[cfe-commits] r120992 - in /cfe/trunk: lib/CodeGen/CGExpr.cpp lib/CodeGen/CGExprAgg.cpp lib/CodeGen/CGExprComplex.cpp test/CodeGenCXX/volatile-1.cpp

[John McCall]

Author: rjmccall
Date: Mon Dec  6 00:10:02 2010
New Revision: 120992

URL: http://llvm.org/viewvc/llvm-project?rev=120992&view=rev
Log:
__block variables require us to evaluate the RHS of an assignment before
the LHS, or else the pointer might be invalid.  This is kindof dumb, but
go ahead and make sure we're doing that for l-value scalar assignment,
which fixes a miscompile of obj-c++.dg/block-seq.mm.

Leave a FIXME for how to solve this problem for agg __blocks.


Modified:
    cfe/trunk/lib/CodeGen/CGExpr.cpp
    cfe/trunk/lib/CodeGen/CGExprAgg.cpp
    cfe/trunk/lib/CodeGen/CGExprComplex.cpp
    cfe/trunk/test/CodeGenCXX/volatile-1.cpp

Modified: cfe/trunk/lib/CodeGen/CGExpr.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGExpr.cpp?rev=120992&r1=120991&r2=120992&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGExpr.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGExpr.cpp Mon Dec  6 00:10:02 2010
@@ -1951,10 +1951,10 @@
   assert(E->getOpcode() == BO_Assign && "unexpected binary l-value");
   
   if (!hasAggregateLLVMType(E->getType())) {
-    // Emit the LHS as an l-value.
+    // __block variables need the RHS evaluated first.
+    RValue RV = EmitAnyExpr(E->getRHS());
     LValue LV = EmitLValue(E->getLHS());
-    // Store the value through the l-value.
-    EmitStoreThroughLValue(EmitAnyExpr(E->getRHS()), LV, E->getType());
+    EmitStoreThroughLValue(RV, LV, E->getType());
     return LV;
   }
 

Modified: cfe/trunk/lib/CodeGen/CGExprAgg.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGExprAgg.cpp?rev=120992&r1=120991&r2=120992&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGExprAgg.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGExprAgg.cpp Mon Dec  6 00:10:02 2010
@@ -389,6 +389,8 @@
   assert(CGF.getContext().hasSameUnqualifiedType(E->getLHS()->getType(),
                                                  E->getRHS()->getType())
          && "Invalid assignment");
+
+  // FIXME:  __block variables need the RHS evaluated first!
   LValue LHS = CGF.EmitLValue(E->getLHS());
 
   // We have to special case property setters, otherwise we must have

Modified: cfe/trunk/lib/CodeGen/CGExprComplex.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGExprComplex.cpp?rev=120992&r1=120991&r2=120992&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGExprComplex.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGExprComplex.cpp Mon Dec  6 00:10:02 2010
@@ -602,7 +602,7 @@
   TestAndClearIgnoreReal();
   TestAndClearIgnoreImag();
 
-  // Emit the RHS.
+  // Emit the RHS.  __block variables need the RHS evaluated first.
   Val = Visit(E->getRHS());
 
   // Compute the address to store into.

Modified: cfe/trunk/test/CodeGenCXX/volatile-1.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/volatile-1.cpp?rev=120992&r1=120991&r2=120992&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCXX/volatile-1.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/volatile-1.cpp Mon Dec  6 00:10:02 2010
@@ -346,9 +346,9 @@
   // CHECK-NEXT: volatile store {{.*}}, [[INT]]* @j
 
   (j=k,i)=i;
+  // CHECK-NEXT: volatile load [[INT]]* @i
   // CHECK-NEXT: volatile load [[INT]]* @k
   // CHECK-NEXT: volatile store {{.*}}, [[INT]]* @j
-  // CHECK-NEXT: volatile load [[INT]]* @i
   // CHECK-NEXT: volatile store {{.*}}, [[INT]]* @i
 
   // CHECK-NEXT: ret void