Fw: question about expand_symtabs_matching()

["Hannes Domani via gdb" <gdb@sourceware.org>]

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Am Freitag, 8. März 2019, 22:13:52 MEZ hat Tom Tromey <tom@tromey.com> Folgendes geschrieben:

> >>>>> "Hannes" == Hannes Domani via gdb <gdb@sourceware.org> writes:
> 
> Hannes> For the case of 'b some_function', with the application I'm testing:
> Hannes> - startup time with the call of cp_canonicalize_string_no_typedefs(): 1m 25s
> Hannes> - startup time without this call: 27s
> 
> Wow.
> 
> Hannes> In my personal build I've changed this:
> Hannes> - only call cp_canonicalize_string_no_typedefs() if it's not a simple function
> Hannes>   name (like 'function_name' or 'Class::member_function')
> Hannes> - only call expand_symtabs_matching() if the lookup_name doesn't contain a '.'
>
 > Hannes> I admit that I don't fully understand what could break with these changes,
> Hannes> but the speedup makes it worth for me right now.
> 
> Could you send the diff?

Both are attached.

As said before, the first improves the startup time (with 1 pending function breakpoint) from 1m 25s to 27s.

And the second improves it (with 1 pending source:line breakpoint) from 27s to 13s.


Regards
Hannes Domani

[-- Attachment #2: 0001-Don-t-expand-typedefs-for-functions-without-argument.patch --]
[-- Type: application/octet-stream, Size: 1530 bytes --]

From 2902f8e28b5d8e3c2bf4010c8bf495ae4bc98ff3 Mon Sep 17 00:00:00 2001
From: Hannes Domani <ssbssa@yahoo.de>
Date: Fri, 1 Mar 2019 14:05:17 +0100
Subject: [PATCH 1/2] Don't expand typedefs for functions without arguments.

---
 gdb/linespec.c | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/gdb/linespec.c b/gdb/linespec.c
index 0f2fcfdff0..b01afadd91 100644
--- a/gdb/linespec.c
+++ b/gdb/linespec.c
@@ -3899,6 +3899,23 @@ find_function_symbols (struct linespec_state *state,
 				  &info, state->search_pspace);
 }
 
+static bool
+is_simple_name (const char *name)
+{
+  do
+    {
+      if (name[0] == ':' && name[1] == ':')
+	name += 2;
+      if (*name == ':')
+	break;
+      while ((*name >= 'A' && *name <= 'Z') || (*name >= 'a' && *name <= 'z')
+	     || (*name >= '0' && *name <= '9') || *name == '_')
+	name++;
+    }
+  while (name[0] == ':' && name[1] == ':');
+  return *name == '\0';
+}
+
 /* Find all symbols named NAME in FILE_SYMTABS, returning debug symbols
    in SYMBOLS and minimal symbols in MINSYMS.  */
 
@@ -3910,7 +3927,9 @@ find_linespec_symbols (struct linespec_state *state,
 		       std::vector <block_symbol> *symbols,
 		       std::vector<bound_minimal_symbol> *minsyms)
 {
-  std::string canon = cp_canonicalize_string_no_typedefs (lookup_name);
+  std::string canon;
+  if (!is_simple_name (lookup_name))
+    canon = cp_canonicalize_string_no_typedefs (lookup_name);
   if (!canon.empty ())
     lookup_name = canon.c_str ();
 
-- 
2.15.1.windows.2


[-- Attachment #3: 0002-Don-t-expand-symtabs-when-looking-for-a-filename.patch --]
[-- Type: application/octet-stream, Size: 767 bytes --]

From 9f1e4c10b9e3a691f674b2d2a5c9d4af305f0b26 Mon Sep 17 00:00:00 2001
From: Hannes Domani <ssbssa@yahoo.de>
Date: Fri, 1 Mar 2019 14:07:47 +0100
Subject: [PATCH 2/2] Don't expand symtabs when looking for a filename.

---
 gdb/linespec.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/gdb/linespec.c b/gdb/linespec.c
index e902b11c8e..0f2fcfdff0 100644
--- a/gdb/linespec.c
+++ b/gdb/linespec.c
@@ -1143,7 +1143,8 @@ iterate_over_all_matching_symtabs
 
     for (objfile *objfile : current_program_space->objfiles ())
       {
-	if (objfile->sf)
+	if (objfile->sf
+	    && lookup_name.name ().find ('.') == std::string::npos)
 	  objfile->sf->qf->expand_symtabs_matching (objfile,
 						    NULL,
 						    lookup_name,
-- 
2.15.1.windows.2