Fix LLVM version check yet again

There were two problems with LLVM version checking:

- The parser would only parse x and x.y formatted versions. E.g. 1.2.3
  would be rejected.

- The version check was too strict and would reject x.y formatted
  versions. E.g. when we support version 7 it'd reject 7.0 ("LLVM
  version 7.0") and only accept 7 ("LLVM version 7").

We now parse versions with arbitrarily deep minor numbering (x.y.z.t...)
and accept versions as long as the major version matches the supported
version (e.g. 7.1, 7.1.2, 7.1.2.3 ...).

1 files changed, 5 insertions, 13 deletions

diff --git a/compiler/main/SysTools/Tasks.hs b/compiler/main/SysTools/Tasks.hs
index eeaadfa5b8..9ee3ba467c 100644
--- a/compiler/main/SysTools/Tasks.hs
+++ b/compiler/main/SysTools/Tasks.hs
@@ -16,14 +16,13 @@ import Outputable
 import GHC.Platform
 import Util
 
-import Data.Char
 import Data.List
 
 import System.IO
 import System.Process
 import GhcPrelude
 
-import LlvmCodeGen.Base (LlvmVersion (..), llvmVersionStr, supportedLlvmVersion)
+import LlvmCodeGen.Base (LlvmVersion, llvmVersionStr, supportedLlvmVersion, parseLlvmVersion)
 
 import SysTools.Process
 import SysTools.Info
@@ -209,7 +208,7 @@ figureLlvmVersion dflags = traceToolCommand dflags "llc" $ do
       -- of the options they've specified. llc doesn't care what other
       -- options are specified when '-version' is used.
       args' = args ++ ["-version"]
-  ver <- catchIO (do
+  catchIO (do
               (pin, pout, perr, _) <- runInteractiveProcess pgm args'
                                               Nothing Nothing
               {- > llc -version
@@ -219,18 +218,12 @@ figureLlvmVersion dflags = traceToolCommand dflags "llc" $ do
               -}
               hSetBinaryMode pout False
               _     <- hGetLine pout
-              vline <- dropWhile (not . isDigit) `fmap` hGetLine pout
-              v     <- case span (/= '.') vline of
-                        ("",_)  -> fail "no digits!"
-                        (x,"") -> return $ LlvmVersion (read x)
-                        (x,y) -> return $ LlvmVersionOld
-                                            (read x)
-                                            (read $ takeWhile isDigit $ drop 1 y)
-
+              vline <- hGetLine pout
+              let mb_ver = parseLlvmVersion vline
               hClose pin
               hClose pout
               hClose perr
-              return $ Just v
+              return mb_ver
             )
             (\err -> do
                 debugTraceMsg dflags 2
@@ -242,7 +235,6 @@ figureLlvmVersion dflags = traceToolCommand dflags "llc" $ do
                           text ("Make sure you have installed LLVM " ++
                                 llvmVersionStr supportedLlvmVersion) ]
                 return Nothing)
-  return ver
 
 
 runLink :: DynFlags -> [Option] -> IO ()