cat <<EOF >a.c
extern int puts(const char*);
char *program;
void fail() {puts(program);}
EOF
cat <<EOF >b.c
extern int puts(const char*);
extern char *program;
extern void fail();
void usage() {puts(program);}
int main(int argc, char *argv[])
{
program = argv[0];
if (argc)
usage();
else
fail();
return 0;
}
EOF
gcc -flto -fuse-linker-plugin -O2 b.c a.c
/usr/lib/gcc/x86_64-pc-linux-gnu/4.5.0-pre9999/../../../../x86_64-pc-linux-gnu/bin/ld:
/tmp/ccvkxseZ.lto.o: in function usage:ccHTGBCK.o(.text+0x3): error: undefined
reference to 'program'
/usr/lib/gcc/x86_64-pc-linux-gnu/4.5.0-pre9999/../../../../x86_64-pc-linux-gnu/bin/ld:
/tmp/ccvkxseZ.lto.o: in function fail:ccHTGBCK.o(.text+0x13): error: undefined
reference to 'program'
/usr/lib/gcc/x86_64-pc-linux-gnu/4.5.0-pre9999/../../../../x86_64-pc-linux-gnu/bin/ld:
/tmp/ccvkxseZ.lto.o: in function main:ccHTGBCK.o(.text+0x2c): error: undefined
reference to 'program'
collect2: ld returned 1 exit status
Works with reversed ordering or without -fuse-linker-plugin
--
Summary: Undefined references with -flto -fuse-linker-plugin,
dependent on object file ordering
Product: gcc
Version: 4.5.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: lto
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: amonakov at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43355
