1 files changed, 23 insertions, 12 deletions
diff --git a/src/Compile.hs b/src/Compile.hs
index f2063ee..bf7817a 100644
--- a/src/Compile.hs
+++ b/src/Compile.hs
@@ -8,7 +8,7 @@
 {-# LANGUAGE PolyKinds #-}
 {-# LANGUAGE TupleSections #-}
 {-# LANGUAGE TypeApplications #-}
-module Compile (compile) where
+module Compile (compile, compileStderr) where
 
 import Control.Applicative (empty)
 import Control.Monad (forM_, when, replicateM)
@@ -71,28 +71,30 @@ debugAllocs :: Bool; debugAllocs = toEnum 0
 -- | Emit extra C code that checks stuff
 emitChecks :: Bool; emitChecks = toEnum 0
 
+-- | Returns compiled function plus compilation output (warnings)
 compile :: SList STy env -> Ex env t
-        -> IO (SList Value env -> IO (Rep t))
+        -> IO (SList Value env -> IO (Rep t), String)
 compile = \env expr -> do
   codeID <- atomicModifyIORef' uniqueIdGenRef (\i -> (i + 1, i))
 
   let (source, offsets) = compileToString codeID env expr
   when debugPrintAST $ hPutStrLn stderr $ "Compiled AST: <<<\n" ++ ppExpr env expr ++ "\n>>>"
   when debugCSource $ hPutStrLn stderr $ "Generated C source: <<<\n\x1B[2m" ++ lineNumbers source ++ "\x1B[0m>>>"
-  lib <- buildKernel source "kernel"
+  (lib, compileOutput) <- buildKernel source "kernel"
 
   let result_type = typeOf expr
       result_size = sizeofSTy result_type
 
-  return $ \val -> do
-    allocaBytes (koResultOffset offsets + result_size) $ \ptr -> do
-      let args = zip (reverse (unSList Some (slistZip env val))) (koArgOffsets offsets)
-      serialiseArguments args ptr $ do
-        callKernelFun lib ptr
-        ok <- peekByteOff @Word8 ptr (koOkResOffset offsets)
-        when (ok /= 1) $
-          ioError (mkIOError userErrorType "fatal error detected during chad kernel execution (memory has been leaked)" Nothing Nothing)
-        deserialise result_type ptr (koResultOffset offsets)
+  let function val = do
+        allocaBytes (koResultOffset offsets + result_size) $ \ptr -> do
+          let args = zip (reverse (unSList Some (slistZip env val))) (koArgOffsets offsets)
+          serialiseArguments args ptr $ do
+            callKernelFun lib ptr
+            ok <- peekByteOff @Word8 ptr (koOkResOffset offsets)
+            when (ok /= 1) $
+              ioError (mkIOError userErrorType "fatal error detected during chad kernel execution (memory has been leaked)" Nothing Nothing)
+            deserialise result_type ptr (koResultOffset offsets)
+  return (function, compileOutput)
   where
     serialiseArguments :: [(Some (Product STy Value), Int)] -> Ptr () -> IO r -> IO r
     serialiseArguments ((Some (Product.Pair t (Value arg)), off) : args) ptr k =
@@ -100,6 +102,15 @@ compile = \env expr -> do
         serialiseArguments args ptr k
     serialiseArguments _ _ k = k
 
+-- | 'compile', but writes any produced C compiler output to stderr.
+compileStderr :: SList STy env -> Ex env t
+              -> IO (SList Value env -> IO (Rep t))
+compileStderr env expr = do
+  (fun, output) <- compile env expr
+  when (not (null output)) $
+    hPutStrLn stderr $ "[chad] Kernel compilation GCC output: <<<\n" ++ output ++ ">>>"
+  return fun
+
 
 data StructDecl = StructDecl
     String  -- ^ name