build: add LLVM bitcode targets

Just an easy way to produce LLVM .bc (bitcode) files.  Not used during
normal builds.

Signed-off-by: David Lamparter <equinox@opensourcerouting.org>

.gitignore

@@ -55,6 +55,8 @@
 *.pb-c.c
 *.pb.cc
 *_clippy.c
+*.bc
+*.cg.json
 
 ### gcov outputs
 

Makefile.am

@@ -93,6 +93,7 @@ EXTRA_PROGRAMS =
 BUILT_SOURCES =
 CLEANFILES =
 DISTCLEANFILES =
+SUFFIXES =
 
 examplesdir = $(exampledir)
 
@@ -232,12 +233,39 @@ EXTRA_DIST += \
 	vrrpd/Makefile \
 	# end
 
-clean-local: clean-python
-.PHONY: clean-python
+AM_V_LLVM_BC = $(am__v_LLVM_BC_$(V))
+am__v_LLVM_BC_ = $(am__v_LLVM_BC_$(AM_DEFAULT_VERBOSITY))
+am__v_LLVM_BC_0 = @echo "  LLVM.BC " $@;
+am__v_LLVM_BC_1 = 
+
+AM_V_LLVM_LD = $(am__v_LLVM_LD_$(V))
+am__v_LLVM_LD_ = $(am__v_LLVM_LD_$(AM_DEFAULT_VERBOSITY))
+am__v_LLVM_LD_0 = @echo "  LLVM.LD " $@;
+am__v_LLVM_LD_1 = 
+
+SUFFIXES += .lo.bc .o.bc
+
+.o.o.bc:
+	$(AM_V_LLVM_BC)$(COMPILE) -emit-llvm -c -o $@ $(patsubst %.o,%.c,$<)
+.lo.lo.bc:
+	$(AM_V_LLVM_BC)$(COMPILE) -emit-llvm -c -o $@ $(patsubst %.lo,%.c,$<)
+
+%.cg.json: %.bc tools/frr-llvm-cg
+	tools/frr-llvm-cg -o $@ $<
+
+# <lib>.la.bc, <lib>.a.bc and <daemon>.bc targets are generated by
+# python/makefile.py
+LLVM_LINK = llvm-link-$(llvm_version)
+
+clean-local: clean-python clean-llvm-bitcode
+.PHONY: clean-python clean-llvm-bitcode
 clean-python:
 	find . -name __pycache__ -o -name .pytest_cache | xargs rm -rf
 	find . -name "*.pyc" -o -name "*_clippy.c" | xargs rm -f
 
+clean-llvm-bitcode:
+	find . -name "*.bc" -o -name "*.cg.json" | xargs rm -f
+
 redistclean:
 	$(MAKE) distclean CONFIG_CLEAN_FILES="$(filter-out $(EXTRA_DIST), $(CONFIG_CLEAN_FILES))"
 

grpc/subdir.am

@@ -26,6 +26,8 @@ am__v_PROTOC_ = $(am__v_PROTOC_$(AM_DEFAULT_VERBOSITY))
 am__v_PROTOC_0 = @echo "  PROTOC" $@;
 am__v_PROTOC_1 =
 
+SUFFIXES += .pb.h .pb.cc .grpc.pb.cc
+
 .proto.pb.cc:
 	$(AM_V_PROTOC)$(PROTOC) -I$(top_srcdir) --cpp_out=$(top_srcdir) $(top_srcdir)/$^
 .proto.grpc.pb.cc:

lib/subdir.am

@@ -415,7 +415,7 @@ am__v_CLIPPY_1 =
 
 CLIPPY_DEPS = $(CLIPPY) $(top_srcdir)/python/clidef.py
 
-SUFFIXES = _clippy.c .proto .pb-c.c .pb-c.h .pb.h .pb.cc .grpc.pb.cc
+SUFFIXES += _clippy.c
 .c_clippy.c:
 	$(AM_V_CLIPPY) $(CLIPPY) $(top_srcdir)/python/clidef.py -o $@ $<
 

python/makefile.py

@@ -54,6 +54,7 @@ ${target}: ${clippybase}_clippy.c
 lines = before.splitlines()
 autoderp = '#AUTODERP# '
 out_lines = []
+bcdeps = []
 make_rule_re = re.compile('^([^:\s]+):\s*([^:\s]+)\s*($|\n)')
 
 while lines:
@@ -77,6 +78,12 @@ while lines:
         out_lines.append(line)
         continue
 
+    target, dep = m.group(1), m.group(2)
+
+    if target.endswith('.lo') or target.endswith('.o'):
+        if not dep.endswith('.h'):
+            bcdeps.append('%s.bc: %s' % (target, target))
+            bcdeps.append('\t$(AM_V_LLVM_BC)$(COMPILE) -emit-llvm -c -o $@ %s' % (dep))
     if m.group(2) in clippy_scan:
         out_lines.append(clippyauxdep.substitute(target=m.group(1), clippybase=m.group(2)[:-2]))
 
@@ -85,6 +92,24 @@ while lines:
 out_lines.append('# clippy{\n# main clippy targets')
 for clippy_file in clippy_scan:
     out_lines.append(clippydep.substitute(clippybase = clippy_file[:-2]))
+
+out_lines.append('')
+out_lines.extend(bcdeps)
+out_lines.append('')
+bc_targets = []
+for varname in ['bin_PROGRAMS', 'sbin_PROGRAMS', 'lib_LTLIBRARIES', 'module_LTLIBRARIES', 'noinst_LIBRARIES']:
+    bc_targets.extend(mv[varname].strip().split())
+for target in bc_targets:
+    amtgt = target.replace('/', '_').replace('.', '_').replace('-', '_')
+    objs = mv[amtgt + '_OBJECTS'].strip().split()
+    objs = [obj + '.bc' for obj in objs]
+    deps = mv.get(amtgt + '_DEPENDENCIES', '').strip().split()
+    deps = [d + '.bc' for d in deps if d.endswith('.a')]
+    objs.extend(deps)
+    out_lines.append('%s.bc: %s' % (target, ' '.join(objs)))
+    out_lines.append('\t$(AM_V_LLVM_LD)$(LLVM_LINK) -o $@ $^')
+    out_lines.append('')
+
 out_lines.append('# }clippy')
 out_lines.append('')
 

qpb/subdir.am

@@ -29,6 +29,7 @@ CLEANFILES += \
 	# end
 
 EXTRA_DIST += qpb/qpb.proto
+SUFFIXES += .proto .pb-c.c .pb-c.h
 
 if HAVE_PROTOBUF
 

tools/subdir.am

@@ -36,9 +36,9 @@ tools_gen_yang_deviations_LDADD = lib/libfrr.la $(LIBYANG_LIBS)
 tools_ssd_SOURCES = tools/start-stop-daemon.c
 
 # don't bother autoconf'ing these for a simple optional tool
-llvm_config = llvm-config-$(shell echo __clang_major__ | $(CC) -xc -P -E -)
-tools_frr_llvm_cg_CFLAGS = $(AM_CFLAGS) `$(llvm_config) --cflags`
-tools_frr_llvm_cg_LDFLAGS = `$(llvm_config) --ldflags --libs`
+llvm_version = $(shell echo __clang_major__ | $(CC) -xc -P -E -)
+tools_frr_llvm_cg_CFLAGS = $(AM_CFLAGS) `llvm-config-$(llvm_version) --cflags`
+tools_frr_llvm_cg_LDFLAGS = `llvm-config-$(llvm_version) --ldflags --libs`
 tools_frr_llvm_cg_SOURCES = \
 	tools/frr-llvm-cg.c \
 	# end