[NaCl SDK] Allow dsc files to omit TOOLS setting

native_client_sdk/src/tools/nacl_llvm.mk

 # Copyright (c) 2012 The Chromium Authors.   All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 #
 # GNU Make based build file.  For details on GNU Make see:
 #   http://www.gnu.org/software/make/manual/make.html
 #
 
 #
@@ skipping 10 matching lines @@
 #
 # Compile Macro
 #
 # $1 = Source Name
 # $2 = Compile Flags
 # $3 = Include Directories
 #
 define C_COMPILER_RULE
 -include $(call SRC_TO_DEP,$(1))
 $(call SRC_TO_OBJ,$(1)): $(1) $(TOP_MAKE) | $(dir $(call SRC_TO_OBJ,$(1)))dir.stamp
-        $(call LOG,CC  ,$$@,$(PNACL_CC) -o $$@ -c $$< $(POSIX_FLAGS) $(2) $(NACL_CFLAGS))
+        $(call LOG,CC  ,$$@,$(PNACL_CC) -o $$@ -c $$< $(POSIX_CFLAGS) $(2) $(NACL_CFLAGS))
         @$(FIXDEPS) $(call SRC_TO_DEP_PRE_FIXUP,$(1))
 endef
 
 define CXX_COMPILER_RULE
 -include $(call SRC_TO_DEP,$(1))
 $(call SRC_TO_OBJ,$(1)): $(1) $(TOP_MAKE) | $(dir $(call SRC_TO_OBJ,$(1)))dir.stamp
-        $(call LOG,CXX ,$$@,$(PNACL_CXX) -o $$@ -c $$< $(POSIX_FLAGS) $(2) $(NACL_CFLAGS))
+        $(call LOG,CXX ,$$@,$(PNACL_CXX) -o $$@ -c $$< $(POSIX_CFLAGS) $(2) $(NACL_CFLAGS))
         @$(FIXDEPS) $(call SRC_TO_DEP_PRE_FIXUP,$(1))
 endef
 
 
 # $1 = Source Name
 # $2 = POSIX Compile Flags
 # $3 = Include Directories
 # $4 = VC Flags (unused)
 define COMPILE_RULE
 ifeq ($(suffix $(1)),.c)
@@ skipping 143 matching lines @@
         $(error Cannot run in sel_ldr unless $$NACL_ARCH is set)
 endif
         $(SEL_LDR_PATH) $(SEL_LDR_ARGS) $(OUTDIR)/$(TARGET)_$(NACL_ARCH).nexe -- $(EXE_ARGS)
 
 debug: $(OUTDIR)/$(TARGET)_$(NACL_ARCH).nexe
 ifndef NACL_ARCH
         $(error Cannot run in sel_ldr unless $$NACL_ARCH is set)
 endif
         $(SEL_LDR_PATH) -d $(SEL_LDR_ARGS) $(OUTDIR)/$(TARGET)_$(NACL_ARCH).nexe -- $(EXE_ARGS)
 endif