GDB no longer works for GCC-generated executables on Sequoia?

[adah1972]

Output of brew config

HOMEBREW_VERSION: 4.4.22-90-g0e1d945
ORIGIN: https://github.com/Homebrew/brew
HEAD: 0e1d94506837ff39def056eaa365fa4d6aa07ca8
Last commit: 30 hours ago
Branch: master
Core tap HEAD: acd55f62d58f0f53d86d6dcc442d6a23d02e5eab
Core tap last commit: 8 months ago
Core tap JSON: 01 Mar 15:29 UTC
Core cask tap HEAD: 37a15905b88846b6f73a1367445f339894179f78
Core cask tap last commit: 8 months ago
Core cask tap JSON: 01 Mar 15:29 UTC
HOMEBREW_PREFIX: /usr/local
HOMEBREW_AUTO_UPDATE_SECS: 86400
HOMEBREW_BAT_THEME: GitHub
HOMEBREW_CASK_OPTS: []
HOMEBREW_EDITOR: /usr/local/bin/vim
HOMEBREW_GITHUB_API_TOKEN: set
HOMEBREW_MAKE_JOBS: 16
HOMEBREW_NO_VERIFY_ATTESTATIONS: set
HOMEBREW_SORBET_RUNTIME: set
http_proxy: http://127.0.0.1:7890
https_proxy: http://127.0.0.1:7890
no_proxy: localhost,.cn
Homebrew Ruby: 3.3.7 => /usr/local/Homebrew/Library/Homebrew/vendor/portable-ruby/3.3.7/bin/ruby
CPU: 16-core 64-bit kabylake
Clang: 16.0.0 build 1600
Git: 2.48.1 => /usr/local/bin/git
Curl: 8.7.1 => /usr/bin/curl
macOS: 15.3.1-x86_64
CLT: 16.2.0.0.1.1733547573
Xcode: N/A

Output of brew doctor

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Description of issue

Before I upgraded to Sequoia, I was able to use g++ -gdwarf-3 to build a program, and use gdb to debug it (though there are always hassles, like codesigning and first-time hangs). But now I cannot in Sequoia.

However, the behaviour is quite complicated, and I am not even sure whom to blame: gcc, gdb, and macOS might all be involved.

1. The problematic combination. Whatever options I use (I tried -g, -gdwarf-3, -gdwarf-4, among others) for gcc, setting a breakpoint on the resulting executable in gdb gives a message like DWARF Error: DW_FORM_line_strp used without required section.
2. The same executable is generally OK under lldb, as well as the case of using other debug options with clang.
3. Weird still, using -gdwarf-3 or -gdwarf-4 with clang results in an executable usable in gdb, though using -g will cause an error message in gdb like: DW_FORM_GNU_str_index or DW_FORM_strx used without .debug_str section in CU at offset 0x0.

So the original purpose of using gdb with gcc no longer works....

Any clues?

[gromgit]

This was reported upstream 5 months ago, with no progress as of this writing: https://sourceware.org/bugzilla/show_bug.cgi?id=32235

You might want to take a look at that bug report and see if you can contribute any other insights.

[yjfvictor]

Also, this: https://stackoverflow.com/questions/79046748/what-does-it-mean-by-dwarf-error-dw-form-line-strp-used-without-required-secti.

[yjfvictor]

I just found out that clang with the -gdwarf-4 option works fine on GDB debugging. However, gcc is still not supported.

OS: macOS Sequoia 15.7.1 (Intel x86-64)
gcc: gcc-15 (Homebrew GCC 15.2.0) 15.2.0
clang: Apple clang version 17.0.0 (clang-1700.3.19.1)
lldb: lldb-1703.0.31.2
gdb: GNU gdb (GDB) 16.3

bash-3.2$ cat hello.c
#include <stdio.h>

int main(void)
{
	printf("Hello World\n");
	return 0;
}
bash-3.2$ clang hello.c -o hello -Wall -ggdb
bash-3.2$ gdb ./hello
warning: Found custom handler for signal 3 (Quit: 3) preinstalled.
warning: Found custom handler for signal 4 (Illegal instruction: 4) preinstalled.
warning: Found custom handler for signal 5 (Trace/BPT trap: 5) preinstalled.
warning: Found custom handler for signal 6 (Abort trap: 6) preinstalled.
warning: Found custom handler for signal 8 (Floating point exception: 8) preinstalled.
warning: Found custom handler for signal 10 (Bus error: 10) preinstalled.
warning: Found custom handler for signal 11 (Segmentation fault: 11) preinstalled.
Some signal dispositions inherited from the environment (SIG_DFL/SIG_IGN)
won't be propagated to spawned programs.
GNU gdb (GDB) 16.3
Copyright (C) 2024 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Type "show copying" and "show warranty" for details.
This GDB was configured as "x86_64-apple-darwin23.6.0".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<https://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
    <http://www.gnu.org/software/gdb/documentation/>.

For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from ./hello...
Reading symbols from /Users/jianfeiye/test/ctest/hello.dSYM/Contents/Resources/DWARF/hello...
DW_FORM_GNU_str_index or DW_FORM_strx used without .debug_str section in CU at offset 0x0 [in module /Users/jianfeiye/test/ctest/hello.dSYM/Contents/Resources/DWARF/hello]
(gdb) b main
DW_FORM_GNU_str_index or DW_FORM_strx used without .debug_str section in CU at offset 0x0 [in module /Users/jianfeiye/test/ctest/hello.dSYM/Contents/Resources/DWARF/hello]
(gdb) run
Starting program: /Users/jianfeiye/test/ctest/hello 
[New Thread 0x2403 of process 40918]
[Thread 0x2403 of process 40918 exited]
[New Thread 0x2903 of process 40918]
warning: unhandled dyld version (17)
Hello World
[Inferior 1 (process 40918) exited normally]
(gdb) q
bash-3.2$ clang hello.c -o hello -Wall -gdwarf-4
bash-3.2$ gdb ./hello
warning: Found custom handler for signal 3 (Quit: 3) preinstalled.
warning: Found custom handler for signal 4 (Illegal instruction: 4) preinstalled.
warning: Found custom handler for signal 5 (Trace/BPT trap: 5) preinstalled.
warning: Found custom handler for signal 6 (Abort trap: 6) preinstalled.
warning: Found custom handler for signal 8 (Floating point exception: 8) preinstalled.
warning: Found custom handler for signal 10 (Bus error: 10) preinstalled.
warning: Found custom handler for signal 11 (Segmentation fault: 11) preinstalled.
Some signal dispositions inherited from the environment (SIG_DFL/SIG_IGN)
won't be propagated to spawned programs.
GNU gdb (GDB) 16.3
Copyright (C) 2024 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Type "show copying" and "show warranty" for details.
This GDB was configured as "x86_64-apple-darwin23.6.0".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<https://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
    <http://www.gnu.org/software/gdb/documentation/>.

For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from ./hello...
Reading symbols from /Users/jianfeiye/test/ctest/hello.dSYM/Contents/Resources/DWARF/hello...
(gdb) b main
Breakpoint 1 at 0x10000047f: file hello.c, line 5.
(gdb) run
Starting program: /Users/jianfeiye/test/ctest/hello 
[New Thread 0x2703 of process 41059]
^C[New Thread 0x2603 of process 41059]
[Thread 0x2703 of process 41059 exited]
warning: unhandled dyld version (17)

Thread 2 hit Breakpoint 1, main () at hello.c:5
5		printf("Hello World\n");
(gdb) q
A debugging session is active.

	Inferior 1 [process 41059] will be killed.

Quit anyway? (y or n) y
bash-3.2$ clang hello.c -o hello -Wall -gdwarf-4
bash-3.2$ gdb ./hello
warning: Found custom handler for signal 3 (Quit: 3) preinstalled.
warning: Found custom handler for signal 4 (Illegal instruction: 4) preinstalled.
warning: Found custom handler for signal 5 (Trace/BPT trap: 5) preinstalled.
warning: Found custom handler for signal 6 (Abort trap: 6) preinstalled.
warning: Found custom handler for signal 8 (Floating point exception: 8) preinstalled.
warning: Found custom handler for signal 10 (Bus error: 10) preinstalled.
warning: Found custom handler for signal 11 (Segmentation fault: 11) preinstalled.
Some signal dispositions inherited from the environment (SIG_DFL/SIG_IGN)
won't be propagated to spawned programs.
GNU gdb (GDB) 16.3
Copyright (C) 2024 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Type "show copying" and "show warranty" for details.
This GDB was configured as "x86_64-apple-darwin23.6.0".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<https://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
    <http://www.gnu.org/software/gdb/documentation/>.

For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from ./hello...
Reading symbols from /Users/jianfeiye/test/ctest/hello.dSYM/Contents/Resources/DWARF/hello...
(gdb) b main
Breakpoint 1 at 0x10000047f: file hello.c, line 5.
(gdb) run
Starting program: /Users/jianfeiye/test/ctest/hello 
[New Thread 0x2203 of process 41193]
[Thread 0x2203 of process 41193 exited]
[New Thread 0x2603 of process 41193]
warning: unhandled dyld version (17)

Thread 2 hit Breakpoint 1, main () at hello.c:5
5		printf("Hello World\n");
(gdb) n
Hello World
6		return 0;
(gdb) 
0x00007ff809dc8530 in ?? ()
(gdb) c
Continuing.
[Inferior 1 (process 41193) exited normally]
(gdb) q
bash-3.2$ gcc-15 hello.c -o hello -Wall -gdwarf-4
bash-3.2$ gdb ./hello
warning: Found custom handler for signal 3 (Quit: 3) preinstalled.
warning: Found custom handler for signal 4 (Illegal instruction: 4) preinstalled.
warning: Found custom handler for signal 5 (Trace/BPT trap: 5) preinstalled.
warning: Found custom handler for signal 6 (Abort trap: 6) preinstalled.
warning: Found custom handler for signal 8 (Floating point exception: 8) preinstalled.
warning: Found custom handler for signal 10 (Bus error: 10) preinstalled.
warning: Found custom handler for signal 11 (Segmentation fault: 11) preinstalled.
Some signal dispositions inherited from the environment (SIG_DFL/SIG_IGN)
won't be propagated to spawned programs.
GNU gdb (GDB) 16.3
Copyright (C) 2024 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Type "show copying" and "show warranty" for details.
This GDB was configured as "x86_64-apple-darwin23.6.0".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<https://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
    <http://www.gnu.org/software/gdb/documentation/>.

For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from ./hello...
Reading symbols from /Users/jianfeiye/test/ctest/hello.dSYM/Contents/Resources/DWARF/hello...
(gdb) b main
DWARF Error: DW_FORM_line_strp used without required section
(gdb) run
Starting program: /Users/jianfeiye/test/ctest/hello 
[New Thread 0x2303 of process 41426]
^C[Thread 0x2303 of process 41426 exited]
[New Thread 0x2403 of process 41426]
warning: unhandled dyld version (17)
Hello World
[Inferior 1 (process 41426) exited normally]
(gdb) q
bash-3.2$ 

[Kediel]

I found the -gdwarf solution to work for gcc and was able to debug my c program using pwndbg.

[adah1972]

I found the -gdwarf solution to work for gcc and was able to debug my c program using pwndbg.

I've just checked and found that pwndbg uses lldb on macOS. lldb never has a problem on macOS.

[yjfvictor]

I found the -gdwarf solution to work for gcc and was able to debug my c program using pwndbg.

lldb always works. It is the gdb's problem.

[Kediel]

I found the -gdwarf solution to work for gcc and was able to debug my c program using pwndbg.

I've just checked and found that pwndbg uses lldb on macOS. lldb never has a problem on macOS.

Where did you check? I have both installed via brew and there are two casks listed. Even following the code down locally shows that gdb is used.

[adah1972]

Where did you check?

On its GitHub page:

Use Case	Supported Debugger
Debugging Linux binaries or ELF files	GDB, LLDB
Debugging Mach-O binaries on macOS	LLDB
Linux kernel debugging (qemu-system)	GDB, LLDB
Linux user-space emulation (qemu-user)	GDB
Embedded debugging (ARM Cortex M* or RISC-V/32)	GDB, LLDB

https://github.com/pwndbg/pwndbg