enable precompiled headers with g++

The original author of gch.py didn't understand how str.strip worked

Author: RedBeard0531

SConstruct

@@ -751,11 +751,9 @@ if nix:
         env.Append( CPPDEFINES=["USE_GDBSERVER"] )
 
     # pre-compiled headers
-    if False and 'Gch' in dir( env ):
+    if 'Gch' in dir( env ):
         print( "using precompiled headers" )
         env['Gch'] = env.Gch( [ "pch.h" ] )[0]
-        #Depends( "pch.o" , "pch.h.gch" )
-        #SideEffect( "dummyGCHSideEffect" , "pch.h.gch" )
 
 if usev8:
     env.Append( CPPPATH=["../v8/include/"] )

gch.py

@@ -37,6 +37,9 @@
 def gen_suffix(env, sources):
     return sources[0].get_suffix() + env['GCHSUFFIX']
 
+def header_path(node):
+    path = node.path
+    return path[:-4] # strip final '.gch'
 
 GchShBuilder = SCons.Builder.Builder(action = GchShAction,
                                      source_scanner = SCons.Scanner.C.CScanner(),
@@ -54,7 +57,7 @@ def static_pch_emitter(target,source,env):
     deps = scanner(source[0], env, path)
 
     if env.has_key('Gch') and env['Gch']:
-        if env['Gch'].path.strip('.gch') in [x.path for x in deps]:
+        if header_path(env['Gch']) in [x.path for x in deps]:
             env.Depends(target, env['Gch'])
 
     return (target, source)
@@ -67,7 +70,7 @@ def shared_pch_emitter(target,source,env):
     deps = scanner(source[0], env, path)
 
     if env.has_key('GchSh') and env['GchSh']:
-        if env['GchSh'].path.strip('.gch') in [x.path for x in deps]:
+        if header_path(env['GchSh']) in [x.path for x in deps]:
             env.Depends(target, env['GchSh'])
     return (target, source)