[GN]: Add asmflags

tools/gn/ninja_binary_target_writer.cc

 // Copyright (c) 2013 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.
 
 #include "tools/gn/ninja_binary_target_writer.h"
 
 #include <cstring>
 #include <set>
 #include <sstream>
 
@@ skipping 333 matching lines @@
   // added as explicit dependencies below. The .gch output files are placed in
   // |pch_other_files|. This is to prevent linking against them.
   std::vector<OutputFile> pch_obj_files;
   std::vector<OutputFile> pch_other_files;
   WritePCHCommands(used_types, order_only_dep,
                    &pch_obj_files, &pch_other_files);
   std::vector<OutputFile>* pch_files = !pch_obj_files.empty() ?
       &pch_obj_files : &pch_other_files;
 
   // Treat all pch output files as explicit dependencies of all
-  // compiles. Some notes:
-  //
-  //  - Only the language-specific one is required for any specific compile, but
-  //    that's more difficult to express and the additional logic doesn't buy
-  //    much reduced parallelism. Just list them all (there's usually only one
-  //    anyway).
+  // compiles that support them. Some notes:
   //
   //  - On Windows, the .pch file is the input to the compile, not the
   //    precompiled header's corresponding object file that we're using here.
   //    But Ninja's depslog doesn't support multiple outputs from the
   //    precompiled header compile step (it outputs both the .pch file and a
   //    corresponding .obj file). So we consistently list the .obj file and the
   //    .pch file we really need comes along with it.
   //
   //  - GCC .gch files are not object files, therefore they are not added to the
   //    object file list.
@@ skipping 43 matching lines @@
         ESCAPE_NINJA_COMMAND);
     RecursiveTargetConfigToStream<SourceDir>(
         target_, &ConfigValues::include_dirs,
         IncludeWriter(include_path_output), out_);
     out_ << std::endl;
   }
 
   bool has_precompiled_headers =
       target_->config_values().has_precompiled_headers();
 
-  // Some toolchains pass cflags to the assembler since it's the same command.
   EscapeOptions opts = GetFlagOptions();
+  if (used_types.Get(SOURCE_S) || used_types.Get(SOURCE_ASM)) {
+    WriteOneFlag(SUBSTITUTION_ASMFLAGS, false, Toolchain::TYPE_NONE,
+                 &ConfigValues::asmflags, opts);
+  }
   if (used_types.Get(SOURCE_C) || used_types.Get(SOURCE_CPP) ||
-      used_types.Get(SOURCE_M) || used_types.Get(SOURCE_MM) ||
-      used_types.Get(SOURCE_S) || used_types.Get(SOURCE_ASM)) {

[brettw, 2015/09/24 18:30:09]

Can you leave the S/ASM check in here and below with a TODO to remove? In
between the time that we roll these GN binary deps and the time we update the
toolchain definition to use asmflags, we won't necessarily write cflags for
targets that have only assembly files. Once we start using asmflags, we can
remove these lines.

[Bons, 2015/09/24 19:41:54]

Done.

+      used_types.Get(SOURCE_M) || used_types.Get(SOURCE_MM)) {
     WriteOneFlag(SUBSTITUTION_CFLAGS, false, Toolchain::TYPE_NONE,
                  &ConfigValues::cflags, opts);
   }
-  if (used_types.Get(SOURCE_C) || used_types.Get(SOURCE_S) ||
-      used_types.Get(SOURCE_ASM)) {
+  if (used_types.Get(SOURCE_C)) {
     WriteOneFlag(SUBSTITUTION_CFLAGS_C, has_precompiled_headers,
                  Toolchain::TYPE_CC, &ConfigValues::cflags_c, opts);
   }
   if (used_types.Get(SOURCE_CPP)) {
     WriteOneFlag(SUBSTITUTION_CFLAGS_CC, has_precompiled_headers,
                  Toolchain::TYPE_CXX, &ConfigValues::cflags_cc, opts);
   }
   if (used_types.Get(SOURCE_M)) {
     WriteOneFlag(SUBSTITUTION_CFLAGS_OBJC, has_precompiled_headers,
                  Toolchain::TYPE_OBJC, &ConfigValues::cflags_objc, opts);
@@ skipping 228 matching lines @@
 
     if (tool_type != Toolchain::TYPE_NONE) {
       // Only include PCH deps that correspond to the tool type, for instance,
       // do not specify target_name.precompile.cc.o (a CXX PCH file) as a dep
       // for the output of a C tool type.
       //
       // This makes the assumption that pch_deps only contains pch output files
       // with the naming scheme specified in GetWindowsPCHObjectExtension or
       // GetGCCPCHOutputExtension.
       const Tool* tool = target_->toolchain()->GetTool(tool_type);
-      for (const auto& dep : pch_deps) {
-        const std::string& output_value = dep.value();
-        std::string output_extension;
-        if (tool->precompiled_header_type() == Tool::PCH_MSVC) {
-          output_extension = GetWindowsPCHObjectExtension(tool_type);
-        } else if (tool->precompiled_header_type() == Tool::PCH_GCC) {
-          output_extension = GetGCCPCHOutputExtension(tool_type);
-        }
-        if (output_value.compare(output_value.size() - output_extension.size(),
-            output_extension.size(), output_extension) == 0) {
-          deps.push_back(dep);
+      if (tool->precompiled_header_type() != Tool::PCH_NONE) {
+        for (const auto& dep : pch_deps) {
+          const std::string& output_value = dep.value();
+          std::string output_extension;
+          if (tool->precompiled_header_type() == Tool::PCH_MSVC) {
+            output_extension = GetWindowsPCHObjectExtension(tool_type);
+          } else if (tool->precompiled_header_type() == Tool::PCH_GCC) {
+            output_extension = GetGCCPCHOutputExtension(tool_type);
+          }
+          if (output_value.compare(output_value.size() -
+              output_extension.size(), output_extension.size(),
+              output_extension) == 0) {
+            deps.push_back(dep);
+          }
         }
       }
       WriteCompilerBuildLine(source, deps, order_only_dep, tool_type,
                              tool_outputs);
     }
 
     // It's theoretically possible for a compiler to produce more than one
     // output, but we'll only link to the first output.
     object_files->push_back(tool_outputs[0]);
   }
@@ skipping 327 matching lines @@
           "\n"
           "In the latter case, either rename one of the files or move one of\n"
           "the sources to a separate source_set to avoid them both being in\n"
           "the same target.");
       g_scheduler->FailWithError(err);
       return false;
     }
   }
   return true;
 }