Fix crash in codegen on casting to bool &.

alexey-bataev · alexey-bataev · commit f2440332caa2 · 2015-10-07T10:22:08.000Z
Currently codegen crashes trying to emit casting to bool &. It happens because bool type is converted to i1 and later then lvalue for reference is converted to i1*. But when codegen tries to load this lvalue it crashes trying to load value from this i1*. Differential Revision: http://reviews.llvm.org/D13325 llvm-svn: 249534
diff --git a/clang/lib/CodeGen/CGExprScalar.cpp b/clang/lib/CodeGen/CGExprScalar.cpp
@@ -1383,7 +1383,7 @@ Value *ScalarExprEmitter::VisitCastExpr(CastExpr *CE) {
   case CK_LValueBitCast:
   case CK_ObjCObjectLValueCast: {
     Address Addr = EmitLValue(E).getAddress();
-    Addr = Builder.CreateElementBitCast(Addr, ConvertType(DestTy));
+    Addr = Builder.CreateElementBitCast(Addr, CGF.ConvertTypeForMem(DestTy));
     LValue LV = CGF.MakeAddrLValue(Addr, DestTy);
     return EmitLoadOfLValue(LV, CE->getExprLoc());
   }
diff --git a/clang/test/CodeGenCXX/cast-to-ref-bool.cpp b/clang/test/CodeGenCXX/cast-to-ref-bool.cpp
@@ -0,0 +1,9 @@
+// RUN: %clang_cc1 -triple x86_64-apple-darwin -emit-llvm -o - %s | FileCheck %s
+
+// CHECK-LABEL: main
+int main(int argc, char **argv) {
+  // CHECK: load i8, i8* %
+  // CHECK-NEXT: trunc i8 %{{.+}} to i1
+  bool b = (bool &)argv[argc][1];
+  return b;
+}

Original file line number	Diff line number	Diff line change
`@@ -1383,7 +1383,7 @@ Value ScalarExprEmitter::VisitCastExpr(CastExpr CE) {`
`1383`	`1383`	`case CK_LValueBitCast:`
`1384`	`1384`	`case CK_ObjCObjectLValueCast: {`
`1385`	`1385`	`Address Addr = EmitLValue(E).getAddress();`
`1386`		`- Addr = Builder.CreateElementBitCast(Addr, ConvertType(DestTy));`
	`1386`	`+ Addr = Builder.CreateElementBitCast(Addr, CGF.ConvertTypeForMem(DestTy));`
`1387`	`1387`	`LValue LV = CGF.MakeAddrLValue(Addr, DestTy);`
`1388`	`1388`	`return EmitLoadOfLValue(LV, CE->getExprLoc());`
`1389`	`1389`	`}`