One of the purposes of the -fgnu-runtime flag is to get hold of the right
libobjc header files when
specified. This does not work when -E is specified at the same time.
Why do I think the mutually exclusion off "-E" and "-fgnu-runtime" is a bug:
The -E option is regularly used by configure scripts to get hold of the
preprocessor output of gcc.
However, this option doesn't seem to work together with the "-fgnu-runtime"
option. I always get
warnings like (whether an additional '-x objective-c' is specified or not
doesn't matter):
cc1: warning: command line option "-fgnu-runtime" is valid for ObjC/ObjC++ but
not for C
and in result gcc also includes the wrong header files:
I have stripped down the testcase to the following small program (conftest.c):
#include <objc/objc-api.h>
main()
{
}
If I use gcc on that like:
localhost:~/GNUstep-Darwin/test lars$ /opt/local/bin/gcc -E -x objective-c
-fgnu-runtime conftest.c
I get:
cc1: warning: command line option "-fgnu-runtime" is valid for ObjC/ObjC++ but
not for C
# 1 "conftest.c"
# 1 "<built-in>"
# 1 "<command line>"
# 1 "conftest.c"
# 1 "/usr/include/objc/objc-api.h" 1 3 4
# 2 "conftest.c" 2
main()
{
}
which is wrong because /usr/include/objc/objc-api.h got included (which is the
objc-api.h of the next-
runtime (default on Darwin)).
If I instead use gcc like:
localhost:~/GNUstep-Darwin/test lars$ /opt/local/bin/gcc -x objective-c
-fgnu-runtime -save-temps
conftest.c
I get a file "conftest.mi" which starts like:
# 1 "conftest.c"
# 1 "<built-in>"
# 1 "<command line>"
# 1 "conftest.c"
# 1
"/opt/local/bin/../lib/gcc/i686-apple-darwin7.2.1/4.0.0/include-gnu-runtime/objc/objc-api.h"
1 3 4
# 30
"/opt/local/bin/../lib/gcc/i686-apple-darwin7.2.1/4.0.0/include-gnu-runtime/objc/objc-api.h"
3 4
Here gcc has included the right (gnu-runtime) objc-api.h
regards, Lars
p.s.:
by the way: Apples gcc (gcc version 3.3 20030304 (Apple Computer, Inc. build
1495)) doesn't warn if it
gets "-E" and "-fgnu-runtime" at once but it also does the the wrong thing.
--
Summary: -fgnu-runtime not working when -E is specified at the
same time
Product: gcc
Version: 4.0.0
Status: UNCONFIRMED
Severity: normal
Priority: P2
Component: libobjc
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: lars dot sonchocky-helldorf at hamburg dot de
CC: gcc-bugs at gcc dot gnu dot org
GCC build triplet: i686-apple-darwin7.2.1
GCC host triplet: i686-apple-darwin7.2.1
GCC target triplet: i686-apple-darwin7.2.1
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18772
