Re: New scope checking patch

["Rob Quill" <rob.quill@gmail.com>]

On 18/01/2008, Jim Blandy <jimb@codesourcery.com> wrote:
>
> "Rob Quill" <rob.quill at gmail.com> writes:
> >> > +                       if (!have_full_symbols () && !have_partial_symbols ())
> >> > +                             error ("No symbol table is loaded.  Use the \"file\" command.");
> >>
> >> Too much indentation?
> >
> > Well, you would think so, but I've changed the tab spacing in vim to 8
> > and the way I have formatted it matches how everything else is
> > formatted.
>
> I swear I'm not harrassing you.  :) Once we can get these minor things
> taken care of, the patch looks ready to me.

Sorry about that. I was just frustrated because it feels like every
time I submit this wrong it makes me look bad :)

> The error should be indented two columns within the 'if'.  Here's what
> I see in most every other use of 'error' in the grammar section of the
> file.
>
>                   if (new_type == NULL)
>                     error ("No type \"%s\" within class or namespace \"%s\".",
>                            ncopy, TYPE_NAME (type));
>
> >> Closing brace should get its own line, since the opening brace did.
> >
> > This is what I thought too, but if you look at the rest of the file
> > (for example the case for "exp : exp ARROW name") the open brace
> > always starts on a new line and always ends on the same line.
>
> Right you are.
>
> >> When I view this (again, with 8-column tab stops), the 'case' is not
> >> lined up with the other cases, and the 'return' is not indented two
> >> spaces within the 'if'.
> >
> > Sorry, missed that. I've attached the fixed copy. I believe that the
> > amount of indentation matches the layout of the current file, and that
> > even though it looks like a lot in the context of the patch, all the
> > other grammar rules in the file use the same large amount of
> > indentation.
>
> This code block looks fine to me in your latest patch.
>
> The only other point left is the ChangeLog entry.  The one you posted
> was:
>
> 2008-01-17   Rob Quill <rob.quill@gmail.com>
>       * c-exp.y : Add $in_scope as a type of expression.
>
> This needs a little rearrangement, and a bit more detail.  A model to
> follow might be:
>
> 2008-01-07  Vladimir Prus  <vladimir@codesourcery.com>
>
>         Ignore change in name of dynamic linker during
>         execution on Solaris.  This also unbreaks pending breakpoints.
>
>         * solist.h (struct target_so_ops): New field same.
>         * solib-svr4.c (svr4_same): New.
>         (_initialize_svr4_solib): Register svr4_same.
>         * solib.c (update_solib_list): Use ops->same, if available.
>
> If the change merits it, it's nice to have a (brief) summary sentence
> at the top (substantial explanation belongs in comments in the code).
> Your "Add $in_scope ..." might go there.  Then, each change is
> attributed to a particular function, top-level declaration, or
> whatever grouping makes sense (in documentation, we put the section
> name in the parens).
>
> So your ChangeLog entry would need to mention IN_SCOPE as a new token
> you're defining, 'exp' (I guess) as the non-terminal symbol to which
> you're adding a grammar rule, and 'yylex' as the function to which
> you're adding a bit of code.

Ok, here we go.

Rob

2008-01-18   Rob Quill <rob.quill@gmail.com>

         Add $in_scope as a type of expression.
         * c-exp.y (IN_SCOPE): New token.
         (exp): IN_SCOPE (name): evaluates to 1 if name is in scope, 0
otherwise.
         (yylex): Match "$in_scope" as IN_SCOPE token

Index: gdb/c-exp.y
===================================================================
RCS file: /cvs/src/src/gdb/c-exp.y,v
retrieving revision 1.42
diff -u -p -r1.42 c-exp.y
--- gdb/c-exp.y	9 Jan 2008 19:27:15 -0000	1.42
+++ gdb/c-exp.y	18 Jan 2008 22:41:05 -0000
@@ -208,6 +208,8 @@ static int parse_number (char *, int, in
 %token TRUEKEYWORD
 %token FALSEKEYWORD

+/* $in_scope opperator */
+%token IN_SCOPE

 %left ','
 %left ABOVE_COMMA
@@ -251,6 +253,30 @@ exp1	:	exp
 	;

 /* Expressions, not including the comma operator.  */
+exp	:	IN_SCOPE '(' name_not_typename ')'
+			{
+			  struct type *int_type;
+			  struct minimal_symbol *min_symbol;
+
+			  /* If there are no symbols then just stop right away */
+			  if (!have_full_symbols () && !have_partial_symbols ())
+			    error ("No symbol table is loaded.  Use the \"file\" command.");
+
+			  /* Otherwise, prepare to write out the value */
+			  int_type = builtin_type (current_gdbarch)->builtin_int;
+			  write_exp_elt_opcode (OP_LONG);
+			  write_exp_elt_type (int_type);
+
+			  min_symbol =
+			    lookup_minimal_symbol (copy_name($3.stoken), NULL, NULL);
+			  if ($3.sym || min_symbol)
+			    write_exp_elt_longcst ((LONGEST) 1);
+			  else
+			    write_exp_elt_longcst ((LONGEST) 0);
+
+			  write_exp_elt_opcode (OP_LONG); }
+	;
+
 exp	:	'*' exp    %prec UNARY
 			{ write_exp_elt_opcode (UNOP_IND); }
 	;
@@ -1678,6 +1704,9 @@ yylex ()
   /* Catch specific keywords.  Should be done with a data structure.  */
   switch (namelen)
     {
+    case 9:
+      if (strncmp (tokstart, "$in_scope", 9) == 0)
+	return IN_SCOPE;
     case 8:
       if (strncmp (tokstart, "unsigned", 8) == 0)
 	return UNSIGNED;