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[RFC/Windows] Remember last tlb type for re-use in windows_get_tlb_type
- From: "Pierre Muller" <pierre dot muller at ics-cnrs dot unistra dot fr>
- To: <gdb-patches at sourceware dot org>
- Date: Mon, 19 Apr 2010 10:59:39 +0200
- Subject: [RFC/Windows] Remember last tlb type for re-use in windows_get_tlb_type
Each time, you examine the convenience variable
$_tlb on Windows executable
the function windows_get_tlb_type is called
and creates a new type.
I copied this behavior from the internal variable _siginfo,
but I think that it is a big waste of time and memory to
regenerate it each time.
Nevertheless, with multi-target GDB, you can possibly create
a type of windows-32 bit another for windows 64-bit
or even one for windows-CE.
Thus I remember the last gdbarch passed
and return the remember type only if gdbarch did not change,
which is most of the time.
I do not know if those kind of patches
are regarded as useful.
Comments welcome.
Pierre Muller
2010-04-19 Pierre Muller <muller@ics.u-strasbg.fr>
* windows-tdep.c (windows_get_tlb_type): Remember
last GDBARCH and created type for re-use.
Index: windows-tdep.c
===================================================================
RCS file: /cvs/src/src/gdb/windows-tdep.c,v
retrieving revision 1.6
diff -u -p -r1.6 windows-tdep.c
--- windows-tdep.c 16 Apr 2010 07:49:35 -0000 1.6
+++ windows-tdep.c 19 Apr 2010 08:45:27 -0000
@@ -97,12 +97,18 @@ static int maint_display_all_tib = 0;
static struct type *
windows_get_tlb_type (struct gdbarch *gdbarch)
{
+ static struct gdbarch *last_gdbarch = NULL;
+ static struct type *last_tlb_type = NULL;
struct type *dword_ptr_type, *dword32_type, *void_ptr_type;
struct type *peb_ldr_type, *peb_ldr_ptr_type;
struct type *peb_type, *peb_ptr_type, *list_type, *list_ptr_type;
struct type *module_list_ptr_type;
struct type *tib_type, *seh_type, *tib_ptr_type, *seh_ptr_type;
+ /* Do not rebuild type if same gdbarch as last time. */
+ if (last_tlb_type && last_gdbarch == gdbarch)
+ return last_tlb_type;
+
dword_ptr_type = arch_integer_type (gdbarch, gdbarch_ptr_bit (gdbarch),
1, "DWORD_PTR");
dword32_type = arch_integer_type (gdbarch, 32,
@@ -210,6 +216,9 @@ windows_get_tlb_type (struct gdbarch *gd
TYPE_LENGTH (void_ptr_type), NULL);
TYPE_TARGET_TYPE (tib_ptr_type) = tib_type;
+ last_tlb_type = tib_ptr_type;
+ last_gdbarch = gdbarch;
+
return tib_ptr_type;
}