https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79476
Bug ID: 79476
Summary: C++ frontend ignores diagnostic pragma in macro
Product: gcc
Version: 6.3.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: j...@jak-linux.org
Target Milestone: ---
Created attachment 40721
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=40721&action=edit
Reproducer
We define three macros in APT:
#define APT_IGNORE_DEPRECATED_PUSH \
_Pragma("GCC diagnostic push") \
_Pragma("GCC diagnostic ignored \"-Wdeprecated-declarations\"")
#define APT_IGNORE_DEPRECATED_POP \
_Pragma("GCC diagnostic pop")
#define APT_IGNORE_DEPRECATED(XXX) \
APT_IGNORE_DEPRECATED_PUSH \
XXX \
APT_IGNORE_DEPRECATED_POP
So you can do stuff like APT_IGNORE_DEPRECATED(f();). This does not work
correctly however. Compiling the attached file with the C compiler results in
no warnings, with the C++ compiler a warning is emitted for
APT_IGNORE_DEPRECATED(f();) but not for using push/pop macros explicitly around
the f(); in the other functions:
$ gcc -c -Wdeprecated-declarations a.c
$ g++ -c -Wdeprecated-declarations a.c
a.c: In function ‘int a()’:
a.c:15:27: warning: ‘int f()’ is deprecated [-Wdeprecated-declarations]
APT_IGNORE_DEPRECATED(f();)
^
a.c:8:3: note: in definition of macro ‘APT_IGNORE_DEPRECATED’
XXX \
^~~
a.c:11:5: note: declared here
int f() __attribute__((deprecated));
^
a.c:15:29: warning: ‘int f()’ is deprecated [-Wdeprecated-declarations]
APT_IGNORE_DEPRECATED(f();)
^
a.c:8:3: note: in definition of macro ‘APT_IGNORE_DEPRECATED’
XXX \
^~~
a.c:11:5: note: declared here
int f() __attribute__((deprecated));
^
According to cpp, all functions expand to the same code.
This used to work at some point a long time ago, but I can't remember when.
