[commit: ghc] master: Warn if using unsupported version of LLVM. (3a8f9ea)

[David Terei]

Repository : ssh://darcs.haskell.org//srv/darcs/ghc

On branch  : master

http://hackage.haskell.org/trac/ghc/changeset/3a8f9ea196fd663fb0c17da88a9c39aea2652dfe

>---------------------------------------------------------------

commit 3a8f9ea196fd663fb0c17da88a9c39aea2652dfe
Author: David Terei <davidterei at gmail.com>
Date:   Mon Jun 25 01:42:44 2012 -0700

    Warn if using unsupported version of LLVM.

>---------------------------------------------------------------

 compiler/llvmGen/LlvmCodeGen.hs      |   21 ++++++++++++++++++---
 compiler/llvmGen/LlvmCodeGen/Base.hs |   11 +++++++++--
 2 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/compiler/llvmGen/LlvmCodeGen.hs b/compiler/llvmGen/LlvmCodeGen.hs
index 4465957..62335b4 100644
--- a/compiler/llvmGen/LlvmCodeGen.hs
+++ b/compiler/llvmGen/LlvmCodeGen.hs
@@ -27,6 +27,7 @@ import UniqSupply
 import Util
 import SysTools ( figureLlvmVersion )
 
+import Control.Monad ( when )
 import Data.IORef ( writeIORef )
 import Data.Maybe ( fromMaybe )
 import System.IO
@@ -51,9 +52,7 @@ llvmCodeGen dflags h us cmms
         dumpIfSet_dyn dflags Opt_D_dump_llvm "LLVM Code" pprLlvmHeader
         bufh <- newBufHandle h
         Prt.bufLeftRender bufh $ withPprStyleDoc dflags (mkCodeStyle CStyle) pprLlvmHeader
-        ver  <- (fromMaybe defaultLlvmVersion) `fmap` figureLlvmVersion dflags
-        -- cache llvm version for later use
-        writeIORef (llvmVersion dflags) ver
+        ver  <- getLlvmVersion
         env' <- {-# SCC "llvm_datas_gen" #-}
                 cmmDataLlvmGens dflags bufh (setLlvmVer ver env) cdata []
         {-# SCC "llvm_procs_gen" #-}
@@ -61,6 +60,22 @@ llvmCodeGen dflags h us cmms
         bFlush bufh
         return  ()
 
+  where
+    -- | Handle setting up the LLVM version.
+    getLlvmVersion = do
+        ver <- (fromMaybe defaultLlvmVersion) `fmap` figureLlvmVersion dflags
+        -- cache llvm version for later use
+        writeIORef (llvmVersion dflags) ver
+        when (ver < minSupportLlvmVersion) $
+            errorMsg dflags (text "You are using an old version of LLVM that"
+                             <> text "isn't supported anymore!"
+                             $+$ text "We will try though...")
+        when (ver > maxSupportLlvmVersion) $
+            putMsg dflags (text "You are using a new version of LLVM that"
+                           <> text "hasn't been tested yet!"
+                           $+$ text "We will try though...")
+        return ver
+
 
 -- -----------------------------------------------------------------------------
 -- | Do LLVM code generation on all these Cmms data sections.
diff --git a/compiler/llvmGen/LlvmCodeGen/Base.hs b/compiler/llvmGen/LlvmCodeGen/Base.hs
index 2239dbb..19ca511 100644
--- a/compiler/llvmGen/LlvmCodeGen/Base.hs
+++ b/compiler/llvmGen/LlvmCodeGen/Base.hs
@@ -9,7 +9,8 @@ module LlvmCodeGen.Base (
         LlvmCmmDecl, LlvmBasicBlock,
         LlvmUnresData, LlvmData, UnresLabel, UnresStatic,
 
-        LlvmVersion, defaultLlvmVersion,
+        LlvmVersion, defaultLlvmVersion, minSupportLlvmVersion,
+        maxSupportLlvmVersion,
 
         LlvmEnv, initLlvmEnv, clearVars, varLookup, varInsert,
         funLookup, funInsert, getLlvmVer, setLlvmVer, getLlvmPlatform,
@@ -144,7 +145,13 @@ type LlvmVersion = Int
 
 -- | The LLVM Version we assume if we don't know
 defaultLlvmVersion :: LlvmVersion
-defaultLlvmVersion = 28
+defaultLlvmVersion = 30
+
+minSupportLlvmVersion :: LlvmVersion
+minSupportLlvmVersion = 28
+
+maxSupportLlvmVersion :: LlvmVersion
+maxSupportLlvmVersion = 31
 
 -- ----------------------------------------------------------------------------
 -- * Environment Handling