[PATCH] Remove iterate_over_block_arg_vars_printing

[PATCH] Remove iterate_over_block_arg_vars_printing

[Tom Tromey]

Back in commit c76bd1b0 ("Remove symbol lookup of arguments"), I
removed some old stabs code that performed a double lookup of argument
symbols.

I was surprised today to find that this double-lookup re-entered the
tree in commit 2465b9e4 ("gdb: add annotation in 'info locals' command
for variables shadowing case").

That patch added copies of a couple of block iteration functions.  The
function in question, iterate_over_block_arg_vars_printing, is not
really needed.  This patch removes it, removing the old stabs code as
a consequence.

Regression tested on x86-64 Fedora 43.
---
 gdb/stack.c | 37 +++++--------------------------------
 gdb/stack.h |  7 -------
 2 files changed, 5 insertions(+), 39 deletions(-)

diff --git a/gdb/stack.c b/gdb/stack.c
index 003811e9c08..c380cf4f7d0 100644
--- a/gdb/stack.c
+++ b/gdb/stack.c
@@ -2453,37 +2453,6 @@ iterate_over_block_arg_vars (const struct block *b,
     }
 }
 
-/* See stack.h.  */
-
-void
-iterate_over_block_arg_vars_printing
-  (const struct block *b,
-   iterate_over_block_arg_local_vars_cb_printing cb)
-{
-  for (struct symbol *sym : block_iterator_range (b))
-    {
-      /* Don't worry about things which aren't arguments.  */
-      if (sym->is_argument ())
-	{
-	  /* We have to look up the symbol because arguments can have
-	     two entries (one a parameter, one a local) and the one we
-	     want is the local, which lookup_symbol will find for us.
-	     This includes gcc1 (not gcc2) on the sparc when passing a
-	     small structure and gcc2 when the argument type is float
-	     and it is passed as a double and converted to float by
-	     the prologue (in the latter case the type of the LOC_ARG
-	     symbol is double and the type of the LOC_LOCAL symbol is
-	     float).  There are also LOC_ARG/LOC_REGISTER pairs which
-	     are not combined in symbol-reading.  */
-
-	  struct symbol *sym2
-	    = lookup_symbol_search_name (sym->search_name (),
-					 b, SEARCH_VAR_DOMAIN).symbol;
-	  cb (sym->print_name (), sym2, var_shadowing::NONE);
-	}
-    }
-}
-
 /* Print all argument variables of the function of FRAME.
    Print them with values to STREAM.
    If REGEXP is not NULL, only print argument variables whose name
@@ -2526,7 +2495,11 @@ print_frame_arg_vars (const frame_info_ptr &frame,
   cb_data.stream = stream;
   cb_data.values_printed = 0;
 
-  iterate_over_block_arg_vars_printing (func->value_block (), cb_data);
+  iterate_over_block_arg_vars (func->value_block (),
+    [&] (const char *print_name, symbol *sym)
+      {
+	cb_data (print_name, sym, var_shadowing::NONE);
+      });
 
   if (!cb_data.values_printed && !quiet)
     {
diff --git a/gdb/stack.h b/gdb/stack.h
index 4f7c223f47f..819f5993004 100644
--- a/gdb/stack.h
+++ b/gdb/stack.h
@@ -39,13 +39,6 @@ void iterate_over_block_arg_vars (const struct block *block,
 void iterate_over_block_local_vars (const struct block *block,
 				    iterate_over_block_arg_local_vars_cb cb);
 
-/* Iterate over all the argument variables in block B, call CB for
-   each variable with its print name, symbol, and shadowing status.  */
-
-void iterate_over_block_arg_vars_printing
-  (const struct block *block,
-   iterate_over_block_arg_local_vars_cb_printing cb);
-
 /* Iterate over all the local variables in block B, including all its
    superblocks, stopping when the top-level block is reached.  Call CB
    for each variable with its print name, symbol, and shadowing status

base-commit: 71400155a3c026269f2602fa168a15b739ae8e39
-- 
2.55.0

Re: [PATCH] Remove iterate_over_block_arg_vars_printing

[Simon Marchi]

On 2026-09-15 12:56, Tom Tromey wrote:
> Back in commit c76bd1b0 ("Remove symbol lookup of arguments"), I
> removed some old stabs code that performed a double lookup of argument
> symbols.
> 
> I was surprised today to find that this double-lookup re-entered the
> tree in commit 2465b9e4 ("gdb: add annotation in 'info locals' command
> for variables shadowing case").
> 
> That patch added copies of a couple of block iteration functions.  The
> function in question, iterate_over_block_arg_vars_printing, is not
> really needed.  This patch removes it, removing the old stabs code as
> a consequence.

I guess the unneeded part is the "we need to look up the argument again
because some things gcc 1 and 2 did".  Looks fine to me.

Approved-By: Simon Marchi <simon.marchi@efficios.com>

Simon