http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56018
Bug #: 56018
Summary: Access to member of unnamed union variable in
structure
Classification: Unclassified
Product: gcc
Version: 4.4.3
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: stephan...@gmail.com
Created attachment 29190
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=29190
ngx_event preprocessed file, where __sigaction_handler automaticaly added
When accessing from structure to unnamed union variable, it's union variable
name automatically added to preprocessed code, without check if it was added in
source.
In nginx(1.3.7, ngx_event.c) there code like:
struct sigaction sa;
sa.sa_handler = ngx_timer_signal_handler;
From preprocessor file I got, that sigaction has next difinition:
# 25 "/usr/include/bits/sigaction.h" 3 4
struct sigaction
{
union
{
__sighandler_t sa_handler;
void (*sa_sigaction) (int, siginfo_t *, void *);
}
__sigaction_handler;
__sigset_t sa_mask;
int sa_flags;
void (*sa_restorer) (void);
};
So when I find the lines above I saw that while accessing the union variable
member, it's name was added(ngx_event.i:13893):
sa.__sigaction_handler.sa_handler = ngx_timer_signal_handler;
When I changed source code to:
sa.__sigaction_handler.sa_handler = ngx_timer_signal_handler;
the preprocessor file of it became:
sa.__sigaction_handler.__sigaction_handler.sa_handler =
ngx_timer_signal_handler;
and I got an error:
gcc -c -pipe -O -W -Wall -Wpointer-arith -Wno-unused-parameter -Werror -g -I
src/core -I src/event -I src/event/modules -I src/os/unix -I objs \
-o objs/src/event/ngx_event.o \
src/event/ngx_event.c
gcc-4.4: warning: -pipe ignored because -save-temps specified
src/event/ngx_event.c: In function ‘ngx_event_process_init’:
src/event/ngx_event.c:644: error: ‘union <anonymous>’ has no member named
‘__sigaction_handler’
make[1]: *** [objs/src/event/ngx_event.o] Error 1
make[1]: Leaving directory `/root/newM/nginx-1.3.7'
make: *** [build] Error 2
