Bug 1378830 - part 1 - define PROG_IS_C_ONLY variables for PROGRAM and SIMPLE_PROGRAMS; r=chmanchester

Similar to the existing LIB_IS_C_ONLY variable, these variables indicate
that the program in question has only C sources and so can be linked by
the C compiler rather than the C++ compiler.  We need to add a little
more information to BaseProgram so we can avoid emitting periods into
Makefile variables.

config/rules.mk

@@ -566,6 +566,10 @@ alltags:
 	$(RM) TAGS
 	find $(topsrcdir) -name dist -prune -o \( -name '*.[hc]' -o -name '*.cp' -o -name '*.cpp' -o -name '*.idl' \) -print | $(TAG_PROGRAM)
 
+define EXPAND_CC_OR_CXX
+$(if $(PROG_IS_C_ONLY_$(1)),$(EXPAND_CC),$(EXPAND_CCC))
+endef
+
 #
 # PROGRAM = Foo
 # creates OBJS, links with LIBS to create Foo
@@ -595,7 +599,7 @@ ifdef MOZ_PROFILE_GENERATE
 	touch -t `date +%Y%m%d%H%M.%S -d 'now+5seconds'` pgo.relink
 endif
 else # !WINNT || GNU_CC
-	$(EXPAND_CCC) -o $@ $(CXXFLAGS) $(PROGOBJS) $(RESFILE) $(WIN32_EXE_LDFLAGS) $(LDFLAGS) $(WRAP_LDFLAGS) $(STATIC_LIBS) $(MOZ_PROGRAM_LDFLAGS) $(SHARED_LIBS) $(EXTRA_LIBS) $(OS_LIBS) $(BIN_FLAGS) $(EXE_DEF_FILE)
+	$(call EXPAND_CC_OR_CXX,$@) -o $@ $(CXXFLAGS) $(PROGOBJS) $(RESFILE) $(WIN32_EXE_LDFLAGS) $(LDFLAGS) $(WRAP_LDFLAGS) $(STATIC_LIBS) $(MOZ_PROGRAM_LDFLAGS) $(SHARED_LIBS) $(EXTRA_LIBS) $(OS_LIBS) $(BIN_FLAGS) $(EXE_DEF_FILE)
 	$(call CHECK_BINARY,$@)
 endif # WINNT && !GNU_CC
 
@@ -654,7 +658,7 @@ ifdef MSMANIFEST_TOOL
 	fi
 endif	# MSVC with manifest tool
 else
-	$(EXPAND_CCC) $(CXXFLAGS) -o $@ $< $(WIN32_EXE_LDFLAGS) $(LDFLAGS) $(WRAP_LDFLAGS) $(STATIC_LIBS) $(MOZ_PROGRAM_LDFLAGS) $(SHARED_LIBS) $(EXTRA_LIBS) $(OS_LIBS) $(BIN_FLAGS)
+	$(call EXPAND_CC_OR_CXX,$@) $(CXXFLAGS) -o $@ $< $(WIN32_EXE_LDFLAGS) $(LDFLAGS) $(WRAP_LDFLAGS) $(STATIC_LIBS) $(MOZ_PROGRAM_LDFLAGS) $(SHARED_LIBS) $(EXTRA_LIBS) $(OS_LIBS) $(BIN_FLAGS)
 	$(call CHECK_BINARY,$@)
 endif # WINNT && !GNU_CC
 

python/mozbuild/mozbuild/backend/configenvironment.py

@@ -141,6 +141,7 @@ class ConfigEnvironment(object):
         else:
             self.import_prefix = self.dll_prefix
             self.import_suffix = self.dll_suffix
+        self.bin_suffix = self.substs.get('BIN_SUFFIX', '')
 
         global_defines = [name for name in self.defines
             if not name in self.non_global_defines]

python/mozbuild/mozbuild/backend/recursivemake.py

@@ -571,7 +571,7 @@ class RecursiveMakeBackend(CommonBackend):
             self._compile_graph[build_target]
 
         elif isinstance(obj, Program):
-            self._process_program(obj.program, backend_file)
+            self._process_program(obj, backend_file)
             self._process_linked_libraries(obj, backend_file)
             self._no_skip['syms'].add(backend_file.relobjdir)
 
@@ -1093,8 +1093,10 @@ class RecursiveMakeBackend(CommonBackend):
             registered_xpt_files=' '.join(sorted(registered_xpt_files)),
         ))
 
-    def _process_program(self, program, backend_file):
-        backend_file.write('PROGRAM = %s\n' % program)
+    def _process_program(self, obj, backend_file):
+        backend_file.write('PROGRAM = %s\n' % obj.program)
+        if not obj.cxx_link and not self.environment.bin_suffix:
+            backend_file.write('PROG_IS_C_ONLY_%s := 1\n' % obj.program)
 
     def _process_host_program(self, program, backend_file):
         backend_file.write('HOST_PROGRAM = %s\n' % program)
@@ -1120,8 +1122,11 @@ class RecursiveMakeBackend(CommonBackend):
     def _process_simple_program(self, obj, backend_file):
         if obj.is_unit_test:
             backend_file.write('CPP_UNIT_TESTS += %s\n' % obj.program)
+            assert obj.cxx_link
         else:
             backend_file.write('SIMPLE_PROGRAMS += %s\n' % obj.program)
+            if not obj.cxx_link and not self.environment.bin_suffix:
+                backend_file.write('PROG_IS_C_ONLY_%s := 1\n' % obj.program)
 
     def _process_host_simple_program(self, program, backend_file):
         backend_file.write('HOST_SIMPLE_PROGRAMS += %s\n' % program)