Teach the Makefile build system how to handle SOURCES which include

subdirectories. The only thing needed here is to create the appropriate
object file directories and add those as dependencies for the
compilation rules.

As a consequence, factor the non-source-file-specific dependencies for
compilation rules into a helper variable. This fixes an issue where the
project makefile wasn't actually a dependency of a bunch of compilation
make rules for no apparant reason.

This should have no observable effect for current makefile usage, but
will simplify how we build other libraries and is something CMake
already supports.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194753 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 34 insertions, 21 deletions

diff --git a/Makefile.rules b/Makefile.rules
index 2458bd81c4..68f6cf8ec5 100644
--- a/Makefile.rules
+++ b/Makefile.rules
@@ -776,8 +776,10 @@ Sources += $(filter %.cpp %.c %.cc,$(BUILT_SOURCES))
 endif
 
 BaseNameSources := $(sort $(basename $(Sources)))
+SourceDirs := $(sort $(dir $(Sources)))
 
 ObjectsO  := $(BaseNameSources:%=$(ObjDir)/%.o)
+ObjectDirs := $(SourceDirs:%=$(ObjDir)/%)
 
 #----------------------------------------------------------
 # For Mingw MSYS bash and Python/w32:
@@ -814,10 +816,19 @@ $(DESTDIR)$(PROJ_bindir) $(DESTDIR)$(PROJ_libdir) $(DESTDIR)$(PROJ_includedir) $
 	$(Verb) $(MKDIR) $* > /dev/null
 	$(Verb) $(DOTDIR_TIMESTAMP_COMMAND) > $@
 
-.PRECIOUS: $(ObjDir)/.dir $(LibDir)/.dir $(ToolDir)/.dir $(ExmplDir)/.dir
+.PRECIOUS: $(LibDir)/.dir $(ToolDir)/.dir $(ExmplDir)/.dir
 .PRECIOUS: $(LLVMLibDir)/.dir $(LLVMToolDir)/.dir $(LLVMExmplDir)/.dir
 
 #---------------------------------------------------------
+# Collect the object directories (as there may be more
+# than one if the source code is spread across
+# subdirectories).
+#---------------------------------------------------------
+
+OBJECT_DIRS := $(ObjDir)/.dir $(ObjectDirs:%=%/.dir)
+.PRECIOUS: $(OBJECT_DIRS)
+
+#---------------------------------------------------------
 # Handle the DIRS options for sequential construction
 #---------------------------------------------------------
 
@@ -1432,6 +1443,8 @@ ifeq ($(HOST_OS),HP-UX)
   DISABLE_AUTO_DEPENDENCIES=1
 endif
 
+COMPILE_DEPS = $(OBJECT_DIRS) $(BUILT_SOURCES) $(PROJ_MAKEFILE)
+
 # Provide rule sets for when dependency generation is enabled
 ifndef DISABLE_AUTO_DEPENDENCIES
 
@@ -1447,27 +1460,27 @@ DEPEND_OPTIONS = -MMD -MP -MF "$(ObjDir)/$*.d.tmp" \
 DEPEND_MOVEFILE = then $(MV) -f "$(ObjDir)/$*.d.tmp" "$(ObjDir)/$*.d"; \
                   else $(RM) "$(ObjDir)/$*.d.tmp"; exit 1; fi
 
-$(ObjDir)/%.o: %.cpp $(ObjDir)/.dir $(BUILT_SOURCES) $(PROJ_MAKEFILE)
+$(ObjDir)/%.o: %.cpp $(COMPILE_DEPS)
 	$(Echo) "Compiling $*.cpp for $(BuildMode) build" $(PIC_FLAG)
 	$(Verb) if $(Compile.CXX) $(DEPEND_OPTIONS) $< -o $(ObjDir)/$*.o ; \
 	        $(DEPEND_MOVEFILE)
 
-$(ObjDir)/%.o: %.mm $(ObjDir)/.dir $(BUILT_SOURCES) $(PROJ_MAKEFILE)
+$(ObjDir)/%.o: %.mm $(COMPILE_DEPS)
 	$(Echo) "Compiling $*.mm for $(BuildMode) build" $(PIC_FLAG)
 	$(Verb) if $(Compile.CXX) $(DEPEND_OPTIONS) $< -o $(ObjDir)/$*.o ; \
 	        $(DEPEND_MOVEFILE)
 
-$(ObjDir)/%.o: %.cc $(ObjDir)/.dir $(BUILT_SOURCES) $(PROJ_MAKEFILE)
+$(ObjDir)/%.o: %.cc $(COMPILE_DEPS)
 	$(Echo) "Compiling $*.cc for $(BuildMode) build" $(PIC_FLAG)
 	$(Verb) if $(Compile.CXX) $(DEPEND_OPTIONS) $< -o $(ObjDir)/$*.o ; \
 	        $(DEPEND_MOVEFILE)
 
-$(ObjDir)/%.o: %.c $(ObjDir)/.dir $(BUILT_SOURCES) $(PROJ_MAKEFILE)
+$(ObjDir)/%.o: %.c $(COMPILE_DEPS)
 	$(Echo) "Compiling $*.c for $(BuildMode) build" $(PIC_FLAG)
 	$(Verb) if $(Compile.C) $(DEPEND_OPTIONS) $< -o $(ObjDir)/$*.o ; \
 	        $(DEPEND_MOVEFILE)
 
-$(ObjDir)/%.o: %.m $(ObjDir)/.dir $(BUILT_SOURCES) $(PROJ_MAKEFILE)
+$(ObjDir)/%.o: %.m $(COMPILE_DEPS)
 	$(Echo) "Compiling $*.m for $(BuildMode) build" $(PIC_FLAG)
 	$(Verb) if $(Compile.C) $(DEPEND_OPTIONS) $< -o $(ObjDir)/$*.o ; \
 	        $(DEPEND_MOVEFILE)
@@ -1475,67 +1488,67 @@ $(ObjDir)/%.o: %.m $(ObjDir)/.dir $(BUILT_SOURCES) $(PROJ_MAKEFILE)
 # Provide alternate rule sets if dependencies are disabled
 else
 
-$(ObjDir)/%.o: %.cpp $(ObjDir)/.dir $(BUILT_SOURCES)
+$(ObjDir)/%.o: %.cpp $(COMPILE_DEPS)
 	$(Echo) "Compiling $*.cpp for $(BuildMode) build" $(PIC_FLAG)
 	$(Compile.CXX) $< -o $@
 
-$(ObjDir)/%.o: %.mm $(ObjDir)/.dir $(BUILT_SOURCES)
+$(ObjDir)/%.o: %.mm $(COMPILE_DEPS)
 	$(Echo) "Compiling $*.mm for $(BuildMode) build" $(PIC_FLAG)
 	$(Compile.CXX) $< -o $@
 
-$(ObjDir)/%.o: %.cc $(ObjDir)/.dir $(BUILT_SOURCES)
+$(ObjDir)/%.o: %.cc $(COMPILE_DEPS)
 	$(Echo) "Compiling $*.cc for $(BuildMode) build" $(PIC_FLAG)
 	$(Compile.CXX) $< -o $@
 
-$(ObjDir)/%.o: %.c $(ObjDir)/.dir $(BUILT_SOURCES)
+$(ObjDir)/%.o: %.c $(COMPILE_DEPS)
 	$(Echo) "Compiling $*.c for $(BuildMode) build" $(PIC_FLAG)
 	$(Compile.C) $< -o $@
 
-$(ObjDir)/%.o: %.m $(ObjDir)/.dir $(BUILT_SOURCES)
+$(ObjDir)/%.o: %.m $(COMPILE_DEPS)
 	$(Echo) "Compiling $*.m for $(BuildMode) build" $(PIC_FLAG)
 	$(Compile.C) $< -o $@
 endif
 
 
 ## Rules for building preprocessed (.i/.ii) outputs.
-$(BuildMode)/%.ii: %.cpp $(ObjDir)/.dir $(BUILT_SOURCES)
+$(BuildMode)/%.ii: %.cpp $(COMPILE_DEPS)
 	$(Echo) "Compiling $*.cpp for $(BuildMode) build to .ii file"
 	$(Verb) $(Preprocess.CXX) $< -o $@
 
-$(BuildMode)/%.ii: %.mm $(ObjDir)/.dir $(BUILT_SOURCES)
+$(BuildMode)/%.ii: %.mm $(COMPILE_DEPS)
 	$(Echo) "Compiling $*.mm for $(BuildMode) build to .ii file"
 	$(Verb) $(Preprocess.CXX) $< -o $@
 
-$(BuildMode)/%.ii: %.cc $(ObjDir)/.dir $(BUILT_SOURCES)
+$(BuildMode)/%.ii: %.cc $(COMPILE_DEPS)
 	$(Echo) "Compiling $*.cc for $(BuildMode) build to .ii file"
 	$(Verb) $(Preprocess.CXX) $< -o $@
 
-$(BuildMode)/%.i: %.c $(ObjDir)/.dir $(BUILT_SOURCES)
+$(BuildMode)/%.i: %.c $(COMPILE_DEPS)
 	$(Echo) "Compiling $*.c for $(BuildMode) build to .i file"
 	$(Verb) $(Preprocess.C) $< -o $@
 
-$(BuildMode)/%.i: %.m $(ObjDir)/.dir $(BUILT_SOURCES)
+$(BuildMode)/%.i: %.m $(COMPILE_DEPS)
 	$(Echo) "Compiling $*.m for $(BuildMode) build to .i file"
 	$(Verb) $(Preprocess.C) $< -o $@
 
 
-$(ObjDir)/%.s: %.cpp $(ObjDir)/.dir $(BUILT_SOURCES)
+$(ObjDir)/%.s: %.cpp $(COMPILE_DEPS)
 	$(Echo) "Compiling $*.cpp to asm for $(BuildMode) build" $(PIC_FLAG)
 	$(Compile.CXX) $< -o $@ -S
 
-$(ObjDir)/%.s: %.mm $(ObjDir)/.dir $(BUILT_SOURCES)
+$(ObjDir)/%.s: %.mm $(COMPILE_DEPS)
 	$(Echo) "Compiling $*.mm to asm for $(BuildMode) build" $(PIC_FLAG)
 	$(Compile.CXX) $< -o $@ -S
 
-$(ObjDir)/%.s: %.cc $(ObjDir)/.dir $(BUILT_SOURCES)
+$(ObjDir)/%.s: %.cc $(COMPILE_DEPS)
 	$(Echo) "Compiling $*.cc to asm for $(BuildMode) build" $(PIC_FLAG)
 	$(Compile.CXX) $< -o $@ -S
 
-$(ObjDir)/%.s: %.c $(ObjDir)/.dir $(BUILT_SOURCES)
+$(ObjDir)/%.s: %.c $(COMPILE_DEPS)
 	$(Echo) "Compiling $*.c to asm for $(BuildMode) build" $(PIC_FLAG)
 	$(Compile.C) $< -o $@ -S
 
-$(ObjDir)/%.s: %.m $(ObjDir)/.dir $(BUILT_SOURCES)
+$(ObjDir)/%.s: %.m $(COMPILE_DEPS)
 	$(Echo) "Compiling $*.m to asm for $(BuildMode) build" $(PIC_FLAG)
 	$(Compile.C) $< -o $@ -S