Adds support for the library_dirs key, which appears in the documentation but was never actually im…

pylib/gyp/generator/ninja.py

Index: pylib/gyp/generator/ninja.py
===================================================================
--- pylib/gyp/generator/ninja.py	(revision 1656)
+++ pylib/gyp/generator/ninja.py	(working copy)
@@ -773,6 +773,20 @@
         [QuoteShellArgument('-I' + self.GypPathToNinja(i, env), self.flavor)
          for i in include_dirs])
 
+    library_dirs = config.get('library_dirs', [])
+    if self.flavor == 'win':
+      library_dirs = [
+          self.msvs_settings.ConvertVSMacros(library_dir, config_name)
+          for library_dir in library_dirs]
+      self.WriteVariableList('libdirs',
+           [QuoteShellArgument('-LIBPATH:' + self.GypPathToNinja(l),
+                               self.flavor)
+           for l in library_dirs])
+    else:
+      self.WriteVariableList('libdirs',
+           [QuoteShellArgument('-L' + self.GypPathToNinja(l), self.flavor)
+           for l in library_dirs])
+
     pch_commands = precompiled_header.GetPchBuildCommands()
     if self.flavor == 'mac':
       self.WriteVariableList('cflags_pch_c',
@@ -1427,12 +1441,12 @@
   master_ninja.rule('solink' + rule_name_suffix,
                     description=dlldesc, command=dllcmd,
                     rspfile='$dll.rsp',
-                    rspfile_content='$libs $in_newline $ldflags',
+                    rspfile_content='$libdirs $libs $in_newline $ldflags',
                     restat=True)
   master_ninja.rule('solink_module' + rule_name_suffix,
                     description=dlldesc, command=dllcmd,
                     rspfile='$dll.rsp',
-                    rspfile_content='$libs $in_newline $ldflags',
+                    rspfile_content='$libdirs $libs $in_newline $ldflags',
                     restat=True)
   # Note that ldflags goes at the end so that it has the option of
   # overriding default settings earlier in the command line.
@@ -1444,7 +1458,7 @@
                     description='LINK%s $out' % rule_name_suffix.upper(),
                     command=exe_cmd,
                     rspfile='$out.rsp',
-                    rspfile_content='$in_newline $libs $ldflags')
+                    rspfile_content='$in_newline $libdirs $libs $ldflags')
 
 
 def GenerateOutputForConfig(target_list, target_dicts, data, params,
@@ -1689,20 +1703,21 @@
       restat=True,
       command=(mtime_preserving_solink_base % {
           'suffix': '-Wl,--whole-archive $in $solibs -Wl,--no-whole-archive '
-          '$libs'}),
+          '$libdirs $libs'}),
       pool='link_pool')
     master_ninja.rule(
       'solink_module',
       description='SOLINK(module) $lib',
       restat=True,
       command=(mtime_preserving_solink_base % {
-          'suffix': '-Wl,--start-group $in $solibs -Wl,--end-group $libs'}),
+          'suffix': '-Wl,--start-group $in $solibs -Wl,--end-group '
+          '$libdirs $libs'}),

[Nico, 2013/07/02 01:20:15]

Is it possible to just add these flags to the "libs" variable? This way ninja
needs to do fewer variable lookups. Have you benchmarked if this change has an
impact on empty build times for chrome?

       pool='link_pool')
     master_ninja.rule(
       'link',
       description='LINK $out',
       command=('$ld $ldflags -o $out '
-               '-Wl,--start-group $in $solibs -Wl,--end-group $libs'),
+               '-Wl,--start-group $in $solibs -Wl,--end-group $libdirs $libs'),
       pool='link_pool')
   elif flavor == 'win':
     master_ninja.rule(
@@ -1769,21 +1784,21 @@
       description='SOLINK $lib, POSTBUILDS',
       restat=True,
       command=(mtime_preserving_solink_base % {
-          'suffix': '$in $solibs $libs$postbuilds'}),
+          'suffix': '$in $solibs $libdirs $libs$postbuilds'}),
       pool='link_pool')
     master_ninja.rule(
       'solink_module',
       description='SOLINK(module) $lib, POSTBUILDS',
       restat=True,
       command=(mtime_preserving_solink_base % {
-          'suffix': '$in $solibs $libs$postbuilds'}),
+          'suffix': '$in $solibs $libdirs $libs$postbuilds'}),
       pool='link_pool')
 
     master_ninja.rule(
       'link',
       description='LINK $out, POSTBUILDS',
       command=('$ld $ldflags -o $out '
-               '$in $solibs $libs$postbuilds'),
+               '$in $solibs $libdirs $libs$postbuilds'),
       pool='link_pool')
     master_ninja.rule(
       'infoplist',