
  if (format_types[info->format_type].flags 
      & (int) FMT_FLAG_PARSE_ARG_CONVERT_EXTERNAL)
    {
      /* We cannot examine this string here - but we can check that it is
	 a valid type.  */
      if (TREE_CODE (format_tree) != CONST_DECL)
	{
	  res->number_non_literal++;
	  return;
	}
      /* Skip to first argument to check.  */
      while (arg_num + 1 < info->first_arg_num)
	{
	  if (params == 0)
	    return;
	  params = TREE_CHAIN (params);
	  ++arg_num;
	}
      return;
    }
  if (TREE_CODE (format_tree) == ARRAY_REF
      && tree_fits_shwi_p (TREE_OPERAND (format_tree, 1))
      && (offset += tree_to_shwi (TREE_OPERAND (format_tree, 1))) >= 0)
    format_tree = TREE_OPERAND (format_tree, 0);
  if (offset < 0)
    {
      res->number_non_literal++;
      return;
    }
  if (VAR_P (format_tree)
      && TREE_CODE (TREE_TYPE (format_tree)) == ARRAY_TYPE
      && (array_init = decl_constant_value (format_tree)) != format_tree
      && TREE_CODE (array_init) == STRING_CST)
    {
      /* Extract the string constant initializer.  Note that this may include
	 a trailing NUL character that is not in the array (e.g.
	 const char a[3] = "foo";).  */
      array_size = DECL_SIZE_UNIT (format_tree);
      format_tree = array_init;
    }
  if (TREE_CODE (format_tree) != STRING_CST)
    {
      res->number_non_literal++;
      return;
    }
  tree underlying_type
    = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (format_tree)));
  if (underlying_type != char_type_node)
    {
      if (underlying_type == char16_type_node
	  || underlying_type == char32_type_node
	  || underlying_type == wchar_type_node)
	res->number_wide++;
      else
	res->number_non_char++;
      return;
    }
  format_chars = TREE_STRING_POINTER (format_tree);
  format_length = TREE_STRING_LENGTH (format_tree);
  if (array_size != 0)
    {
      /* Variable length arrays can't be initialized.  */
      gcc_assert (TREE_CODE (array_size) == INTEGER_CST);

      if (tree_fits_shwi_p (array_size))
	{
	  HOST_WIDE_INT array_size_value = tree_to_shwi (array_size);
	  if (array_size_value > 0
	      && array_size_value == (int) array_size_value
	      && format_length > array_size_value)
	    format_length = array_size_value;
	}
    }
  if (offset)
    {
      if (offset >= format_length)
	{
	  res->number_non_literal++;
	  return;
	}
      format_chars += offset;
      format_length -= offset;
    }
  if (format_length < 1 || format_chars[--format_length] != 0)
    {
      res->number_unterminated++;
      return;
    }
  if (format_length == 0)
    {
      res->number_empty++;
      return;
    }

  /* Skip to first argument to check.  */
  while (arg_num + 1 < info->first_arg_num)
    {
      if (params == 0)
	return;
      params = TREE_CHAIN (params);
      ++arg_num;
    }
  /* Provisionally increment res->number_other; check_format_info_main
     will decrement it if it finds there are extra arguments, but this way
     need not adjust it for every return.  */
  res->number_other++;
  object_allocator <format_wanted_type> fwt_pool ("format_wanted_type pool");
  check_format_info_main (res, info, format_chars, fmt_param_loc, format_tree,
			  format_length, params, arg_num, fwt_pool, arglocs);
}

/* Support class for argument_parser and check_format_info_main.
   Tracks any flag characters that have been applied to the
   current argument.  */

class flag_chars_t
{
 public:
  flag_chars_t ();
  bool has_char_p (char ch) const;
  void add_char (char ch);
  void validate (const format_kind_info *fki,
		 const format_char_info *fci,
		 const format_flag_spec *flag_specs,
		 const char * const format_chars,
		 tree format_string_cst,
		 location_t format_string_loc,
		 const char * const orig_format_chars,
		 char format_char,
		 bool quoted);
  int get_alloc_flag (const format_kind_info *fki);
  int assignment_suppression_p (const format_kind_info *fki);

 private:
  char m_flag_chars[256];
};

/* Support struct for argument_parser and check_format_info_main.
   Encapsulates any length modifier applied to the current argument.  */

struct length_modifier
{
  length_modifier ()
  : chars (NULL), val (FMT_LEN_none), std (STD_C89),
    scalar_identity_flag (0)
  {
  }

  length_modifier (const char *chars_,
		   enum format_lengths val_,
		   enum format_std_version std_,
		   int scalar_identity_flag_)
  : chars (chars_), val (val_), std (std_),
    scalar_identity_flag (scalar_identity_flag_)
  {
  }

  const char *chars;
  enum format_lengths val;
  enum format_std_version std;
  int scalar_identity_flag;
};

/* Parsing one argument within a format string.  */

class argument_parser
{
 public:
  argument_parser (function_format_info *info, const char *&format_chars,
		   tree format_string_cst,
		   const char * const orig_format_chars,
		   location_t format_string_loc, flag_chars_t &flag_chars,
		   int &has_operand_number, tree first_fillin_param,
		   object_allocator <format_wanted_type> &fwt_pool_,
		   vec<location_t> *arglocs);

  bool read_any_dollar ();

  bool read_format_flags ();

  bool
  read_any_format_width (tree &params,
			 unsigned HOST_WIDE_INT &arg_num);

  void
  read_any_format_left_precision ();

  bool
  read_any_format_precision (tree &params,
			     unsigned HOST_WIDE_INT &arg_num);

  void handle_alloc_chars ();

  length_modifier read_any_length_modifier ();

  void read_any_other_modifier ();

  const format_char_info *find_format_char_info (char format_char);

  void
  validate_flag_pairs (const format_char_info *fci,
		       char format_char);

  void
  give_y2k_warnings (const format_char_info *fci,
		     char format_char);

  void parse_any_scan_set (const format_char_info *fci);

  bool handle_conversions (const format_char_info *fci,
			   const length_modifier &len_modifier,
			   tree &wanted_type,
			   const char *&wanted_type_name,
			   unsigned HOST_WIDE_INT &arg_num,
			   tree &params,
			   char format_char);

  bool
  check_argument_type (const format_char_info *fci,
		       const struct kernel_ext_fmt *kef,
		       const length_modifier &len_modifier,
		       tree &wanted_type,
		       const char *&wanted_type_name,
		       const bool suppressed,
		       unsigned HOST_WIDE_INT &arg_num,
		       tree &params,
		       const int alloc_flag,
		       const char * const format_start,
		       const char * const type_start,
		       location_t fmt_param_loc,
		       char conversion_char);

 private:
  const function_format_info *const info;
  const format_kind_info * const fki;
  const format_flag_spec * const flag_specs;
  const char *start_of_this_format;
  const char *&format_chars;
  const tree format_string_cst;
  const char * const orig_format_chars;
  const location_t format_string_loc;
  object_allocator <format_wanted_type> &fwt_pool;
  flag_chars_t &flag_chars;
  int main_arg_num;
  tree main_arg_params;
  int &has_operand_number;
  const tree first_fillin_param;
  format_wanted_type width_wanted_type;
  format_wanted_type precision_wanted_type;
 public:
  format_wanted_type main_wanted_type;
 private:
  format_wanted_type *first_wanted_type;
  format_wanted_type *last_wanted_type;
  vec<location_t> *arglocs;
};

/* flag_chars_t's constructor.  */

flag_chars_t::flag_chars_t ()
{
  m_flag_chars[0] = 0;
}

/* Has CH been seen as a flag within the current argument?  */

bool
flag_chars_t::has_char_p (char ch) const
{
  return strchr (m_flag_chars, ch) != 0;
}

/* Add CH to the flags seen within the current argument.  */

void
flag_chars_t::add_char (char ch)
{
  int i = strlen (m_flag_chars);
  m_flag_chars[i++] = ch;
  m_flag_chars[i] = 0;
}

/* Validate the individual flags used, removing any that are invalid.  */

void
flag_chars_t::validate (const format_kind_info *fki,
			const format_char_info *fci,
			const format_flag_spec *flag_specs,
			const char * const format_chars,
			tree format_string_cst,
			location_t format_string_loc,
			const char * const orig_format_chars,
			char format_char,
			bool quoted)
{
  int i;
  int d = 0;
  bool quotflag = false;

  for (i = 0; m_flag_chars[i] != 0; i++)
    {
      const format_flag_spec *s = get_flag_spec (flag_specs,
						 m_flag_chars[i], NULL);
      m_flag_chars[i - d] = m_flag_chars[i];
      if (m_flag_chars[i] == fki->length_code_char)
	continue;

      /* Remember if a quoting flag is seen.  */
      quotflag |= s->quoting;

      if (strchr (fci->flag_chars, m_flag_chars[i]) == 0)
	{
	  format_warning_at_char (format_string_loc, format_string_cst,
				  format_chars - orig_format_chars,
				  OPT_Wformat_,
				  "%s used with %<%%%c%> %s format",
				  _(s->name), format_char, fki->name);
	  d++;
	  continue;
	}
      if (pedantic)
	{
	  const format_flag_spec *t;
	  if (ADJ_STD (s->std) > C_STD_VER)
	    warning_at (format_string_loc, OPT_Wformat_,
			"%s does not support %s",
			C_STD_NAME (s->std), _(s->long_name));
	  t = get_flag_spec (flag_specs, m_flag_chars[i], fci->flags2);
	  if (t != NULL && ADJ_STD (t->std) > ADJ_STD (s->std))
	    {
	      const char *long_name = (t->long_name != NULL
				       ? t->long_name
				       : s->long_name);
	      if (ADJ_STD (t->std) > C_STD_VER)
		warning_at (format_string_loc, OPT_Wformat_,
			    "%s does not support %s with the %<%%%c%> %s format",
			    C_STD_NAME (t->std), _(long_name),
			    format_char, fki->name);
	    }
	}

      /* Detect quoting directives used within a quoted sequence, such
	 as GCC's "%<...%qE".  */
      if (quoted && s->quoting)
	{
	  format_warning_at_char (format_string_loc, format_string_cst,
				  format_chars - orig_format_chars - 1,
				  OPT_Wformat_,
				  "%s used within a quoted sequence",
				  _(s->name));
	}
    }
  m_flag_chars[i - d] = 0;

  if (!quoted
      && !quotflag
      && strchr (fci->flags2, '\''))
    {
      format_warning_at_char (format_string_loc, format_string_cst,
			      format_chars - orig_format_chars,
			      OPT_Wformat_,
			      "%qc conversion used unquoted",
			      format_char);
    }
}

/* Determine if an assignment-allocation has been set, requiring
   an extra char ** for writing back a dynamically-allocated char *.
   This is for handling the optional 'm' character in scanf.  */

int
flag_chars_t::get_alloc_flag (const format_kind_info *fki)
{
  if ((fki->flags & (int) FMT_FLAG_SCANF_A_KLUDGE)
      && has_char_p ('a'))
    return 1;
  if (fki->alloc_char && has_char_p (fki->alloc_char))
    return 1;
  return 0;
}

/* Determine if an assignment-suppression character was seen.
   ('*' in scanf, for discarding the converted input).  */

int
flag_chars_t::assignment_suppression_p (const format_kind_info *fki)
{
  if (fki->suppression_char
      && has_char_p (fki->suppression_char))
    return 1;
  return 0;
}

/* Constructor for argument_parser.  Initialize for parsing one
   argument within a format string.  */

argument_parser::
argument_parser (function_format_info *info_, const char *&format_chars_,
		 tree format_string_cst_,
		 const char * const orig_format_chars_,
		 location_t format_string_loc_,
		 flag_chars_t &flag_chars_,
		 int &has_operand_number_,
		 tree first_fillin_param_,
		 object_allocator <format_wanted_type> &fwt_pool_,
		 vec<location_t> *arglocs_)
: info (info_),
  fki (&format_types[info->format_type]),
  flag_specs (fki->flag_specs),
  start_of_this_format (format_chars_),
  format_chars (format_chars_),
  format_string_cst (format_string_cst_),
  orig_format_chars (orig_format_chars_),
  format_string_loc (format_string_loc_),
  fwt_pool (fwt_pool_),
  flag_chars (flag_chars_),
  main_arg_num (0),
  main_arg_params (NULL),
  has_operand_number (has_operand_number_),
  first_fillin_param (first_fillin_param_),
  first_wanted_type (NULL),
  last_wanted_type (NULL),
  arglocs (arglocs_)
{
}

/* Handle dollars at the start of format arguments, setting up main_arg_params
   and main_arg_num.

   Return true if format parsing is to continue, false otherwise.  */

bool
argument_parser::read_any_dollar ()
{
  if ((fki->flags & (int) FMT_FLAG_USE_DOLLAR) && has_operand_number != 0)
    {
      /* Possibly read a $ operand number at the start of the format.
	 If one was previously used, one is required here.  If one
	 is not used here, we can't immediately conclude this is a
	 format without them, since it could be printf %m or scanf %*.  */
      int opnum;
      opnum = maybe_read_dollar_number (&format_chars, 0,
					first_fillin_param,
					&main_arg_params, fki);
      if (opnum == -1)
	return false;
      else if (opnum > 0)
	{
	  has_operand_number = 1;
	  main_arg_num = opnum + info->first_arg_num - 1;
	}
    }
  else if (fki->flags & FMT_FLAG_USE_DOLLAR)
    {
      if (avoid_dollar_number (format_chars))
	return false;
    }
  return true;
}

/* Read any format flags, but do not yet validate them beyond removing
   duplicates, since in general validation depends on the rest of
   the format.

   Return true if format parsing is to continue, false otherwise.  */

bool
argument_parser::read_format_flags ()
{
  while (*format_chars != 0
	 && strchr (fki->flag_chars, *format_chars) != 0)
    {
      const format_flag_spec *s = get_flag_spec (flag_specs,
						 *format_chars, NULL);
      if (flag_chars.has_char_p (*format_chars))
	{
	  format_warning_at_char (format_string_loc, format_string_cst,
				  format_chars + 1 - orig_format_chars,
				  OPT_Wformat_,
				  "repeated %s in format", _(s->name));
	}
      else
	flag_chars.add_char (*format_chars);

      if (s->skip_next_char)
	{
	  ++format_chars;
	  if (*format_chars == 0)
	    {
	      warning_at (format_string_loc, OPT_Wformat_,
			  "missing fill character at end of strfmon format");
	      return false;
	    }
	}
      ++format_chars;
    }

  return true;
}

/* Read any format width, possibly * or *m$.

   Return true if format parsing is to continue, false otherwise.  */

bool
argument_parser::
read_any_format_width (tree &params,
		       unsigned HOST_WIDE_INT &arg_num)
{
  if (!fki->width_char)
    return true;

  if (fki->width_type != NULL && *format_chars == '*')
    {
      flag_chars.add_char (fki->width_char);
      /* "...a field width...may be indicated by an asterisk.
	 In this case, an int argument supplies the field width..."  */
      ++format_chars;
      if (has_operand_number != 0)
	{
	  int opnum;
	  opnum = maybe_read_dollar_number (&format_chars,
					    has_operand_number == 1,
					    first_fillin_param,
					    &params, fki);
	  if (opnum == -1)
	    return false;
	  else if (opnum > 0)
	    {
	      has_operand_number = 1;
	      arg_num = opnum + info->first_arg_num - 1;
	    }
	  else
	    has_operand_number = 0;
	}
      else
	{
	  if (avoid_dollar_number (format_chars))
	    return false;
	}
      if (info->first_arg_num != 0)
	{
	  tree cur_param;
	  if (params == 0)
	    cur_param = NULL;
	  else
	    {
	      cur_param = TREE_VALUE (params);
	      if (has_operand_number <= 0)
		{
		  params = TREE_CHAIN (params);
		  ++arg_num;
		}
	    }
	  width_wanted_type.wanted_type = *fki->width_type;
	  width_wanted_type.wanted_type_name = NULL;
	  width_wanted_type.pointer_count = 0;
	  width_wanted_type.char_lenient_flag = 0;
	  width_wanted_type.scalar_identity_flag = 0;
	  width_wanted_type.writing_in_flag = 0;
	  width_wanted_type.reading_from_flag = 0;
	  width_wanted_type.kind = CF_KIND_FIELD_WIDTH;
	  width_wanted_type.format_start = format_chars - 1;
	  width_wanted_type.format_length = 1;
	  width_wanted_type.param = cur_param;
	  width_wanted_type.arg_num = arg_num;
	  width_wanted_type.offset_loc =
	    format_chars - orig_format_chars;
	  width_wanted_type.next = NULL;
	  if (last_wanted_type != 0)
	    last_wanted_type->next = &width_wanted_type;
	  if (first_wanted_type == 0)
	    first_wanted_type = &width_wanted_type;
	  last_wanted_type = &width_wanted_type;
	}
    }
  else
    {
      /* Possibly read a numeric width.  If the width is zero,
	 we complain if appropriate.  */
      int non_zero_width_char = FALSE;
      int found_width = FALSE;
      while (ISDIGIT (*format_chars))
	{
	  found_width = TRUE;
	  if (*format_chars != '0')
	    non_zero_width_char = TRUE;
	  ++format_chars;
	}
      if (found_width && !non_zero_width_char &&
	  (fki->flags & (int) FMT_FLAG_ZERO_WIDTH_BAD))
	warning_at (format_string_loc, OPT_Wformat_,
		    "zero width in %s format", fki->name);
      if (found_width)
	flag_chars.add_char (fki->width_char);
    }

  return true;
}

/* Read any format left precision (must be a number, not *).  */
void
argument_parser::read_any_format_left_precision ()
{
  if (fki->left_precision_char == 0)
    return;
  if (*format_chars != '#')
    return;

  ++format_chars;
  flag_chars.add_char (fki->left_precision_char);
  if (!ISDIGIT (*format_chars))
    format_warning_at_char (format_string_loc, format_string_cst,
			    format_chars - orig_format_chars,
			    OPT_Wformat_,
			    "empty left precision in %s format", fki->name);
  while (ISDIGIT (*format_chars))
    ++format_chars;
}

/* Read any format precision, possibly * or *m$.

   Return true if format parsing is to continue, false otherwise.  */

bool
argument_parser::
read_any_format_precision (tree &params,
			   unsigned HOST_WIDE_INT &arg_num)
{
  if (fki->precision_char == 0)
    return true;
  if (*format_chars != '.')
    return true;

  ++format_chars;
  flag_chars.add_char (fki->precision_char);
  if (fki->precision_type != NULL && *format_chars == '*')
    {
      /* "...a...precision...may be indicated by an asterisk.
	 In this case, an int argument supplies the...precision."  */
      ++format_chars;
      if (has_operand_number != 0)
	{
	  int opnum;
	  opnum = maybe_read_dollar_number (&format_chars,
					    has_operand_number == 1,
					    first_fillin_param,
					    &params, fki);
	  if (opnum == -1)
	    return false;
	  else if (opnum > 0)
	    {
	      has_operand_number = 1;
	      arg_num = opnum + info->first_arg_num - 1;
	    }
	  else
	    has_operand_number = 0;
	}
      else
	{
	  if (avoid_dollar_number (format_chars))
	    return false;
	}
      if (info->first_arg_num != 0)
	{
	  tree cur_param;
	  if (params == 0)
	    cur_param = NULL;
	  else
	    {
	      cur_param = TREE_VALUE (params);
	      if (has_operand_number <= 0)
		{
		  params = TREE_CHAIN (params);
		  ++arg_num;
		}
	    }
	  precision_wanted_type.wanted_type = *fki->precision_type;
	  precision_wanted_type.wanted_type_name = NULL;
	  precision_wanted_type.pointer_count = 0;
	  precision_wanted_type.char_lenient_flag = 0;
	  precision_wanted_type.scalar_identity_flag = 0;
	  precision_wanted_type.writing_in_flag = 0;
	  precision_wanted_type.reading_from_flag = 0;
	  precision_wanted_type.kind = CF_KIND_FIELD_PRECISION;
	  precision_wanted_type.param = cur_param;
	  precision_wanted_type.format_start = format_chars - 2;
	  precision_wanted_type.format_length = 2;
	  precision_wanted_type.arg_num = arg_num;
	  precision_wanted_type.offset_loc =
	    format_chars - orig_format_chars;
	  precision_wanted_type.next = NULL;
	  if (last_wanted_type != 0)
	    last_wanted_type->next = &precision_wanted_type;
	  if (first_wanted_type == 0)
	    first_wanted_type = &precision_wanted_type;
	  last_wanted_type = &precision_wanted_type;
	}
    }
  else
    {
      if (!(fki->flags & (int) FMT_FLAG_EMPTY_PREC_OK)
	  && !ISDIGIT (*format_chars))
	format_warning_at_char (format_string_loc, format_string_cst,
				format_chars - orig_format_chars,
				OPT_Wformat_,
				"empty precision in %s format", fki->name);
      while (ISDIGIT (*format_chars))
	++format_chars;
    }

  return true;
}

/* Parse any assignment-allocation flags, which request an extra
   char ** for writing back a dynamically-allocated char *.
   This is for handling the optional 'm' character in scanf,
   and, before C99, 'a' (for compatibility with a non-standard
   GNU libc extension).  */

void
argument_parser::handle_alloc_chars ()
{
  if (fki->alloc_char && fki->alloc_char == *format_chars)
    {
      flag_chars.add_char (fki->alloc_char);
      format_chars++;
    }

  /* Handle the scanf allocation kludge.  */
  if (fki->flags & (int) FMT_FLAG_SCANF_A_KLUDGE)
    {
      if (*format_chars == 'a' && !flag_isoc99)
	{
	  if (format_chars[1] == 's' || format_chars[1] == 'S'
	      || format_chars[1] == '[')
	    {
	      /* 'a' is used as a flag.  */
	      flag_chars.add_char ('a');
	      format_chars++;
	    }
	}
    }
}

/* Look for length modifiers within the current format argument,
   returning a length_modifier instance describing it (or the
   default if one is not found).

   Issue warnings about non-standard modifiers.  */

length_modifier
argument_parser::read_any_length_modifier ()
{
  length_modifier result;

  const format_length_info *fli = fki->length_char_specs;
  if (!fli)
    return result;

  while (fli->name != 0
	 && strncmp (fli->name, format_chars, strlen (fli->name)))
    fli++;
  if (fli->name != 0)
    {
      format_chars += strlen (fli->name);
      if (fli->double_name != 0 && fli->name[0] == *format_chars)
	{
	  format_chars++;
	  result = length_modifier (fli->double_name, fli->double_index,
				    fli->double_std, 0);
	}
      else
	{
	  result = length_modifier (fli->name, fli->index, fli->std,
				    fli->scalar_identity_flag);
	}
      flag_chars.add_char (fki->length_code_char);
    }
  if (pedantic)
    {
      /* Warn if the length modifier is non-standard.  */
      if (ADJ_STD (result.std) > C_STD_VER)
	warning_at (format_string_loc, OPT_Wformat_,
		    "%s does not support the %qs %s length modifier",
		    C_STD_NAME (result.std), result.chars,
		    fki->name);
    }

  return result;
}

/* Read any other modifier (strftime E/O).  */

void
argument_parser::read_any_other_modifier ()
{
  if (fki->modifier_chars == NULL)
    return;

  while (*format_chars != 0
	 && strchr (fki->modifier_chars, *format_chars) != 0)
    {
      if (flag_chars.has_char_p (*format_chars))
	{
	  const format_flag_spec *s = get_flag_spec (flag_specs,
						     *format_chars, NULL);
	  format_warning_at_char (format_string_loc, format_string_cst,
				  format_chars - orig_format_chars,
				  OPT_Wformat_,
				  "repeated %s in format", _(s->name));
	}
      else
	flag_chars.add_char (*format_chars);
      ++format_chars;
    }
}

/* Return the format_char_info corresponding to FORMAT_CHAR,
   potentially issuing a warning if the format char is
   not supported in the C standard version we are checking
   against.

   Issue a warning and return NULL if it is not found.

   Issue warnings about non-standard modifiers.  */

const format_char_info *
argument_parser::find_format_char_info (char format_char)
{
  const format_char_info *fci = fki->conversion_specs;

  while (fci->format_chars != 0
	 && strchr (fci->format_chars, format_char) == 0)
    ++fci;
  if (fci->format_chars == 0)
    {
      format_warning_at_char (format_string_loc, format_string_cst,
			      format_chars - orig_format_chars,
			      OPT_Wformat_,
			      "unknown conversion type character %qc in format",
			      format_char);
      return NULL;
    }

  if (pedantic)
    {
      if (ADJ_STD (fci->std) > C_STD_VER)
	format_warning_at_char (format_string_loc, format_string_cst,
				format_chars - orig_format_chars,
				OPT_Wformat_,
				"%s does not support the %<%%%c%> %s format",
				C_STD_NAME (fci->std), format_char, fki->name);
    }

  return fci;
}

/* Validate the pairs of flags used.
   Issue warnings about incompatible combinations of flags.  */

void
argument_parser::validate_flag_pairs (const format_char_info *fci,
				      char format_char)
{
  const format_flag_pair * const bad_flag_pairs = fki->bad_flag_pairs;

  for (int i = 0; bad_flag_pairs[i].flag_char1 != 0; i++)
    {
      const format_flag_spec *s, *t;
      if (!flag_chars.has_char_p (bad_flag_pairs[i].flag_char1))
	continue;
      if (!flag_chars.has_char_p (bad_flag_pairs[i].flag_char2))
	continue;
      if (bad_flag_pairs[i].predicate != 0
	  && strchr (fci->flags2, bad_flag_pairs[i].predicate) == 0)
	continue;
      s = get_flag_spec (flag_specs, bad_flag_pairs[i].flag_char1, NULL);
      t = get_flag_spec (flag_specs, bad_flag_pairs[i].flag_char2, NULL);
      if (bad_flag_pairs[i].ignored)
	{
	  if (bad_flag_pairs[i].predicate != 0)
	    warning_at (format_string_loc, OPT_Wformat_,
			"%s ignored with %s and %<%%%c%> %s format",
			_(s->name), _(t->name), format_char,
			fki->name);
	  else
	    warning_at (format_string_loc, OPT_Wformat_,
			"%s ignored with %s in %s format",
			_(s->name), _(t->name), fki->name);
	}
      else
	{
	  if (bad_flag_pairs[i].predicate != 0)
	    warning_at (format_string_loc, OPT_Wformat_,
			"use of %s and %s together with %<%%%c%> %s format",
			_(s->name), _(t->name), format_char,
			fki->name);
	  else
	    warning_at (format_string_loc, OPT_Wformat_,
			"use of %s and %s together in %s format",
			_(s->name), _(t->name), fki->name);
	}
    }
}

/* Give Y2K warnings.  */

void
argument_parser::give_y2k_warnings (const format_char_info *fci,
				    char format_char)
{
  if (!warn_format_y2k)
    return;

  int y2k_level = 0;
  if (strchr (fci->flags2, '4') != 0)
    if (flag_chars.has_char_p ('E'))
      y2k_level = 3;
    else
      y2k_level = 2;
  else if (strchr (fci->flags2, '3') != 0)
    y2k_level = 3;
  else if (strchr (fci->flags2, '2') != 0)
    y2k_level = 2;
  if (y2k_level == 3)
    warning_at (format_string_loc, OPT_Wformat_y2k,
		"%<%%%c%> yields only last 2 digits of year in some locales", format_char);
  else if (y2k_level == 2)
    warning_at (format_string_loc, OPT_Wformat_y2k,
		"%<%%%c%> yields only last 2 digits of year",
		format_char);
}

/* Parse any "scan sets" enclosed in square brackets, e.g.
   for scanf-style calls.  */

void
argument_parser::parse_any_scan_set (const format_char_info *fci)
{
  if (strchr (fci->flags2, '[') == NULL)
    return;

  /* Skip over scan set, in case it happens to have '%' in it.  */
  if (*format_chars == '^')
    ++format_chars;
  /* Find closing bracket; if one is hit immediately, then
     it's part of the scan set rather than a terminator.  */
  if (*format_chars == ']')
    ++format_chars;
  while (*format_chars && *format_chars != ']')
    ++format_chars;
  if (*format_chars != ']')
    /* The end of the format string was reached.  */
    format_warning_at_char (format_string_loc, format_string_cst,
			    format_chars - orig_format_chars,
			    OPT_Wformat_,
			    "no closing %<]%> for %<%%[%> format");
}

/* Return true if this argument is to be continued to be parsed,
   false to skip to next argument.  */

bool
argument_parser::handle_conversions (const format_char_info *fci,
				     const length_modifier &len_modifier,
				     tree &wanted_type,
				     const char *&wanted_type_name,
				     unsigned HOST_WIDE_INT &arg_num,
				     tree &params,
				     char format_char)
{
  enum format_std_version wanted_type_std;

  if (!(fki->flags & (int) FMT_FLAG_ARG_CONVERT))
    return true;

  wanted_type = (fci->types[len_modifier.val].type
		 ? *fci->types[len_modifier.val].type : 0);
  wanted_type_name = fci->types[len_modifier.val].name;
  wanted_type_std = fci->types[len_modifier.val].std;
  if (wanted_type == 0)
    {
      format_warning_at_char (format_string_loc, format_string_cst,
			      format_chars - orig_format_chars,
			      OPT_Wformat_,
			      "use of %qs length modifier with %qc type character has either no effect or undefined behavior",
			      len_modifier.chars, format_char);
      /* Heuristic: skip one argument when an invalid length/type
	 combination is encountered.  */
      arg_num++;
      if (params != 0)
	params = TREE_CHAIN (params);
      return false;
    }
  else if (pedantic
	   /* Warn if non-standard, provided it is more non-standard
	      than the length and type characters that may already
	      have been warned for.  */
	   && ADJ_STD (wanted_type_std) > ADJ_STD (len_modifier.std)
	   && ADJ_STD (wanted_type_std) > ADJ_STD (fci->std))
    {
      if (ADJ_STD (wanted_type_std) > C_STD_VER)
	format_warning_at_char (format_string_loc, format_string_cst,
				format_chars - orig_format_chars,
				OPT_Wformat_,
				"%s does not support the %<%%%s%c%> %s format",
				C_STD_NAME (wanted_type_std),
				len_modifier.chars,
				format_char, fki->name);
    }

  return true;
}

/* Check type of argument against desired type.

   Return true if format parsing is to continue, false otherwise.  */

bool
argument_parser::
check_argument_type (const format_char_info *fci,
		     const struct kernel_ext_fmt *kef,
		     const length_modifier &len_modifier,
		     tree &wanted_type,
		     const char *&wanted_type_name,
		     const bool suppressed,
		     unsigned HOST_WIDE_INT &arg_num,
		     tree &params,
		     const int alloc_flag,
		     const char * const format_start,
		     const char * const type_start,
		     location_t fmt_param_loc,
		     char conversion_char)
{
  if (info->first_arg_num == 0)
    return true;

  if ((fci->pointer_count == 0 && wanted_type == void_type_node)
      || suppressed)
    {
      if (main_arg_num != 0)
	{
	  if (suppressed)
	    warning_at (format_string_loc, OPT_Wformat_,
			"operand number specified with suppressed assignment");
	  else
	    warning_at (format_string_loc, OPT_Wformat_,
			"operand number specified for format taking no argument");
	}
    }
  else
    {
      format_wanted_type *wanted_type_ptr;

      if (main_arg_num != 0)
	{
	  arg_num = main_arg_num;
	  params = main_arg_params;
	}
      else
	{
	  ++arg_num;
	  if (has_operand_number > 0)
	    {
	      warning_at (format_string_loc, OPT_Wformat_,
			  "missing $ operand number in format");
	      return false;
	    }
	  else
	    has_operand_number = 0;
	}

      wanted_type_ptr = &main_wanted_type;
      while (fci)
	{
	  tree cur_param;
	  if (params == 0)
	    cur_param = NULL;
	  else
	    {
	      cur_param = TREE_VALUE (params);
	      params = TREE_CHAIN (params);
	    }

	  wanted_type_ptr->wanted_type = wanted_type;
	  wanted_type_ptr->wanted_type_name = wanted_type_name;
	  wanted_type_ptr->pointer_count = fci->pointer_count + alloc_flag;
	  wanted_type_ptr->char_lenient_flag = 0;
	  if (strchr (fci->flags2, 'c') != 0)
	    wanted_type_ptr->char_lenient_flag = 1;
	  wanted_type_ptr->scalar_identity_flag = 0;
	  if (len_modifier.scalar_identity_flag)
	    wanted_type_ptr->scalar_identity_flag = 1;
	  wanted_type_ptr->writing_in_flag = 0;
	  wanted_type_ptr->reading_from_flag = 0;
	  if (alloc_flag)
	    wanted_type_ptr->writing_in_flag = 1;
	  else
	    {
	      if (strchr (fci->flags2, 'W') != 0)
		wanted_type_ptr->writing_in_flag = 1;
	      if (strchr (fci->flags2, 'R') != 0)
		wanted_type_ptr->reading_from_flag = 1;
	    }
	  wanted_type_ptr->kind = CF_KIND_FORMAT;
	  wanted_type_ptr->param = cur_param;
	  wanted_type_ptr->arg_num = arg_num;
	  wanted_type_ptr->format_start = format_start;
	  wanted_type_ptr->format_length = format_chars - format_start;
	  wanted_type_ptr->offset_loc = format_chars - orig_format_chars;
	  wanted_type_ptr->next = NULL;
	  if (last_wanted_type != 0)
	    last_wanted_type->next = wanted_type_ptr;
	  if (first_wanted_type == 0)
	    first_wanted_type = wanted_type_ptr;
	  last_wanted_type = wanted_type_ptr;

	  fci = fci->chain;
	  if (fci)
	    {
	      wanted_type_ptr = fwt_pool.allocate ();
	      arg_num++;
	      wanted_type = *fci->types[len_modifier.val].type;
	      wanted_type_name = fci->types[len_modifier.val].name;
	    }
	}
    }

  if (first_wanted_type != 0)
    {
      ptrdiff_t offset_to_format_start = (start_of_this_format - 1) - orig_format_chars;
      ptrdiff_t offset_to_format_end = (format_chars - 1) - orig_format_chars;
      /* By default, use the end of the range for the caret location.  */
      substring_loc fmt_loc (fmt_param_loc, TREE_TYPE (format_string_cst),
			     offset_to_format_end,
			     offset_to_format_start, offset_to_format_end);
      ptrdiff_t offset_to_type_start = type_start - orig_format_chars;
      check_format_types (fmt_loc, first_wanted_type, fki,
			  offset_to_type_start,
			  conversion_char, arglocs);

      /* note printf extension type checks are *additional* - %p must always
       * be pointer compatible, %d always int compatible.
       */
      if (first_wanted_type->kind != CF_KIND_FORMAT || !kef)
	return true;

      const struct kernel_ext_fmt *kef_now;
      bool success;

      for (kef_now = kef; kef_now->suffix && !strcmp (kef->suffix, kef_now->suffix); kef_now++)
	{
	  success = check_kef_type (fmt_loc, kef_now,
	      first_wanted_type->arg_num,
	      first_wanted_type->param,
	      kef_now->type, fki, offset_to_type_start, conversion_char, arglocs);

	  if (success)
	    return true;
	}

      location_t param_loc;

      if (EXPR_HAS_LOCATION (first_wanted_type->param))
	param_loc = EXPR_LOCATION (first_wanted_type->param);
      else if (arglocs)
	{
	  /* arg_num is 1-based.  */
	  gcc_assert (first_wanted_type->arg_num > 0);
	  param_loc = (*arglocs)[first_wanted_type->arg_num - 1];
	}

      format_type_warning (fmt_loc, param_loc, first_wanted_type,
			   kef->type, TREE_TYPE (first_wanted_type->param),
			   fki, offset_to_type_start, conversion_char);
    }

  return true;
}

/* Do the main part of checking a call to a format function.  FORMAT_CHARS
   is the NUL-terminated format string (which at this point may contain
   internal NUL characters); FORMAT_LENGTH is its length (excluding the
   terminating NUL character).  ARG_NUM is one less than the number of
   the first format argument to check; PARAMS points to that format
   argument in the list of arguments.  */

static void
check_format_info_main (format_check_results *res,
			function_format_info *info, const char *format_chars,
			location_t fmt_param_loc, tree format_string_cst,
			int format_length, tree params,
			unsigned HOST_WIDE_INT arg_num,
			object_allocator <format_wanted_type> &fwt_pool,
			vec<location_t> *arglocs)
{
  const char * const orig_format_chars = format_chars;
  const tree first_fillin_param = params;

  const format_kind_info * const fki = &format_types[info->format_type];
  const format_flag_spec * const flag_specs = fki->flag_specs;
  const location_t format_string_loc = res->format_string_loc;

  /* -1 if no conversions taking an operand have been found; 0 if one has
     and it didn't use $; 1 if $ formats are in use.  */
  int has_operand_number = -1;

  /* Vector of pointers to opening quoting directives (like GCC "%<").  */
  auto_vec<const char*> quotdirs;

  /* Pointers to the most recent color directives (like GCC's "%r or %R").
     A starting color directive much be terminated before the end of
     the format string.  A terminating directive makes no sense without
     a prior starting directive.  */
  const char *color_begin = NULL;
  const char *color_end = NULL;

  init_dollar_format_checking (info->first_arg_num, first_fillin_param);

  while (*format_chars != 0)
    {
      if (*format_chars++ != '%')
	continue;
      if (*format_chars == 0)
	{
	  format_warning_at_char (format_string_loc, format_string_cst,
				  format_chars - orig_format_chars,
				  OPT_Wformat_,
				  "spurious trailing %<%%%> in format");
	  continue;
	}
      if (*format_chars == '%')
	{
	  ++format_chars;
	  continue;
	}

      flag_chars_t flag_chars;
      argument_parser arg_parser (info, format_chars, format_string_cst,
				  orig_format_chars, format_string_loc,
				  flag_chars, has_operand_number,
				  first_fillin_param, fwt_pool, arglocs);

      if (!arg_parser.read_any_dollar ())
	return;

      if (!arg_parser.read_format_flags ())
	return;

      /* Read any format width, possibly * or *m$.  */
      if (!arg_parser.read_any_format_width (params, arg_num))
	return;

      /* Read any format left precision (must be a number, not *).  */
      arg_parser.read_any_format_left_precision ();

      /* Read any format precision, possibly * or *m$.  */
      if (!arg_parser.read_any_format_precision (params, arg_num))
	return;

      const char *format_start = format_chars;

      arg_parser.handle_alloc_chars ();

      /* The rest of the conversion specification is the length modifier
	 (if any), and the conversion specifier, so this is where the
	 type information starts.  If we need to issue a suggestion
	 about a type mismatch, then we should preserve everything up
	 to here. */
      const char *type_start = format_chars;

      /* Read any length modifier, if this kind of format has them.  */
      const length_modifier len_modifier
	= arg_parser.read_any_length_modifier ();

      /* Read any modifier (strftime E/O).  */
      arg_parser.read_any_other_modifier ();

      char format_char = *format_chars;
      if (format_char == 0
	  || (!(fki->flags & (int) FMT_FLAG_FANCY_PERCENT_OK)
	      && format_char == '%'))
	{
	  format_warning_at_char (format_string_loc, format_string_cst,
			     format_chars - orig_format_chars,
			     OPT_Wformat_,
			     "conversion lacks type at end of format");
	  continue;
	}
      format_chars++;

      const format_char_info * const fci
	= arg_parser.find_format_char_info (format_char);
      if (!fci)
	continue;

      struct kernel_ext_fmt *etab = fci->kernel_ext;

      if (etab && format_chars[0] >= 'A' && format_chars[0] <= 'Z')
        {
          struct kernel_ext_fmt *etab_end = etab + ETAB_SZ;

          for (; etab < etab_end && etab->suffix; etab++)
            {
              if (!strncmp (etab->suffix, format_chars, strlen (etab->suffix)))
                break;
            }

          if (!etab->suffix || etab == etab_end)
            {
	      format_warning_at_char (format_string_loc, format_string_cst,
				      format_chars - orig_format_chars + 1,
				      OPT_Wformat_,
				      "unrecognized printf extension suffix");
              etab = NULL;
            }
	  else
	    {
	      format_chars += strlen (etab->suffix);
	    }
        }
      else
	etab = NULL;

      flag_chars.validate (fki, fci, flag_specs, format_chars,
			   format_string_cst,
			   format_string_loc, orig_format_chars, format_char,
			   quotdirs.length () > 0);

      const int alloc_flag = flag_chars.get_alloc_flag (fki);
      const bool suppressed = flag_chars.assignment_suppression_p (fki);

      /* Diagnose nested or unmatched quoting directives such as GCC's
	 "%<...%<" and "%>...%>".  */
      bool quot_begin_p = strchr (fci->flags2, '<');
      bool quot_end_p = strchr (fci->flags2, '>');

      if (quot_begin_p && !quot_end_p)
	{
	  if (quotdirs.length ())
	    format_warning_at_char (format_string_loc, format_string_cst,
				    format_chars - orig_format_chars,
				    OPT_Wformat_,
				    "nested quoting directive");
	  quotdirs.safe_push (format_chars);
	}
      else if (!quot_begin_p && quot_end_p)
	{
	  if (quotdirs.length ())
	    quotdirs.pop ();
	  else
	    format_warning_at_char (format_string_loc, format_string_cst,
				    format_chars - orig_format_chars,
				    OPT_Wformat_,
				    "unmatched quoting directive");
	}

      bool color_begin_p = strchr (fci->flags2, '/');
      if (color_begin_p)
	{
	  color_begin = format_chars;
	  color_end = NULL;
	}
      else if (strchr (fci->flags2, '\\'))
	{
	  if (color_end)
	    format_warning_at_char (format_string_loc, format_string_cst,
				    format_chars - orig_format_chars,
				    OPT_Wformat_,
				    "%qc directive redundant after prior occurence of the same", format_char);
	  else if (!color_begin)
	    format_warning_at_char (format_string_loc, format_string_cst,
				    format_chars - orig_format_chars,
				    OPT_Wformat_,
				    "unmatched color reset directive");
	  color_end = format_chars;
	}

      /* Diagnose directives that shouldn't appear in a quoted sequence.
	 (They are denoted by a double quote in FLAGS2.)  */
      if (quotdirs.length ())
	{
	  if (strchr (fci->flags2, '"'))
	    format_warning_at_char (format_string_loc, format_string_cst,
				    format_chars - orig_format_chars,
				    OPT_Wformat_,
				    "%qc conversion used within a quoted sequence",
				    format_char);
	}

      /* Validate the pairs of flags used.  */
      arg_parser.validate_flag_pairs (fci, format_char);

      arg_parser.give_y2k_warnings (fci, format_char);

      arg_parser.parse_any_scan_set (fci);

      tree wanted_type = NULL;
      const char *wanted_type_name = NULL;

      if (!arg_parser.handle_conversions (fci, len_modifier,
					  wanted_type, wanted_type_name,
					  arg_num,
					  params,
					  format_char))
	continue;

      arg_parser.main_wanted_type.next = NULL;

      /* Finally. . .check type of argument against desired type!  */
      if (!arg_parser.check_argument_type (fci, etab, len_modifier,
					   wanted_type, wanted_type_name,
					   suppressed,
					   arg_num, params,
					   alloc_flag,
					   format_start, type_start,
					   fmt_param_loc,
					   format_char))
	return;
    }

  if (format_chars - orig_format_chars != format_length)
    format_warning_at_char (format_string_loc, format_string_cst,
			    format_chars + 1 - orig_format_chars,
			    OPT_Wformat_contains_nul,
			    "embedded %<\\0%> in format");
  if (info->first_arg_num != 0 && params != 0
      && has_operand_number <= 0)
    {
      res->number_other--;
      res->number_extra_args++;
    }
  if (has_operand_number > 0)
    finish_dollar_format_checking (res, fki->flags & (int) FMT_FLAG_DOLLAR_GAP_POINTER_OK);

  if (quotdirs.length ())
    format_warning_at_char (format_string_loc, format_string_cst,
			    quotdirs.pop () - orig_format_chars,
			    OPT_Wformat_, "unterminated quoting directive");
  if (color_begin && !color_end)
    format_warning_at_char (format_string_loc, format_string_cst,
			    color_begin - orig_format_chars,
			    OPT_Wformat_, "unterminated color directive");
}

/* Check the argument types from a single format conversion (possibly
   including width and precision arguments).

   FMT_LOC is the location of the format conversion.

   TYPES is a singly-linked list expressing the parts of the format
   conversion that expect argument types, and the arguments they
   correspond to.

   OFFSET_TO_TYPE_START is the offset within the execution-charset encoded
   format string to where type information begins for the conversion
   (the length modifier and conversion specifier).

   CONVERSION_CHAR is the user-provided conversion specifier.

   For example, given:

     sprintf (d, "before %-+*.*lld after", arg3, arg4, arg5);

   then FMT_LOC covers this range:

     sprintf (d, "before %-+*.*lld after", arg3, arg4, arg5);
                         ^^^^^^^^^

   and TYPES in this case is a three-entry singly-linked list consisting of:
   (1) the check for the field width here:
         sprintf (d, "before %-+*.*lld after", arg3, arg4, arg5);
                                ^              ^^^^
       against arg3, and
   (2) the check for the field precision here:
         sprintf (d, "before %-+*.*lld after", arg3, arg4, arg5);
                                 ^^                  ^^^^
       against arg4, and
   (3) the check for the length modifier and conversion char here:
         sprintf (d, "before %-+*.*lld after", arg3, arg4, arg5);
                                   ^^^                     ^^^^
       against arg5.

   OFFSET_TO_TYPE_START is 13, the offset to the "lld" within the
   STRING_CST:

                  0000000000111111111122
                  0123456789012345678901
     sprintf (d, "before %-+*.*lld after", arg3, arg4, arg5);
                               ^ ^
                               | ` CONVERSION_CHAR: 'd'
                               type starts here.  */
tree type_normalize (tree type, tree *cousin, tree target = NULL)
{
  while (1)
    {
      if (TREE_CODE (type) == FUNCTION_TYPE || TREE_CODE (type) == POINTER_TYPE
	  || TREE_CODE (type) == ARRAY_TYPE)
	return type;
      if (target)
	/* Strip off any "const" etc.  */
        type = build_qualified_type (type, 0);
      if (TREE_CODE (TYPE_NAME (type)) != TYPE_DECL)
	return type;

      if (target && (type == target || TYPE_NAME (type) == target))
	return target;

      struct type_special *t;
      for (t = special_types; t->match; t++)
        {
	  if (!*t->match)
	    continue;
	  if (TYPE_NAME (type) != *t->match)
	    continue;
	  if (t->cousin && *t->cousin)
	    *cousin = *t->cousin;
	  if (t->replace)
	    return *t->replace ? *t->replace : type;
	  return type;
        }

      tree orig = DECL_ORIGINAL_TYPE (TYPE_NAME (type));
      if (!orig)
	return type;

      type = orig;
    }
  return type;
}

/* gcc-10 asserts when you give a TYPE_DECL instead of the actual TYPE */
static tree
decl_deref(tree typ)
{
  while (TREE_CODE (typ) == TYPE_DECL)
    typ = DECL_ORIGINAL_TYPE (typ);

  return typ;
}

static void
check_format_types (const substring_loc &fmt_loc,
		    format_wanted_type *types, const format_kind_info *fki,
		    int offset_to_type_start,
		    char conversion_char,
		    vec<location_t> *arglocs)
{
  for (; types != 0; types = types->next)
    {
      tree cur_param;
      tree cur_type;
      tree cur_type_cousin = NULL;
      tree orig_cur_type;
      tree wanted_type;
      int arg_num;
      int i;
      int char_type_flag;

      wanted_type = types->wanted_type;
      arg_num = types->arg_num;

      wanted_type = decl_deref(wanted_type);

      /* The following should not occur here.  */
      gcc_assert (wanted_type);
      gcc_assert (wanted_type != void_type_node || types->pointer_count);

      if (types->pointer_count == 0)
	wanted_type = lang_hooks.types.type_promotes_to (wanted_type);

      switch (TREE_CODE (wanted_type))
        {
	  case IDENTIFIER_NODE:
	    break;
	  case TYPE_DECL:
	    wanted_type = TYPE_MAIN_VARIANT (DECL_ORIGINAL_TYPE (wanted_type));
	    break;
	  default:
	    wanted_type = TYPE_MAIN_VARIANT (wanted_type);
	    break;
        }

      cur_param = types->param;
      if (!cur_param)
        {
	  format_type_warning (fmt_loc, UNKNOWN_LOCATION, types, wanted_type,
			       NULL, fki, offset_to_type_start,
			       conversion_char);
          continue;
        }

      cur_type = TREE_TYPE (cur_param);
      if (cur_type == error_mark_node)
	continue;
      orig_cur_type = cur_type;
      char_type_flag = 0;

      location_t param_loc = UNKNOWN_LOCATION;
      if (EXPR_HAS_LOCATION (cur_param))
	param_loc = EXPR_LOCATION (cur_param);
      else if (arglocs)
	{
	  /* arg_num is 1-based.  */
	  gcc_assert (types->arg_num > 0);
	  param_loc = (*arglocs)[types->arg_num - 1];
	}

      STRIP_NOPS (cur_param);

      /* Check the types of any additional pointer arguments
	 that precede the "real" argument.  */
      for (i = 0; i < types->pointer_count; ++i)
	{
	  if (TREE_CODE (cur_type) == POINTER_TYPE)
	    {
	      cur_type = TREE_TYPE (cur_type);
	      if (cur_type == error_mark_node)
		break;

	      /* Check for writing through a NULL pointer.  */
	      if (types->writing_in_flag
		  && i == 0
		  && cur_param != 0
		  && integer_zerop (cur_param))
		warning (OPT_Wformat_, "writing through null pointer (argument %d)", arg_num);

	      /* Check for reading through a NULL pointer.  */
	      if (types->reading_from_flag
		  && i == 0
		  && cur_param != 0
		  && integer_zerop (cur_param))
		warning (OPT_Wformat_, "reading through null pointer (argument %d)", arg_num);

	      if (cur_param != 0 && TREE_CODE (cur_param) == ADDR_EXPR)
		cur_param = TREE_OPERAND (cur_param, 0);
	      else
		cur_param = 0;

	      /* See if this is an attempt to write into a const type with
		 scanf or with printf "%n".  Note: the writing in happens
		 at the first indirection only, if for example
		 void * const * is passed to scanf %p; passing
		 const void ** is simply passing an incompatible type.  */
	      if (types->writing_in_flag
		  && i == 0
		  && (TYPE_READONLY (cur_type)
		      || (cur_param != 0
			  && (CONSTANT_CLASS_P (cur_param)
			      || (DECL_P (cur_param)
				  && TREE_READONLY (cur_param))))))
		warning (OPT_Wformat_, "writing into constant object (argument %d)", arg_num);

	      /* If there are extra type qualifiers beyond the first
		 indirection, then this makes the types technically
		 incompatible.  */
	      if (i > 0
		  && pedantic
		  && (TYPE_READONLY (cur_type)
		      || TYPE_VOLATILE (cur_type)
		      || TYPE_ATOMIC (cur_type)
		      || TYPE_RESTRICT (cur_type)))
		warning (OPT_Wformat_, "extra type qualifiers in format argument (argument %d)",
			 arg_num);

	    }
	  else
	    {
	      format_type_warning (fmt_loc, param_loc,
				   types, wanted_type, orig_cur_type, fki,
				   offset_to_type_start, conversion_char);
	      break;
	    }
	}

      if (i < types->pointer_count)
	continue;

      cur_type = type_normalize (cur_type, &cur_type_cousin);

      /* Check whether the argument type is a character type.  This leniency
	 only applies to certain formats, flagged with 'c'.  */
      if (types->char_lenient_flag)
	char_type_flag = (cur_type == char_type_node
			  || cur_type == signed_char_type_node
			  || cur_type == unsigned_char_type_node);

      int compat = lang_hooks.types_compatible_p (decl_deref (wanted_type), decl_deref (cur_type));
      /* Check the type of the "real" argument, if there's a type we want.  */
      if ((TREE_CODE (wanted_type) != INTEGER_TYPE || types->pointer_count)
	  && compat)
	continue;
      if (TREE_CODE (wanted_type) == INTEGER_TYPE && !types->pointer_count
	  && compat)
        {
compat_inner:
	  if (TREE_CODE (cur_param) == INTEGER_CST)
	    continue;

	  if (TREE_CODE (types->wanted_type) == TYPE_DECL
	      && TREE_CODE (cur_type) == TYPE_DECL)
	    {
	      if (types->wanted_type == cur_type)
		continue;
	      format_type_warning (fmt_loc, param_loc, types,
				   wanted_type, orig_cur_type, fki,
				   offset_to_type_start, conversion_char,
				   " (strict match required [A])");
	      continue;
	    }
	  else if (TREE_CODE (types->wanted_type) == TYPE_DECL)
	    {
	      if (types->wanted_type == TYPE_NAME(cur_type))
		continue;
	      format_type_warning (fmt_loc, param_loc, types,
				   wanted_type, orig_cur_type, fki,
				   offset_to_type_start, conversion_char,
				   " (strict match required [B])");
	      continue;
	    }
	  else if (wanted_type == cur_type)
	    continue;
	  else if (cur_type_cousin)
	    {
	      format_type_warning (fmt_loc, param_loc, types,
				   wanted_type, orig_cur_type, fki,
				   offset_to_type_start, conversion_char,
				   " (strict match required [C])");
	    }

	  /*
	  format_type_warning (fmt_loc, param_loc, types,
			       wanted_type, orig_cur_type, fki,
			       offset_to_type_start, conversion_char,
			       " (ultra-pedantic mode)");
	  */
	  continue;
        }

      /* If we want 'void *', allow any pointer type.
	 (Anything else would already have got a warning.)
	 With -Wpedantic, only allow pointers to void and to character
	 types.  */
      if (wanted_type == void_type_node
	  && (!pedantic || (i == 1 && char_type_flag)))
	continue;
      /* Don't warn about differences merely in signedness, unless
	 -Wpedantic.  With -Wpedantic, warn if the type is a pointer
	 target and not a character type, and for character types at
	 a second level of indirection.  */
      if (TREE_CODE (wanted_type) == INTEGER_TYPE
	  && TREE_CODE (cur_type) == INTEGER_TYPE
	  && ((!pedantic && !warn_format_signedness)
	      || (i == 0 && !warn_format_signedness)
	      || (i == 1 && char_type_flag))
	  && (TYPE_UNSIGNED (wanted_type)
	      ? wanted_type == c_common_unsigned_type (cur_type)
	      : wanted_type == c_common_signed_type (cur_type)))
        {
	  if (cur_type_cousin)
	    {
	      if (TREE_CODE (types->wanted_type) == TYPE_DECL
		  && TREE_CODE (cur_type_cousin) == TYPE_DECL)
		{
		  if (types->wanted_type == cur_type_cousin)
		    continue;
		  format_type_warning (fmt_loc, param_loc, types,
				       wanted_type, orig_cur_type, fki,
				       offset_to_type_start, conversion_char,
				       " (strict match required [X])");
		  continue;
		}
	      else if (TREE_CODE (types->wanted_type) == TYPE_DECL)
		{
		  if (types->wanted_type == TYPE_NAME(cur_type_cousin))
		    continue;
		  format_type_warning (fmt_loc, param_loc, types,
				       wanted_type, orig_cur_type, fki,
				       offset_to_type_start, conversion_char,
				       " (strict match required [Y])");
		  continue;
		}
	      else if (wanted_type == cur_type_cousin)
		continue;
	      else
	        {
		  format_type_warning (fmt_loc, param_loc, types,
				       wanted_type, orig_cur_type, fki,
				       offset_to_type_start, conversion_char,
				       " (strict match required [Z])");
		}
	    }

	  goto compat_inner;
	}
      /* Don't warn about differences merely in signedness if we know
	 that the current type is integer-promoted and its original type
	 was unsigned such as that it is in the range of WANTED_TYPE.  */
      if (TREE_CODE (wanted_type) == INTEGER_TYPE
	  && TREE_CODE (cur_type) == INTEGER_TYPE
	  && warn_format_signedness
	  && TYPE_UNSIGNED (wanted_type)
	  && cur_param != NULL_TREE
	  && TREE_CODE (cur_param) == NOP_EXPR)
	{
	  tree t = TREE_TYPE (TREE_OPERAND (cur_param, 0));
	  if (TYPE_UNSIGNED (t)
	      && cur_type == lang_hooks.types.type_promotes_to (t))
	    continue;
	}
      /* Likewise, "signed char", "unsigned char" and "char" are
	 equivalent but the above test won't consider them equivalent.  */
      if (wanted_type == char_type_node
	  && (!pedantic || i < 2)
	  && char_type_flag)
	continue;
      if (types->scalar_identity_flag
	  && (TREE_CODE (cur_type) == TREE_CODE (wanted_type)
	      || (INTEGRAL_TYPE_P (cur_type)
		  && INTEGRAL_TYPE_P (wanted_type)))
	  && TYPE_PRECISION (cur_type) == TYPE_PRECISION (wanted_type))
	continue;
      /* Now we have a type mismatch.  */
      format_type_warning (fmt_loc, param_loc, types,
			   wanted_type, orig_cur_type, fki,
			   offset_to_type_start, conversion_char);
    }
}

static bool
check_kef_type (const substring_loc &fmt_loc,
		const struct kernel_ext_fmt *kef,
		unsigned arg_num,
		tree cur_param,
		tree wanted_type,
		const format_kind_info *fki,
		int offset_to_type_start,
		char conversion_char,
		vec<location_t> *arglocs)
{
  tree cur_type;
  bool ok = true;
  int i;

  /* The following should not occur here.  */
  gcc_assert (wanted_type);
  gcc_assert (wanted_type != void_type_node || kef->ptrlevel);

  if (TREE_CODE (wanted_type) == TYPE_DECL)
    wanted_type = DECL_ORIGINAL_TYPE (wanted_type);

  if (!cur_param)
    return false;

  cur_type = TREE_TYPE (cur_param);
  if (cur_type == error_mark_node)
    return false;

  location_t param_loc = UNKNOWN_LOCATION;
  if (EXPR_HAS_LOCATION (cur_param))
    param_loc = EXPR_LOCATION (cur_param);
  else if (arglocs)
    {
      /* arg_num is 1-based.  */
      gcc_assert (arg_num > 0);
      param_loc = (*arglocs)[arg_num - 1];
    }
  (void)param_loc;

  STRIP_NOPS (cur_param);

  /* Check the types of any additional pointer arguments
     that precede the "real" argument.  */
  for (i = 0; i < kef->ptrlevel; ++i)
    {
      if (TREE_CODE (cur_type) == POINTER_TYPE)
	{
	  cur_type = TREE_TYPE (cur_type);
	  if (cur_type == error_mark_node)
	    break;

	  if (cur_param != 0 && TREE_CODE (cur_param) == ADDR_EXPR)
	    cur_param = TREE_OPERAND (cur_param, 0);
	  else
	    cur_param = 0;

	  /* If there are extra type qualifiers beyond the first
	     indirection, then this makes the types technically
	     incompatible.  */
	  if (i > 0
	      && pedantic
	      && (TYPE_READONLY (cur_type)
		  || TYPE_VOLATILE (cur_type)
		  || TYPE_ATOMIC (cur_type)
		  || TYPE_RESTRICT (cur_type)))
	    warning (OPT_Wformat_, "extra type qualifiers in format argument (argument %d)",
		     arg_num);

	}
      else
	{
	  ok = false;
	  break;
	}
    }

  if (i < kef->ptrlevel)
    return ok;

  int compat = lang_hooks.types_compatible_p (wanted_type, cur_type);

  if (!compat)
    return false;

  tree cousin;
  tree normal_type;

  normal_type = type_normalize (cur_type, &cousin, wanted_type);

  return normal_type == wanted_type;
}


/* Given type TYPE, attempt to dereference the type N times
   (e.g. from ("int ***", 2) to "int *")

   Return the derefenced type, with any qualifiers
   such as "const" stripped from the result, or
   NULL if unsuccessful (e.g. TYPE is not a pointer type).  */

static tree
deref_n_times (tree type, int n)
{
  gcc_assert (type);

  for (int i = n; i > 0; i--)
    {
      if (TREE_CODE (type) != POINTER_TYPE)
	return NULL_TREE;
      type = TREE_TYPE (type);
    }
  /* Strip off any "const" etc.  */
  return build_qualified_type (type, 0);
}

/* Lookup the format code for FORMAT_LEN within FLI,
   returning the string code for expressing it, or NULL
   if it is not found.  */

static const char *
get_modifier_for_format_len (const format_length_info *fli,
			     enum format_lengths format_len)
{
  for (; fli->name; fli++)
    {
      if (fli->index == format_len)
	return fli->name;
      if (fli->double_index == format_len)
	return fli->double_name;
    }
  return NULL;
}

#if CHECKING_P

namespace selftest {

static void
test_get_modifier_for_format_len ()
{
  ASSERT_STREQ ("h",
		get_modifier_for_format_len (printf_length_specs, FMT_LEN_h));
  ASSERT_STREQ ("hh",
		get_modifier_for_format_len (printf_length_specs, FMT_LEN_hh));
  ASSERT_STREQ ("L",
		get_modifier_for_format_len (printf_length_specs, FMT_LEN_L));
  ASSERT_EQ (NULL,
	     get_modifier_for_format_len (printf_length_specs, FMT_LEN_none));
}

} // namespace selftest

#endif /* CHECKING_P */

/* Determine if SPEC_TYPE and ARG_TYPE are sufficiently similar for a
   format_type_detail using SPEC_TYPE to be offered as a suggestion for
   Wformat type errors where the argument has type ARG_TYPE.  */

static bool
matching_type_p (tree spec_type, tree arg_type)
{
  gcc_assert (spec_type);
  gcc_assert (arg_type);

  spec_type = decl_deref (spec_type);
  arg_type = decl_deref (arg_type);

  /* If any of the types requires structural equality, we can't compare
     their canonical types.  */
  if (TYPE_STRUCTURAL_EQUALITY_P (spec_type)
      || TYPE_STRUCTURAL_EQUALITY_P (arg_type))
    return false;

  spec_type = TYPE_CANONICAL (spec_type);
  arg_type = TYPE_CANONICAL (arg_type);

  if (TREE_CODE (spec_type) == INTEGER_TYPE
      && TREE_CODE (arg_type) == INTEGER_TYPE
      && (TYPE_UNSIGNED (spec_type)
	  ? spec_type == c_common_unsigned_type (arg_type)
	  : spec_type == c_common_signed_type (arg_type)))
    return true;

  return spec_type == arg_type;
}

/* Subroutine of get_format_for_type.

   Generate a string containing the length modifier and conversion specifier
   that should be used to format arguments of type ARG_TYPE within FKI
   (effectively the inverse of the checking code).

   If CONVERSION_CHAR is not zero (the first pass), the resulting suggestion
   is required to use it, for correcting bogus length modifiers.
   If CONVERSION_CHAR is zero (the second pass), then allow any suggestion
   that matches ARG_TYPE.

   If successful, returns a non-NULL string which should be freed
   by the caller.
   Otherwise, returns NULL.  */

static char *
get_format_for_type_1 (const format_kind_info *fki, tree arg_type,
		       char conversion_char)
{
  gcc_assert (arg_type);

  const format_char_info *spec;
  for (spec = &fki->conversion_specs[0];
       spec->format_chars;
       spec++)
    {
      if (conversion_char)
	if (!strchr (spec->format_chars, conversion_char))
	  continue;

      tree effective_arg_type = deref_n_times (arg_type,
					       spec->pointer_count);
      if (!effective_arg_type)
	continue;
      for (int i = 0; i < FMT_LEN_MAX; i++)
	{
	  const format_type_detail *ftd = &spec->types[i];
	  if (!ftd->type)
	    continue;
	  if (matching_type_p (*ftd->type, effective_arg_type))
	    {
	      const char *len_modifier
		= get_modifier_for_format_len (fki->length_char_specs,
					       (enum format_lengths)i);
	      if (!len_modifier)
		len_modifier = "";

	      if (conversion_char)
		/* We found a match, using the given conversion char - the
		   length modifier was incorrect (or absent).
		   Provide a suggestion using the conversion char with the
		   correct length modifier for the type.  */
		return xasprintf ("%s%c", len_modifier, conversion_char);
	      else
		/* 2nd pass: no match was possible using the user-provided
		   conversion char, but we do have a match without using it.
		   Provide a suggestion using the first conversion char
		   listed for the given type.  */
		return xasprintf ("%s%c", len_modifier, spec->format_chars[0]);
	    }
	}
   }

  return NULL;
}

/* Generate a string containing the length modifier and conversion specifier
   that should be used to format arguments of type ARG_TYPE within FKI
   (effectively the inverse of the checking code).

   If successful, returns a non-NULL string which should be freed
   by the caller.
   Otherwise, returns NULL.  */

static char *
get_format_for_type (const format_kind_info *fki, tree arg_type,
		     char conversion_char)
{
  gcc_assert (arg_type);
  gcc_assert (conversion_char);

  /* First pass: look for a format_char_info containing CONVERSION_CHAR
     If we find one, then presumably the length modifier was incorrect
     (or absent).  */
  char *result = get_format_for_type_1 (fki, arg_type, conversion_char);
  if (result)
    return result;

  /* Second pass: we didn't find a match for CONVERSION_CHAR, so try
     matching just on the type. */
  return get_format_for_type_1 (fki, arg_type, '\0');
}

/* Attempt to get a string for use as a replacement fix-it hint for the
   source range in FMT_LOC.

   Preserve all of the text within the range of FMT_LOC up to
   OFFSET_TO_TYPE_START, replacing the rest with an appropriate
   length modifier and conversion specifier for ARG_TYPE, attempting
   to keep the user-provided CONVERSION_CHAR if possible.

   For example, given a long vs long long mismatch for arg5 here:

    000000000111111111122222222223333333333|
    123456789012345678901234567890123456789` column numbers
                   0000000000111111111122|
                   0123456789012345678901` string offsets
                          V~~~~~~~~ : range of FMT_LOC, from cols 23-31
      sprintf (d, "before %-+*.*lld after", arg3, arg4, arg5);
                                ^ ^
                                | ` CONVERSION_CHAR: 'd'
                                type starts here

   where OFFSET_TO_TYPE_START is 13 (the offset to the "lld" within the
   STRING_CST), where the user provided:
     %-+*.*lld
   the result (assuming "long" argument 5) should be:
     %-+*.*ld

   If successful, returns a non-NULL string which should be freed
   by the caller.
   Otherwise, returns NULL.  */

static char *
get_corrected_substring (const substring_loc &fmt_loc,
			 format_wanted_type *type, tree arg_type,
			 const format_kind_info *fki,
			 int offset_to_type_start, char conversion_char)
{
  /* Attempt to provide hints for argument types, but not for field widths
     and precisions.  */
  if (!arg_type)
    return NULL;
  if (type->kind != CF_KIND_FORMAT)
    return NULL;

  /* Locate the current code within the source range, rejecting
     any awkward cases where the format string occupies more than
     one line.
     Lookup the place where the type starts (including any length
     modifiers), getting it as the caret location.  */
  substring_loc type_loc (fmt_loc);
  type_loc.set_caret_index (offset_to_type_start);

  location_t fmt_substring_loc;
  const char *err = type_loc.get_location (&fmt_substring_loc);
  if (err)
    return NULL;

  source_range fmt_substring_range
    = get_range_from_loc (line_table, fmt_substring_loc);

  expanded_location caret
    = expand_location_to_spelling_point (fmt_substring_loc);
  expanded_location start
    = expand_location_to_spelling_point (fmt_substring_range.m_start);
  expanded_location finish
    = expand_location_to_spelling_point (fmt_substring_range.m_finish);
  if (caret.file != start.file)
    return NULL;
  if (start.file != finish.file)
    return NULL;
  if (caret.line != start.line)
    return NULL;
  if (start.line != finish.line)
    return NULL;
  if (start.column > caret.column)
    return NULL;
  if (start.column > finish.column)
    return NULL;
  if (caret.column > finish.column)
    return NULL;

#if BUILDING_GCC_VERSION >= 9000
  char_span line = location_get_source_line (start.file, start.line);
  if (!line)
    return NULL;

  /* If we got this far, then we have the line containing the
     existing conversion specification.

     Generate a trimmed copy, containing the prefix part of the conversion
     specification, up to the (but not including) the length modifier.
     In the above example, this would be "%-+*.*".  */
  int length_up_to_type = caret.column - start.column;
  char_span prefix_span = line.subspan (start.column - 1, length_up_to_type);
  char *prefix = prefix_span.xstrdup ();
#else
  char *prefix = NULL;
#endif

  /* Now attempt to generate a suggestion for the rest of the specification
     (length modifier and conversion char), based on ARG_TYPE and
     CONVERSION_CHAR.
     In the above example, this would be "ld".  */
  char *format_for_type = get_format_for_type (fki, arg_type, conversion_char);
  if (!format_for_type)
    {
      free (prefix);
      return NULL;
    }

  /* Success.  Generate the resulting suggestion for the whole range of
     FMT_LOC by concatenating the two strings.
     In the above example, this would be "%-+*.*ld".  */
  char *result = concat (prefix, format_for_type, NULL);
  free (format_for_type);
  free (prefix);
  return result;
}

/* Helper class for adding zero or more trailing '*' to types.

   The format type and name exclude any '*' for pointers, so those
   must be formatted manually.  For all the types we currently have,
   this is adequate, but formats taking pointers to functions or
   arrays would require the full type to be built up in order to
   print it with %T.  */

class indirection_suffix
{
 public:
  indirection_suffix (int pointer_count) : m_pointer_count (pointer_count) {}

  /* Determine the size of the buffer (including NUL-terminator).  */

  size_t get_buffer_size () const
  {
    return m_pointer_count + 2;
  }

  /* Write the '*' to DST and add a NUL-terminator.  */

  void fill_buffer (char *dst) const
  {
    if (m_pointer_count == 0)
      dst[0] = 0;
    else if (c_dialect_cxx ())
      {
	memset (dst, '*', m_pointer_count);
	dst[m_pointer_count] = 0;
      }
    else
      {
	dst[0] = ' ';
	memset (dst + 1, '*', m_pointer_count);
	dst[m_pointer_count + 1] = 0;
      }
  }

 private:
  int m_pointer_count;
};

#if BUILDING_GCC_VERSION >= 9000
/* not exported by GCC... need a local copy :( */
class frr_range_label_for_type_mismatch : public range_label
{
 public:
  frr_range_label_for_type_mismatch (tree labelled_type, tree other_type)
  : m_labelled_type (labelled_type), m_other_type (other_type)
  {
  }

  label_text get_text (unsigned range_idx) const override;

 protected:
  tree m_labelled_type;
  tree m_other_type;
};

/* Print T to CPP.  */

static void
print_type (c_pretty_printer *cpp, tree t, bool *quoted)
{
  gcc_assert (TYPE_P (t));
  struct obstack *ob = pp_buffer (cpp)->obstack;
  char *p = (char *) obstack_base (ob);
  /* Remember the end of the initial dump.  */
  int len = obstack_object_size (ob);

  tree name = TYPE_NAME (t);
  if (name && TREE_CODE (name) == TYPE_DECL && DECL_NAME (name))
    pp_identifier (cpp, lang_hooks.decl_printable_name (name, 2));
  else
    cpp->type_id (t);

  /* If we're printing a type that involves typedefs, also print the
     stripped version.  But sometimes the stripped version looks
     exactly the same, so we don't want it after all.  To avoid
     printing it in that case, we play ugly obstack games.  */
  if (TYPE_CANONICAL (t) && t != TYPE_CANONICAL (t))
    {
      c_pretty_printer cpp2;
      /* Print the stripped version into a temporary printer.  */
      cpp2.type_id (TYPE_CANONICAL (t));
      struct obstack *ob2 = cpp2.buffer->obstack;
      /* Get the stripped version from the temporary printer.  */
      const char *aka = (char *) obstack_base (ob2);
      int aka_len = obstack_object_size (ob2);
      int type1_len = obstack_object_size (ob) - len;

      /* If they are identical, bail out.  */
      if (aka_len == type1_len && memcmp (p + len, aka, aka_len) == 0)
	return;

      /* They're not, print the stripped version now.  */
      if (*quoted)
	pp_end_quote (cpp, pp_show_color (cpp));
      pp_c_whitespace (cpp);
      pp_left_brace (cpp);
      pp_c_ws_string (cpp, _("aka"));
      pp_c_whitespace (cpp);
      if (*quoted)
	pp_begin_quote (cpp, pp_show_color (cpp));
      cpp->type_id (TYPE_CANONICAL (t));
      if (*quoted)
	pp_end_quote (cpp, pp_show_color (cpp));
      pp_right_brace (cpp);
      /* No further closing quotes are needed.  */
      *quoted = false;
    }
}

/* C-specific implementation of range_label::get_text () vfunc for
   range_label_for_type_mismatch.  */
#if BUILDING_GCC_VERSION >= 10000
#define label_borrow(text) label_text::borrow(text)
#define label_take(text)   label_text::take(text)
#else
#define label_borrow(text) label_text((char *)text, false)
#define label_take(text)   label_text(text, true)
#endif

label_text
frr_range_label_for_type_mismatch::get_text (unsigned /*range_idx*/) const
{
  if (m_labelled_type == NULL_TREE)
    return label_borrow("(null tree)");

  c_pretty_printer cpp;
  bool quoted = false;
  print_type (&cpp, m_labelled_type, &quoted);
  return label_take(xstrdup (pp_formatted_text (&cpp)));
}

#define range_label_for_type_mismatch frr_range_label_for_type_mismatch
#endif

/* Subclass of range_label for labelling the range in the format string
   with the type in question, adding trailing '*' for pointer_count.  */

class range_label_for_format_type_mismatch
  : public range_label_for_type_mismatch
{
 public:
  range_label_for_format_type_mismatch (tree labelled_type, tree other_type,
					int pointer_count)
  : range_label_for_type_mismatch (labelled_type, other_type),
    m_pointer_count (pointer_count)
  {
  }

#if BUILDING_GCC_VERSION >= 13000
#define text_get(text) text.get()
#define text_return(text, result) return label_text::take(result)
#else
#define text_get(text) text.m_buffer
#define text_return(text, result) text.maybe_free(); return label_take(result)
#endif

  label_text get_text (unsigned range_idx) const final override
  {
    label_text text = range_label_for_type_mismatch::get_text (range_idx);
    if (text_get(text) == NULL)
      return text;

    indirection_suffix suffix (m_pointer_count);
    char *p = (char *) alloca (suffix.get_buffer_size ());
    suffix.fill_buffer (p);

    char *result = concat (text_get(text), p, NULL);
    text_return(text, result);
  }

 private:
  int m_pointer_count;
};

/* Give a warning about a format argument of different type from that expected.
   The range of the diagnostic is taken from WHOLE_FMT_LOC; the caret location
   is based on the location of the char at TYPE->offset_loc.
   PARAM_LOC is the location of the relevant argument, or UNKNOWN_LOCATION
   if this is unavailable.
   WANTED_TYPE is the type the argument should have,
   possibly stripped of pointer dereferences.  The description (such as "field
   precision"), the placement in the format string, a possibly more
   friendly name of WANTED_TYPE, and the number of pointer dereferences
   are taken from TYPE.  ARG_TYPE is the type of the actual argument,
   or NULL if it is missing.

   OFFSET_TO_TYPE_START is the offset within the execution-charset encoded
   format string to where type information begins for the conversion
   (the length modifier and conversion specifier).
   CONVERSION_CHAR is the user-provided conversion specifier.

   For example, given a type mismatch for argument 5 here:

    00000000011111111112222222222333333333344444444445555555555|
    12345678901234567890123456789012345678901234567890123456789` column numbers
                   0000000000111111111122|
                   0123456789012345678901` offsets within STRING_CST
                          V~~~~~~~~ : range of WHOLE_FMT_LOC, from cols 23-31
      sprintf (d, "before %-+*.*lld after", int_expr, int_expr, long_expr);
                                ^ ^                             ^~~~~~~~~
                                | ` CONVERSION_CHAR: 'd'        PARAM_LOC
                                type starts here

   OFFSET_TO_TYPE_START is 13, the offset to the "lld" within the
   STRING_CST.  */

static void
format_type_warning (const substring_loc &whole_fmt_loc,
		     location_t param_loc,
		     format_wanted_type *type,
		     tree wanted_type, tree arg_type,
		     const format_kind_info *fki,
		     int offset_to_type_start,
		     char conversion_char,
		     const char *extra)
{
  enum format_specifier_kind kind = type->kind;
  const char *wanted_type_name = type->wanted_type_name;
  const char *format_start = type->format_start;
  int format_length = type->format_length;
  int pointer_count = type->pointer_count;
  int arg_num = type->arg_num;

  if (!extra)
    extra = "";

  /* If ARG_TYPE is a typedef with a misleading name (for example,
     size_t but not the standard size_t expected by printf %zu), avoid
     printing the typedef name.  */
  if (wanted_type_name
      && arg_type
      && TYPE_NAME (arg_type)
      && TREE_CODE (TYPE_NAME (arg_type)) == TYPE_DECL
      && DECL_NAME (TYPE_NAME (arg_type))
      && !strcmp (wanted_type_name,
		  lang_hooks.decl_printable_name (TYPE_NAME (arg_type), 2)))
    arg_type = TYPE_MAIN_VARIANT (arg_type);

  indirection_suffix suffix (pointer_count);
  char *p = (char *) alloca (suffix.get_buffer_size ());
  suffix.fill_buffer (p);

  /* WHOLE_FMT_LOC has the caret at the end of the range.
     Set the caret to be at the offset from TYPE.  Subtract one
     from the offset for the same reason as in format_warning_at_char.  */
  substring_loc fmt_loc (whole_fmt_loc);
  fmt_loc.set_caret_index (type->offset_loc - 1);

#if BUILDING_GCC_VERSION >= 9000
  range_label_for_format_type_mismatch fmt_label (wanted_type, arg_type,
						  pointer_count);
  range_label_for_type_mismatch param_label (arg_type, wanted_type);

  /* Get a string for use as a replacement fix-it hint for the range in
     fmt_loc, or NULL.  */
  char *corrected_substring
    = get_corrected_substring (fmt_loc, type, arg_type, fki,
			       offset_to_type_start, conversion_char);
  format_string_diagnostic_t diag (fmt_loc, &fmt_label, param_loc, &param_label,
				   corrected_substring);
# define format_warning_at_substring(a,b,c,d,e,...) \
	diag.emit_warning(__VA_ARGS__)
#else
# define format_warning_at_substring(a,b,c,d,...) \
	format_warning_at_substring(a,c,__VA_ARGS__)
  /* Get a string for use as a replacement fix-it hint for the range in
     fmt_loc, or NULL.  */
  char *corrected_substring
    = get_corrected_substring (fmt_loc, type, arg_type, fki,
			       offset_to_type_start, conversion_char);

#endif

  if (wanted_type_name)
    {
      if (arg_type)
	format_warning_at_substring
	  (fmt_loc, &fmt_label, param_loc, &param_label,
	   corrected_substring, OPT_Wformat_,
	   "%s %<%s%.*s%> expects argument of type %<%s%s%>, but argument %d has type %qT%s",
	   gettext (kind_descriptions[kind]),
	   (kind == CF_KIND_FORMAT ? "%" : ""),
	   format_length, format_start,
	   wanted_type_name, p, arg_num, arg_type, extra);
      else
	format_warning_at_substring
	  (fmt_loc, &fmt_label, param_loc, &param_label,
	   corrected_substring, OPT_Wformat_,
	   "%s %<%s%.*s%> expects a matching %<%s%s%> argument%s",
	   gettext (kind_descriptions[kind]),
	   (kind == CF_KIND_FORMAT ? "%" : ""),
	   format_length, format_start, wanted_type_name, p, extra);
    }
  else
    {
      if (arg_type)
	format_warning_at_substring
	  (fmt_loc, &fmt_label, param_loc, &param_label,
	   corrected_substring, OPT_Wformat_,
	   "%s %<%s%.*s%> expects argument of type %<%T%s%>, but argument %d has type %qT%s",
	   gettext (kind_descriptions[kind]),
	   (kind == CF_KIND_FORMAT ? "%" : ""),
	   format_length, format_start,
	   wanted_type, p, arg_num, arg_type, extra);
      else
	format_warning_at_substring
	  (fmt_loc, &fmt_label, param_loc, &param_label,
	   corrected_substring, OPT_Wformat_,
	   "%s %<%s%.*s%> expects a matching %<%T%s%> argument%s",
	   gettext (kind_descriptions[kind]),
	   (kind == CF_KIND_FORMAT ? "%" : ""),
	   format_length, format_start, wanted_type, p, extra);
    }

  free (corrected_substring);
}


#if 0
/* Given a format_char_info array FCI, and a character C, this function
   returns the index into the conversion_specs where that specifier's
   data is located.  The character must exist.  */
static unsigned int
find_char_info_specifier_index (const format_char_info *fci, int c)
{
  unsigned i;

  for (i = 0; fci->format_chars; i++, fci++)
    if (strchr (fci->format_chars, c))
      return i;

  /* We shouldn't be looking for a non-existent specifier.  */
  gcc_unreachable ();
}

/* Given a format_length_info array FLI, and a character C, this
   function returns the index into the conversion_specs where that
   modifier's data is located.  The character must exist.  */
static unsigned int
find_length_info_modifier_index (const format_length_info *fli, int c)
{
  unsigned i;

  for (i = 0; fli->name; i++, fli++)
    if (strchr (fli->name, c))
      return i;

  /* We shouldn't be looking for a non-existent modifier.  */
  gcc_unreachable ();
}
#endif

#ifdef TARGET_FORMAT_TYPES
extern const format_kind_info TARGET_FORMAT_TYPES[];
#endif

#ifdef TARGET_OVERRIDES_FORMAT_ATTRIBUTES
extern const target_ovr_attr TARGET_OVERRIDES_FORMAT_ATTRIBUTES[];
#endif
#ifdef TARGET_OVERRIDES_FORMAT_INIT
  extern void TARGET_OVERRIDES_FORMAT_INIT (void);
#endif

/* Attributes such as "printf" are equivalent to those such as
   "gnu_printf" unless this is overridden by a target.  */
static const target_ovr_attr gnu_target_overrides_format_attributes[] =
{
  { NULL,           NULL }
};

/* Translate to unified attribute name. This is used in decode_format_type and
   decode_format_attr. In attr_name the user specified argument is passed. It
   returns the unified format name from TARGET_OVERRIDES_FORMAT_ATTRIBUTES
   or the attr_name passed to this function, if there is no matching entry.  */
static const char *
convert_format_name_to_system_name (const char *attr_name)
{
  int i;

  if (attr_name == NULL || *attr_name == 0
      || strncmp (attr_name, "gcc_", 4) == 0)
    return attr_name;
#ifdef TARGET_OVERRIDES_FORMAT_INIT
  TARGET_OVERRIDES_FORMAT_INIT ();
#endif

#ifdef TARGET_OVERRIDES_FORMAT_ATTRIBUTES
  /* Check if format attribute is overridden by target.  */
  if (TARGET_OVERRIDES_FORMAT_ATTRIBUTES != NULL
      && TARGET_OVERRIDES_FORMAT_ATTRIBUTES_COUNT > 0)
    {
      for (i = 0; i < TARGET_OVERRIDES_FORMAT_ATTRIBUTES_COUNT; ++i)
        {
          if (cmp_attribs (TARGET_OVERRIDES_FORMAT_ATTRIBUTES[i].named_attr_src,
			   attr_name))
            return attr_name;
          if (cmp_attribs (TARGET_OVERRIDES_FORMAT_ATTRIBUTES[i].named_attr_dst,
			   attr_name))
            return TARGET_OVERRIDES_FORMAT_ATTRIBUTES[i].named_attr_src;
        }
    }
#endif
  /* Otherwise default to gnu format.  */
  for (i = 0;
       gnu_target_overrides_format_attributes[i].named_attr_src != NULL;
       ++i)
    {
      if (cmp_attribs (gnu_target_overrides_format_attributes[i].named_attr_src,
		       attr_name))
        return attr_name;
      if (cmp_attribs (gnu_target_overrides_format_attributes[i].named_attr_dst,
		       attr_name))
        return gnu_target_overrides_format_attributes[i].named_attr_src;
    }

  return attr_name;
}

/* Handle a "format" attribute; arguments as in
   struct attribute_spec.handler.  */
tree
handle_frr_format_attribute (tree *node, tree ARG_UNUSED (name), tree args,
			 int flags, bool *no_add_attrs)
{
  tree type = *node;
  function_format_info info;

  /* Canonicalize name of format function.  */
  if (TREE_CODE (TREE_VALUE (args)) == IDENTIFIER_NODE)
    TREE_VALUE (args) = canonicalize_attr_name (TREE_VALUE (args));

  if (!decode_format_attr (args, &info, 0))
    {
      *no_add_attrs = true;
      return NULL_TREE;
    }

  if (prototype_p (type))
    {
      if (!check_format_string (type, info.format_num, flags,
				no_add_attrs, info.format_type))
	return NULL_TREE;

      if (info.first_arg_num != 0)
	{
	  unsigned HOST_WIDE_INT arg_num = 1;
	  function_args_iterator iter;
	  tree arg_type;

	  /* Verify that first_arg_num points to the last arg,
	     the ...  */
	  FOREACH_FUNCTION_ARGS (type, arg_type, iter)
	    arg_num++;

	  if (arg_num != info.first_arg_num)
	    {
	      if (!(flags & (int) ATTR_FLAG_BUILT_IN))
		error ("arguments to be formatted is not %<...%>");
	      *no_add_attrs = true;
	      return NULL_TREE;
	    }
	}
    }

  /* Check if this is a strftime variant. Just for this variant
     FMT_FLAG_ARG_CONVERT is not set.  */
  if ((format_types[info.format_type].flags & (int) FMT_FLAG_ARG_CONVERT) == 0
      && info.first_arg_num != 0)
    {
      error ("strftime formats cannot format arguments");
      *no_add_attrs = true;
      return NULL_TREE;
    }

  return NULL_TREE;
}

#if CHECKING_P

namespace selftest {

/* Selftests of location handling.  */

/* Get the format_kind_info with the given name.  */

static const format_kind_info *
get_info (const char *name)
{
  int idx = decode_format_type (name);
  const format_kind_info *fki = &format_types[idx];
  ASSERT_STREQ (fki->name, name);
  return fki;
}

/* Verify that get_format_for_type (FKI, TYPE, CONVERSION_CHAR)
   is EXPECTED_FORMAT.  */

static void
assert_format_for_type_streq (const location &loc, const format_kind_info *fki,
			      const char *expected_format, tree type,
			      char conversion_char)
{
  gcc_assert (fki);
  gcc_assert (expected_format);
  gcc_assert (type);

  char *actual_format = get_format_for_type (fki, type, conversion_char);
  ASSERT_STREQ_AT (loc, expected_format, actual_format);
  free (actual_format);
}

/* Selftests for get_format_for_type.  */

#define ASSERT_FORMAT_FOR_TYPE_STREQ(EXPECTED_FORMAT, TYPE, CONVERSION_CHAR) \
  assert_format_for_type_streq (SELFTEST_LOCATION, (fki), (EXPECTED_FORMAT), \
				(TYPE), (CONVERSION_CHAR))

/* Selftest for get_format_for_type for "printf"-style functions.  */

static void
test_get_format_for_type_printf ()
{
  const format_kind_info *fki = get_info ("gnu_printf");
  ASSERT_NE (fki, NULL);

  ASSERT_FORMAT_FOR_TYPE_STREQ ("f", double_type_node, 'i');
  ASSERT_FORMAT_FOR_TYPE_STREQ ("Lf", long_double_type_node, 'i');
  ASSERT_FORMAT_FOR_TYPE_STREQ ("f", double_type_node, 'o');
  ASSERT_FORMAT_FOR_TYPE_STREQ ("Lf", long_double_type_node, 'o');
  ASSERT_FORMAT_FOR_TYPE_STREQ ("f", double_type_node, 'x');
  ASSERT_FORMAT_FOR_TYPE_STREQ ("Lf", long_double_type_node, 'x');
  ASSERT_FORMAT_FOR_TYPE_STREQ ("f", double_type_node, 'X');
  ASSERT_FORMAT_FOR_TYPE_STREQ ("Lf", long_double_type_node, 'X');
  ASSERT_FORMAT_FOR_TYPE_STREQ ("d", integer_type_node, 'd');
  ASSERT_FORMAT_FOR_TYPE_STREQ ("i", integer_type_node, 'i');
  ASSERT_FORMAT_FOR_TYPE_STREQ ("o", integer_type_node, 'o');
  ASSERT_FORMAT_FOR_TYPE_STREQ ("x", integer_type_node, 'x');
  ASSERT_FORMAT_FOR_TYPE_STREQ ("X", integer_type_node, 'X');
  ASSERT_FORMAT_FOR_TYPE_STREQ ("d", unsigned_type_node, 'd');
  ASSERT_FORMAT_FOR_TYPE_STREQ ("i", unsigned_type_node, 'i');
  ASSERT_FORMAT_FOR_TYPE_STREQ ("o", unsigned_type_node, 'o');
  ASSERT_FORMAT_FOR_TYPE_STREQ ("x", unsigned_type_node, 'x');
  ASSERT_FORMAT_FOR_TYPE_STREQ ("X", unsigned_type_node, 'X');
  ASSERT_FORMAT_FOR_TYPE_STREQ ("ld", long_integer_type_node, 'd');
  ASSERT_FORMAT_FOR_TYPE_STREQ ("li", long_integer_type_node, 'i');
  ASSERT_FORMAT_FOR_TYPE_STREQ ("lx", long_integer_type_node, 'x');
  ASSERT_FORMAT_FOR_TYPE_STREQ ("lo", long_unsigned_type_node, 'o');
  ASSERT_FORMAT_FOR_TYPE_STREQ ("lx", long_unsigned_type_node, 'x');
  ASSERT_FORMAT_FOR_TYPE_STREQ ("lld", long_long_integer_type_node, 'd');
  ASSERT_FORMAT_FOR_TYPE_STREQ ("lli", long_long_integer_type_node, 'i');
  ASSERT_FORMAT_FOR_TYPE_STREQ ("llo", long_long_unsigned_type_node, 'o');
  ASSERT_FORMAT_FOR_TYPE_STREQ ("llx", long_long_unsigned_type_node, 'x');
  ASSERT_FORMAT_FOR_TYPE_STREQ ("s", build_pointer_type (char_type_node), 'i');
}

/* Selftest for get_format_for_type for "scanf"-style functions.  */

static void
test_get_format_for_type_scanf ()
{
  const format_kind_info *fki = get_info ("gnu_scanf");
  ASSERT_NE (fki, NULL);
  ASSERT_FORMAT_FOR_TYPE_STREQ ("d", build_pointer_type (integer_type_node), 'd');
  ASSERT_FORMAT_FOR_TYPE_STREQ ("u", build_pointer_type (unsigned_type_node), 'u');
  ASSERT_FORMAT_FOR_TYPE_STREQ ("ld",
				build_pointer_type (long_integer_type_node), 'd');
  ASSERT_FORMAT_FOR_TYPE_STREQ ("lu",
				build_pointer_type (long_unsigned_type_node), 'u');
  ASSERT_FORMAT_FOR_TYPE_STREQ
    ("lld", build_pointer_type (long_long_integer_type_node), 'd');
  ASSERT_FORMAT_FOR_TYPE_STREQ
    ("llu", build_pointer_type (long_long_unsigned_type_node), 'u');
  ASSERT_FORMAT_FOR_TYPE_STREQ ("e", build_pointer_type (float_type_node), 'e');
  ASSERT_FORMAT_FOR_TYPE_STREQ ("le", build_pointer_type (double_type_node), 'e');
}

#undef ASSERT_FORMAT_FOR_TYPE_STREQ

/* Exercise the type-printing label code, to give some coverage
   under "make selftest-valgrind" (in particular, to ensure that
   the label-printing machinery doesn't leak).  */

static void
test_type_mismatch_range_labels ()
{
  /* Create a tempfile and write some text to it.
     ....................0000000001 11111111 12 22222222
     ....................1234567890 12345678 90 12345678.  */
  const char *content = "  printf (\"msg: %i\\n\", msg);\n";
  temp_source_file tmp (SELFTEST_LOCATION, ".c", content);
  line_table_test ltt;

  linemap_add (line_table, LC_ENTER, false, tmp.get_filename (), 1);

  location_t c17 = linemap_position_for_column (line_table, 17);
  ASSERT_EQ (LOCATION_COLUMN (c17), 17);
  location_t c18 = linemap_position_for_column (line_table, 18);
  location_t c24 = linemap_position_for_column (line_table, 24);
  location_t c26 = linemap_position_for_column (line_table, 26);

  /* Don't attempt to run the tests if column data might be unavailable.  */
  if (c26 > LINE_MAP_MAX_LOCATION_WITH_COLS)
    return;

  location_t fmt = make_location (c18, c17, c18);
  ASSERT_EQ (LOCATION_COLUMN (fmt), 18);

  location_t param = make_location (c24, c24, c26);
  ASSERT_EQ (LOCATION_COLUMN (param), 24);

  range_label_for_format_type_mismatch fmt_label (char_type_node,
						  integer_type_node, 1);
  range_label_for_type_mismatch param_label (integer_type_node,
					     char_type_node);
  gcc_rich_location richloc (fmt, &fmt_label);
  richloc.add_range (param, SHOW_RANGE_WITHOUT_CARET, &param_label);

  test_diagnostic_context dc;
  diagnostic_show_locus (&dc, &richloc, DK_ERROR);
  if (c_dialect_cxx ())
    /* "char*", without a space.  */
    ASSERT_STREQ ("\n"
		  "   printf (\"msg: %i\\n\", msg);\n"
		  "                 ~^     ~~~\n"
		  "                  |     |\n"
		  "                  char* int\n",
		  pp_formatted_text (dc.printer));
  else
    /* "char *", with a space.  */
    ASSERT_STREQ ("\n"
		  "   printf (\"msg: %i\\n\", msg);\n"
		  "                 ~^     ~~~\n"
		  "                  |     |\n"
		  "                  |     int\n"
		  "                  char *\n",
		  pp_formatted_text (dc.printer));
}

/* Run all of the selftests within this file.  */

void
c_format_c_tests ()
{
  test_get_modifier_for_format_len ();
  test_get_format_for_type_printf ();
  test_get_format_for_type_scanf ();
  test_type_mismatch_range_labels ();
}

} // namespace selftest

#endif /* CHECKING_P */

// include "gt-c-family-c-format.h"

static const struct attribute_spec frr_format_attribute_table[] =
{
  /* { name, min_len, max_len, decl_req, type_req, fn_type_req,
       affects_type_identity, handler, exclude } */
  { "frr_format",             3, 3, false, true,  true, false,
			      handle_frr_format_attribute, NULL },
  { "frr_format_arg",         1, 1, false, true,  true, false,
			      handle_frr_format_arg_attribute, NULL },
  { NULL,                     0, 0, false, false, false, false, NULL, NULL }
};

static void
register_attributes (void *event_data, void *data)
{
  // warning (0, G_("Callback to register attributes"));
  register_attribute (frr_format_attribute_table);
}

tree
cb_walk_tree_fn (tree * tp, int * walk_subtrees, void * data ATTRIBUTE_UNUSED)
{
  if (TREE_CODE (*tp) != CALL_EXPR)
    return NULL_TREE;

  tree call_expr = *tp;

  int nargs = call_expr_nargs(call_expr);
  tree fn = CALL_EXPR_FN(call_expr);

  if (!fn || TREE_CODE (fn) != ADDR_EXPR)
    return NULL_TREE;

  tree fndecl = TREE_OPERAND (fn, 0);
  if (TREE_CODE (fndecl) != FUNCTION_DECL)
    return NULL_TREE;

#if 0
  warning (0, G_("function call to %s, %d args"),
           IDENTIFIER_POINTER (DECL_NAME (fndecl)),
	   nargs);
#endif

  tree *fargs = (tree *) alloca (nargs * sizeof (tree));

  for (int j = 0; j < nargs; j++)
    {
      tree arg = CALL_EXPR_ARG(call_expr, j);

      /* For -Wformat undo the implicit passing by hidden reference
	 done by convert_arg_to_ellipsis.  */
      if (TREE_CODE (arg) == ADDR_EXPR
	  && TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
	fargs[j] = TREE_OPERAND (arg, 0);
      else
	fargs[j] = arg;
    }

  check_function_format (TYPE_ATTRIBUTES (TREE_TYPE (fndecl)), nargs, fargs, NULL);
  return NULL_TREE;
}

static void
setup_type (const char *name, tree *dst)
{
  tree tmp;

  if (*dst && *dst != void_type_node)
    return;

  *dst = maybe_get_identifier (name);
  if (!*dst)
    return;

  tmp = identifier_global_value (*dst);
  if (tmp && TREE_CODE (tmp) != TYPE_DECL)
    {
      warning (0, "%qs is not defined as a type", name);
      *dst = NULL;
      return;
    }
  if (tmp && TREE_CODE (tmp) == TYPE_DECL)
    *dst = tmp;
  else
    *dst = NULL;
}

static void
handle_finish_parse (void *event_data, void *data)
{
  tree fndecl = (tree) event_data;
  gcc_assert (TREE_CODE (fndecl) == FUNCTION_DECL);

  setup_type ("uint64_t", &local_uint64_t_node);
  setup_type ("int64_t", &local_int64_t_node);

  setup_type ("size_t", &local_size_t_node);
  setup_type ("ssize_t", &local_ssize_t_node);
  setup_type ("atomic_size_t", &local_atomic_size_t_node);
  setup_type ("atomic_ssize_t", &local_atomic_ssize_t_node);
  setup_type ("ptrdiff_t", &local_ptrdiff_t_node);

  setup_type ("pid_t", &local_pid_t_node);
  setup_type ("uid_t", &local_uid_t_node);
  setup_type ("gid_t", &local_gid_t_node);
  setup_type ("time_t", &local_time_t_node);
  setup_type ("__suseconds_t", &local_suseconds_t_node);
  setup_type ("__suseconds64_t", &local_suseconds64_t_node);

  setup_type ("socklen_t", &local_socklen_t_node);
  setup_type ("in_addr_t", &local_in_addr_t_node);

  const format_char_info *fci;

  for (fci = print_char_table; fci->format_chars; fci++)
    {
      if (!fci->kernel_ext)
	continue;

      struct kernel_ext_fmt *etab = fci->kernel_ext;
      struct kernel_ext_fmt *etab_end = etab + ETAB_SZ;

      for (; etab->suffix && etab < etab_end; etab++)
        {
	  tree identifier, node;

          if (etab->type && etab->type != void_type_node)
	    continue;

	  identifier = maybe_get_identifier (etab->type_str);

	  if (!identifier || identifier == error_mark_node)
	    continue;

	  if (etab->type_code)
	    {
	      node = identifier_global_tag (identifier);
	      if (!node)
	        continue;

	      if (node->base.code != etab->type_code)
	        {
		  if (!etab->warned)
		    {
		      warning (0, "%qs tag category (struct/union/enum) mismatch", etab->type_str);
		      etab->warned = true;
		    }
		  continue;
	        }
	    }
	  else
	    {
	      node = identifier_global_value (identifier);
	      if (!node)
	        continue;

	      if (TREE_CODE (node) != TYPE_DECL)
		{
		  if (!etab->warned)
		    {
		      warning (0, "%qs is defined as a non-type", etab->type_str);
		      etab->warned = true;
		    }
		  continue;
		}
	      node = TREE_TYPE (node);

	      if (etab->t_unsigned)
		node = c_common_unsigned_type (node);
	      else if (etab->t_signed)
		node = c_common_signed_type (node);
	    }

	  etab->type = node;
        }
    }

  walk_tree (&DECL_SAVED_TREE (fndecl), cb_walk_tree_fn, NULL, NULL);
}

static void
handle_pragma_printfrr_ext (cpp_reader *dummy)
{
  tree token = 0;
  location_t loc;
  enum cpp_ttype ttype;

  ttype = pragma_lex (&token, &loc);
  if (ttype != CPP_STRING)
    {
      error_at (loc, "%<#pragma FRR printfrr_ext%> requires string argument");
      return;
    }

  const char *s = TREE_STRING_POINTER (token);

  if (s[0] != '%')
    {
      error_at (loc, "%<#pragma FRR printfrr_ext%>: invalid format string, needs to start with '%%'");
      return;
    }

  switch (s[1])
    {
      case 'p':
      case 'd':
      case 'i':
        break;
      default:
        error_at (loc, "%<#pragma FRR printfrr_ext%>: invalid format string, needs to be %%p, %%d or %%i");
        return;
    }

  const format_char_info *fci;

  for (fci = print_char_table; fci->format_chars; fci++)
    if (strchr (fci->format_chars, s[1]))
      break;

  gcc_assert (fci->format_chars);
  gcc_assert (fci->kernel_ext);

  struct kernel_ext_fmt *etab = fci->kernel_ext;
  struct kernel_ext_fmt *etab_end = etab + ETAB_SZ;

  switch (s[2])
    {
      case 'A' ... 'Z':
        break;

      default:
        error_at (loc, "%<#pragma FRR printfrr_ext%>: invalid format string, suffix must start with an uppercase letter");
        return;
    }

  /* -2 -- need to keep the sentinel at the end */
  if (etab[ETAB_SZ - 2].suffix)
    {
      error_at (loc, "%<#pragma FRR printfrr_ext%>: out of space for format suffixes");
      return;
    }

  for (; etab->suffix && etab < etab_end; etab++)
    {
      if (!strcmp(s + 2, etab->suffix))
        {
          memmove (etab + 1, etab, (etab_end - etab - 1) * sizeof (*etab));

          if (0)
            {
              warning_at (loc, OPT_Wformat_,
                          "%<#pragma FRR printfrr_ext%>: duplicate printf format suffix %qs", s);
              warning_at (etab->origin_loc, OPT_Wformat_,
                          "%<#pragma FRR printfrr_ext%>: previous definition was here");
              return;
            }

          break;
        }

      if (!strncmp(s + 2, etab->suffix, MIN(strlen(s + 2), strlen(etab->suffix))))
        {
          warning_at (loc, OPT_Wformat_,
                      "%<#pragma FRR printfrr_ext%>: overlapping printf format suffix %qs", s);
          warning_at (etab->origin_loc, OPT_Wformat_,
                      "%<#pragma FRR printfrr_ext%>: previous definition for %<%%%c%s%> was here", s[1], etab->suffix);
          return;
        }
    }

  gcc_assert (etab < etab_end);

  memset (etab, 0, sizeof (*etab));
  etab->suffix = xstrdup(s + 2);
  etab->origin_loc = loc;
  etab->type = void_type_node;

  ttype = pragma_lex (&token, &loc);
  if (ttype != CPP_OPEN_PAREN)
    {
      error_at (loc, "%<#pragma FRR printfrr_ext%> expected %<(%>");
      goto out_drop;
    }

  ttype = pragma_lex (&token, &loc);

  /* qualifiers */
  while (ttype == CPP_NAME)
    {
      if (!strcmp (IDENTIFIER_POINTER (token), "const"))
        etab->t_const = true;
      else if (!strcmp (IDENTIFIER_POINTER (token), "signed"))
        etab->t_signed = true;
      else if (!strcmp (IDENTIFIER_POINTER (token), "unsigned"))
        etab->t_unsigned = true;
      else
        break;

      ttype = pragma_lex (&token, &loc);
    }

  /* tagged types */
  if (ttype == CPP_NAME && !strcmp (IDENTIFIER_POINTER (token), "struct"))
    {
      etab->type_code = RECORD_TYPE;
      ttype = pragma_lex (&token, &loc);
    }
  else if (ttype == CPP_NAME && !strcmp (IDENTIFIER_POINTER (token), "union"))
    {
      etab->type_code = UNION_TYPE;
      ttype = pragma_lex (&token, &loc);
    }
  else if (ttype == CPP_NAME && !strcmp (IDENTIFIER_POINTER (token), "enum"))
    {
      etab->type_code = ENUMERAL_TYPE;
      ttype = pragma_lex (&token, &loc);
    }

  /* type name */
  if (ttype != CPP_NAME)
    {
      error_at (loc, "%<#pragma FRR printfrr_ext%>: expected typename identifier");
      goto out_drop;
    }

  etab->type_str = xstrdup (IDENTIFIER_POINTER (token));

  while ((ttype = pragma_lex (&token, &loc)) != CPP_CLOSE_PAREN)
    {
      switch (ttype) {
      case CPP_NAME:
        error_at (loc, "%<#pragma FRR printfrr_ext%>: unexpected identifier.  Note the only supported qualifier is %<const%>");
        goto out_drop;

      case CPP_MULT:
        etab->ptrlevel++;
        break;

      case CPP_EOF:
        error_at (loc, "%<#pragma FRR printfrr_ext%>: premature end of line, missing %<)%>");
        goto out_drop;

      default:
        error_at (loc, "%<#pragma FRR printfrr_ext%>: unsupported token");
        goto out_drop;
      }
    }

  ttype = pragma_lex (&token, &loc);
  if (ttype != CPP_EOF)
    warning_at (loc, OPT_Wformat_,
                "%<#pragma FRR printfrr_ext%>: garbage at end of line");

  return;

out_drop:
  memset (etab, 0, sizeof (*etab));
}

static void
register_pragma_printfrr_ext (void *event_data, void *data)
{
  c_register_pragma_with_expansion ("FRR", "printfrr_ext", handle_pragma_printfrr_ext);
}

static void
define_vars (void *gcc_data, void *user_data)
{
  cpp_define (parse_in, "_FRR_ATTRIBUTE_PRINTFRR=0x10000");
}

#ifndef __visible
#define __visible __attribute__((visibility("default")))
#endif

__visible int plugin_is_GPL_compatible;

__visible int
plugin_init (struct plugin_name_args *plugin_info,
             struct plugin_gcc_version *version)
{
  const char *plugin_name = plugin_info->base_name;

  if (!plugin_default_version_check(version, &gcc_version))
    {
      error(G_("incompatible gcc/plugin versions"));
      return 1;
    }

  memset (ext_p, 0, sizeof (ext_p));
  memset (ext_d, 0, sizeof (ext_d));

  register_callback (plugin_name, PLUGIN_FINISH_PARSE_FUNCTION, handle_finish_parse, NULL);
  register_callback (plugin_name, PLUGIN_ATTRIBUTES, register_attributes, NULL);
  register_callback (plugin_name, PLUGIN_START_UNIT, define_vars, NULL);
  register_callback (plugin_name, PLUGIN_PRAGMAS, register_pragma_printfrr_ext, NULL);
  return 0;
}
