https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77481
Bug ID: 77481
Summary: @finally not executed if exception not caught or
rethrown
Product: gcc
Version: 7.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: objc
Assignee: unassigned at gcc dot gnu.org
Reporter: vries at gcc dot gnu.org
Target Milestone: ---
Consider finally.m, testing 4 scenarios:
1. no exception
2. caught exception
3. uncaught exception
4. rethrown exception
finally.m:
...
#import <objc/Object.h>
#import <stdio.h>
#if F == 1
int
main (void)
{
id o = nil;
@try {
printf ("trying\n");
} @catch (id ue) {
printf ("catching id\n");
} @finally {
printf ("finalizing\n");
}
printf ("done\n");
return 0;
}
#endif
#if F == 2
int
main (void)
{
id o = nil;
@try {
printf ("trying\n");
@throw o;
} @catch (id ue) {
printf ("catching id\n");
} @finally {
printf ("finalizing\n");
}
printf ("done\n");
return 0;
}
#endif
#if F == 3
int
main (void)
{
id o = nil;
@try {
printf ("trying\n");
@throw o;
} @catch (Object *ue) {
printf ("catching id\n");
} @finally {
printf ("finalizing\n");
}
printf ("done\n");
return 0;
}
#endif
#if F == 4
int
main (void)
{
id o = nil;
@try {
printf ("trying\n");
@throw o;
} @catch (id ue) {
printf ("catching id\n");
@throw;
} @finally {
printf ("finalizing\n");
}
printf ("done\n");
return 0;
}
#endif
...
Executing with gcc gives:
...
$ for n in $(seq 1 4); do echo executing case $n; gcc -DF=$n finally.m
-fobjc-exceptions -lobjc -static && ./a.out ; echo $?; echo ; done
executing case 1
trying
finalizing
done
0
executing case 2
trying
catching id
finalizing
done
0
executing case 3
trying
Aborted (core dumped)
134
executing case 4
trying
catching id
Aborted (core dumped)
134
...
As we can see, in the cases of the uncaught and rethrown exception, finally is
not executed.
If we try the same with clang, we see that finally is executed in all four
cases:
...
$ for n in $(seq 1 4); do echo executing case $n; clang finally.m -lobjc
-fobjc-exceptions -static -fexceptions -DF=1 $n && ./a.out; echo $? ; echo;
done
executing case 1
trying
finalizing
done
0
executing case 2
trying
catching id
finalizing
done
0
executing case 3
trying
finalizing
Aborted (core dumped)
134
executing case 4
trying
catching id
finalizing
Aborted (core dumped)
134
...
