Add os_posix gyp variable, nesting variables dicts as needed to do so.
Review URL: https://codereview.appspot.com/5845050
git-svn-id: http://skia.googlecode.com/svn/trunk/gyp@3418 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/common.gypi b/common.gypi
index aa6e276..ad684c2 100644
--- a/common.gypi
+++ b/common.gypi
@@ -6,17 +6,9 @@
# This file is automatically included by gyp_skia when building any target.
{
- # Define all variables, allowing for override in GYP_DEFINES.
- #
- # One such variable is 'skia_os', which we use instead of 'OS' throughout
- # our gyp files. We set it automatically based on 'OS', but allow the
- # user to override it via GYP_DEFINES if they like.
- 'variables': {
- 'skia_scalar%': 'float',
- 'skia_os%': '<(OS)',
- 'skia_mesa%': 0,
- 'skia_target_arch%': 'x86',
- },
+ 'includes': [
+ 'common_variables.gypi',
+ ],
'target_defaults': {
@@ -32,7 +24,7 @@
],
},
'includes': [
- 'common_conditions.gypi'
+ 'common_conditions.gypi',
],
'conditions': [
[ 'skia_scalar == "float"',
diff --git a/common_variables.gypi b/common_variables.gypi
new file mode 100644
index 0000000..eb58de0
--- /dev/null
+++ b/common_variables.gypi
@@ -0,0 +1,80 @@
+# Copyright 2012 The Android Open Source Project
+#
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+{
+ # Get ready for the ugly...
+ #
+ # - We have to nest our variables dictionaries multiple levels deep, so that
+ # this and other gyp files can rely on previously-set variable values in
+ # their 'variables': { 'conditions': [] } clauses.
+ #
+ # Example 1:
+ # Within this file, we use the value of variable 'skia_os' to set the
+ # value of variable 'os_posix', so 'skia_os' must be defined within a
+ # "more inner" (enclosed) scope than 'os_posix'.
+ #
+ # Example 2:
+ # http://src.chromium.org/viewvc/chrome/trunk/src/third_party/libjpeg/libjpeg.gyp?revision=102306 ,
+ # which we currently import into our build, uses the value of 'os_posix'
+ # within the 'conditions' list in its 'variables' dict.
+ # In order for that to work, it needs the value of 'os_posix' to have been
+ # set within a "more inner" (enclosed) scope than its own 'variables' dict.
+ #
+ # - On the other hand, key/value pairs of a given 'variable' dict are only
+ # inherited by:
+ # 1. directly enclosing 'variable' dicts, and
+ # 2. "sibling" 'variable' dicts (which, I guess, are combined into a single
+ # 'variable' dict during gyp processing)
+ # and NOT inherited by "uncles" (siblings of directly enclosing 'variable'
+ # dicts), so we have to re-define every variable at every enclosure level
+ # within our ridiculous matryoshka doll of 'variable' dicts. That's why
+ # we have variable definitions like this: 'skia_os%': '<(skia_os)',
+ #
+ # See http://src.chromium.org/viewvc/chrome/trunk/src/build/common.gypi?revision=127004 ,
+ # which deals with these same constraints in a similar manner.
+ #
+ 'variables': { # level 1
+ 'variables': { # level 2
+
+ # Variables needed by conditions list within the level-2 variables dict.
+ 'variables': { # level 3
+ # We use 'skia_os' instead of 'OS' throughout our gyp files, to allow
+ # for cross-compilation (e.g. building for either MacOS or iOS on Mac).
+ # We set it automatically based on 'OS' (the host OS), but allow the
+ # user to override it via GYP_DEFINES if they like.
+ 'skia_os%': '<(OS)',
+ },
+
+ # Re-define all variables defined within the level-3 'variables' dict,
+ # so that siblings of the level-2 'variables' dict can see them.
+ 'skia_os%': '<(skia_os)',
+
+ 'conditions': [
+ ['skia_os == "win"', {
+ 'os_posix%': 0,
+ }, {
+ 'os_posix%': 1,
+ }],
+ ],
+
+ 'skia_scalar%': 'float',
+ 'skia_mesa%': 0,
+ 'skia_target_arch%': 'x86',
+ },
+
+ # Re-define all variables defined within the level-2 'variables' dict,
+ # so that siblings of the level-1 'variables' dict can see them.
+ 'skia_os%': '<(skia_os)',
+ 'os_posix%': '<(os_posix)',
+ 'skia_scalar%': '<(skia_scalar)',
+ 'skia_mesa%': '<(skia_mesa)',
+ 'skia_target_arch%': '<(skia_target_arch)',
+ },
+}
+# Local Variables:
+# tab-width:2
+# indent-tabs-mode:nil
+# End:
+# vim: set expandtab tabstop=2 shiftwidth=2:
