tools/gn: sync documentation with reality

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 "tools/gn/err.h"
 #include "tools/gn/functions.h"
 #include "tools/gn/parse_tree.h"
@@ skipping 248 matching lines @@
     "      arguments specified by the toolchain_args section of the toolchain\n"
     "      definition (see \"gn help toolchain_args\").\n"
     "   3. Loads the destination build file in the context of the\n"
     "      configuration file in the previous step.\n"
     "\n"
     "Example:\n"
     "  toolchain(\"plugin_toolchain\") {\n"
     "    concurrent_links = 8\n"
     "\n"
     "    tool(\"cc\") {\n"
-    "      command = \"gcc $in\"\n"
+    "      command = \"gcc {{source}}\"\n"
     "      ...\n"
     "    }\n"
     "\n"
     "    toolchain_args() {\n"
     "      is_plugin = true\n"
     "      is_32bit = true\n"
     "      is_64bit = false\n"
     "    }\n"
     "  }\n";
 
@@ skipping 266 matching lines @@
     "  current directory for running all tools. These expansions are\n"
     "  available to all tools:\n"
     "\n"
     "    {{label}}\n"
     "        The label of the current target. This is typically used in the\n"
     "        \"description\" field for link tools. The toolchain will be\n"
     "        omitted from the label for targets in the default toolchain, and\n"
     "        will be included for targets in other toolchains.\n"
     "\n"
     "    {{output}}\n"
-    "        The relative path and name of the output)((s) of the current\n"
+    "        The relative path and name of the output(s) of the current\n"
     "        build step. If there is more than one output, this will expand\n"
     "        to a list of all of them.\n"
     "        Example: \"out/base/my_file.o\"\n"
     "\n"
     "    {{target_gen_dir}}\n"
     "    {{target_out_dir}}\n"
     "        The directory of the generated file and output directories,\n"
     "        respectively, for the current target. There is no trailing\n"
     "        slash.\n"
     "        Example: \"out/base/test\"\n"
@@ skipping 57 matching lines @@
     "\n"
     "        The \"_newline\" version will separate the input files with\n"
     "        newlines instead of spaces. This is useful in response files:\n"
     "        some linkers can take a \"-filelist\" flag which expects newline\n"
     "        separated files, and some Microsoft tools have a fixed-sized\n"
     "        buffer for parsing each line of a response file.\n"
     "\n"
     "    {{ldflags}}\n"
     "        Expands to the processed set of ldflags and library search paths\n"
     "        specified for the target.\n"
-    "        Example: \"-m64, -fPIC -pthread -L/usr/local/mylib\"\n"
+    "        Example: \"-m64 -fPIC -pthread -L/usr/local/mylib\"\n"
     "\n"
     "    {{libs}}\n"
     "        Expands to the list of system libraries to link to. Each will\n"
     "        be prefixed by the \"lib_prefix\".\n"
     "\n"
     "        As a special case to support Mac, libraries with names ending in\n"
     "        \".framework\" will be added to the {{libs}} with \"-framework\"\n"
     "        preceeding it, and the lib prefix will be ignored.\n"
     "\n"
     "        Example: \"-lfoo -lbar\"\n"
@@ skipping 36 matching lines @@
     "  it will always assume that running a command updates the output):\n"
     "\n"
     "    tool(\"solink\") {\n"
     "      command = \"...\"\n"
     "      outputs = [\n"
     "        \"{{root_out_dir}}/{{target_output_name}}{{output_extension}}\",\n"
     "        \"{{root_out_dir}}/{{target_output_name}}"
                  "{{output_extension}}.TOC\",\n"
     "      ]\n"
     "      link_output =\n"
-    "        \"{{root_out_dir}}/{{target_output_name}}{{output_extension}}\",\n"
+    "        \"{{root_out_dir}}/{{target_output_name}}{{output_extension}}\"\n"
     "      depend_output =\n"
     "        \"{{root_out_dir}}/{{target_output_name}}"
-                 "{{output_extension}}.TOC\",\n"
+                 "{{output_extension}}.TOC\"\n"
     "      restat = true\n"
     "    }\n"
     "\n"
     "Example\n"
     "\n"
     "  toolchain(\"my_toolchain\") {\n"
     "    # Put these at the top to apply to all tools below.\n"
     "    lib_prefix = \"-l\"\n"
     "    lib_dir_prefix = \"-L\"\n"
     "\n"
     "    tool(\"cc\") {\n"
-    "      command = \"gcc \\$in -o \\$out\"\n"
-    "      outputs = [ \"{{source_out_dir}}/{{source_name_part}}.o\"\n"
-    "      description = \"GCC \\$in\"\n"
+    "      command = \"gcc {{source}} -o {{output}}\"\n"
+    "      outputs = [ \"{{source_out_dir}}/{{source_name_part}}.o\" ]\n"
+    "      description = \"GCC {{source}}\"\n"
     "    }\n"
     "    tool(\"cxx\") {\n"
-    "      command = \"g++ \\$in -o \\$out\"\n"
-    "      outputs = [ \"{{source_out_dir}}/{{source_name_part}}.o\"\n"
-    "      description = \"G++ \\$in\"\n"
+    "      command = \"g++ {{source}} -o {{output}}\"\n"
+    "      outputs = [ \"{{source_out_dir}}/{{source_name_part}}.o\" ]\n"
+    "      description = \"G++ {{source}}\"\n"
     "    }\n"
     "  }\n";
 
 Value RunTool(Scope* scope,
               const FunctionCallNode* function,
               const std::vector<Value>& args,
               BlockNode* block,
               Err* err) {
   // Find the toolchain definition we're executing inside of. The toolchain
   // function will set a property pointing to it that we'll pick up.
@@ skipping 187 matching lines @@
     return Value();
 
   Scope::KeyValueMap values;
   block_scope.GetCurrentScopeValues(&values);
   toolchain->args() = values;
 
   return Value();
 }
 
 }  // namespace functions