Changes the ninja generator to output phony targets for uninteresting targets

This way you can pass these targets to the build system and not get
errors.

BUG=410410
TEST=covered by test now
R=thakis@chromium.org

Review URL: https://codereview.chromium.org/543743003

git-svn-id: http://gyp.googlecode.com/svn/trunk@1973 78cadc50-ecff-11dd-a971-7dbc132099af

3 files changed, 45 insertions, 0 deletions

diff --git a/pylib/gyp/generator/ninja.py b/pylib/gyp/generator/ninja.py
index 3336a896..f5e1be96 100644
--- a/pylib/gyp/generator/ninja.py
+++ b/pylib/gyp/generator/ninja.py
@@ -2150,6 +2150,10 @@ def GenerateOutputForConfig(target_list, target_dicts, data, params,
   # objects.
   target_short_names = {}
 
+  # short name of targets that were skipped because they didn't contain anything
+  # interesting.
+  empty_target_names = []
+
   for qualified_target in target_list:
     # qualified_target is like: third_party/icu/icu.gyp:icui18n#target
     build_file, name, toolset = \
@@ -2193,6 +2197,8 @@ def GenerateOutputForConfig(target_list, target_dicts, data, params,
       target_outputs[qualified_target] = target
       if qualified_target in all_targets:
         all_outputs.add(target.FinalOutput())
+    else:
+      empty_target_names.append(name)
 
   if target_short_names:
     # Write a short name to build this target.  This benefits both the
@@ -2204,6 +2210,15 @@ def GenerateOutputForConfig(target_list, target_dicts, data, params,
       master_ninja.build(short_name, 'phony', [x.FinalOutput() for x in
                                                target_short_names[short_name]])
 
+  if empty_target_names:
+    # Write out any targets that were skipped because they didn't contain
+    # anything interesting. This way the targets can still be built without
+    # causing build errors.
+    master_ninja.newline()
+    master_ninja.comment('Empty targets (output for completeness).')
+    for name in sorted(empty_target_names):
+      master_ninja.build(name, 'phony')
+
   if all_outputs:
     master_ninja.newline()
     master_ninja.build('all', 'phony', list(all_outputs))
diff --git a/test/empty-target/empty-target.gyp b/test/empty-target/empty-target.gyp
new file mode 100644
index 00000000..feefa280
--- /dev/null
+++ b/test/empty-target/empty-target.gyp
@@ -0,0 +1,12 @@
+# Copyright (c) 2014 Google Inc. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+{
+  'targets': [
+    {
+      'target_name': 'empty_target',
+      'type': 'none',
+    },
+  ],
+}
diff --git a/test/empty-target/gyptest-empty-target.py b/test/empty-target/gyptest-empty-target.py
new file mode 100644
index 00000000..ecadd4a8
--- /dev/null
+++ b/test/empty-target/gyptest-empty-target.py
@@ -0,0 +1,18 @@
+#!/usr/bin/env python
+
+# Copyright (c) 2014 Google Inc. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""
+Verifies building a target with nothing succeeds.
+"""
+
+import os
+import sys
+import TestGyp
+
+test = TestGyp.TestGyp()
+test.run_gyp('empty-target.gyp')
+test.build('empty-target.gyp', target='empty_target')
+test.pass_test()