https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117977
Bug ID: 117977
Summary: duplicated warnings output
Product: gcc
Version: 15.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: alexey.lapshin at espressif dot com
Target Milestone: ---
Test code:
#include <stddef.h>
#include <assert.h>
#define SPI1_HOST 1
#define SPI_HOST _Pragma ("GCC warning \"use SPI1_HOST\"") SPI1_HOST
#define ERROR_CHECK(x) do { \
assert(x); \
} while(0)
int foo(int host_id, void *ptr) {
ptr = ptr;
return host_id;
}
void main(void) {
ERROR_CHECK(foo(SPI_HOST,
NULL));
}
Compiling with the latest GCC (15.0) gives doubled warnings:
In file included from <source>:2:
<source>:5:21: warning: use SPI1_HOST
5 | #define SPI_HOST _Pragma ("GCC warning \"use SPI1_HOST\"")
SPI1_HOST
| ^~~~~~~
<source>:16:5: note: in expansion of macro 'ERROR_CHECK'
16 | ERROR_CHECK(foo(SPI_HOST,
| ^~~~~~~~~~~
<source>:16:21: note: in expansion of macro 'SPI_HOST'
16 | ERROR_CHECK(foo(SPI_HOST,
| ^~~~~~~~
<source>:5:21: warning: use SPI1_HOST
5 | #define SPI_HOST _Pragma ("GCC warning \"use SPI1_HOST\"")
SPI1_HOST
| ^~~~~~~
<source>:16:5: note: in expansion of macro 'ERROR_CHECK'
16 | ERROR_CHECK(foo(SPI_HOST,
| ^~~~~~~~~~~
<source>:16:21: note: in expansion of macro 'SPI_HOST'
16 | ERROR_CHECK(foo(SPI_HOST,
| ^~~~~~~~
This is a bit weird because the preprocessor outputs only one use of _Pragma.
C++ front-end handles this as expected.
https://godbolt.org/z/ov3K3h5aP
