[cfe-commits] r85157 - in /cfe/trunk: lib/AST/ExprConstant.cpp test/CodeGen/object-size.c

[Mike Stump]

Author: mrs
Date: Mon Oct 26 16:38:39 2009
New Revision: 85157

URL: http://llvm.org/viewvc/llvm-project?rev=85157&view=rev
Log:
__builtin_object_size refinements.  When we run out of object, be sure
to clamp at 0 bytes left.  WIP.

Modified:
    cfe/trunk/lib/AST/ExprConstant.cpp
    cfe/trunk/test/CodeGen/object-size.c

Modified: cfe/trunk/lib/AST/ExprConstant.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/ExprConstant.cpp?rev=85157&r1=85156&r2=85157&view=diff

==============================================================================
--- cfe/trunk/lib/AST/ExprConstant.cpp (original)
+++ cfe/trunk/lib/AST/ExprConstant.cpp Mon Oct 26 16:38:39 2009
@@ -884,7 +884,11 @@
         if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(LVBase)) {
           if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl())) {
             uint64_t Size = Info.Ctx.getTypeSize(VD->getType()) / 8;
-            Size -= Base.Val.getLValueOffset();
+            uint64_t Offset = Base.Val.getLValueOffset();
+            if (Offset <= Size)
+              Size -= Base.Val.getLValueOffset();
+            else
+              Size = 0;
             return Success(Size, E);
           }
         }

Modified: cfe/trunk/test/CodeGen/object-size.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/object-size.c?rev=85157&r1=85156&r2=85157&view=diff

==============================================================================
--- cfe/trunk/test/CodeGen/object-size.c (original)
+++ cfe/trunk/test/CodeGen/object-size.c Mon Oct 26 16:38:39 2009
@@ -21,13 +21,29 @@
   strcpy(gbuf, "Hi there");
 }
 
+void test3() {
+  // CHECK:       movabsq $0, %rdx
+  // CHECK-NEXT:  movq    %rax, %rdi
+  // CHECK-NEXT:  movq    %rcx, %rsi
+  // CHECK-NEXT:  call    ___strcpy_chk
+  strcpy(&gbuf[100], "Hi there");
+}
+
 void test4() {
+  // CHECK:       movabsq $0, %rdx
+  // CHECK-NEXT:  movq    %rax, %rdi
+  // CHECK-NEXT:  movq    %rcx, %rsi
+  // CHECK-NEXT:  call    ___strcpy_chk
+  strcpy((char*)(void*)&gbuf[-1], "Hi there");
+}
+
+void test5() {
   // CHECK:       call    ___inline_strcpy_chk
-  strcpy(gp, "Hi");
+  strcpy(gp, "Hi there");
 }
 
-void test3() {
+void test6() {
   int i;
   // CHECK:       call    ___inline_strcpy_chk
-  strcpy((++i, gbuf), "Hi");
+  strcpy((++i, gbuf), "Hi there");
 }