Build and use libraries locally in the nacl build, not requiring "partial SDK"

site_scons/site_tools/component_builders.py

 #!/usr/bin/python2.4
 # Copyright 2009, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 # notice, this list of conditions and the following disclaimer.
@@ skipping 115 matching lines @@
 
   # This supports a NaCl convention that was previously supported with a
   # modification to SCons.  Previously, EXTRA_LIBS was interpolated into LIBS
   # using the ${EXTRA_LIBS} syntax.  It appears, however, that SCons naturally
   # computes library dependencies before interpolation, so EXTRA_LIBS will not
   # be correctly depended upon if interpolated.  In the past, SCons was modified
   # to force interpolation before library dependencies were computed.  This new
   # approach allows us to use an unmodified version of SCons.
   # In general, the use of EXTRA_LIBS is discouraged.
   if 'EXTRA_LIBS' in env:
-    env['LIBS'] = env['EXTRA_LIBS'] + env['LIBS']
+    # The SubstList2 method expands and flattens so that scons will
+    # correctly know about the library dependencies in cases like
+    # EXTRA_LIBS=['${FOO_LIBS}', 'bar'].
+    env['LIBS'] = env.SubstList2('${EXTRA_LIBS}', '${LIBS}')
 
   # Call platform-specific component setup function, if any
   if env.get('COMPONENT_PLATFORM_SETUP'):
     env['COMPONENT_PLATFORM_SETUP'](env, builder_name)
 
   # Return the modified environment
   return env
 
 #------------------------------------------------------------------------------
 
@@ skipping 322 matching lines @@
     # raise Exception("Program name shouldn't have a suffix")
     prog_name = env.subst(prog_name)
     prog_name = prog_name[:-len(env['PROGSUFFIX'])]
 
   # Call env.Program()
   out_nodes = env.Program(prog_name, *args, **kwargs)
 
   # Add dependencies on includes
   env.Depends(out_nodes, env['INCLUDES'])
 
+  # Add dependencies on libraries marked as implicitly included in the link.
+  # These are libraries that are not passed on the command line, but are
+  # always linked in by the toolchain, i.e. startup files and -lc and such.
+  if 'IMPLICIT_LIBS' in env:
+    env.Depends(out_nodes, env['IMPLICIT_LIBS'])
+
   # Publish output
   env.Publish(prog_name, 'run', out_nodes[0])
   env.Publish(prog_name, 'debug', out_nodes[1:])
 
   # Add an alias to build the program to the right groups
   a = env.Alias(prog_name, out_nodes)
   for group in env['COMPONENT_PROGRAM_GROUPS']:
     SCons.Script.Alias(group, a)
 
   # Store list of components for this program
@@ skipping 139 matching lines @@
   # Add our target groups
   AddTargetGroup('all_libraries', 'libraries can be built')
   AddTargetGroup('all_programs', 'programs can be built')
   AddTargetGroup('all_test_programs', 'tests can be built')
   AddTargetGroup('all_packages', 'packages can be built')
   AddTargetGroup('run_all_tests', 'tests can be run')
   AddTargetGroup('run_disabled_tests', 'tests are disabled')
   AddTargetGroup('run_small_tests', 'small tests can be run')
   AddTargetGroup('run_medium_tests', 'medium tests can be run')
   AddTargetGroup('run_large_tests', 'large tests can be run')
-