https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60517
Martin Sebor <msebor at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |RESOLVED
CC| |msebor at gcc dot gnu.org
Known to work| |9.1.0
Resolution|--- |FIXED
Known to fail| |4.9.1, 5.5.0, 6.4.0, 7.4.0,
| |8.3.0
--- Comment #25 from Martin Sebor <msebor at gcc dot gnu.org> ---
GCC 9 rejects the test case with the error below:
$ cat pr60517.C && gcc -Wall -S pr60517.C
class B {
public:
double x[2];
};
class A {
B b;
public:
B getB(void) { return b; }
};
double foo(A a) {
double * x = &(a.getB().x[0]);
return x[0];
}
pr60517.C: In function ‘double foo(A)’:
pr60517.C:12:33: error: taking address of rvalue [-fpermissive]
12 | double * x = &(a.getB().x[0]);
| ^
The change that introduced the error is r260621:
CWG 616, 1213 - value category of subobject references.
* tree.c (lvalue_kind): A reference to a subobject of a prvalue is
an xvalue.
* typeck2.c (build_m_component_ref): Likewise.
* typeck.c (cp_build_addr_expr_1, lvalue_or_else): Remove diagnostic
distinction between temporary and xvalue.
I don't see a test case for this error so let me add one and resolve the bug.
