__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.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@120992 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/CGExpr.cpp b/lib/CodeGen/CGExpr.cpp
index 011233c58f4fae2c2b0d77d61c743d2f305b6172..6cc573c0cfc7cafc01f7375642a520d2d06a3e5d 100644 (file)
--- a/lib/CodeGen/CGExpr.cpp
+++ b/lib/CodeGen/CGExpr.cpp
@@ -1951,10 +1951,10 @@ LValue CodeGenFunction::EmitBinaryOperatorLValue(const BinaryOperator *E) {
   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;
   }
 

diff --git a/lib/CodeGen/CGExprAgg.cpp b/lib/CodeGen/CGExprAgg.cpp
index 73bb9ef3fb799e3f004e2f0c418ef9541c81eaf2..ffe1739a0ecd296451edcbadfa5165c51b0029bd 100644 (file)
--- a/lib/CodeGen/CGExprAgg.cpp
+++ b/lib/CodeGen/CGExprAgg.cpp
@@ -389,6 +389,8 @@ void AggExprEmitter::VisitBinAssign(const BinaryOperator *E) {
   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

diff --git a/lib/CodeGen/CGExprComplex.cpp b/lib/CodeGen/CGExprComplex.cpp
index 89a3a26ed61c6fa143e9c88d76a96e57c1b3bcf9..7896504d86b2a283e9cd3aff220e037162e81a71 100644 (file)
--- a/lib/CodeGen/CGExprComplex.cpp
+++ b/lib/CodeGen/CGExprComplex.cpp
@@ -602,7 +602,7 @@ LValue ComplexExprEmitter::EmitBinAssignLValue(const BinaryOperator *E,
   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.

diff --git a/test/CodeGenCXX/volatile-1.cpp b/test/CodeGenCXX/volatile-1.cpp
index ba43471abf1e1d888b6be0aed124057e6e426c69..0569150101c7c1d6bf6e10cc030ae2141d495edc 100644 (file)
--- a/test/CodeGenCXX/volatile-1.cpp
+++ b/test/CodeGenCXX/volatile-1.cpp
@@ -346,9 +346,9 @@ void test() {
   // 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