[AArch64] Refactor aarch64_make_prologue_cache

Message ID 1436438207-33028-1-git-send-email-pierre.langlois@arm.com
State New, archived
Headers

Commit Message

Pierre Langlois July 9, 2015, 10:36 a.m. UTC
  Hi Yao,

I'll push this patch if you're happy with the comment.

Thanks for the reviews,
Pierre

---

We would previously have to make sure the frame cache was not already
created before calling aarch64_make_prologue_cache.  This patch makes
this function check it so that the caller does not need to do so.

gdb/ChangeLog:

	* aarch64-tdep.c (aarch64_prologue_cache): Update comment.  New
	argument this_cache.  Return early if this_cache is already set.
	Set this_cache.
	(aarch64_prologue_this_id): Update call to
	aarch64_prologue_cache.
	(aarch64_prologue_prev_register): Likewise.
	(aarch64_normal_frame_base): Likewise.
---
 gdb/aarch64-tdep.c | 33 +++++++++++++++------------------
 1 file changed, 15 insertions(+), 18 deletions(-)
  

Comments

Pierre Langlois July 9, 2015, 3:37 p.m. UTC | #1
> -/* Allocate an aarch64_prologue_cache and fill it with information
> -   about the prologue of *THIS_FRAME.  */
> +/* Allocate and fill in *THIS_CACHE with information about the prologue of
> +   *THIS_FRAME.  Do not do this is if *THIS_CACHE was already allocated.
> +   Return a pointer to the current aarch64_prologue_cache in *THIS_CACHE.
> +   */

Pushed with this comment's formatting fixed.

Thanks,
Pierre
  

Patch

diff --git a/gdb/aarch64-tdep.c b/gdb/aarch64-tdep.c
index 9650a7a..0496536 100644
--- a/gdb/aarch64-tdep.c
+++ b/gdb/aarch64-tdep.c
@@ -930,18 +930,24 @@  aarch64_scan_prologue (struct frame_info *this_frame,
     }
 }
 
-/* Allocate an aarch64_prologue_cache and fill it with information
-   about the prologue of *THIS_FRAME.  */
+/* Allocate and fill in *THIS_CACHE with information about the prologue of
+   *THIS_FRAME.  Do not do this is if *THIS_CACHE was already allocated.
+   Return a pointer to the current aarch64_prologue_cache in *THIS_CACHE.
+   */
 
 static struct aarch64_prologue_cache *
-aarch64_make_prologue_cache (struct frame_info *this_frame)
+aarch64_make_prologue_cache (struct frame_info *this_frame, void **this_cache)
 {
   struct aarch64_prologue_cache *cache;
   CORE_ADDR unwound_fp;
   int reg;
 
+  if (*this_cache != NULL)
+    return *this_cache;
+
   cache = FRAME_OBSTACK_ZALLOC (struct aarch64_prologue_cache);
   cache->saved_regs = trad_frame_alloc_saved_regs (this_frame);
+  *this_cache = cache;
 
   aarch64_scan_prologue (this_frame, cache);
 
@@ -970,14 +976,11 @@  static void
 aarch64_prologue_this_id (struct frame_info *this_frame,
 			  void **this_cache, struct frame_id *this_id)
 {
-  struct aarch64_prologue_cache *cache;
+  struct aarch64_prologue_cache *cache
+    = aarch64_make_prologue_cache (this_frame, this_cache);
   struct frame_id id;
   CORE_ADDR pc, func;
 
-  if (*this_cache == NULL)
-    *this_cache = aarch64_make_prologue_cache (this_frame);
-  cache = *this_cache;
-
   /* This is meant to halt the backtrace at "_start".  */
   pc = get_frame_pc (this_frame);
   if (pc <= gdbarch_tdep (get_frame_arch (this_frame))->lowest_pc)
@@ -999,11 +1002,8 @@  aarch64_prologue_prev_register (struct frame_info *this_frame,
 				void **this_cache, int prev_regnum)
 {
   struct gdbarch *gdbarch = get_frame_arch (this_frame);
-  struct aarch64_prologue_cache *cache;
-
-  if (*this_cache == NULL)
-    *this_cache = aarch64_make_prologue_cache (this_frame);
-  cache = *this_cache;
+  struct aarch64_prologue_cache *cache
+    = aarch64_make_prologue_cache (this_frame, this_cache);
 
   /* If we are asked to unwind the PC, then we need to return the LR
      instead.  The prologue may save PC, but it will point into this
@@ -1120,11 +1120,8 @@  struct frame_unwind aarch64_stub_unwind =
 static CORE_ADDR
 aarch64_normal_frame_base (struct frame_info *this_frame, void **this_cache)
 {
-  struct aarch64_prologue_cache *cache;
-
-  if (*this_cache == NULL)
-    *this_cache = aarch64_make_prologue_cache (this_frame);
-  cache = *this_cache;
+  struct aarch64_prologue_cache *cache
+    = aarch64_make_prologue_cache (this_frame, this_cache);
 
   return cache->prev_sp - cache->framesize;
 }