[llvm-commits] [llvm-gcc-4.2] r108206 - /llvm-gcc-4.2/trunk/gcc/llvm-convert.cpp

[Eric Christopher]

Author: echristo
Date: Mon Jul 12 18:02:56 2010
New Revision: 108206

URL: http://llvm.org/viewvc/llvm-project?rev=108206&view=rev
Log:
Make sure that the requested alignment isn't greater than the stack alignment
for a vla - we won't adhere to it anyways so make it an error.

Fixes rdar://7506902

Modified:
    llvm-gcc-4.2/trunk/gcc/llvm-convert.cpp

Modified: llvm-gcc-4.2/trunk/gcc/llvm-convert.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm-gcc-4.2/trunk/gcc/llvm-convert.cpp?rev=108206&r1=108205&r2=108206&view=diff
==============================================================================
--- llvm-gcc-4.2/trunk/gcc/llvm-convert.cpp (original)
+++ llvm-gcc-4.2/trunk/gcc/llvm-convert.cpp Mon Jul 12 18:02:56 2010
@@ -39,6 +39,7 @@
 #include "llvm/Target/TargetLowering.h"
 #include "llvm/Target/TargetData.h"
 #include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/TargetFrameInfo.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/ADT/DenseMap.h"
 
@@ -1755,6 +1756,15 @@
   if (isGimpleTemporary(decl))
     return;
 
+  /* If this is a vla type and we requested an alignment greater than the stack
+     alignment, error out since we're not going to dynamically realign
+     variable length array allocations.  We're placing this here instead of
+     later in case it's a relatively unused variable.  */
+  if (TREE_CODE (type) == ARRAY_TYPE && C_TYPE_VARIABLE_SIZE (type) &&
+      DECL_ALIGN(decl)/8u > TheTarget->getFrameInfo()->getStackAlignment())
+        error ("alignment for %q+D is greater than the stack alignment, "
+               "we cannot guarantee the alignment.", decl);
+
   // If this is just the rotten husk of a variable that the gimplifier
   // eliminated all uses of, but is preserving for debug info, ignore it.
   if (TREE_CODE(decl) == VAR_DECL && DECL_VALUE_EXPR(decl))