Don't try to use -MMD / .o.d depfiles for ninja with .s files.

pylib/gyp/generator/ninja.py

 # Copyright (c) 2012 Google Inc. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import copy
 import hashlib
 import multiprocessing
 import os.path
 import re
 import signal
@@ skipping 764 matching lines @@
       self.WriteVariableList('cflags_objcc', map(self.ExpandSpecial,
                                                  cflags_objcc))
     self.ninja.newline()
     outputs = []
     for source in sources:
       filename, ext = os.path.splitext(source)
       ext = ext[1:]
       obj_ext = self.obj_ext
       if ext in ('cc', 'cpp', 'cxx'):
         command = 'cxx'
-      elif ext == 'c' or (ext in ('s', 'S') and self.flavor != 'win'):
+      elif ext == 'c' or (ext == 'S' and self.flavor != 'win'):
         command = 'cc'
+      elif ext == 's' and self.flavor != 'win':  # Doesn't generate .o.d files.
+        command = 'cc_s'
       elif (self.flavor == 'win' and ext == 'asm' and
             self.msvs_settings.GetTargetPlatform(config_name) == 'Win32'):
         # Asm files only get auto assembled for x86 (not x64).
         command = 'asm'
         # Add the _asm suffix as msvs is capable of handling .cc and
         # .asm files of the same name without collision.
         obj_ext = '_asm.obj'
       elif self.flavor == 'mac' and ext == 'm':
         command = 'objc'
       elif self.flavor == 'mac' and ext == 'mm':
@@ skipping 627 matching lines @@
   master_ninja.newline()
 
   if flavor != 'win':
     master_ninja.rule(
       'cc',
       description='CC $out',
       command=('$cc -MMD -MF $out.d $defines $includes $cflags $cflags_c '
               '$cflags_pch_c -c $in -o $out'),
       depfile='$out.d')
     master_ninja.rule(
+      'cc_s',
+      description='CC $out',
+      command=('$cc $defines $includes $cflags $cflags_c '
+              '$cflags_pch_c -c $in -o $out'))
+    master_ninja.rule(
       'cxx',
       description='CXX $out',
       command=('$cxx -MMD -MF $out.d $defines $includes $cflags $cflags_cc '
               '$cflags_pch_cc -c $in -o $out'),
       depfile='$out.d')
   else:
     # Template for compile commands mostly shared between compiling files
     # and generating PCH. In the case of PCH, the "output" is specified by /Fp
     # rather than /Fo (for object files), but we still need to specify an /Fo
     # when compiling PCH.
@@ skipping 329 matching lines @@
           arglists.append(
               (target_list, target_dicts, data, params, config_name))
           pool.map(CallGenerateOutputForConfig, arglists)
       except KeyboardInterrupt, e:
         pool.terminate()
         raise e
     else:
       for config_name in config_names:
         GenerateOutputForConfig(target_list, target_dicts, data, params,
                                 config_name)