Force a load when creating a reference to a temporary copied from a bitfield.
For this source:
const int &ref = someStruct.bitfield;
We used to generate this AST:
DeclStmt [...]
`-VarDecl [...] ref 'const int &'
`-MaterializeTemporaryExpr [...] 'const int' lvalue
`-ImplicitCastExpr [...] 'const int' lvalue <NoOp>
`-MemberExpr [...] 'int' lvalue bitfield .bitfield [...]
`-DeclRefExpr [...] 'struct X' lvalue ParmVar [...] 'someStruct' 'struct X'
Notice the lvalue inside the MaterializeTemporaryExpr, which is very
confusing (and caused an assertion to fire in the analyzer - PR15694).
We now generate this:
DeclStmt [...]
`-VarDecl [...] ref 'const int &'
`-MaterializeTemporaryExpr [...] 'const int' lvalue
`-ImplicitCastExpr [...] 'int' <LValueToRValue>
`-MemberExpr [...] 'int' lvalue bitfield .bitfield [...]
`-DeclRefExpr [...] 'struct X' lvalue ParmVar [...] 'someStruct' 'struct X'
Which makes a lot more sense. This allows us to remove code in both
CodeGen and AST that hacked around this special case.
The commit also makes Clang accept this (legal) C++11 code:
int &&ref = std::move(someStruct).bitfield
PR15694 / <rdar://problem/13600396>
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@179250 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/Analysis/reference.cpp b/test/Analysis/reference.cpp
index 8dd0baf..bcab80b 100644
--- a/test/Analysis/reference.cpp
+++ b/test/Analysis/reference.cpp
@@ -224,3 +224,13 @@
return *x; // no-warning
}
}
+
+namespace PR15694 {
+ class C {
+ bool bit : 1;
+ template <class T> void bar(const T &obj) {}
+ void foo() {
+ bar(bit); // don't crash
+ }
+ };
+}
diff --git a/test/CXX/dcl.decl/dcl.init/dcl.init.ref/p5-0x.cpp b/test/CXX/dcl.decl/dcl.init/dcl.init.ref/p5-0x.cpp
index 812d0de..fdfa678 100644
--- a/test/CXX/dcl.decl/dcl.init/dcl.init.ref/p5-0x.cpp
+++ b/test/CXX/dcl.decl/dcl.init/dcl.init.ref/p5-0x.cpp
@@ -200,3 +200,37 @@
X &&f1(Y &y) { return y; } // expected-error{{rvalue reference to type 'rdar13278115::X' cannot bind to lvalue of type 'rdar13278115::Y'}}
const X &&f2(Y &y) { return y; } // expected-error{{rvalue reference to type 'const rdar13278115::X' cannot bind to lvalue of type 'rdar13278115::Y'}}
}
+
+namespace bitfields {
+ struct IntBitfield {
+ int i : 17; // expected-note 3 {{bit-field is declared here}}
+ };
+
+ // A simplified version of std::move.
+ template <typename T>
+ T &&move(T &obj) {
+ return static_cast<T &&>(obj);
+ }
+
+ void test() {
+ int & ir1 = (lvalue<IntBitfield>().i); // expected-error{{non-const reference cannot bind to bit-field 'i'}}
+ int & ir2 = (xvalue<IntBitfield>().i); // expected-error{{non-const lvalue reference to type 'int' cannot bind to a temporary of type 'int'}}
+ int && ir3 = (xvalue<IntBitfield>().i); // no-warning
+ int && ir4 = move(lvalue<IntBitfield>()).i; // no-warning
+
+ volatile int & vir1 = (lvalue<IntBitfield>().i); // expected-error{{non-const reference cannot bind to bit-field 'i'}}
+ volatile int & vir2 = (xvalue<IntBitfield>().i); // expected-error{{volatile lvalue reference to type 'volatile int' cannot bind to a temporary of type 'int'}}
+ volatile int && vir3 = (xvalue<IntBitfield>().i); // no-warning
+ volatile int && vir4 = move(lvalue<IntBitfield>()).i; // no-warning
+
+ const int & cir1 = (lvalue<IntBitfield>().i); // no-warning
+ const int & cir2 = (xvalue<IntBitfield>().i); // no-warning
+ const int && cir3 = (xvalue<IntBitfield>().i); // no-warning
+ const int && cir4 = move(lvalue<IntBitfield>()).i; // no-warning
+
+ const volatile int & cvir1 = (lvalue<IntBitfield>().i); // expected-error{{non-const reference cannot bind to bit-field 'i'}}
+ const volatile int & cvir2 = (xvalue<IntBitfield>().i); // expected-error{{volatile lvalue reference to type 'const volatile int' cannot bind to a temporary of type 'int'}}
+ const volatile int && cvir3 = (xvalue<IntBitfield>().i); // no-warning
+ const volatile int && cvir4 = move(lvalue<IntBitfield>()).i; // no-warning
+ }
+}