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Do not walk through member-accesses on bitfields when looking for the object 

which is lifetime-extended by a reference binding. An additional temporary is
created for such a bitfield access (although we have no explicit AST
representation for it).

llvm-svn: 183095
This commit is contained in:
Richard Smith 2013-06-03 07:13:35 +00:00
parent f80d72f149
commit 2d18790b3a
2 changed files with 17 additions and 3 deletions
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2
clang/lib/AST/Expr.cpp
View File

@ -76,11 +76,13 @@ const Expr *Expr::skipRValueSubobjectAdjustments(
if (!ME->isArrow() && ME->getBase()->isRValue()) {
assert(ME->getBase()->getType()->isRecordType());
if (FieldDecl *Field = dyn_cast<FieldDecl>(ME->getMemberDecl())) {
if (!Field->isBitField()) {
E = ME->getBase();
Adjustments.push_back(SubobjectAdjustment(Field));
continue;
}
}
}
} else if (const BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
if (BO->isPtrMemOp()) {
assert(BO->getRHS()->isRValue());

12
clang/test/CodeGenCXX/temporaries.cpp
View File

@ -604,3 +604,15 @@ namespace BindToSubobject {
// CHECK: store i32* {{.*}}, i32** @_ZN15BindToSubobject1dE, align 8
int &&d = (B().a).*h();
}
namespace Bitfield {
struct S { int a : 5; ~S(); };
// Do not lifetime extend the S() temporary here.
  // CHECK: alloca
  // CHECK: call {{.*}}memset
  // CHECK: store i32 {{.*}}, i32* @_ZGRN8Bitfield1rE, align 4
// CHECK: call void @_ZN8Bitfield1SD1
  // CHECK: store i32* @_ZGRN8Bitfield1rE, i32** @_ZN8Bitfield1rE, align 8
int &&r = S().a;
}