Support building for a single target architecture.

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@80943 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 44 insertions, 6 deletions

diff --git a/Makefile b/Makefile
index 16ee1a460..4f6a2e087 100644
--- a/Makefile
+++ b/Makefile
@@ -44,19 +44,24 @@ $(call Set,ActiveLibGen,$(ActiveObjPath)/libcompiler_rt.Generic.a)
 $(call Set,ActiveLibOpt,$(ActiveObjPath)/libcompiler_rt.Optimized.a)
 
 # The sublibraries to use for a generic version.
-$(call Set,GenericInputs,$(foreach arch,$(Archs),$(ActiveObjPath)/$(arch)/libcompiler_rt.Generic.a))
+$(call Set,GenericInputs,$(foreach arch,$(TargetArchs),$(ActiveObjPath)/$(arch)/libcompiler_rt.Generic.a))
 # The sublibraries to use for an optimized version.
-$(call Set,OptimizedInputs,$(foreach arch,$(Archs),$(ActiveObjPath)/$(arch)/libcompiler_rt.Optimized.a))
+$(call Set,OptimizedInputs,$(foreach arch,$(TargetArchs),$(ActiveObjPath)/$(arch)/libcompiler_rt.Optimized.a))
 
-# Provide top-level fat archive targets.
+# Provide top-level fat archive targets. We make sure to not try to lipo if only
+# building one target arch.
 $(ActiveLibGen): $(GenericInputs) $(ActiveObjPath)/.dir
 	$(Summary) "  UNIVERSAL: $(ActiveConfig): $$@"
 	-$(Verb) $(RM) $$@
-	$(Verb) $(Lipo) -create -output $$@ $(GenericInputs)
+	$(if $(TargetArch), \
+	  $(Verb) $(CP) $(GenericInputs) $$@, \
+	  $(Verb) $(Lipo) -create -output $$@ $(GenericInputs))
 $(ActiveLibOpt): $(OptimizedInputs) $(ActiveObjPath)/.dir
 	$(Summary) "  UNIVERSAL: $(ActiveConfig): $$@"
 	-$(Verb) $(RM) $$@
-	$(Verb) $(Lipo) -create -output $$@ $(OptimizedInputs)
+	$(if $(TargetArch), \
+	  $(Verb) $(CP) $(GenericInputs) $$@, \
+	  $(Verb) $(Lipo) -create -output $$@ $(OptimizedInputs))
 .PRECIOUS: $(ActiveObjPath)/.dir
 
 # Add to target lists.
diff --git a/make/config.mk b/make/config.mk
index 726e8ba41..d2c614c9a 100644
--- a/make/config.mk
+++ b/make/config.mk
@@ -1,6 +1,8 @@
 ###
 # Configuration variables.
 
+OS := $(shell uname)
+
 # Assume make is always run from top-level of source directory. Note
 # than an Apple style build overrides these variables later in the
 # makefile.
@@ -8,8 +10,20 @@ ProjSrcRoot := $(shell pwd)
 ProjObjRoot := $(ProjSrcRoot)
 
 Configs := Debug Release Profile
+
+# The full list of architectures we support.
 Archs := i386 ppc x86_64
 
+# If TargetArch is defined, only build for that architecture (and don't use
+# -arch).
+ifeq ($(OS), Darwin)
+  TargetArch :=
+  TargetArchs := $(Archs)
+else
+  TargetArch := i386
+  TargetArchs := $(TargetArch)
+endif
+
 Common.CFLAGS := -Wall -Werror
 
 # These names must match the configs, see GetArgs function.
@@ -17,10 +31,23 @@ Debug.CFLAGS := -g
 Release.CFLAGS := -O3 -fomit-frame-pointer
 Profile.CFLAGS := -pg -g
 
+# Function: GetArchArgs arch
+#
+# Return the compiler flags for the given arch.
+ifeq ($(OS), Darwin)
+  GetArchArgs = -arch $(1)
+else
+  # Check that we are only trying to build the target arch.
+  GetArchArgs = $(if $(subst $(TargetArch),,$(1)), \
+	$(error "Invalid configuration, no -arch support: $(1)"), \
+	)
+endif
+
 # Function: GetArgs config arch
 #
 # Return the compiler flags for the given config & arch.
-GetArgs = $(if $($(1).CFLAGS),$(Common.CFLAGS) $($(1).CFLAGS) -arch $(2), \
+GetArgs = $(if $($(1).CFLAGS), \
+	        $(Common.CFLAGS) $($(1).CFLAGS) $(call GetArchArgs,$(2)), \
 		$(error "Invalid configuration: $(1)"))
 
 ###
@@ -37,6 +64,7 @@ RANLIB := ranlib
 # FIXME: Remove these pipes once ranlib errors are fixed.
 RANLIB.Flags := 2> /dev/null
 LIPO := lipo
+CP := cp
 
 ###
 # Automatic and derived variables.
diff --git a/make/subdir.mk b/make/subdir.mk
index 3aea16c73..f3a9d52cb 100644
--- a/make/subdir.mk
+++ b/make/subdir.mk
@@ -23,6 +23,11 @@ else
   ArchsToTraverse := $(OnlyArchs)
 endif
 
+# If we are only targetting a single arch, only traverse that.
+ifneq ($(TargetArch),)
+  ArchsToTraverse := $(filter $(TargetArch), $(ArchsToTraverse))
+endif
+
 $(foreach config,$(ConfigsToTraverse), \
   $(foreach arch,$(ArchsToTraverse), \
     $(eval $(call CNA_subdir_template,$(config),$(arch),$(Dir)))))