[cfe-commits] r138627 - in /cfe/trunk: lib/CodeGen/CGExprAgg.cpp lib/CodeGen/CGExprCXX.cpp lib/CodeGen/CGValue.h test/CodeGenCXX/conditional-expr-lvalue.cpp

[John McCall]

Author: rjmccall
Date: Fri Aug 26 02:31:35 2011
New Revision: 138627

URL: http://llvm.org/viewvc/llvm-project?rev=138627&view=rev
Log:
Since the 'is aliased' bit is critical for correctness in C++, it
really shouldn't be optional.  Fix the remaining place where a
temporary was being passed as potentially-aliased memory.

Fixes PR10756.


Modified:
    cfe/trunk/lib/CodeGen/CGExprAgg.cpp
    cfe/trunk/lib/CodeGen/CGExprCXX.cpp
    cfe/trunk/lib/CodeGen/CGValue.h
    cfe/trunk/test/CodeGenCXX/conditional-expr-lvalue.cpp

Modified: cfe/trunk/lib/CodeGen/CGExprAgg.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGExprAgg.cpp?rev=138627&r1=138626&r2=138627&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGExprAgg.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGExprAgg.cpp Fri Aug 26 02:31:35 2011
@@ -444,7 +444,8 @@
         LValue RHS = CGF.EmitLValue(E->getRHS());
         LValue LHS = CGF.EmitLValue(E->getLHS());
         Dest = AggValueSlot::forLValue(LHS, AggValueSlot::IsDestructed,
-                                       needsGC(E->getLHS()->getType()));
+                                       needsGC(E->getLHS()->getType()),
+                                       AggValueSlot::IsAliased);
         EmitFinalDestCopy(E, RHS, true);
         return;
       }
@@ -469,7 +470,8 @@
     // Codegen the RHS so that it stores directly into the LHS.
     AggValueSlot LHSSlot =
       AggValueSlot::forLValue(LHS, AggValueSlot::IsDestructed, 
-                              needsGC(E->getLHS()->getType()));
+                              needsGC(E->getLHS()->getType()),
+                              AggValueSlot::IsAliased);
     CGF.EmitAggExpr(E->getRHS(), LHSSlot, false);
     EmitFinalDestCopy(E, LHS, true);
   }
@@ -1052,7 +1054,8 @@
   llvm::Value *Temp = CreateMemTemp(E->getType());
   LValue LV = MakeAddrLValue(Temp, E->getType());
   EmitAggExpr(E, AggValueSlot::forLValue(LV, AggValueSlot::IsNotDestructed,
-                                         AggValueSlot::DoesNotNeedGCBarriers));
+                                         AggValueSlot::DoesNotNeedGCBarriers,
+                                         AggValueSlot::IsNotAliased));
   return LV;
 }
 

Modified: cfe/trunk/lib/CodeGen/CGExprCXX.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGExprCXX.cpp?rev=138627&r1=138626&r2=138627&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGExprCXX.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGExprCXX.cpp Fri Aug 26 02:31:35 2011
@@ -705,7 +705,8 @@
     AggValueSlot Slot
       = AggValueSlot::forAddr(NewPtr, AllocType.getQualifiers(),
                               AggValueSlot::IsDestructed,
-                              AggValueSlot::DoesNotNeedGCBarriers);
+                              AggValueSlot::DoesNotNeedGCBarriers,
+                              AggValueSlot::IsNotAliased);
     CGF.EmitAggExpr(Init, Slot);
   }
 }

Modified: cfe/trunk/lib/CodeGen/CGValue.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGValue.h?rev=138627&r1=138626&r2=138627&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGValue.h (original)
+++ cfe/trunk/lib/CodeGen/CGValue.h Fri Aug 26 02:31:35 2011
@@ -383,7 +383,7 @@
   static AggValueSlot forAddr(llvm::Value *addr, Qualifiers quals,
                               IsDestructed_t isDestructed,
                               NeedsGCBarriers_t needsGC,
-                              IsAliased_t isAliased = IsAliased,
+                              IsAliased_t isAliased,
                               IsZeroed_t isZeroed = IsNotZeroed) {
     AggValueSlot AV;
     AV.Addr = addr;
@@ -397,7 +397,7 @@
 
   static AggValueSlot forLValue(LValue LV, IsDestructed_t isDestructed,
                                 NeedsGCBarriers_t needsGC,
-                                IsAliased_t isAliased = IsAliased,
+                                IsAliased_t isAliased,
                                 IsZeroed_t isZeroed = IsNotZeroed) {
     return forAddr(LV.getAddress(), LV.getQuals(),
                    isDestructed, needsGC, isAliased, isZeroed);

Modified: cfe/trunk/test/CodeGenCXX/conditional-expr-lvalue.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/conditional-expr-lvalue.cpp?rev=138627&r1=138626&r2=138627&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCXX/conditional-expr-lvalue.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/conditional-expr-lvalue.cpp Fri Aug 26 02:31:35 2011
@@ -5,3 +5,16 @@
   
   (flag ? a : b) = 3;
 }
+
+// PR10756
+namespace test0 {
+  struct A {
+    A(const A &);
+    A &operator=(const A &);
+    A sub() const;
+    void foo() const;
+  };
+  void foo(bool cond, const A &a) {
+    (cond ? a : a.sub()).foo();
+  }
+}