https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101382
Bug ID: 101382
Summary: function declarations with identical asm label
aliasing a target function does not compile with -flto
Product: gcc
Version: 11.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: lto
Assignee: unassigned at gcc dot gnu.org
Reporter: fabian.parzefall at mailbox dot org
CC: marxin at gcc dot gnu.org
Target Milestone: ---
Created attachment 51120
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=51120&action=edit
Input reproducing the bug
GCC cannot compile a module containing two function declarations with the same
asm label and the same alias attribute when -flto is enabled. Here is an
excerpt from the attachment:
void a(void) { ... }
extern typeof(a) b asm("x") __attribute__((alias("a")));
extern typeof(a) c asm("x") __attribute__((alias("a")));
When compiling with:
gcc -flto -c -o gcc-lto-asm-label-bug.o gcc-lto-asm-label-bug.c
gcc -flto -o gcc-lto-asm-label-bug gcc-lto-asm-label-bug.o
The second command invoked produces this error message:
lto1: fatal error: missing resolution data for *x
compilation terminated.
lto-wrapper: fatal error: gcc returned 1 exit status
compilation terminated.
/usr/bin/ld: error: lto-wrapper failed
collect2: error: ld returned 1 exit status
Compiling without -flto works as expected. GCC versions tested are 9.3.0 and
11.1.0 on Ubuntu 20.04.
