diff options
| -rw-r--r-- | compiler/GHC/CmmToLlvm/Base.hs | 20 |
1 files changed, 16 insertions, 4 deletions
diff --git a/compiler/GHC/CmmToLlvm/Base.hs b/compiler/GHC/CmmToLlvm/Base.hs index 33592092de..390ba4c55a 100644 --- a/compiler/GHC/CmmToLlvm/Base.hs +++ b/compiler/GHC/CmmToLlvm/Base.hs @@ -58,7 +58,7 @@ import GHC.Utils.Logger import Data.Maybe (fromJust) import Control.Monad (ap) -import Data.List (sortBy, groupBy) +import Data.List (sortBy, groupBy, isPrefixOf) import Data.Ord (comparing) -- ---------------------------------------------------------------------------- @@ -504,6 +504,12 @@ generateExternDecls = do modifyEnv $ \env -> env { envAliases = emptyUniqSet } return (concat defss, []) +-- | Is a variable one of the special @$llvm@ globals? +isBuiltinLlvmVar :: LlvmVar -> Bool +isBuiltinLlvmVar (LMGlobalVar lbl _ _ _ _ _) = + "$llvm" `isPrefixOf` unpackFS lbl +isBuiltinLlvmVar _ = False + -- | Here we take a global variable definition, rename it with a -- @$def@ suffix, and generate the appropriate alias. aliasify :: LMGlobal -> LlvmM [LMGlobal] @@ -511,8 +517,9 @@ aliasify :: LMGlobal -> LlvmM [LMGlobal] -- Here we obtain the indirectee's precise type and introduce -- fresh aliases to both the precise typed label (lbl$def) and the i8* -- typed (regular) label of it with the matching new names. -aliasify (LMGlobal (LMGlobalVar lbl ty@LMAlias{} link sect align Alias) - (Just orig)) = do +aliasify (LMGlobal var@(LMGlobalVar lbl ty@LMAlias{} link sect align Alias) + (Just orig)) + | not $ isBuiltinLlvmVar var = do let defLbl = llvmDefLabel lbl LMStaticPointer (LMGlobalVar origLbl _ oLnk Nothing Nothing Alias) = orig defOrigLbl = llvmDefLabel origLbl @@ -525,7 +532,8 @@ aliasify (LMGlobal (LMGlobalVar lbl ty@LMAlias{} link sect align Alias) pure [ LMGlobal (LMGlobalVar defLbl ty link sect align Alias) (Just defOrig) , LMGlobal (LMGlobalVar lbl i8Ptr link sect align Alias) (Just orig') ] -aliasify (LMGlobal var val) = do +aliasify (LMGlobal var val) + | not $ isBuiltinLlvmVar var = do let LMGlobalVar lbl ty link sect align const = var defLbl = llvmDefLabel lbl @@ -543,6 +551,7 @@ aliasify (LMGlobal var val) = do return [ LMGlobal defVar val , LMGlobal aliasVar (Just aliasVal) ] +aliasify global = pure [global] -- Note [Llvm Forward References] -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ @@ -601,3 +610,6 @@ aliasify (LMGlobal var val) = do -- away with casting the alias to the desired type in @getSymbolPtr@ -- and instead just emit a reference to the definition symbol directly. -- This is the @Just@ case in @getSymbolPtr@. +-- +-- Note that we must take care not to turn LLVM's builtin variables into +-- aliases (e.g. $llvm.global_ctors) since this confuses LLVM. |