Fix LLVM version check yet againwip/backport-T16912

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 ...).

(cherry picked from commit bf9dfe1ca32270f5e946e0f8ac1bb97184de6e4c)

1 files changed, 5 insertions, 5 deletions

diff --git a/compiler/main/DriverPipeline.hs b/compiler/main/DriverPipeline.hs
index ef6152430d..bf79ea5d02 100644
--- a/compiler/main/DriverPipeline.hs
+++ b/compiler/main/DriverPipeline.hs
@@ -56,7 +56,7 @@ import StringBuffer     ( hGetStringBuffer, hPutStringBuffer )
 import BasicTypes       ( SuccessFlag(..) )
 import Maybes           ( expectJust )
 import SrcLoc
-import LlvmCodeGen      ( LlvmVersion (..), llvmFixupAsm )
+import LlvmCodeGen      ( llvmFixupAsm, llvmVersionList )
 import MonadUtils
 import Platform
 import TcRnTypes
@@ -2170,10 +2170,10 @@ doCpp dflags raw input_fn output_fn = do
 getBackendDefs :: DynFlags -> IO [String]
 getBackendDefs dflags | hscTarget dflags == HscLlvm = do
     llvmVer <- figureLlvmVersion dflags
-    return $ case llvmVer of
-               Just (LlvmVersion n) -> [ "-D__GLASGOW_HASKELL_LLVM__=" ++ format (n,0) ]
-               Just (LlvmVersionOld m n) -> [ "-D__GLASGOW_HASKELL_LLVM__=" ++ format (m,n) ]
-               _      -> []
+    return $ case fmap llvmVersionList llvmVer of
+               Just [m] -> [ "-D__GLASGOW_HASKELL_LLVM__=" ++ format (m,0) ]
+               Just (m:n:_) -> [ "-D__GLASGOW_HASKELL_LLVM__=" ++ format (m,n) ]
+               _ -> []
   where
     format (major, minor)
       | minor >= 100 = error "getBackendDefs: Unsupported minor version"