Created attachment 14300 [details]
clang++ -g -gdwarf-5 x.cpp

via: https://github.com/compiler-explorer/compiler-explorer/issues/3991

It looks like `objdump -dl a.out` isn't able to parse file info correctly from DWARFv5 binaries generated by Clang.

I'm not sure if Clang is perhaps generating invalid debug info, but it seems that llvm-objdump is able to parse output from either GCC or Clang.

```
$ cat x.cpp
int square(int num) {
    return num * num;
}

int main () {
    return square(3);
}
$ g++ -g -gdwarf-5 x.cpp
$ objdump -dl a.out | grep main\>: -A 13
0000000000001138 <main>:
main():
/tmp/x.cpp:5
    1138:	55                   	push   %rbp
    1139:	48 89 e5             	mov    %rsp,%rbp
/tmp/x.cpp:6
    113c:	bf 03 00 00 00       	mov    $0x3,%edi
    1141:	e8 e3 ff ff ff       	call   1129 <_Z6squarei>
    1146:	90                   	nop
/tmp/x.cpp:7
    1147:	5d                   	pop    %rbp
    1148:	c3                   	ret
    1149:	0f 1f 80 00 00 00 00 	nopl   0x0(%rax)
$ llvm-objdump -dl a.out| grep main\>: -A 13
0000000000001138 <main>:
; main():
; /tmp/x.cpp:5
    1138: 55                           	pushq	%rbp
    1139: 48 89 e5                     	movq	%rsp, %rbp
; /tmp/x.cpp:6
    113c: bf 03 00 00 00               	movl	$3, %edi
    1141: e8 e3 ff ff ff               	callq	0x1129 <_Z6squarei>
    1146: 90                           	nop
; /tmp/x.cpp:7
    1147: 5d                           	popq	%rbp
    1148: c3                           	retq
    1149: 0f 1f 80 00 00 00 00         	nopl	(%rax)
$ clang++ -g -gdwarf-5 x.cpp
$ llvm-objdump -dl a.out| grep main\>: -A 13
0000000000001140 <main>:
; main():
; /tmp/x.cpp:5
    1140: 55                           	pushq	%rbp
    1141: 48 89 e5                     	movq	%rsp, %rbp
    1144: 48 83 ec 10                  	subq	$16, %rsp
    1148: c7 45 fc 00 00 00 00         	movl	$0, -4(%rbp)
; /tmp/x.cpp:6
    114f: bf 03 00 00 00               	movl	$3, %edi
    1154: e8 d7 ff ff ff               	callq	0x1130 <_Z6squarei>
    1159: 48 83 c4 10                  	addq	$16, %rsp
    115d: 5d                           	popq	%rbp
    115e: c3                           	retq
    115f: 90                           	nop
$ objdump -dl a.out | grep main\>: -A 13    
0000000000001140 <main>:
main():
<unknown>:5
    1140:	55                   	push   %rbp
    1141:	48 89 e5             	mov    %rsp,%rbp
    1144:	48 83 ec 10          	sub    $0x10,%rsp
    1148:	c7 45 fc 00 00 00 00 	movl   $0x0,-0x4(%rbp)
<unknown>:6
    114f:	bf 03 00 00 00       	mov    $0x3,%edi
    1154:	e8 d7 ff ff ff       	call   1130 <_Z6squarei>
    1159:	48 83 c4 10          	add    $0x10,%rsp
    115d:	5d                   	pop    %rbp
    115e:	c3                   	ret
    115f:	90                   	nop
```

See those `<unknown>` in the above.

```
$ clang --version
clang version 16.0.0 (git@github.com:llvm/llvm-project.git 51a643230eadd67bf5ac18befc28d85ed4e83c81)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /android0/llvm-project/llvm/build/bin

$ g++ --version
g++ (Debian 11.3.0-5) 11.3.0
Copyright (C) 2021 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

$ objdump --version
GNU objdump (GNU Binutils for Debian) 2.38.90.20220713
Copyright (C) 2022 Free Software Foundation, Inc.
This program is free software; you may redistribute it under the terms of
the GNU General Public License version 3 or (at your option) any later version.
This program has absolutely no warranty.

$ llvm-objdump --version | head -n 2
LLVM (http://llvm.org/):
  LLVM version 16.0.0git
```