[compiler-rt] r197028 - Only build embedded darwin variants if the compiler supports them

[Tim Northover]

Author: tnorthover
Date: Wed Dec 11 05:25:53 2013
New Revision: 197028

URL: http://llvm.org/viewvc/llvm-project?rev=197028&view=rev
Log:
Only build embedded darwin variants if the compiler supports them

We need to filter out architectures that the compiler hasn't been built to
target (most likely the ARM ones) before attemptint to build a version of
libcompiler_rt.

This can result in a completely empty library (e.g. soft-float doesn't have any
x86 variants), in which case we shouldn't even try the build

Modified:
    compiler-rt/trunk/make/platform/clang_darwin_embedded.mk

Modified: compiler-rt/trunk/make/platform/clang_darwin_embedded.mk
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/make/platform/clang_darwin_embedded.mk?rev=197028&r1=197027&r2=197028&view=diff
==============================================================================
--- compiler-rt/trunk/make/platform/clang_darwin_embedded.mk (original)
+++ compiler-rt/trunk/make/platform/clang_darwin_embedded.mk Wed Dec 11 05:25:53 2013
@@ -6,6 +6,25 @@
 
 Description := Static runtime libraries for embedded clang/Darwin
 
+# A function that ensures we don't try to build for architectures that we
+# don't have working toolchains for.
+CheckArches = \
+  $(shell \
+    result=""; \
+    for arch in $(1); do \
+      if $(CC) -arch $$arch -c \
+	  -integrated-as \
+	  $(ProjSrcRoot)/make/platform/clang_darwin_test_input.c \
+	  -isysroot $(ProjSrcRoot)/SDKs/darwin \
+	  -o /dev/null > /dev/null 2> /dev/null; then \
+        result="$$result$$arch "; \
+      else \
+	printf 1>&2 \
+	  "warning: clang_darwin.mk: dropping arch '$$arch' from lib '$(2)'\n"; \
+      fi; \
+    done; \
+    echo $$result)
+
 XCRun = \
   $(shell \
     result=`xcrun -find $(1) 2> /dev/null`; \
@@ -27,20 +46,20 @@ UniversalArchs :=
 # Soft-float version of the runtime. No floating-point instructions will be used
 # and the ABI (out of necessity) passes floating values in normal registers:
 # non-VFP variant of the AAPCS.
-Configs += soft_static
-UniversalArchs.soft_static := armv6m armv7m armv7em armv7
+UniversalArchs.soft_static := $(call CheckArches,armv6m armv7m armv7em armv7,soft_static)
+Configs += $(if $(UniversalArchs.soft_static),soft_static)
 
 # Hard-float version of the runtime. On ARM VFP instructions and registers are
 # allowed, and floating point values get passed in them. VFP variant of the
 # AAPCS.
-Configs += hard_static
-UniversalArchs.hard_static := armv7em armv7 i386 x86_64
+UniversalArchs.hard_static := $(call CheckArches,armv7em armv7 i386 x86_64,hard_static)
+Configs += $(if $(UniversalArchs.hard_static),hard_static)
 
-Configs += soft_pic
-UniversalArchs.soft_pic := armv6m armv7m armv7em armv7
+UniversalArchs.soft_pic := $(call CheckArches,armv6m armv7m armv7em armv7,soft_pic)
+Configs += $(if $(UniversalArchs.soft_pic),soft_pic)
 
-Configs += hard_pic
-UniversalArchs.hard_pic := armv7em armv7 i386 x86_64
+UniversalArchs.hard_pic := $(call CheckArches,armv7em armv7 i386 x86_64,hard_pic)
+Configs += $(if $(UniversalArchs.hard_pic),hard_pic)
 
 CFLAGS := -Wall -Werror -Oz -fomit-frame-pointer -ffreestanding