[iOS/GN] Replace the last to gyp-mac-tool commands with standalone scripts.

This adds write_framework_hmap.py and write_framework_modulemap.py under
//build/config/ios/.

BUG=616813
R=sdefresne@chromium.org

Review-Url: https://codereview.chromium.org/2082573006
Cr-Original-Commit-Position: refs/heads/master@{#401228}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: fc86361978c030bac431d9745c2de6a8eed6d014

config/ios/rules.gni

@@ -428,7 +428,7 @@ template("ios_framework_bundle") {
     _compile_headers_map_target = _target_name + "_compile_headers_map"
     action(_compile_headers_map_target) {
       visibility = [ ":$_framework_headers_target" ]
-      script = "$root_out_dir/gyp-mac-tool"
+      script = "//build/config/ios/write_framework_hmap.py"
       outputs = [
         _header_map_filename,
       ]
@@ -448,7 +448,6 @@ template("ios_framework_bundle") {
       set_sources_assignment_filter([])
 
       args = [
-               "compile-ios-framework-header-map",
                rebase_path(_header_map_filename),
                rebase_path(_framework_root, root_out_dir),
              ] + rebase_path(sources, root_out_dir)
@@ -457,14 +456,11 @@ template("ios_framework_bundle") {
     _create_module_map_target = _target_name + "_module_map"
     action(_create_module_map_target) {
       visibility = [ ":$_framework_headers_target" ]
-      script = "$root_out_dir/gyp-mac-tool"
+      script = "//build/config/ios/write_framework_modulemap.py"
       outputs = [
         "$_framework_root/Modules/module.modulemap",
       ]
-      args = [
-        "package-ios-framework",
-        rebase_path("$_framework_root", root_out_dir),
-      ]
+      args = [ rebase_path("$_framework_root", root_out_dir) ]
     }
 
     _copy_public_headers_target = _target_name + "_copy_public_headers"

config/ios/write_framework_hmap.py

@@ -0,0 +1,97 @@
+# Copyright 2016 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.
+
+import os
+import struct
+import sys
+
+def Main(args):
+  if len(args) < 4:
+    print >> sys.stderr, "Usage: %s output.hmap Foo.framework header1.h..." %\
+        (args[0])
+    return 1
+
+  (out, framework, all_headers) = args[1], args[2], args[3:]
+
+  framework_name = os.path.basename(framework).split('.')[0]
+  all_headers = map(os.path.abspath, all_headers)
+  filelist = {}
+  for header in all_headers:
+    filename = os.path.basename(header)
+    filelist[filename] = header
+    filelist[os.path.join(framework_name, filename)] = header
+  WriteHmap(out, filelist)
+  return 0
+
+
+def NextGreaterPowerOf2(x):
+  return 2**(x).bit_length()
+
+
+def WriteHmap(output_name, filelist):
+  """Generates a header map based on |filelist|.
+
+  Per Mark Mentovai:
+    A header map is structured essentially as a hash table, keyed by names used
+    in #includes, and providing pathnames to the actual files.
+
+  The implementation below and the comment above comes from inspecting:
+    http://www.opensource.apple.com/source/distcc/distcc-2503/distcc_dist/include_server/headermap.py?txt
+  while also looking at the implementation in clang in:
+    https://llvm.org/svn/llvm-project/cfe/trunk/lib/Lex/HeaderMap.cpp
+  """
+  magic = 1751998832
+  version = 1
+  _reserved = 0
+  count = len(filelist)
+  capacity = NextGreaterPowerOf2(count)
+  strings_offset = 24 + (12 * capacity)
+  max_value_length = len(max(filelist.items(), key=lambda (k,v):len(v))[1])
+
+  out = open(output_name, 'wb')
+  out.write(struct.pack('<LHHLLLL', magic, version, _reserved, strings_offset,
+                        count, capacity, max_value_length))
+
+  # Create empty hashmap buckets.
+  buckets = [None] * capacity
+  for file, path in filelist.items():
+    key = 0
+    for c in file:
+      key += ord(c.lower()) * 13
+
+    # Fill next empty bucket.
+    while buckets[key & capacity - 1] is not None:
+      key = key + 1
+    buckets[key & capacity - 1] = (file, path)
+
+  next_offset = 1
+  for bucket in buckets:
+    if bucket is None:
+      out.write(struct.pack('<LLL', 0, 0, 0))
+    else:
+      (file, path) = bucket
+      key_offset = next_offset
+      prefix_offset = key_offset + len(file) + 1
+      suffix_offset = prefix_offset + len(os.path.dirname(path) + os.sep) + 1
+      next_offset = suffix_offset + len(os.path.basename(path)) + 1
+      out.write(struct.pack('<LLL', key_offset, prefix_offset, suffix_offset))
+
+  # Pad byte since next offset starts at 1.
+  out.write(struct.pack('<x'))
+
+  for bucket in buckets:
+    if bucket is not None:
+      (file, path) = bucket
+      out.write(struct.pack('<%ds' % len(file), file))
+      out.write(struct.pack('<s', '\0'))
+      base = os.path.dirname(path) + os.sep
+      out.write(struct.pack('<%ds' % len(base), base))
+      out.write(struct.pack('<s', '\0'))
+      path = os.path.basename(path)
+      out.write(struct.pack('<%ds' % len(path), path))
+      out.write(struct.pack('<s', '\0'))
+
+
+if __name__ == '__main__':
+  sys.exit(Main(sys.argv))

config/ios/write_framework_modulemap.py

@@ -0,0 +1,26 @@
+# Copyright 2016 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.
+
+import os
+import sys
+
+def Main(framework):
+  # Find the name of the binary based on the part before the ".framework".
+  binary = os.path.basename(framework).split('.')[0]
+  module_path = os.path.join(framework, 'Modules');
+  if not os.path.exists(module_path):
+    os.mkdir(module_path)
+  module_template = 'framework module %s {\n' \
+                    '  umbrella header "%s.h"\n' \
+                    '\n' \
+                    '  export *\n' \
+                    '  module * { export * }\n' \
+                    '}\n' % (binary, binary)
+
+  module_file = open(os.path.join(module_path, 'module.modulemap'), 'w')
+  module_file.write(module_template)
+  module_file.close()
+
+if __name__ == '__main__':
+  Main(sys.argv[1])