find_headers.py to better find headers.

The find_headers.py script claims to "recursively search each include
directory for headers" but the recursive part has been left out.

This changes find_headers to instead find all the sources which are in
public include directories and list them with the shortest possible
path. This removes the need for a blacklist and also handles includes in
subdirectories of public include directories.

Change-Id: Ib59256a2059d37d4459686c421923207ac7acf38
Reviewed-on: https://skia-review.googlesource.com/129660
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Ben Wagner <bungeman@google.com>

1 files changed, 47 insertions, 22 deletions

diff --git a/gn/find_headers.py b/gn/find_headers.py
index 2f20e1e7d0..ed20647c2a 100755
--- a/gn/find_headers.py
+++ b/gn/find_headers.py
@@ -5,43 +5,68 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import collections
+import json
 import os
+import subprocess
 import sys
 
-# We'll recursively search each include directory for headers,
-# then write them to skia.h with a small blacklist.
+# Finds all public sources in include directories then write them to skia.h.
 
-# We'll also write skia.h.deps, which Ninja uses to track dependencies. It's the
+# Also write skia.h.deps, which Ninja uses to track dependencies. It's the
 # very same mechanism Ninja uses to know which .h files affect which .cpp files.
 
-skia_h       = sys.argv[1]
-include_dirs = sys.argv[2:]
+gn              = sys.argv[1]
+absolute_source = sys.argv[2]
+skia_h          = sys.argv[3]
+include_dirs    = sys.argv[4:]
 
-blacklist = {
-  "GrGLConfig_chrome.h",
-  "SkFontMgr_fontconfig.h",
-}
+absolute_source = os.path.normpath(absolute_source)
 
-headers = []
-for directory in include_dirs:
-  for f in os.listdir(directory):
-    if os.path.isfile(os.path.join(directory, f)):
-      if f.endswith('.h') and f not in blacklist:
-        headers.append(os.path.join(directory,f))
-headers.sort()
+include_dirs = [os.path.join(os.path.normpath(include_dir), '')
+                for include_dir in include_dirs]
+include_dirs.sort(key=len, reverse=True)
 
-with open(skia_h, "w") as f:
+# If skia ever uses 'public' that will need to be considered as well or instead.
+gn_sources_cmd = [gn, 'desc', '.', '--format=json', '*', 'sources']
+sources_json = json.loads(subprocess.check_output(gn_sources_cmd))
+sources = {os.path.join(absolute_source, os.path.normpath(source[2:]))
+           for target in sources_json.itervalues()
+           for source in target.get('sources', [])}
+
+Header = collections.namedtuple('Header', ['absolute', 'include'])
+headers = {}
+for source in sources:
+  source_as_include = [source[len(include_dir):]
+                       for include_dir in include_dirs
+                       if source.startswith(include_dir)]
+  if not source_as_include:
+    continue
+  statinfo = os.stat(source)
+  key = str(statinfo.st_ino) + ':' + str(statinfo.st_dev)
+  # On Windows os.stat st_ino is 0 until 3.3.4 and st_dev is 0 until 3.4.0.
+  if key == '0:0':
+    key = source
+  include_path = source_as_include[0]
+  if key not in headers or len(include_path) < len(headers[key].include):
+    headers[key] = Header(source, include_path)
+
+headers = headers.values()
+headers.sort(key=lambda x: x.include)
+
+with open(skia_h, 'w') as f:
   f.write('// skia.h generated by GN.\n')
   f.write('#ifndef skia_h_DEFINED\n')
   f.write('#define skia_h_DEFINED\n')
-  for h in headers:
-    f.write('#include "' + os.path.basename(h) + '"\n')
+  for header in headers:
+    f.write('#include "' + header.include + '"\n')
   f.write('#endif//skia_h_DEFINED\n')
 
-with open(skia_h + '.deps', "w") as f:
+with open(skia_h + '.deps', 'w') as f:
   f.write(skia_h + ':')
-  for h in headers:
-    f.write(' ' + h)
+  for header in headers:
+    f.write(' ' + header.absolute)
+  f.write(' build.ninja.d')
   f.write('\n')
 
 # Temporary: during development this file wrote skia.h.d, not skia.h.deps,