https://gcc.gnu.org/bugzilla/show_bug.cgi?id=10852
Martin Sebor <msebor at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |RESOLVED
CC| |msebor at gcc dot gnu.org
Resolution|--- |FIXED
--- Comment #7 from Martin Sebor <msebor at gcc dot gnu.org> ---
I think this works correctly now. In C++ 98 mode GCC complains with
-fpermissive. In C++ 11 and later it accepts the code as expected. Resolving
as fixed.
$ (set -x; cat t.C && for y in 98 11 17; do gcc -S -Wall -Wextra -Wpedantic
-std=c++$y t.C; done)
+ cat t.C
namespace X {
int i;
}
void f() {
for (int i=0; i<10; ++i)
;
using namespace X;
i;
}
+ for y in 98 11 17
+ gcc -S -Wall -Wextra -Wpedantic -std=c++98 t.C
t.C: In function ‘void f()’:
t.C:9:3: error: name lookup of ‘i’ changed for ISO ‘for’ scoping [-fpermissive]
i;
^
t.C:9:3: note: (if you use ‘-fpermissive’ G++ will accept your code)
t.C:9:4: warning: statement has no effect [-Wunused-value]
i;
^
+ for y in 98 11 17
+ gcc -S -Wall -Wextra -Wpedantic -std=c++11 t.C
t.C: In function ‘void f()’:
t.C:9:4: warning: statement has no effect [-Wunused-value]
i;
^
+ for y in 98 11 17
+ gcc -S -Wall -Wextra -Wpedantic -std=c++17 t.C
t.C: In function ‘void f()’:
t.C:9:4: warning: statement has no effect [-Wunused-value]
i;
^
Conversely, the test case from comment #5 is rejected in C++ 11 and later and
accepted in C++ 98 mode:
$ (set -x; cat t.C && for y in 98 11 17; do gcc -S -Wall -Wextra -Wpedantic
-std=c++$y t.C; done)
+ cat t.C
namespace N
{
int i;
}
int i;
void foo()
{
for (int i=0; i<10; ++i) ;
using namespace N;
i;
}
+ for y in 98 11 17
+ gcc -S -Wall -Wextra -Wpedantic -std=c++98 t.C
t.C: In function ‘void foo()’:
t.C:12:5: warning: name lookup of ‘i’ changed
i;
^
t.C:6:5: warning: matches this ‘i’ under ISO standard rules
int i;
^
t.C:10:14: warning: matches this ‘i’ under old rules
for (int i=0; i<10; ++i) ;
^
t.C:12:6: warning: statement has no effect [-Wunused-value]
i;
^
+ for y in 98 11 17
+ gcc -S -Wall -Wextra -Wpedantic -std=c++11 t.C
t.C: In function ‘void foo()’:
t.C:12:5: error: reference to ‘i’ is ambiguous
i;
^
t.C:6:5: note: candidates are: int i
int i;
^
t.C:3:9: note: int N::i
int i;
^
+ for y in 98 11 17
+ gcc -S -Wall -Wextra -Wpedantic -std=c++17 t.C
t.C: In function ‘void foo()’:
t.C:12:5: error: reference to ‘i’ is ambiguous
i;
^
t.C:6:5: note: candidates are: int i
int i;
^
t.C:3:9: note: int N::i
int i;
^
