gdb evaluate function in process core

Question

Is there a way to execute function in process core context in GDB?

The incentive is to run a function that will go through a large tree to find a specific node. I can walk the tree manually but I would like to build a function that will help me analyze the core.

Hence either a function or "GDB script" to run over the data tree.

Related question: (use pretty printer): [c++ - gdb pretty printing with direct function calls - Stack Overflow](https://stackoverflow.com/questions/8578320/gdb-pretty-printing-with-direct-function-calls) — user202729, Mar 10 '22 at 02:10

score 4 · Accepted Answer · answered Jan 17 '12 at 19:20

Is there a way to execute function in process core context in GDB?

No: you need a "live" inferior process for that.

I can walk the tree manually but I would like to build a function that will help me analyze the core.

You can do that using Python scripting built into recent GDB versions.

score 2 · Answer 2 · edited Jan 17 '12 at 10:57

2

gdb can call C functions. If you type p myfunction(...parameters...), gdb will evaluate the expression and print the returned value. Of course, the program you're debugging must be stopped.

edited Jan 17 '12 at 10:57

unwind

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answered Jan 17 '12 at 10:53

Giuseppe Guerrini

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I understand that on a running program this will work (and thanks for the input). My problem is that the program has already crashed and I need to call a function from the core context no a running program. – Hagai Jan 17 '12 at 12:44
Uhm... no, too late :( . The only hope is a gdb script, sorry – Giuseppe Guerrini Jan 17 '12 at 13:16
Of course, if you can catch the exception in gdb, the process is still alive and you can call your function. – Giuseppe Guerrini Jan 17 '12 at 13:18
No exception in my world **C** :) – Hagai Jan 17 '12 at 15:34
Oh, sorry! I'd say "segmentation fault" :D – Giuseppe Guerrini Jan 17 '12 at 16:36

gdb evaluate function in process core

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