From 703bfe1afe5a3b2bcc26906413fa62686e6b1a42 Mon Sep 17 00:00:00 2001
From: Neil Brown <neil@twistedsquare.com>
Date: Tue, 19 May 2009 12:58:22 +0000
Subject: [PATCH] Added better error messages for problems with C types in the
 backend

---
 backends/GenerateC.hs      | 9 ++++++---
 backends/GenerateCBased.hs | 6 +++---
 2 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/backends/GenerateC.hs b/backends/GenerateC.hs
index 491ea73..239d3cc 100644
--- a/backends/GenerateC.hs
+++ b/backends/GenerateC.hs
@@ -701,7 +701,8 @@ cgenVariableWithAM checkValid v am fct
        ct <- call getCType m t am >>* fct
        -- Temporary, for debugging:
        -- tell ["/* ", show (snd iv), " , trying to get: ", show ct, " */"]
-       dressUp m iv ct
+       vtext <- showCode v
+       dressUp (m, "for variable: " ++ vtext) iv ct
   where
     m = findMeta v
 
@@ -724,13 +725,15 @@ cgenVariableWithAM checkValid v am fct
                   return (do tell ["("]
                              cast
                              tell ["(("]
-                             dressUp m (cg, ct) (Pointer $ Plain "mt_array_t")
+                             vtext <- showCode v
+                             dressUp (m, "for variable: " ++ vtext) (cg, ct) (Pointer $ Plain "mt_array_t")
                              tell [")->data))"]
                          , Pointer $ innerCT)
              _ -> inner v
     inner wholeV@(A.DirectedVariable m dir v)
       = do (cg, ctInner) <- inner v
-           let cg' = dressUp m (cg, ctInner) (stripPointers ctInner)
+           vtext <- showCode v
+           let cg' = dressUp (m, "for variable: " ++ vtext) (cg, ctInner) (stripPointers ctInner)
            t <- astTypeOf v
            wholeT <- astTypeOf wholeV
            ct <- call getCType m wholeT A.Original
diff --git a/backends/GenerateCBased.hs b/backends/GenerateCBased.hs
index 3000b4f..2935fa8 100644
--- a/backends/GenerateCBased.hs
+++ b/backends/GenerateCBased.hs
@@ -319,7 +319,7 @@ closeEnough _ _ = False
 
 -- Given some code to generate, and its type, and the type that you actually want,
 -- adds the required decorators.  Only pass it simplified types!
-dressUp :: Meta -> (CGen (), CType) -> CType -> CGen ()
+dressUp :: (Meta, String) -> (CGen (), CType) -> CType -> CGen ()
 dressUp _ (gen, t) t' | t `closeEnough` t' = gen
 --Every line after here is not close enough, so we know equality fails:
 dressUp m (gen, Pointer t) (Pointer t')
@@ -332,8 +332,8 @@ dressUp m (gen, t) (Pointer t')
   = dressUp m (tell ["&"] >> gen, t) t'
 dressUp m (gen, Pointer t) t'
   = dressUp m (tell ["*"] >> gen, t) t'
-dressUp m (gen, t) t'
-  = dieP m $ "Types cannot be brought together: " ++ show t ++ " and " ++ show t'
+dressUp (m, s) (gen, t) t'
+  = dieP m $ "Types cannot be brought together (" ++ s ++ "): " ++ show t ++ " and " ++ show t'
 
 genType :: A.Type -> CGen ()
 genType t = do ct <- call getCType emptyMeta t A.Original