Enable /analyze in gn builds

build/config/win/visual_studio_version.gni

 # Copyright 2014 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.
 
 declare_args() {
   # Path to Visual Studio. If empty, the default is used which is to use the
   # automatic toolchain in depot_tools. If set, you must also set the
   # visual_studio_version and wdk_path.
   visual_studio_path = ""
 
   # Version of Visual Studio pointed to by the visual_studio_path.
   # Use "2013" for Visual Studio 2013, or "2013e" for the Express version.
   visual_studio_version = ""
 
   # Directory of the Windows driver kit. If visual_studio_path is empty, this
   # will be auto-filled.
   wdk_path = ""
 
   # Full path to the Windows SDK, not including a backslash at the end.
   # This value is the default location, override if you have a different
   # installation location.
   windows_sdk_path = "C:\Program Files (x86)\Windows Kits\10"
 
   is_win_fastlink = false
+
+  # Set this to true to enable static analysis through Visual Studio's
+  # /analyze. This dramatically slows compiles and reports thousands of
+  # warnings, so normally this is done on a build machine and only the new
+  # warnings are examined.
+  is_win_analyze = false

[brettw, 2016/02/03 18:48:00]

Does this need to be usable by anywhere other than in the one BUILD file? If
not, then move this declaration to that build file.

[brucedawson, 2016/02/06 01:07:30]

It's need by ffmpeg's build file.

[brettw, 2016/02/19 22:03:05]

With our discussion in chat, I think you can make ffmpeg always remove this
config, so this build flag can be moved to build/config/win/BUILD.gn and not
shared in a .gni file.

Also, can you call this maybe "use_vs_code_analysis"? The problem is that there
are bot steps called "analyze" which seem possibly confusing with the presence
of this name.

[brucedawson, 2016/02/19 22:45:33]

Ah... now I see the advantage of unconditionally removing this in ffmpeg. Okay,
done.
This is a tradeoff. On the one hand the compiler switch is called /analyze and
that's how it's usually discussed, and the gyp files use win_analyze. On the
other hand, confusion with the other analyze steps is real. I think going with
vs_code_analysis makes sense, in which case the config should also be renamed to
win:vs_code_analysis.

 }
 
 if (visual_studio_path == "") {
   toolchain_data =
       exec_script("../../vs_toolchain.py", [ "get_toolchain_dir" ], "scope")
   visual_studio_path = toolchain_data.vs_path
   windows_sdk_path = toolchain_data.sdk_path
   visual_studio_version = toolchain_data.vs_version
   wdk_path = toolchain_data.wdk_dir
   visual_studio_runtime_dirs = toolchain_data.runtime_dirs
 } else {
   assert(visual_studio_version != "",
          "You must set the visual_studio_version if you set the path")
   assert(wdk_path != "",
          "You must set the wdk_path if you set the visual studio path")
   visual_studio_runtime_dirs = []
 }