Re: [PATCH 1/2] Fix "list ambiguous_variable"

Keith Seitz
2017-09-06T18:41:08Z

On 09/04/2017 11:47 AM, Pedro Alves wrote:
> The "list" command allows specifying the name of variables as
> argument, not just functions, so that users can type "list
> a_global_variable".
>
> That support is a broken when it comes to ambiguous locations though.

Very nice!

FWIW, I have only one trivial nit (below).

Keith

PS. Out of curiosity, I hacked up a test program with multiple symbols named "ambiguous," both functions and variables. Well done!

(gdb) set listsize 3
(gdb) list ambiguous
file: "amb1.c", line number: 5, symbol: "ambiguous"
4
5 static int ambiguous = 0;
6
file: "amb2.c", line number: 3, symbol: "ambiguous"
2 ambiguous (void)
3 {
4 return 0;
file: "amb3.c", line number: 3, symbol: "ambiguous"
2 ambiguous (void)
3 {
4 return 0;
file: "amb4.c", line number: 1, symbol: "ambiguous"
1 static int ambiguous = 0;
2
3 int

> diff --git a/gdb/linespec.c b/gdb/linespec.c
> index 4801808..d72d19d 100644
> --- a/gdb/linespec.c
> +++ b/gdb/linespec.c
> @@ -4318,35 +4318,45 @@ minsym_found (struct linespec_state *self, struct objfile *objfile,
> CORE_ADDR pc;
> struct symtab_and_line sal;
>
> - sal = find_pc_sect_line (MSYMBOL_VALUE_ADDRESS (objfile, msymbol),
> - (struct obj_section *) 0, 0);
> - sal.section = MSYMBOL_OBJ_SECTION (objfile, msymbol);
> + if (msymbol_is_text (msymbol))
> + {
> + sal = find_pc_sect_line (MSYMBOL_VALUE_ADDRESS (objfile, msymbol),
> + (struct obj_section *) 0, 0);
> + sal.section = MSYMBOL_OBJ_SECTION (objfile, msymbol);
>
> - /* The minimal symbol might point to a function descriptor;
> - resolve it to the actual code address instead. */
> - pc = gdbarch_convert_from_func_ptr_addr (gdbarch, sal.pc, &current_target);
> - if (pc != sal.pc)
> - sal = find_pc_sect_line (pc, NULL, 0);
> + /* The minimal symbol might point to a function descriptor;
> + resolve it to the actual code address instead. */
> + pc = gdbarch_convert_from_func_ptr_addr (gdbarch, sal.pc, &current_target);

This line exceeds the 80-char line length limit.

> + if (pc != sal.pc)
> + sal = find_pc_sect_line (pc, NULL, 0);
>
> - if (self->funfirstline)
> - {
> - if (sal.symtab != NULL
> - && (COMPUNIT_LOCATIONS_VALID (SYMTAB_COMPUNIT (sal.symtab))
> - || SYMTAB_LANGUAGE (sal.symtab) == language_asm))
> + if (self->funfirstline)
> {
> - /* If gdbarch_convert_from_func_ptr_addr does not apply then
> - sal.SECTION, sal.LINE&co. will stay correct from above.
> - If gdbarch_convert_from_func_ptr_addr applies then
> - sal.SECTION is cleared from above and sal.LINE&co. will
> - stay correct from the last find_pc_sect_line above. */
> - sal.pc = MSYMBOL_VALUE_ADDRESS (objfile, msymbol);
> - sal.pc = gdbarch_convert_from_func_ptr_addr (gdbarch, sal.pc,
> - &current_target);
> - if (gdbarch_skip_entrypoint_p (gdbarch))
> - sal.pc = gdbarch_skip_entrypoint (gdbarch, sal.pc);
> + if (sal.symtab != NULL
> + && (COMPUNIT_LOCATIONS_VALID (SYMTAB_COMPUNIT (sal.symtab))
> + || SYMTAB_LANGUAGE (sal.symtab) == language_asm))
> + {
> + /* If gdbarch_convert_from_func_ptr_addr does not apply then
> + sal.SECTION, sal.LINE&co. will stay correct from above.
> + If gdbarch_convert_from_func_ptr_addr applies then
> + sal.SECTION is cleared from above and sal.LINE&co. will
> + stay correct from the last find_pc_sect_line above. */
> + sal.pc = MSYMBOL_VALUE_ADDRESS (objfile, msymbol);
> + sal.pc = gdbarch_convert_from_func_ptr_addr (gdbarch, sal.pc,
> + &current_target);
> + if (gdbarch_skip_entrypoint_p (gdbarch))
> + sal.pc = gdbarch_skip_entrypoint (gdbarch, sal.pc);
> + }
> + else
> + skip_prologue_sal (&sal);
> }
> - else
> - skip_prologue_sal (&sal);
> + }
> + else
> + {
> + sal.objfile = objfile;
> + sal.pc = MSYMBOL_VALUE_ADDRESS (objfile, msymbol);
> + sal.pspace = current_program_space;
> + sal.section = MSYMBOL_OBJ_SECTION (objfile, msymbol);
> }
>
> if (maybe_add_address (self->addr_set, objfile->pspace, sal.pc))