Re: variable objects and registers

Nick Roberts
2006-12-06T10:57:23Z

Vladimir Prus writes:
> This patch adds new command -var-registers that creates and returns a list of
> variable objects for all registers gdb knows. The command takes one option --
> the frame, which is specified just like for -var-create. While not all
> registers are saved, and so gdb might not know values of some registers in
> parent frames, for some registers it's possible, and frontends might want to
> access those values.

> Here's example output:

> -var-registers *
> ^done,registers={
^done,registers=[

> {name="var1",exp="$eax",numchild="0",value="16",type="int"},
> ............
> {name="var10",exp="$eflags",numchild="0",value="[ SF IF ID ]",

Since this command creates new variable objects, perhaps it should be called
something like -var-create-registers.

Alternatively, taking things further, instead of reusing some code for each
command through create_varobj_in_frame, perhaps you could have just one
command:

"-var-create" and "-var-create -r" for registers ("-var-create -m" for
memory-mapped registers).

I've not thought it through, I'm just brainstorming.

--- gdb/mi/mi-cmd-var.c (/patches/gdb/varobj_printing/gdb_mainline) (revision 2338)
+++ gdb/mi/mi-cmd-var.c (/patches/gdb/varobj_for_registers/gdb_mainline) (revision 2338)
@@ -68,16 +68,39 @@

/* VAROBJ operations */

+static struct varobj *
+create_varobj_in_frame (char *name, char *expression, char *frame)
+{
+ CORE_ADDR frameaddr = 0;
+ struct cleanup *cleanup;
+ enum varobj_type var_type;
+
+ if (strcmp (frame, "*") == 0)
+ var_type = USE_CURRENT_FRAME;
+ else if (strcmp (frame, "@") == 0)
+ var_type = USE_SELECTED_FRAME;
+ else
+ {
+ var_type = USE_SPECIFIED_FRAME;
+ frameaddr = string_to_core_addr (frame);
+ }
+
+ if (varobjdebug)
+ fprintf_unfiltered (gdb_stdlog,
+ "Name=\"%s\", Frame=\"%s\" (0x%s), Expression=\"%s\"\n",
+ name, frame, paddr (frameaddr), expression);
+
+ return varobj_create (name, expression, frameaddr, var_type);
+}
+

I think the function above should go in varobj.c

...
+ numregs = NUM_REGS + NUM_PSEUDO_REGS;
+
+ make_cleanup_ui_out_tuple_begin_end (uiout, "registers");

I think this should be

make_cleanup_ui_out_list_begin_end (uiout, "registers");

+
+ for (regnum = 0; regnum < numregs; regnum++)
+ {
+ if (REGISTER_NAME (regnum) != NULL
+ && *(REGISTER_NAME (regnum)) != '\0')
+ {
+ char *name;
+ char *expression;
+ struct varobj *var;
+ struct cleanup *cleanup_child;
+
+ name = varobj_gen_name ();
+ make_cleanup (free_current_contents, &name);
+
+ expression = xstrprintf ("$%s", REGISTER_NAME (regnum));
+ make_cleanup (xfree, expression);
+
+ var = create_varobj_in_frame (name, expression, frame);
+
+ cleanup_child = make_cleanup_ui_out_tuple_begin_end (uiout, NULL);
+ print_varobj (var, PRINT_ALL_VALUES, 1 /* print expression */);
+ do_cleanups (cleanup_child);
+ }
+ }
+
+ do_cleanups (cleanup);
+ return MI_CMD_DONE;
+}
+
+
+enum mi_cmd_result
mi_cmd_var_delete (char *command, char **argv, int argc)
{
char *name;

Daniel Jacobowitz writes:

> No one else had any comments, and it looks fine to me. The patch looks
> OK too. It'll want a testcase, naturally.

And documentation too, hopefully!

--
Nick http://www.inet.net.nz/~nickrob