[gn] Add gn support to gcmole

tools/gcmole/gcmole.lua

 -- Copyright 2011 the V8 project authors. All rights reserved.
 -- Redistribution and use in source and binary forms, with or without
 -- modification, are permitted provided that the following conditions are
 -- met:
 --
 --     * Redistributions of source code must retain the above copyright
 --       notice, this list of conditions and the following disclaimer.
 --     * Redistributions in binary form must reproduce the above
 --       copyright notice, this list of conditions and the following
 --       disclaimer in the documentation and/or other materials provided
@@ skipping 165 matching lines @@
       local pipe = io.popen(action)
       local success = SplitResults(pipe:lines(), func)
       local closed = pipe:close()
       if not (success and closed) then error("Failed to run: " .. action) end
    end
 end
 
 -------------------------------------------------------------------------------
 -- GYP file parsing
 
+-- TODO(machenbach): Remove this when deprecating gyp.
 local function ParseGYPFile()
    local result = {}
    local gyp_files = {
        { "src/v8.gyp",             "'([^']-%.cc)'",      "src/"         },
        { "test/cctest/cctest.gyp", "'(test-[^']-%.cc)'", "test/cctest/" }
    }
 
    for i = 1, #gyp_files do
       local filename = gyp_files[i][1]
       local pattern = gyp_files[i][2]
       local prefix = gyp_files[i][3]
       local gyp_file = assert(io.open(filename), "failed to open GYP file")
       local gyp = gyp_file:read('*a')
       for condition, sources in
          gyp:gmatch "%[.-### gcmole%((.-)%) ###(.-)%]" do
          if result[condition] == nil then result[condition] = {} end
          for file in sources:gmatch(pattern) do
             table.insert(result[condition], prefix .. file)
          end
       end
       gyp_file:close()
    end
 
    return result
 end
 
+local function ParseGNFile()
+   local result = {}
+   local gn_files = {
+       { "BUILD.gn",             '"([^"]-%.cc)"',      ""         },
+       { "test/cctest/BUILD.gn", '"(test-[^"]-%.cc)"', "test/cctest/" }
+   }
+
+   for i = 1, #gn_files do
+      local filename = gn_files[i][1]
+      local pattern = gn_files[i][2]
+      local prefix = gn_files[i][3]
+      local gn_file = assert(io.open(filename), "failed to open GN file")
+      local gn = gn_file:read('*a')
+      for condition, sources in
+         gn:gmatch "### gcmole%((.-)%) ###(.-)%]" do
+         if result[condition] == nil then result[condition] = {} end
+         for file in sources:gmatch(pattern) do
+            table.insert(result[condition], prefix .. file)
+         end
+      end
+      gn_file:close()
+   end
+
+   return result
+end
+
 local function EvaluateCondition(cond, props)
    if cond == 'all' then return true end
 
    local p, v = cond:match "(%w+):(%w+)"
 
    assert(p and v, "failed to parse condition: " .. cond)
    assert(props[p] ~= nil, "undefined configuration property: " .. p)
 
    return props[p] == v
 end
 
 local function BuildFileList(sources, props)
    local list = {}
    for condition, files in pairs(sources) do
       if EvaluateCondition(condition, props) then
          for i = 1, #files do table.insert(list, files[i]) end
       end
    end
    return list
 end
 
-local sources = ParseGYPFile()
+
+local gyp_sources = ParseGYPFile()
+local gn_sources = ParseGNFile()
+
+-- TODO(machenbach): Remove this comparison logic when deprecating gyp.
+local function CompareSources(sources1, sources2, what)
+  for condition, files1 in pairs(sources1) do
+    local files2 = sources2[condition]
+    assert(
+      files2 ~= nil,
+      "Missing gcmole condition in " .. what .. ": " .. condition)
+
+    -- Turn into set for speed.
+    files2_set = {}
+    for i, file in pairs(files2) do files2_set[file] = true end
+
+    for i, file in pairs(files1) do
+      assert(
+        files2_set[file] ~= nil,
+        "Missing file " .. file .. " in " .. what .. " for condition " ..
+        condition)
+    end
+  end
+end
+
+CompareSources(gyp_sources, gn_sources, "GN")
+CompareSources(gn_sources, gyp_sources, "GYP")
+
 
 local function FilesForArch(arch)
-   return BuildFileList(sources, { os = 'linux',
-                                   arch = arch,
-                                   mode = 'debug',
-                                   simulator = ''})
+   return BuildFileList(gn_sources, { os = 'linux',
+                                      arch = arch,
+                                      mode = 'debug',
+                                      simulator = ''})
 end
 
 local mtConfig = {}
 
 mtConfig.__index = mtConfig
 
 local function config (t) return setmetatable(t, mtConfig) end
 
 function mtConfig:extend(t)
    local e = {}
@@ skipping 193 matching lines @@
 
 for _, arch in ipairs(ARCHS) do
    if not ARCHITECTURES[arch] then
       error ("Unknown arch: " .. arch)
    end
 
    errors = SafeCheckCorrectnessForArch(arch, report) or errors
 end
 
 os.exit(errors and 1 or 0)