From: Serge Pavlov <sepavloff@gmail.com>
Date: Tue, 16 Jul 2013 07:14:18 +0000 (+0000)
Subject: Limit number of bits in size representation so that bit size fit 64 bits.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=e8caa30d6124b915fb6bfb3fb2d0eb4857381d08;p=clang

Limit number of bits in size representation so that bit size fit 64 bits.
This fixes PR8256 and some others.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@186385 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/AST/Type.cpp b/lib/AST/Type.cpp
index af4ea09672..4068b2b898 100644
--- a/lib/AST/Type.cpp
+++ b/lib/AST/Type.cpp
@@ -111,11 +111,12 @@ unsigned ConstantArrayType::getNumAddressingBits(ASTContext &Context,
 unsigned ConstantArrayType::getMaxSizeBits(ASTContext &Context) {
   unsigned Bits = Context.getTypeSize(Context.getSizeType());
   
-  // GCC appears to only allow 63 bits worth of address space when compiling
-  // for 64-bit, so we do the same.
-  if (Bits == 64)
-    --Bits;
-  
+  // Limit the number of bits in size_t so that maximal bit size fits 64 bit
+  // integer (see PR8256).  We can do this as currently there is no hardware
+  // that supports full 64-bit virtual space.
+  if (Bits > 61)
+    Bits = 61;
+
   return Bits;
 }
 
diff --git a/test/Sema/array-size-64.c b/test/Sema/array-size-64.c
index f22e8e77d2..0e094bfa6b 100644
--- a/test/Sema/array-size-64.c
+++ b/test/Sema/array-size-64.c
@@ -2,6 +2,11 @@
 
 void f() {
   int a[2147483647U][2147483647U]; // expected-error{{array is too large}}
-  int b[1073741825U - 1U][2147483647U];
-  int c[18446744073709551615U/sizeof(int)/2];
+  int b[1073741825U - 1U][2147483647U]; // expected-error{{array is too large}}
 }
+
+void pr8256 () {
+  typedef char a[1LL<<61];  // expected-error {{array is too large}}
+  typedef char b[(long long)sizeof(a)-1];
+}
+
diff --git a/test/Sema/offsetof-64.c b/test/Sema/offsetof-64.c
index fb3d6e98d1..4a80dee2fc 100644
--- a/test/Sema/offsetof-64.c
+++ b/test/Sema/offsetof-64.c
@@ -2,7 +2,7 @@
 
 // PR15216
 // Don't crash when taking computing the offset of structs with large arrays.
-const unsigned long Size = (1l << 62);
+const unsigned long Size = (1l << 60);
 
 struct Chunk1 {
   char padding[Size];