make: remove hacks used for shared-object builds

pylib/gyp/generator/make.py

 #!/usr/bin/python
 
 # Copyright (c) 2011 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.
 
 # Notes:
 #
 # This is all roughly based on the Makefile system used by the Linux
 # kernel, but is a non-recursive make -- we put the entire dependency
@@ skipping 190 matching lines @@
 # send stderr to /dev/null to ignore messages when linking directories.
 cmd_copy = ln -f $< $@ 2>/dev/null || cp -af $< $@
 
 # Due to circular dependencies between libraries :(, we wrap the
 # special "figure out circular dependencies" flags around the entire
 # input list during linking.
 quiet_cmd_link = LINK($(TOOLSET)) $@
 cmd_link = $(LINK.$(TOOLSET)) $(GYP_LDFLAGS) $(LDFLAGS.$(TOOLSET)) -o $@ -Wl,--start-group $(filter-out FORCE_DO_CMD, $^) -Wl,--end-group $(LIBS)
 
 # Shared-object link (for generating .so).
-# Set SONAME to the library filename so our binaries don't reference the local,
-# absolute paths used on the link command-line.
-# TODO: perhaps this can share with the LINK command above?
+# - Set SONAME to the library filename so our binaries don't reference
+# the local, absolute paths used on the link command-line.
+# - Use --whole-archive so that the .a files we combine end up in the public
+# API of the shared object.  (Note that --whole-archive is incompatible with
+# the --start-group used in normal linking.)
 quiet_cmd_solink = SOLINK($(TOOLSET)) $@
-cmd_solink = $(LINK.$(TOOLSET)) -shared $(GYP_LDFLAGS) $(LDFLAGS.$(TOOLSET)) -Wl,-soname=$(@F) -o $@ -Wl,--start-group $(filter-out FORCE_DO_CMD, $^) -Wl,--end-group $(LIBS)
+cmd_solink = $(LINK.$(TOOLSET)) -shared $(GYP_LDFLAGS) $(LDFLAGS.$(TOOLSET)) -Wl,-soname=$(@F) -o $@ -Wl,--whole-archive $(filter-out FORCE_DO_CMD, $^) -Wl,--no-whole-archive $(LIBS)

[Michael Moss, 2011/05/02 22:39:28]

Is --whole-archive advisable for all types of shared objects? For instance, what
about loadable-modules? This may be what we want for Chrome components, but will
it add unwanted bloat in the general case?

 """
 r"""
 # Define an escape_quotes function to escape single quotes.
 # This allows us to handle quotes properly as long as we always use
 # use single quotes and escape_quotes.
 escape_quotes = $(subst ','\'',$(1))
 # This comment is here just to include a ' to unconfuse syntax highlighting.
 # Define an escape_vars function to escape '$' variable syntax.
 # This allows us to read/write command lines with shell variables (e.g.
 # $LD_LIBRARY_PATH), without triggering make substitution.
@@ skipping 262 matching lines @@
   """Convert a path to its source directory form."""
   if '$(' in path:
     return path
   if os.path.isabs(path):
     return path
   return srcdir_prefix + path
 
 
 # Map from qualified target to path to output.
 target_outputs = {}
-# Map from qualified target to a list of all linker dependencies,
-# transitively expanded.
-# Used in building shared-library-based executables.
+# Map from qualified target to a list of linkable outputs.  A subset
+# of target_outputs.  E.g. when mybinary depends on liba, we want to
+# include liba in the linker line; when otherbinary depends on
+# mybinary, we just want to build mybinary first.
 target_link_deps = {}
 
 
 class MakefileWriter:
   """MakefileWriter packages up the writing of one target-specific foobar.mk.
 
   Its only real entry point is Write(), and is mostly used for namespacing.
   """
 
   def __init__(self):
@@ skipping 83 matching lines @@
         self.WriteLn('# End of this set of suffix rules')
 
 
     self.WriteTarget(spec, configs, deps,
                      extra_link_deps + link_deps, extra_outputs, part_of_all)
 
     # Update global list of target outputs, used in dependency tracking.
     target_outputs[qualified_target] = install_path
 
     # Update global list of link dependencies.
-    if self.type == 'static_library':
+    if self.type in ('static_library', 'shared_library'):
       target_link_deps[qualified_target] = [self.output]
-    elif self.type == 'shared_library':
-      # Anyone that uses us transitively depend on all of our link
-      # dependencies.
-      target_link_deps[qualified_target] = [self.output] + link_deps
 
     self.fp.close()
 
 
   def WriteSubMake(self, output_filename, makefile_path, targets, build_dir):
     """Write a "sub-project" Makefile.
 
     This is a small, wrapper Makefile that calls the top-level Makefile to build
     the targets from a single gyp file (i.e. a sub-project).
 
@@ skipping 805 matching lines @@
   # Add a check to make sure we tried to process all the .d files.
   all_deps += """
   ifneq ($(word %(last)d,$(d_files)),)
     $(error Found unprocessed dependency files (gyp didn't generate enough rules!))
   endif
 """ % { 'last': ((num_outputs / 1000) + 1) * 1000 + 1 }
 
   root_makefile.write(SHARED_FOOTER % { 'generate_all_deps': all_deps })
 
   root_makefile.close()