The location for a built-in macro token is BUILTIN_LOCATION. When we
see that location value, we cannot know if that token was used in a
system header or not. And that can trigger some unwanted warnings on
e.g, the use of __LONG_LONG_MAX__ built-in macro in system headers
when we compile with -pedantic, like in the test case accompanying
this patch.
In that case, I think we ought to step-up to see where the built-in
macro has been expanded, until we see a location that is not for a
built-in macro. Then we can check if the resulting location is in a
system header or not.
Now that we step up to the location of first non-built-in-macro token,
it appeared that for
testsuite/c-c++-common/dfp/convert-int-saturate.c, G++ then fails to
emit the warning in:
volatile unsigned int usi;
int
main ()
{
usi = DEC32_MAX; /* { dg-warning "overflow in implicit constant conversion" } */
...
}
Because DEC32_MAX is defined in the system header float.h as a
built-in macro:
#define DEC32_MAX __DEC32_MAX__
And during the parsing of the assignment expression that should have
led to the warning above, input_location is set to the location for
the DEC32_MAX, which is actually the location for the built-in
__DECL32_MAX_EXP.
A possible fix is to use the location of the "=" operator as the
default location for assignment expressions. This is what the patch
does.
I had to adjust a couple of tests to arrange for this.
Bootstrapped and tested on x86_64-unknown-linux-gnu against trunk.
libcpp/
PR preprocessor/53463
* line-map.c (linemap_location_in_system_header_p): For built-in
macro tokens, check the first expansion point location for that is
not for a token coming from a built-in macro.
gcc/cp/
PR preprocessor/53463
* parser.c (cp_parser_assignment_expression): Use the location
for the LHS as the default location for the expression.
gcc/testsuite/
PR preprocessor/53463
* g++.dg/cpp/limits.C: New test.
* g++.dg/parse/error19.C: Adjust.
* g++.dg/warn/Wconversion-real-integer2.C: Likewise.
* g++.dg/warn/pr35635.C: Likewise.
* g++.old-deja/g++.pt/assign1.C: Likewise.
From-SVN: r188203
7ca643e17e