* symtab.c (multiple_symbols_ask, multiple_symbols_all)

        (multiple_symbols_cancel): New constants.
        (multiple_symbols_modes, multiple_symbols_mode): New static globals.
        (multiple_symbols_select_mode): New function.
        (_initialize_symtab): Add new set/show multiple-symbols commands.
        * symtab.h (multiple_symbols_ask, multiple_symbols_all)
        (multiple_symbols_cancel, multiple_symbols_select_mode): Declare.
        * ada-lang.c (user_select_syms): Add handling of new multiple-symbols
        setting.
        * linespec.c (decode_line_2): Likewise.

5 files changed, 106 insertions, 22 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 5c30714640a..e47a277f609 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,16 @@
+2008-04-03  Joel Brobecker  <brobecker@adacore.com>
+
+	* symtab.c (multiple_symbols_ask, multiple_symbols_all)
+	(multiple_symbols_cancel): New constants.
+	(multiple_symbols_modes, multiple_symbols_mode): New static globals.
+	(multiple_symbols_select_mode): New function.
+	(_initialize_symtab): Add new set/show multiple-symbols commands.
+	* symtab.h (multiple_symbols_ask, multiple_symbols_all)
+	(multiple_symbols_cancel, multiple_symbols_select_mode): Declare.
+	* ada-lang.c (user_select_syms): Add handling of new multiple-symbols
+	setting.
+	* linespec.c (decode_line_2): Likewise.
+
 2008-04-03  Doug Evans  <dje@sebabeach.org>
 
 	* symtab.h (enum free_code): Delete free_contents, unused.
diff --git a/gdb/ada-lang.c b/gdb/ada-lang.c
index 2f0f55f5fb8..6e829f057d2 100644
--- a/gdb/ada-lang.c
+++ b/gdb/ada-lang.c
@@ -3312,12 +3312,24 @@ user_select_syms (struct ada_symbol_info *syms, int nsyms, int max_results)
   int *chosen = (int *) alloca (sizeof (int) * nsyms);
   int n_chosen;
   int first_choice = (max_results == 1) ? 1 : 2;
+  const char *select_mode = multiple_symbols_select_mode ();
 
   if (max_results < 1)
     error (_("Request to select 0 symbols!"));
   if (nsyms <= 1)
     return nsyms;
 
+  if (select_mode == multiple_symbols_cancel)
+    error (_("\
+canceled because the command is ambiguous\n\
+See set/show multiple-symbol."));
+  
+  /* If select_mode is "all", then return all possible symbols.
+     Only do that if more than one symbol can be selected, of course.
+     Otherwise, display the menu as usual.  */
+  if (select_mode == multiple_symbols_all && max_results > 1)
+    return nsyms;
+
   printf_unfiltered (_("[0] cancel\n"));
   if (max_results > 1)
     printf_unfiltered (_("[1] all\n"));
diff --git a/gdb/linespec.c b/gdb/linespec.c
index b3a46b46a23..f78a681406d 100644
--- a/gdb/linespec.c
+++ b/gdb/linespec.c
@@ -491,7 +491,13 @@ decode_line_2 (struct symbol *sym_arr[], int nelts, int funfirstline,
   char *symname;
   struct cleanup *old_chain;
   char **canonical_arr = (char **) NULL;
+  const char *select_mode = multiple_symbols_select_mode ();
 
+  if (select_mode == multiple_symbols_cancel)
+    error (_("\
+canceled because the command is ambiguous\n\
+See set/show multiple-symbol."));
+  
   values.sals = (struct symtab_and_line *)
     alloca (nelts * sizeof (struct symtab_and_line));
   return_values.sals = (struct symtab_and_line *)
@@ -507,38 +513,52 @@ decode_line_2 (struct symbol *sym_arr[], int nelts, int funfirstline,
     }
 
   i = 0;
-  printf_unfiltered (_("[0] cancel\n[1] all\n"));
   while (i < nelts)
     {
       init_sal (&return_values.sals[i]);	/* Initialize to zeroes.  */
       init_sal (&values.sals[i]);
       if (sym_arr[i] && SYMBOL_CLASS (sym_arr[i]) == LOC_BLOCK)
-	{
-	  values.sals[i] = find_function_start_sal (sym_arr[i], funfirstline);
-	  if (values.sals[i].symtab)
-	    printf_unfiltered ("[%d] %s at %s:%d\n",
-			       (i + 2),
-			       SYMBOL_PRINT_NAME (sym_arr[i]),
-			       values.sals[i].symtab->filename,
-			       values.sals[i].line);
-	  else
-	    printf_unfiltered (_("[%d] %s at ?FILE:%d [No symtab? Probably broken debug info...]\n"),
-			       (i + 2),
-			       SYMBOL_PRINT_NAME (sym_arr[i]),
-			       values.sals[i].line);
-
-	}
-      else
-	printf_unfiltered (_("?HERE\n"));
+	values.sals[i] = find_function_start_sal (sym_arr[i], funfirstline);
       i++;
     }
 
-  prompt = getenv ("PS2");
-  if (prompt == NULL)
+  /* If select_mode is "all", then do not print the multiple-choice
+     menu and act as if the user had chosen choice "1" (all).  */
+  if (select_mode == multiple_symbols_all)
+    args = "1";
+  else
     {
-      prompt = "> ";
+      i = 0;
+      printf_unfiltered (_("[0] cancel\n[1] all\n"));
+      while (i < nelts)
+        {
+          if (sym_arr[i] && SYMBOL_CLASS (sym_arr[i]) == LOC_BLOCK)
+            {
+              if (values.sals[i].symtab)
+                printf_unfiltered ("[%d] %s at %s:%d\n",
+                                   (i + 2),
+                                   SYMBOL_PRINT_NAME (sym_arr[i]),
+                                   values.sals[i].symtab->filename,
+                                   values.sals[i].line);
+              else
+                printf_unfiltered (_("[%d] %s at ?FILE:%d [No symtab? Probably broken debug info...]\n"),
+                                   (i + 2),
+                                   SYMBOL_PRINT_NAME (sym_arr[i]),
+                                   values.sals[i].line);
+
+            }
+          else
+            printf_unfiltered (_("?HERE\n"));
+          i++;
+        }
+
+      prompt = getenv ("PS2");
+      if (prompt == NULL)
+        {
+          prompt = "> ";
+        }
+      args = command_line_input (prompt, 0, "overload-choice");
     }
-  args = command_line_input (prompt, 0, "overload-choice");
 
   if (args == 0 || *args == 0)
     error_no_arg (_("one or more choice numbers"));
diff --git a/gdb/symtab.c b/gdb/symtab.c
index ddd2310165d..aa401ad034e 100644
--- a/gdb/symtab.c
+++ b/gdb/symtab.c
@@ -124,6 +124,30 @@ void _initialize_symtab (void);
 
 /* */
 
+/* Allow the user to configure the debugger behavior with respect
+   to multiple-choice menus when more than one symbol matches during
+   a symbol lookup.  */
+
+const char const multiple_symbols_ask[] = "ask";
+const char const multiple_symbols_all[] = "all";
+const char const multiple_symbols_cancel[] = "cancel";
+static const char *multiple_symbols_modes[] =
+{
+  multiple_symbols_ask,
+  multiple_symbols_all,
+  multiple_symbols_cancel,
+  NULL
+};
+static const char *multiple_symbols_mode = multiple_symbols_all;
+
+/* Read-only accessor to AUTO_SELECT_MODE.  */
+
+const char *
+multiple_symbols_select_mode (void)
+{
+  return multiple_symbols_mode;
+}
+
 /* The single non-language-specific builtin type */
 struct type *builtin_type_error;
 
@@ -4422,6 +4446,15 @@ All global and static variable names, or those matching REGEXP."));
 All global and static variable names, or those matching REGEXP."));
     }
 
+  add_setshow_enum_cmd ("multiple-symbols", no_class,
+                        multiple_symbols_modes, &multiple_symbols_mode,
+                        _("\
+Set the debugger behavior when more than one symbol are possible matches\n\
+in an expression."), _("\
+Show how the debugger handles ambiguities in expressions."), _("\
+Valid values are \"ask\", \"all\", \"cancel\", and the default is \"all\"."),
+                        NULL, NULL, &setlist, &showlist);
+
   /* Initialize the one built-in type that isn't language dependent... */
   builtin_type_error = init_type (TYPE_CODE_ERROR, 0, 0,
 				  "<unknown type>", (struct objfile *) NULL);
diff --git a/gdb/symtab.h b/gdb/symtab.h
index 9fec2e79fb3..65b1cb4edf1 100644
--- a/gdb/symtab.h
+++ b/gdb/symtab.h
@@ -998,6 +998,12 @@ extern int asm_demangle;
 
 /* symtab.c lookup functions */
 
+extern const char const multiple_symbols_ask[];
+extern const char const multiple_symbols_all[];
+extern const char const multiple_symbols_cancel[];
+
+const char *multiple_symbols_select_mode (void);
+
 /* lookup a symbol table by source file name */
 
 extern struct symtab *lookup_symtab (const char *);