[Issue 3387] New: gdb: symbols in the backtrace are not demangled

Oct 12, 2009

Leandro Lucarella

Oct 12, 2009

Leandro Lucarella

Oct 20, 2009

Leandro Lucarella

Apr 02, 2010

Robert Clipsham

October 12, 2009

[Issue 3387] New: gdb: symbols in the backtrace are not demangled

Posted by Leandro Lucarella

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Leandro Lucarella

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http://d.puremagic.com/issues/show_bug.cgi?id=3387

           Summary: gdb: symbols in the backtrace are not demangled
           Product: D
           Version: 1.047
          Platform: x86
        OS/Version: Linux
            Status: NEW
          Severity: regression
          Priority: P2
         Component: DMD
        AssignedTo: nobody@puremagic.com
        ReportedBy: llucax@gmail.com


--- Comment #0 from Leandro Lucarella <llucax@gmail.com> 2009-10-12 13:04:56 PDT ---
In DMD 1.046 or older, the backtrace were broken but the symbol were demangled (using the D GDB patch at least).

Starting at version 1.047, the symbols are not demangled anymore in GDB.

Same test program as bug 136:

--------
void main() {
    static int i = 0;
    while (i++ < 10)
        main();
    *(cast(int *)0) = 0;
}
--------

DMD evolution:

1.046
=====
--------------------
GNU gdb (GDB) 7.0.50.20090919
[...]
Reading symbols from /home/luca/tesis/dmd-1.049/dmd/linux/bug136...done.
(gdb) bt
No stack.
(gdb) run
Starting program: /home/luca/tesis/dmd-1.049/dmd/linux/bug136
[Thread debugging using libthread_db enabled]

Program received signal SIGSEGV, Segmentation fault.
0x08049b12 in D main ()
Current language:  auto
The current source language is "auto; currently asm".
(gdb) bt
#0  0x08049b12 in D main ()
#1  0xbffff4d4 in ?? ()
#2  0xbffff4a0 in ?? ()
#3  0x08049b0c in D main ()
Backtrace stopped: previous frame inner to this frame (corrupt stack?)
--------------------


1.047
=====
--------------------
GNU gdb (GDB) 7.0.50.20090919
[...]
Reading symbols from /home/luca/tesis/dmd-1.049/dmd/linux/bug136...done.
(gdb) run
Starting program: /home/luca/tesis/dmd-1.049/dmd/linux/bug136
[Thread debugging using libthread_db enabled]

Program received signal SIGSEGV, Segmentation fault.
0x08049b12 in _Dmain () at bin/bug136.d:6
6        *(cast(int *)0) = 0;
Current language:  auto
The current source language is "auto; currently d".
(gdb) bt
#0  0x08049b12 in _Dmain () at bin/bug136.d:6
#1  0xbffff4d4 in ?? ()
#2  0xbffff4a0 in ?? ()
#3  0x08049b0c in _Dmain () at bin/bug136.d:5
Backtrace stopped: previous frame inner to this frame (corrupt stack?)
--------------------


1.049
=====
--------------------
--------------------
GNU gdb (GDB) 7.0.50.20090919
[...]
Reading symbols from /home/luca/tesis/dmd-1.049/dmd/linux/bug136...done.
(gdb) run
Starting program: /home/luca/tesis/dmd-1.049/dmd/linux/bug136
[Thread debugging using libthread_db enabled]

Program received signal SIGSEGV, Segmentation fault.
0x08049b12 in _Dmain () at bin/bug136.d:6
6        *(cast(int *)0) = 0;
Current language:  auto
The current source language is "auto; currently d".
(gdb) bt
#0  0x08049b12 in _Dmain () at bin/bug136.d:6
#1  0x08049b0c in _Dmain () at bin/bug136.d:5
#2  0x08049b0c in _Dmain () at bin/bug136.d:5
#3  0x08049b0c in _Dmain () at bin/bug136.d:5
#4  0x08049b0c in _Dmain () at bin/bug136.d:5
#5  0x08049b0c in _Dmain () at bin/bug136.d:5
#6  0x08049b0c in _Dmain () at bin/bug136.d:5
#7  0x08049b0c in _Dmain () at bin/bug136.d:5
#8  0x08049b0c in _Dmain () at bin/bug136.d:5
#9  0x08049b0c in _Dmain () at bin/bug136.d:5
#10 0x08049b0c in _Dmain () at bin/bug136.d:5
#11 0x08057599 in main ()
--------------------

The backtrace looks nice in DMD 1.049 but the symbols can't be demangled by GDB.

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http://d.puremagic.com/issues/show_bug.cgi?id=3387 --- Comment #1 from Leandro Lucarella <llucax@gmail.com> 2009-10-12 13:59:32 PDT --- BTW DMD 2.034 works fine: ---------- (gdb) bt #0 0x080490cb in D main () #1 0x080490c5 in D main () #2 0x080490c5 in D main () #3 0x080490c5 in D main () #4 0x080490c5 in D main () #5 0x080490c5 in D main () #6 0x080490c5 in D main () #7 0x080490c5 in D main () #8 0x080490c5 in D main () #9 0x080490c5 in D main () #10 0x080490c5 in D main () #11 0x080493b4 in rt.dmain2.main() () #12 0x080491bd in rt.dmain2.main() () #13 0x080493f6 in rt.dmain2.main() () #14 0x080491bd in rt.dmain2.main() () #15 0x08049168 in main () ------------ -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------

http://d.puremagic.com/issues/show_bug.cgi?id=3387 Leandro Lucarella <llucax@gmail.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Version|1.047 |1.051 Severity|regression |normal --- Comment #2 from Leandro Lucarella <llucax@gmail.com> 2009-10-19 19:07:58 PDT --- It doesn't look like a regression after all, it seems to depend on whatever -g or -gc is used. With -g I get the properly demangled names, but with -gc I don't. The problem is, -g is broken with GDB, so I can't use -g. It would be a problem to have -gc producing the necessary debug info to get properly demangled names? Sorry for the noise. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------

http://d.puremagic.com/issues/show_bug.cgi?id=3387 Robert Clipsham <robert@octarineparrot.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Keywords|wrong-code | Status|NEW |RESOLVED CC| |robert@octarineparrot.com Resolution| |INVALID --- Comment #3 from Robert Clipsham <robert@octarineparrot.com> 2010-04-02 22:46:37 BST --- I've removed the wrong-code keyword, and closing this bug, as it isn't a dmd issue. The code generated is correct, as -gc means D should pretend to be C... Which means symbol names have to be mangled, as otherwise they are not valid C symbols. It also means gdb won't demangle them, as it detects C and not D. The correct solution for this bug is to add support for the D extensions to gdb, there's nothing dmd can do about this without adding another debugging mode, something I think is best avoided. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------

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