Re: expanding c-macros in gdb

Choi, Jang-Wook
2001-12-05T11:40:20Z

Hi, let me tell you my method.

I use gdb through emacs and use emacs shortcut key C-c C-e after set
region for the macro, then emacs expand & show the macro to me.

After that I print the value in gdb.

cjw

On Wed, 5 Dec 2001, Howind Axel, Externer Dienstleister wrote:

> Hello,
>
> we are using gcc/gdb for development in C. The C code uses some
> macros for accessing data, for example:
>
> #define REFP_XYZ(i) xyz_ptr->s_xyz.r_xyz[i].xyz
> ...
> if (REFP_XYZ(a).abc != 0) ...
> ...
>
> Is there a way to make gdb understand that the command
> print REFP_XYZ(a).abc is the same as print xyz_ptr->s_xyz.r_xyz[i].xyz.abc?
>
> I have read in the gcc manual that compiling with -g3 stores information
> about
> all defined macros, so that "Some debuggers support macro expansion when you
> use `-g3'."
> This does not seem to work with gdb (gcc 2.95.2, gdb 5.0, on HP-UX 10.20).
>
> Then I thought about defining a macro printmac in gdb, but I have not found
> a way to
> do the expansion. What I'm thinking about is to call a shell- or sed-skript
> that does
> the expansion and pass the result on to the print command, something like
> this
> (transform is the name of a sed-script, that does the actual expansion):
>
> define printmac(arg)
> print `echo $arg | sed -f transform`
>
> Is something like this possible in gdb? Can I use a hook?
>
> Thanks in advance,
>
> Axel Howind
>
>