[NaCl SDK] Allow dsc files to omit TOOLS setting

native_client_sdk/src/tools/common.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 308 matching lines @@
 endif
 
 
 #
 # Common Compile Options
 #
 # For example, -DNDEBUG is added to release builds by default
 # so that calls to assert(3) are not included in the build.
 #
 ifeq ($(CONFIG),Release)
-POSIX_FLAGS ?= -g -O2 -pthread -MMD -DNDEBUG
+POSIX_CFLAGS ?= -g -O2 -pthread -MMD -DNDEBUG
 NACL_LDFLAGS ?= -O2
 PNACL_LDFLAGS ?= -O2
 else
-POSIX_FLAGS ?= -g -O0 -pthread -MMD -DNACL_SDK_DEBUG
+POSIX_CFLAGS ?= -g -O0 -pthread -MMD -DNACL_SDK_DEBUG
 endif
 
 NACL_CFLAGS ?= -Wno-long-long -Werror
 NACL_CXXFLAGS ?= -Wno-long-long -Werror
 NACL_LDFLAGS += -Wl,-as-needed -pthread
 
 #
 # Default Paths
 #
 INC_PATHS := $(shell $(NACL_CONFIG) -t $(TOOLCHAIN) --include-dirs) $(EXTRA_INC_PATHS)
@@ skipping 192 matching lines @@
 # uppercase aliases (for backward compatibility)
 .PHONY: CHECK_FOR_CHROME DEBUG LAUNCH RUN
 CHECK_FOR_CHROME: check_for_chrome
 DEBUG: debug
 LAUNCH: run
 RUN: run
 
 endif  # TOOLCHAIN is valid...
 
 endif  # TOOLCHAIN=all