Disassembly window/mode

[cgdb]

Disassembly window/mode

[mikesart]

You should be able to hit and then type ":set dis" to get disassembly now...

[mikesart]

+1 on this. I've been using disassemble-next-line as workaround, but it'd sure be fantastic to have a full disassemble window... Thanks!

[ScoreUnder]

+1 for an essential debugging feature. When you get a crash in an empty destructor, source is no help!

[ashwin]

+1 Disassembly and registers windows!

[stevenhoneyman]

+1 ...it was looking like a good frontend until I went looking for this feature

[akrasuski1]

+1 I discovered cgdb recently, and it's awesome. But with disassembly window instead of source it would be even better ;)

[oblitum]

I've been using https://github.com/cyrus-and/gdb-dashboard instead of cgdb which I used for a long time. I prefer now the dashboard, it doesn't have the nice keybindings, etc, but also, it's nearer to GDB itself and provides nice visuals.

[mikesart]

We've been doing some work on cgdb on this fork: https://github.com/scottlu/cgdb
One of our primary goals is to add a disassembly window. Going to take a month or two as we need to switch over to gdb/mi first.
But yeah, I've been using cgdb for several years now and I love it. Can't wait to get a disassembly window - that is the main feature I really miss.

Hi @mikesart, have you completed the work or are you still working on this issue? If it works now, could you please share it? I also would like to use disassembly window and register windows in the long term. I have checkout your source and run it but couldn't see if it is supported or not.

[mikesart]

We have to switch over to gdb/mi, and get a full window manager in. These are decently large work items, so it's going to take a bit of time. Talking with Bob and Mike (cgdb authors) about getting some of our fixes in and doing this work right now, so hopefully our work will merge here sometime fairly soon and we'll start on the disassembly window. Thanks nexus226.

[honggyukim]

Hi @mikesart,

I put :set dis but it doesn't show the source window and disassembly window at the same time. The source window is switched to disassembly window. Is there any way to see both?

[brasko]

Here is the disasm expected behavior from the docs:

This option is used to enable or disable showing assembly code in cgdb.
The default value is off. When off, CGDB will display the source code
to the user. When no source code is available, CGDB will display the
assembly code.

When this option is enabled, CGDB will display the mixed
source and assembly when the source code is enabled and assembly code
when the source code is not available. Please note that when assembly
mode is displayed, it's displayed per function instead of per file.

Is this helpful?

[honggyukim]

@brasko Thanks for the comment. But it seems that it doesn't mean that :set dis shows the source code and assembly at the same time with separate windows. Please correct me if I'm wrong.

[mikesart]

This version added the ability to show disassembly in the source window and mixed mode source + disassembly if you're running gdb v7.11 or higher. You are correct in that it isn't in a separate window, but I believe this new functionality is extremely useful (I've been using it a lot) and I think it addresses the original bug entry, at least if you've got gdb v7.11+. When we get a full window manager in we'll be able to add separate source / disassembly / register / watch windows - some of those features are requested in bug #43. Thanks honggyukim.

[honggyukim]

Ah.. I see. I've just upgraded gdb to v7.12 and found what you meant. I would love to use this feature although it doesn't have separate windows. I just put the screen so that other people can see the actual output.

 1| Dump of assembler code for function main:
 2| /home/honggyu/hello.c:
 3| 4       {
 4|    0x00000000004005bd <+0>:     push   %rbp
 5|    0x00000000004005be <+1>:     mov    %rsp,%rbp
 6|
 7| 5         printf("Hello World!
 8|    0x00000000004005c1 <+4>:     mov    $0x400674,%edi
 9|    0x00000000004005c6 <+9>:     callq  0x400490 <puts@plt>
10|
11| 6         fflush(stdout);
12+--> 0x00000000004005cb <+14>:    mov    0x200a7e(%rip),%rax        # 0x601050 <stdout@@GLIBC_2.2.5>
13|    0x00000000004005d2 <+21>:    mov    %rax,%rdi
14|    0x00000000004005d5 <+24>:    callq  0x4004c0 <fflush@plt>
15|
16| 7         return 0;
17|    0x00000000004005da <+29>:    mov    $0x0,%eax
18|
19| 8       }
20|    0x00000000004005df <+34>:    pop    %rbp
21|    0x00000000004005e0 <+35>:    retq
22| End of assembler dump.

Thanks a lot for this work!

[honggyukim]

Hm.. after keep using it. It doesn't seem to be stable. I found two problems.

1. The arrow is not properly updated as I executed a single instruction.
2. source and assembly mixed window is not always shown when I do :set disasm. Sometimes it just shows assembly window only.

I will see if the problem is shown all the time.

[mikesart]

For 2, can you check that source is available using the "disasm /s $pc" gdb command? If it is, please enter a bug about it.

And 1 just sounds like a bug. Please enter a new one with whatever repro instructions you can on it.

Thanks Honggyukim.

[honggyukim]

For 2, can you check that source is available using the "disasm /s $pc" gdb command? If it is, please enter a bug about it.

The source code is available but the source window randomly shows "source and assembly mixed" or "assembly only". I just compiled the source with -g option. Please see #117.

And 1 just sounds like a bug. Please enter a new one with whatever repro instructions you can on it.

To reproduce it, just set a breakpoint at main function and run it. Then just give si commands. But it doesn't update the arrow one by one for each instruction. The sequence is simple but I will create a new issue for it. Please see #118.

[Freed-Wu]

Can gdb-dashboard be helpful?

[Freed-Wu]

Similar issue: #162