https://sourceware.org/bugzilla/show_bug.cgi?id=21066
--- Comment #4 from Joshua Oreman <oremanj at gmail dot com> ---
As I pointed out in PR 23482, hot/cold function splitting (the new gcc
-freorder-blocks-and-partition optimization) can make this an issue even
without any LSDA at all. Seems a full fix will need to consider the CIE/FDE
contents that are relevant to the function as well.
Example uses asm for clarity, but I can obtain analogous issues using
gcc-produced code, as demonstrated on the above PR.
$ g++ -o t.nofold t.cc -fuse-ld=gold
$ g++ -o t.fold t.cc -fuse-ld=gold -Wl,--icf=safe
$ ./t.nofold
caught 1: 42
caught 2: 42
$ ./t.fold
caught 1: 42
terminate called after throwing an instance of 'int'
Aborted (core dumped)
$ cat t.cc
extern "C" int printf(const char *fmt, ...);
void throw_it() { throw 42; }
extern void call_1(void(*)());
extern void call_2(void(*)());
asm(R"(
.section .text._Z6call_1PFvvE,"ax",@progbits
.globl _Z6call_1PFvvE
.type _Z6call_1PFvvE, @function
_Z6call_1PFvvE:
.cfi_startproc
pushq %rbx
.cfi_def_cfa_offset 16
.cfi_offset 3, -16
jmp _Z6call_1PFvvE.cold
.cfi_endproc
.section .text.unlikely._Z6call_1PFvvE,"ax",@progbits
.type _Z6call_1PFvvE.cold, @function
_Z6call_1PFvvE.cold:
.cfi_startproc
.cfi_def_cfa_offset 16
.cfi_offset 3, -16
call *%rdi
.cfi_endproc
.section .text._Z6call_2PFvvE,"ax",@progbits
.globl _Z6call_2PFvvE
.type _Z6call_2PFvvE, @function
_Z6call_2PFvvE:
.cfi_startproc
subq $24, %rsp
.cfi_def_cfa_offset 32
jmp _Z6call_2PFvvE.cold
.cfi_endproc
.section .text.unlikely._Z6call_2PFvvE,"ax",@progbits
.type _Z6call_2PFvvE.cold, @function
_Z6call_2PFvvE.cold:
.cfi_startproc
.cfi_def_cfa_offset 32
call *%rdi
.cfi_endproc
)");
int main() {
try {
call_1(throw_it);
} catch (int val) {
printf("caught 1: %d\n", val);
}
try {
call_2(throw_it);
} catch (int val) {
printf("caught 2: %d\n", val);
}
}
--
You are receiving this mail because:
You are on the CC list for the bug.
_______________________________________________
bug-binutils mailing list
bug-binutils@gnu.org
https://lists.gnu.org/mailman/listinfo/bug-binutils
