Make the linespec/location completer ignore data symbols

Currently "b foo[TAB]" offers data symbols as completion candidates.
This doesn't make sense, since you can't set a breakpoint on data
symbols, only on code symbols.

 (gdb) b globa[TAB]
 (gdb) b global [ENTER]
 Function "global" not defined.
 Make breakpoint pending on future shared library load? (y or [n]) n
 (gdb) info symbol global
 global in section .rodata

So this patch makes linespec completion ignore data symbols.

gdb/ChangeLog:
2017-11-08  Pedro Alves  <palves@redhat.com>

	* ada-lang.c (ada_make_symbol_completion_list): Use
	completion_skip_symbol.
	* symtab.c (symbol_is_function_or_method(minimal_symbol*)): New.
	(symbol_is_function_or_method(symbol*)): New.
	(add_symtab_completions): Add complete_symbol_mode parameter.  Use
	completion_skip_symbol.
	(default_collect_symbol_completion_matches_break_on): Use
	completion_skip_symbol.  Pass down mode.
	(collect_file_symbol_completion_matches): Pass down mode.
	* symtab.h (symbol_is_function_or_method): New declarations.
	(completion_skip_symbol): New template function.

1 files changed, 20 insertions, 0 deletions

diff --git a/gdb/symtab.h b/gdb/symtab.h
index 868c435..7b8b5cc 100644
--- a/gdb/symtab.h
+++ b/gdb/symtab.h
@@ -1803,6 +1803,26 @@ extern void collect_file_symbol_completion_matches
 extern completion_list
   make_source_files_completion_list (const char *, const char *);
 
+/* Return whether SYM is a function/method, as opposed to a data symbol.  */
+
+extern bool symbol_is_function_or_method (symbol *sym);
+
+/* Return whether MSYMBOL is a function/method, as opposed to a data
+   symbol */
+
+extern bool symbol_is_function_or_method (minimal_symbol *msymbol);
+
+/* Return whether SYM should be skipped in completion mode MODE.  In
+   linespec mode, we're only interested in functions/methods.  */
+
+template<typename Symbol>
+static bool
+completion_skip_symbol (complete_symbol_mode mode, Symbol *sym)
+{
+  return (mode == complete_symbol_mode::LINESPEC
+	  && !symbol_is_function_or_method (sym));
+}
+
 /* symtab.c */
 
 int matching_obj_sections (struct obj_section *, struct obj_section *);