ninja mac: Smarter dylib linking.

pylib/gyp/generator/ninja.py

Index: pylib/gyp/generator/ninja.py
===================================================================
--- pylib/gyp/generator/ninja.py	(revision 1425)
+++ pylib/gyp/generator/ninja.py	(working copy)
@@ -153,14 +153,16 @@
     """Return true if this is a target that can be linked against."""
     return self.type in ('static_library', 'shared_library')
 
-  def SharedLinkable(self):
+  def SharedLinkable(self, flavor):
     """Return true if this is a shared library/module."""
+    if flavor == 'win':

[Ami GONE FROM CHROMIUM, 2012/06/30 22:37:04]

I almost did this in my CL but couldn't justify this change without changing the
method name and didn't have a better name...

+      return False
     return self.type in ('shared_library', 'loadable_module')
 
   def PreActionInput(self, flavor):
     """Return the path, if any, that should be used as a dependency of
     any dependent action step."""
-    if self.SharedLinkable() and flavor not in ['mac', 'win']:
+    if self.SharedLinkable(flavor):
       return self.FinalOutput() + '.TOC'
     return self.FinalOutput() or self.preaction_stamp
 
@@ -840,7 +842,7 @@
             extra_link_deps |= set(target.component_objs)
           elif self.flavor == 'win' and target.import_lib:
             extra_link_deps.add(target.import_lib)
-          elif target.SharedLinkable() and self.flavor not in ['mac', 'win']:
+          elif target.SharedLinkable(self.flavor):
             solibs.add(target.binary)
             implicit_deps.add(target.binary + '.TOC')
           else:
@@ -895,7 +897,7 @@
         extra_bindings.append(('dll', output))
         extra_bindings.append(('implib', self.target.import_lib))
         output = [output, self.target.import_lib]
-      elif self.flavor != 'mac':
+      else:
         output = [output, output + '.TOC']
 
     if len(solibs):
@@ -1476,23 +1478,41 @@
       command='rm -f $out && '
               './gyp-mac-tool filter-libtool libtool -static -o $out $in'
               '$postbuilds')
+
+    # Record the public interface of $lib in $lib.TOC. See the corresponding
+    # comment in the posix section above for details.
+    mtime_preserving_solink_base = (
+        'if [ ! -e $lib -o ! -e ${lib}.TOC ]; then '
+        '%(solink)s && %(extract_toc)s > ${lib}.TOC; else '
+        '%(solink)s && %(extract_toc)s > ${lib}.tmp && '
+        'if ! cmp -s ${lib}.tmp ${lib}.TOC; then mv ${lib}.tmp ${lib}.TOC ; '
+        'fi; fi'
+        % { 'solink':
+              '$ld -shared $ldflags -o $lib %(suffix)s',
+            'extract_toc':
+              ('{ ' #readelf -d ${lib} | grep SONAME ; '
+               'nm -U -P ${lib} |cut -f1-2 -d\' \' |grep \'[A-Z]$$\'; }')})

[Ami GONE FROM CHROMIUM, 2012/06/30 22:37:04]

I don't know what this means, but FTR in the other thread Mark said:

For example, on the Mac, you’d want to consider the values in the LC_ID_DYLIB
load command to be part of the public API. That part is simple, but there’s also
LC_REEXPORT_DYLIB, which can get a little recursive.

+
     # TODO(thakis): The solink_module rule is likely wrong. Xcode seems to pass
     # -bundle -single_module here (for osmesa.so).
     master_ninja.rule(
       'solink',
-      description='SOLINK $out, POSTBUILDS',
-      command=('$ld -shared $ldflags -o $out '
-               '$in $libs$postbuilds'))
+      description='SOLINK $lib, POSTBUILDS',
+      restat=True,
+      command=(mtime_preserving_solink_base % {
+          'suffix': '$in $solibs $libs$postbuilds'}))
     master_ninja.rule(
       'solink_module',
-      description='SOLINK(module) $out, POSTBUILDS',
-      command=('$ld -shared $ldflags -o $out '
-               '$in $libs$postbuilds'))
+      description='SOLINK(module) $lib, POSTBUILDS',
+      restat=True,
+      command=(mtime_preserving_solink_base % {
+          'suffix': '$in $solibs $libs$postbuilds'}))
+
     master_ninja.rule(
       'link',
       description='LINK $out, POSTBUILDS',
       command=('$ld $ldflags -o $out '
-               '$in $libs$postbuilds'))
+               '$in $solibs $libs$postbuilds'))
     master_ninja.rule(
       'infoplist',
       description='INFOPLIST $out',