ninja: make cross-compilation use $CC/$CXX for the target compiler

pylib/gyp/generator/ninja.py

Index: pylib/gyp/generator/ninja.py
diff --git a/pylib/gyp/generator/ninja.py b/pylib/gyp/generator/ninja.py
index 8aee8749ac3280fd1c02148c30c4947688bb193d..f7ba0b44c8a59766e094169206c15aef3d58566d 100644
--- a/pylib/gyp/generator/ninja.py
+++ b/pylib/gyp/generator/ninja.py
@@ -58,7 +58,12 @@ generator_extra_sources_for_rules = []
 # TODO: figure out how to not build extra host objects in the non-cross-compile
 # case when this is enabled, and enable unconditionally.
 generator_supports_multiple_toolsets = (
-  os.environ.get('AR_target') or os.environ.get('CC_target') or
+  os.environ.get('GYP_CROSSCOMPILE') or
+  os.environ.get('AR_host') or
+  os.environ.get('CC_host') or
+  os.environ.get('CXX_host') or
+  os.environ.get('AR_target') or
+  os.environ.get('CC_target') or
   os.environ.get('CXX_target'))
 
 
@@ -705,11 +710,11 @@ class NinjaWriter:
   def WriteSources(self, config_name, config, sources, predepends,
                    precompiled_header):
     """Write build rules to compile all of |sources|."""
-    if self.toolset == 'target':
-      self.ninja.variable('ar', '$ar_target')
-      self.ninja.variable('cc', '$cc_target')
-      self.ninja.variable('cxx', '$cxx_target')
-      self.ninja.variable('ld', '$ld_target')
+    if self.toolset == 'host':
+      self.ninja.variable('ar', '$ar_host')
+      self.ninja.variable('cc', '$cc_host')
+      self.ninja.variable('cxx', '$cxx_host')
+      self.ninja.variable('ld', '$ld_host')
 
     extra_defines = []
     if self.flavor == 'mac':
@@ -1267,6 +1272,13 @@ def OpenOutput(path, mode='w'):
   return open(path, mode)
 
 
+def GetEnvironFallback(var_list, default):
+  for var in var_list:
+    if var in os.environ:
+      return os.environ[var]
+  return default
+
+
 def GenerateOutputForConfig(target_list, target_dicts, data, params,
                             config_name):
   options = params['options']
@@ -1288,24 +1300,45 @@ def GenerateOutputForConfig(target_list, target_dicts, data, params,
   gyp.common.CopyTool(flavor, toplevel_build)
 
   # Grab make settings for CC/CXX.
+  # The rules are
+  # - The priority from low to high is gcc/g++, the 'make_global_settings' in
+  #   gyp, the environment variable.
+  # - If there is no 'make_global_settings' for CC.host/CXX.host or
+  #   'CC_host'/'CXX_host' enviroment variable, cc_host/cxx_host should be set
+  #   to cc/cxx.
   if flavor == 'win':
     cc = cxx = 'cl.exe'
     gyp.msvs_emulation.GenerateEnvironmentFiles(
         toplevel_build, generator_flags, OpenOutput)
   else:
     cc, cxx = 'gcc', 'g++'
+  cc_host = None
+  cxx_host = None
+  cc_host_global_setting = None
+  cxx_host_global_setting = None
+
   build_file, _, _ = gyp.common.ParseQualifiedTarget(target_list[0])
   make_global_settings = data[build_file].get('make_global_settings', [])
   build_to_root = InvertRelativePath(build_dir)
   for key, value in make_global_settings:
     if key == 'CC': cc = os.path.join(build_to_root, value)
     if key == 'CXX': cxx = os.path.join(build_to_root, value)
+    if key == 'CC.host': cc_host = os.path.join(build_to_root, value)
+    if key == 'CXX.host': cxx_host = os.path.join(build_to_root, value)
+    if key == 'CC.host': cc_host_global_setting = value
+    if key == 'CXX.host': cxx_host_global_setting = value
 
   flock = 'flock'
   if flavor == 'mac':
     flock = './gyp-mac-tool flock'
-  master_ninja.variable('cc', os.environ.get('CC', cc))
-  master_ninja.variable('cxx', os.environ.get('CXX', cxx))
+  cc = GetEnvironFallback(['CC_target', 'CC'], cc)
+  master_ninja.variable('cc', cc)
+  cxx = GetEnvironFallback(['CXX_target', 'CXX'], cxx)
+  master_ninja.variable('cxx', cxx)
+
+  if not cc_host: cc_host = cc
+  if not cxx_host: cxx_host = cxx
+
   if flavor == 'win':
     master_ninja.variable('ld', 'link.exe')
     master_ninja.variable('idl', 'midl.exe')
@@ -1316,15 +1349,23 @@ def GenerateOutputForConfig(target_list, target_dicts, data, params,
     master_ninja.variable('use_dep_database', '1')
   else:
     master_ninja.variable('ld', flock + ' linker.lock $cxx')
-    master_ninja.variable('ar', os.environ.get('AR', 'ar'))
-
-  master_ninja.variable('ar_target', os.environ.get('AR_target', '$ar'))
-  master_ninja.variable('cc_target', os.environ.get('CC_target', '$cc'))
-  master_ninja.variable('cxx_target', os.environ.get('CXX_target', '$cxx'))
+    master_ninja.variable('ar', GetEnvironFallback(['AR_target', 'AR'], 'ar'))
+
+  master_ninja.variable('ar_host', GetEnvironFallback(['AR_host'], 'ar'))
+  cc_host = GetEnvironFallback(['CC_host'], cc_host)
+  cxx_host = GetEnvironFallback(['CXX_host'], cxx_host)
+  # The environment variable could be used in 'make_global_settings', like
+  # ['CC.host', '$(CC)'] or ['CXX.host', '$(CXX)'], transform them here.
+  if cc_host.find('$(CC)') != -1 and cc_host_global_setting:
+    cc_host = cc_host_global_setting.replace('$(CC)', cc)
+  if cxx_host.find('$(CXX)') != -1 and cxx_host_global_setting:
+    cxx_host = cxx_host_global_setting.replace('$(CXX)', cxx)

[Nico, 2012/08/08 17:36:11]

I understand that you need to add a "cc_host = " in the beginning. Sorry for not
catching that.

I don't understand why you need cc_host_global_setting and the if. Do things
work without them?

[michaelbai, 2012/08/08 17:40:42]

The cc_host_global_setting stores the raw value without adjusting the path.

for example,
cc_host = '../../$(CC)'
cc_host_global_setting = '$(CC)'

So, the cc_host could be replace to 'gcc' instead of '../../gcc'.




On 2012/08/08 17:36:11, Nico wrote:

+  master_ninja.variable('cc_host', cc_host)
+  master_ninja.variable('cxx_host', cxx_host)
   if flavor == 'win':
-    master_ninja.variable('ld_target', os.environ.get('LD_target', '$ld'))
+    master_ninja.variable('ld_host', os.environ.get('LD_host', '$ld'))
   else:
-    master_ninja.variable('ld_target', flock + ' linker.lock $cxx_target')
+    master_ninja.variable('ld_host', flock + ' linker.lock $cxx_host')
 
   if flavor == 'mac':
     master_ninja.variable('mac_tool', os.path.join('.', 'gyp-mac-tool'))