https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78539
Bug ID: 78539
Summary: feature request: __noextension__
Product: gcc
Version: 7.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: jim at meyering dot net
Target Milestone: ---
Please consider adding a __noextension__(...) operator.
If we had a __noextension__(...) operator to counteract the effect of a
preceding __extension__(...), I could write this in glibc's definition of
assert:
#define assert(expr) \
__extension__ ({ \
if (__noextension__ (expr)) \
; \
else
__assert_failed (...); \
(void)0; \
})
Without that, I have to resort to using two cases: one for __STRICT_ANSI__
and one without, so that gcc -Wpedantic can still reliably diagnose "assert(
({1;}) );"
This was first suggested in https://gcc.gnu.org/ml/gcc/2001-04/msg00642.html
If you do add this, please ensure that the __noextension__(...) parentheses do
not end up suppressing the detection performed by gcc's -Wparentheses.
For reference, this came up recently in the following thread:
https://sourceware.org/ml/libc-alpha/2016-11/msg00866.html
