Add arflags to GN

tools/gn/function_toolchain.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 <algorithm>
 #include <limits>
 #include <utility>
 
 #include "tools/gn/err.h"
 #include "tools/gn/functions.h"
@@ skipping 176 matching lines @@
 bool IsCompilerTool(Toolchain::ToolType type) {
   return type == Toolchain::TYPE_CC ||
          type == Toolchain::TYPE_CXX ||
          type == Toolchain::TYPE_OBJC ||
          type == Toolchain::TYPE_OBJCXX ||
          type == Toolchain::TYPE_RC ||
          type == Toolchain::TYPE_ASM;
 }
 
 bool IsLinkerTool(Toolchain::ToolType type) {
-  return type == Toolchain::TYPE_ALINK ||
-         type == Toolchain::TYPE_SOLINK ||
+  // "alink" is not counted as in the generic "linker" tool list.
+  return type == Toolchain::TYPE_SOLINK ||
          type == Toolchain::TYPE_SOLINK_MODULE ||
          type == Toolchain::TYPE_LINK;
 }
 
 bool IsPatternInOutputList(const SubstitutionList& output_list,
                            const SubstitutionPattern& pattern) {
   for (const auto& cur : output_list.list()) {
     if (pattern.ranges().size() == cur.ranges().size() &&
         std::equal(pattern.ranges().begin(), pattern.ranges().end(),
                    cur.ranges().begin()))
@@ skipping 474 matching lines @@
     "\n"
     "    {{source_gen_dir}}\n"
     "    {{source_out_dir}}\n"
     "        The directory in the generated file and output directories,\n"
     "        respectively, for the current input file. If the source file\n"
     "        is in the same directory as the target is declared in, they will\n"
     "        will be the same as the \"target\" versions above.\n"
     "        Example: \"gen/base/test\"\n"
     "\n"
     "  Linker tools have multiple inputs and (potentially) multiple outputs\n"
+    "  The static library tool (\"alink\") is not considered a linker tool.\n"
     "  The following expansions are available:\n"
     "\n"
     "    {{inputs}}\n"
     "    {{inputs_newline}}\n"
     "        Expands to the inputs to the link step. This will be a list of\n"
     "        object files and static libraries.\n"
     "        Example: \"obj/foo.o obj/bar.o obj/somelibrary.a\"\n"
     "\n"
     "        The \"_newline\" version will separate the input files with\n"
     "        newlines instead of spaces. This is useful in response files:\n"
@@ skipping 39 matching lines @@
     "\n"
     "    {{solibs}}\n"
     "        Extra libraries from shared library dependencide not specified\n"
     "        in the {{inputs}}. This is the list of link_output files from\n"
     "        shared libraries (if the solink tool specifies a \"link_output\"\n"
     "        variable separate from the \"depend_output\").\n"
     "\n"
     "        These should generally be treated the same as libs by your tool.\n"
     "        Example: \"libfoo.so libbar.so\"\n"
     "\n"
+    "  The static library (\"alink\") tool allows {{arflags}} plus the common\n"
+    "  tool substitutions.\n"
+    "\n"
     "  The copy tool allows the common compiler/linker substitutions, plus\n"
     "  {{source}} which is the source of the copy. The stamp tool allows\n"
     "  only the common tool substitutions.\n"
     "\n"
     "  The copy_bundle_data and compile_xcassets tools only allows the common\n"
     "  tool substitutions. Both tools are required to create iOS/OS X bundles\n"
     "  and need only be defined on those platforms.\n"
     "\n"
     "  The copy_bundle_data tool will be called with one source and needs to\n"
     "  copy (optionally optimizing the data representation) to its output. It\n"
@@ skipping 90 matching lines @@
   // tool type. There are different validators for the "outputs" than for the
   // rest of the strings.
   bool (*subst_validator)(SubstitutionType) = nullptr;
   bool (*subst_output_validator)(SubstitutionType) = nullptr;
   if (IsCompilerTool(tool_type)) {
     subst_validator = &IsValidCompilerSubstitution;
     subst_output_validator = &IsValidCompilerOutputsSubstitution;
   } else if (IsLinkerTool(tool_type)) {
     subst_validator = &IsValidLinkerSubstitution;
     subst_output_validator = &IsValidLinkerOutputsSubstitution;
+  } else if (tool_type == Toolchain::TYPE_ALINK) {
+    subst_validator = &IsValidALinkSubstitution;
+    // ALink uses the standard output file patterns as other linker tools.
+    subst_output_validator = &IsValidLinkerOutputsSubstitution;
   } else if (tool_type == Toolchain::TYPE_COPY ||
              tool_type == Toolchain::TYPE_COPY_BUNDLE_DATA) {
     subst_validator = &IsValidCopySubstitution;
     subst_output_validator = &IsValidCopySubstitution;
   } else if (tool_type == Toolchain::TYPE_COMPILE_XCASSETS) {
     subst_validator = &IsValidCompileXCassetsSubstitution;
     subst_output_validator = &IsValidCompileXCassetsSubstitution;
   } else {
     subst_validator = &IsValidToolSubstitution;
     subst_output_validator = &IsValidToolSubstitution;
@@ skipping 170 matching lines @@
     return Value();
 
   Scope::KeyValueMap values;
   block_scope.GetCurrentScopeValues(&values);
   toolchain->args() = values;
 
   return Value();
 }
 
 }  // namespace functions