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

[Keith Seitz <keiths@redhat.com>]

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))