commit 757ee41ef1b1ef3b7f0ace64efad8ad70101f279
author Luis Lozano <llozano@chromium.org> Mon Jul 18 22:38:19 2016
committer chrome-bot <chrome-bot@chromium.org> Thu Jul 21 05:22:29 2016
tree e9a171fd6471f01d2d84145f8685efced6822b06
parent 482e6739fa49dde4531c1c94b6763dfb8ea9b183

Fix Simple Chrome workflow to use cros Clang.

Changes to allow simple chrome workflow to use the cros Clang and
linker. Before, it was using the chrome bundled clang and system linker.

BUG=chromium:587960
TEST=used simple chrome for falco, daisy and alex-x86

Change-Id: I83d756800a9ae9856201fe44ed2ec86c7b5f40c9
Reviewed-on: https://chromium-review.googlesource.com/361502
Commit-Ready: Luis Lozano <llozano@chromium.org>
Tested-by: Luis Lozano <llozano@chromium.org>
Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Reviewed-by: Caroline Tice <cmtice@chromium.org>

cli/cros/cros_chrome_sdk.py

diff --git a/cli/cros/cros_chrome_sdk.py b/cli/cros/cros_chrome_sdk.py
index 50b9bf0..2a6d7ac 100644
--- a/cli/cros/cros_chrome_sdk.py
+++ b/cli/cros/cros_chrome_sdk.py
@@ -408,7 +408,7 @@
   _GOMA_URL = ('https://clients5.google.com/cxx-compiler-service/'
                'download/goma_ctl.py')
 
-  _CLANG_DIR = 'third_party/llvm-build/Release+Asserts/bin'
+  _CHROME_CLANG_DIR = 'third_party/llvm-build/Release+Asserts/bin'
   _HOST_BINUTILS_DIR = 'third_party/binutils/Linux_x64/Release/bin/'
 
   EBUILD_ENV = (
@@ -604,24 +604,22 @@
     for var in ('CXX', 'CC', 'LD'):
       env[var] = self._FixGoldPath(env[var], target_tc_path)
 
-    clang_path = os.path.join(options.chrome_src, self._CLANG_DIR)
-    if options.clang:
-      # Tell clang where to find the gcc headers and libraries.
-      flags = ['--gcc-toolchain=' + os.path.join(target_tc_path, 'usr'),
-               '--target=' + sdk_ctx.target_tc]
-      # TODO: It'd be nicer to inject these flags via some gyp variable.
-      # Note: It's important they're only passed to target targets, not host
-      # targets. They are intentionally added only to CC and not CC_host.
-      clang_bin = os.path.join(clang_path, 'clang')
-      env['CC'] = ' '.join([clang_bin] + flags + [env['CC'].split()[-1]])
-      clangxx_bin = os.path.join(clang_path, 'clang++')
-      env['CXX'] = ' '.join([clangxx_bin] + flags + [env['CXX'].split()[-1]])
+    chrome_clang_path = os.path.join(options.chrome_src, self._CHROME_CLANG_DIR)
 
-    # The host compiler intentionally doesn't use the libstdc++ from sdk_ctx,
-    # so that host binaries link against the system libstdc++ and can run
-    # without a special rpath.
-    env['CC_host'] = os.path.join(clang_path, 'clang')
-    env['CXX_host'] = os.path.join(clang_path, 'clang++')
+    if options.clang:
+      clang_flags = ['-Wno-unknown-warning-option']
+      env['CC'] = ' '.join([sdk_ctx.target_tc + '-clang'] +
+                           env['CC'].split()[1:] + clang_flags)
+      env['CXX'] = ' '.join([sdk_ctx.target_tc + '-clang++'] +
+                            env['CXX'].split()[1:] + clang_flags)
+      env['LD'] = env['CXX']
+      # TODO(llozano): remove the workaround below. See crosbug/628524.
+      env['LD'] += ' -Wl,--as-needed -lstdc++ -lm'
+
+    # For host compiler, we use the compiler that comes with Chrome
+    # instead of the target compiler.
+    env['CC_host'] = os.path.join(chrome_clang_path, 'clang')
+    env['CXX_host'] = os.path.join(chrome_clang_path, 'clang++')
     env['LD_host'] = env['CXX_host']
 
     binutils_path = os.path.join(options.chrome_src, self._HOST_BINUTILS_DIR)