From: Tim Chevalier <chevalier@alum.wellesley.edu>
Date: Thu, 15 May 2008 23:04:05 +0000 (+0000)
Subject: don't rebuild PrimEnv if genprimopcode and/or primops.txt don't exist
X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=commitdiff_plain;h=bca61eb59ad615793175e4d1a3de7a243b41de44

don't rebuild PrimEnv if genprimopcode and/or primops.txt don't exist

This helps if, for example, you want to build the Core tools on a machine that doesn't have a GHC build tree, and have a pre-existing copy of PrimEnv.hs.
---

diff --git a/utils/ext-core/Setup.lhs b/utils/ext-core/Setup.lhs
index bdcd784..806e9ff 100644
--- a/utils/ext-core/Setup.lhs
+++ b/utils/ext-core/Setup.lhs
@@ -28,6 +28,10 @@ Mostly snarfed from ghc-prim's Setup.hs.
 \begin{code}
 type Hook a = PackageDescription -> LocalBuildInfo -> UserHooks -> a -> IO ()
 
+
+-- Hack: If PrimEnv.hs exists *and* genprimopcode or
+-- primops.txt doesn't exist, don't rebuild PrimEnv.hs
+
 build_primitive_sources :: Hook a -> Hook a
 build_primitive_sources f pd lbi uhs x
  = do when (compilerFlavor (compiler lbi) == GHC) $ do
@@ -37,10 +41,14 @@ build_primitive_sources f pd lbi uhs x
                                   "primops.txt"]
               primhs = joinPath ["Language", "Core", "PrimEnv.hs"]
               primhs_tmp = addExtension primhs "tmp"
-          maybeExit $ system (genprimopcode ++ " --make-ext-core-source < "
+          primEnvExists <- doesFileExist primhs
+          genprimopcodeExists <- doesFileExist genprimopcode
+          primopsExists <- doesFileExist primops
+          unless (primEnvExists && !genprimopcodeExists && !primopsExists) do
+             maybeExit $ system (genprimopcode ++ " --make-ext-core-source < "
                            ++ primops ++ " > " ++ primhs_tmp)
-          maybeUpdateFile primhs_tmp primhs
-          maybeExit $ system ("make -C lib/GHC_ExtCore")
+             maybeUpdateFile primhs_tmp primhs
+             maybeExit $ system ("make -C lib/GHC_ExtCore")
       f pd lbi uhs x
 
 -- Replace a file only if the new version is different from the old.