[binutils-gdb] [AArch64] Refactor aarch64_make_prologue_cache

[Pierre Langlois <planglois at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=7c8edfae86385f922dca6ef1ab7c7d378d4fd30f

commit 7c8edfae86385f922dca6ef1ab7c7d378d4fd30f
Author: Pierre Langlois <pierre.langlois@arm.com>
Date:   Thu Jul 9 16:35:10 2015 +0100

    [AArch64] Refactor aarch64_make_prologue_cache
    
    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_make_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_make_prologue_cache.
    	(aarch64_prologue_prev_register): Likewise.
    	(aarch64_normal_frame_base): Likewise.

Diff:
---
 gdb/ChangeLog      | 10 ++++++++++
 gdb/aarch64-tdep.c | 33 +++++++++++++++------------------
 2 files changed, 25 insertions(+), 18 deletions(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index b5b80a3..672b297 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,13 @@
+2015-07-09  Pierre Langlois  <pierre.langlois@arm.com>
+
+	* aarch64-tdep.c (aarch64_make_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_make_prologue_cache.
+	(aarch64_prologue_prev_register): Likewise.
+	(aarch64_normal_frame_base): Likewise.
+
 2015-07-09  Simon Marchi  <simon.marchi@ericsson.com>
 
 	* c-valprint.c (c_val_print): Factor out memberptr printing code
diff --git a/gdb/aarch64-tdep.c b/gdb/aarch64-tdep.c
index 9650a7a..6f3a643 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;
 }