From: Richard Trieu <rtrieu@google.com>
Date: Thu, 16 May 2013 01:46:09 +0000 (+0000)
Subject: Return QualType() when a too large array is attempting to be created.  This
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=ee2f8f2f7c4eacfa305a29fcd916d63c650ca847;p=clang

Return QualType() when a too large array is attempting to be created.  This
prevents further errors and some overflows in size calculations.
One overflow was previously triggering an assert.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@181970 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Sema/SemaType.cpp b/lib/Sema/SemaType.cpp
index 0959f7d66a..e4eafc5ee7 100644
--- a/lib/Sema/SemaType.cpp
+++ b/lib/Sema/SemaType.cpp
@@ -1549,10 +1549,12 @@ QualType Sema::BuildArrayType(QualType T, ArrayType::ArraySizeModifier ASM,
       // Is the array too large?
       unsigned ActiveSizeBits
         = ConstantArrayType::getNumAddressingBits(Context, T, ConstVal);
-      if (ActiveSizeBits > ConstantArrayType::getMaxSizeBits(Context))
+      if (ActiveSizeBits > ConstantArrayType::getMaxSizeBits(Context)) {
         Diag(ArraySize->getLocStart(), diag::err_array_too_large)
           << ConstVal.toString(10)
           << ArraySize->getSourceRange();
+        return QualType();
+      }
     }
 
     T = Context.getConstantArrayType(T, ConstVal, ASM, Quals);
diff --git a/test/Sema/offsetof-64.c b/test/Sema/offsetof-64.c
index 1cabec9842..fb3d6e98d1 100644
--- a/test/Sema/offsetof-64.c
+++ b/test/Sema/offsetof-64.c
@@ -1,15 +1,22 @@
 // RUN: %clang_cc1 -fsyntax-only -verify %s -triple x86_64-linux-gnu
-// expected-no-diagnostics
 
 // PR15216
 // Don't crash when taking computing the offset of structs with large arrays.
 const unsigned long Size = (1l << 62);
 
-struct Chunk {
+struct Chunk1 {
   char padding[Size];
   char more_padding[1][Size];
   char data;
 };
 
-int test1 = __builtin_offsetof(struct Chunk, data);
+int test1 = __builtin_offsetof(struct Chunk1, data);
 
+struct Chunk2 {
+  char padding[Size][Size][Size];  // expected-error 2{{array is too large}}
+  char data;
+};
+
+// FIXME: Remove this error when the constant evaluator learns to
+// ignore bad types.
+int test2 = __builtin_offsetof(struct Chunk2, data);  // expected-error{{initializer element is not a compile-time constant}}