[PATCH 3/7]: Regcache: Remove xmalloc/xfree methods

[PATCH 3/7]: Regcache: Remove xmalloc/xfree methods

[Alan Hayward]

Regcache is a class. There is no need for explicit xmalloc
and xfree methods, it is much simpler to use new and delete.


Tested on a --enable-targets=all build with board files unix,
native-gdbserver and unittest.exp.


2017-08-16  Alan Hayward  <alan.hayward@arm.com>

	* frame.c (frame_save_as_regcache): Use new.
	(frame_pop): Update name.
	* infrun.c (discard_infcall_suspend_state): Use delete.
	* jit.c (jit_dealloc_cache): Use delete.
	(jit_frame_sniffer): Use new.
	* linux-fork.c (free_fork): Use delete.
	(fork_save_infrun_state): Likewise.
	* mi/mi-main.c (mi_cmd_data_list_changed_registers): Update name.
	* ppc-linux-tdep.c (ppu2spu_sniffer): Use new.
	(ppu2spu_dealloc_cache): Use delete.
	* regcache.c (regcache_xmalloc): Remove.
	(regcache_xfree): Remove.
	(do_regcache_delete): Update name.
	(make_cleanup_regcache_delete): Likewise.
	* regcache.h: Remove functions and rename.
	* spu-tdep.c (spu2ppu_dealloc_cache): Use delete.


diff --git a/gdb/frame.c b/gdb/frame.c
index 30e4aeab7e2901074c289ac4d96ebda885805a29..7fd4b07a2e95f28b2eb6a18dea4d2071f0ece4e2 100644
--- a/gdb/frame.c
+++ b/gdb/frame.c
@@ -1021,13 +1021,12 @@ struct regcache *
frame_save_as_regcache (struct frame_info *this_frame)
{
  struct address_space *aspace = get_frame_address_space (this_frame);
-  struct regcache *regcache = regcache_xmalloc (get_frame_arch (this_frame),
-						aspace);
-  struct cleanup *cleanups = make_cleanup_regcache_xfree (regcache);
+  regcache *backup = new regcache (get_frame_arch (this_frame), aspace);
+  struct cleanup *cleanups = make_cleanup_regcache_delete (backup);

-  regcache_save (regcache, do_frame_register_read, this_frame);
+  regcache_save (backup, do_frame_register_read, this_frame);
  discard_cleanups (cleanups);
-  return regcache;
+  return backup;
}

void
@@ -1063,7 +1062,7 @@ frame_pop (struct frame_info *this_frame)
     trying to extract the old values from the current regcache while
     at the same time writing new values into that same cache.  */
  scratch = frame_save_as_regcache (prev_frame);
-  cleanups = make_cleanup_regcache_xfree (scratch);
+  cleanups = make_cleanup_regcache_delete (scratch);

  /* FIXME: cagney/2003-03-16: It should be possible to tell the
     target's register cache that it is about to be hit with a burst
diff --git a/gdb/infrun.c b/gdb/infrun.c
index d6723fde85c90bce2a93d1ab308332f9387c3f15..6510aec548f6495ca64f5b566ff3628734698113 100644
--- a/gdb/infrun.c
+++ b/gdb/infrun.c
@@ -8963,7 +8963,7 @@ make_cleanup_restore_infcall_suspend_state
void
discard_infcall_suspend_state (struct infcall_suspend_state *inf_state)
{
-  regcache_xfree (inf_state->registers);
+  delete inf_state->registers;
  xfree (inf_state->siginfo_data);
  xfree (inf_state);
}
diff --git a/gdb/jit.c b/gdb/jit.c
index 725d41ef0a5b01a22d5994bdd4b7b336fd3c10a9..e96572a8d1d7fe16561be7ba8a61b56d6bb1e85d 100644
--- a/gdb/jit.c
+++ b/gdb/jit.c
@@ -1168,7 +1168,7 @@ jit_dealloc_cache (struct frame_info *this_frame, void *cache)
  struct jit_unwind_private *priv_data = (struct jit_unwind_private *) cache;

  gdb_assert (priv_data->regcache != NULL);
-  regcache_xfree (priv_data->regcache);
+  delete priv_data->regcache;
  xfree (priv_data);
}

@@ -1206,7 +1206,7 @@ jit_frame_sniffer (const struct frame_unwind *self,

  *cache = XCNEW (struct jit_unwind_private);
  priv_data = (struct jit_unwind_private *) *cache;
-  priv_data->regcache = regcache_xmalloc (gdbarch, aspace);
+  priv_data->regcache = new regcache (gdbarch, aspace);
  priv_data->this_frame = this_frame;

  callbacks.priv_data = priv_data;
diff --git a/gdb/linux-fork.c b/gdb/linux-fork.c
index 573a3e9ecf040bb77b3f116e60289ba60266ffd0..032ff62807b728be336bf0e5daf59e47615d4799 100644
--- a/gdb/linux-fork.c
+++ b/gdb/linux-fork.c
@@ -129,7 +129,7 @@ free_fork (struct fork_info *fp)
  if (fp)
    {
      if (fp->savedregs)
-	regcache_xfree (fp->savedregs);
+	delete fp->savedregs;
      if (fp->filepos)
	xfree (fp->filepos);
      xfree (fp);
@@ -295,7 +295,7 @@ fork_save_infrun_state (struct fork_info *fp, int clobber_regs)
  DIR *d;

  if (fp->savedregs)
-    regcache_xfree (fp->savedregs);
+    delete fp->savedregs;

  fp->savedregs = regcache_dup (get_current_regcache ());
  fp->clobber_regs = clobber_regs;
diff --git a/gdb/mi/mi-main.c b/gdb/mi/mi-main.c
index 0bf587ffe702c68f538fe2877cce6114e64ee1bd..1edcf752c82230fc65669f675e10735ac8e4f654 100644
--- a/gdb/mi/mi-main.c
+++ b/gdb/mi/mi-main.c
@@ -1051,7 +1051,7 @@ mi_cmd_data_list_changed_registers (const char *command, char **argv, int argc)

  prev_regs = this_regs;
  this_regs = frame_save_as_regcache (get_selected_frame (NULL));
-  cleanup = make_cleanup_regcache_xfree (prev_regs);
+  cleanup = make_cleanup_regcache_delete (prev_regs);

  /* Note that the test for a valid register must include checking the
     gdbarch_register_name because gdbarch_num_regs may be allocated
diff --git a/gdb/ppc-linux-tdep.c b/gdb/ppc-linux-tdep.c
index 324b29d90c1266a73f172da20a6015174189625f..42aff2cd1bf3834268b0b58dcf00dac1c52add96 100644
--- a/gdb/ppc-linux-tdep.c
+++ b/gdb/ppc-linux-tdep.c
@@ -1364,13 +1364,13 @@ ppu2spu_sniffer (const struct frame_unwind *self,
	    = FRAME_OBSTACK_CALLOC (1, struct ppu2spu_cache);

	  struct address_space *aspace = get_frame_address_space (this_frame);
-	  struct regcache *regcache = regcache_xmalloc (data.gdbarch, aspace);
-	  struct cleanup *cleanups = make_cleanup_regcache_xfree (regcache);
-	  regcache_save (regcache, ppu2spu_unwind_register, &data);
+	  regcache *backup = new regcache (data.gdbarch, aspace);
+	  struct cleanup *cleanups = make_cleanup_regcache_delete (backup);
+	  regcache_save (backup, ppu2spu_unwind_register, &data);
	  discard_cleanups (cleanups);

	  cache->frame_id = frame_id_build (base, func);
-	  cache->regcache = regcache;
+	  cache->regcache = backup;
	  *this_prologue_cache = cache;
	  return 1;
	}
@@ -1383,7 +1383,7 @@ static void
ppu2spu_dealloc_cache (struct frame_info *self, void *this_cache)
{
  struct ppu2spu_cache *cache = (struct ppu2spu_cache *) this_cache;
-  regcache_xfree (cache->regcache);
+  delete cache->regcache;
}

static const struct frame_unwind ppu2spu_unwind = {
diff --git a/gdb/regcache.h b/gdb/regcache.h
index aeac54e8d7b91e2bcf6a3e1ce8e781c3f994306b..00b87db7d145205b74859c08ca5a9d852441a4aa 100644
--- a/gdb/regcache.h
+++ b/gdb/regcache.h
@@ -36,10 +36,7 @@ extern target_regcache *get_thread_arch_aspace_regcache (ptid_t,
							 struct gdbarch *,
							 struct address_space *);

-void regcache_xfree (struct regcache *regcache);
-struct cleanup *make_cleanup_regcache_xfree (struct regcache *regcache);
-struct regcache *regcache_xmalloc (struct gdbarch *gdbarch,
-				   struct address_space *aspace);
+struct cleanup *make_cleanup_regcache_delete (regcache *regcache);

/* Return REGCACHE's ptid.  */

@@ -261,12 +258,7 @@ public:
  regcache (const regcache &) = delete;
  void operator= (const regcache &) = delete;

-  /* class regcache is only extended in unit test, so only mark it
-     virtual when selftest is enabled.  */
-#if GDB_SELF_TEST
-  virtual
-#endif
-  ~regcache ()
+  virtual ~regcache ()
  {
    xfree (m_registers);
    xfree (m_register_status);
diff --git a/gdb/regcache.c b/gdb/regcache.c
index 524ac5754f6d2c1b00097b15a40b928845e45a59..e7da5a622e861e1e6a1938f91a0dd9a39942a050 100644
--- a/gdb/regcache.c
+++ b/gdb/regcache.c
@@ -249,31 +249,18 @@ regcache_get_ptid (const struct regcache *regcache)
  return regcache->ptid ();
}

-struct regcache *
-regcache_xmalloc (struct gdbarch *gdbarch, struct address_space *aspace)
-{
-  return new regcache (gdbarch, aspace);
-}
-
-void
-regcache_xfree (struct regcache *regcache)
-{
-  if (regcache == NULL)
-    return;
-
-  delete regcache;
-}
-
static void
-do_regcache_xfree (void *data)
+do_regcache_delete (void *data)
{
-  regcache_xfree ((struct regcache *) data);
+  if (data == NULL)
+    return;
+  delete (regcache *) data;
}

struct cleanup *
-make_cleanup_regcache_xfree (struct regcache *regcache)
+make_cleanup_regcache_delete (struct regcache *regcache)
{
-  return make_cleanup (do_regcache_xfree, regcache);
+  return make_cleanup (do_regcache_delete, regcache);
}

/* Cleanup routines for invalidating a register.  */
diff --git a/gdb/spu-tdep.c b/gdb/spu-tdep.c
index ca1a3fc99f99a506446925a20bd3598631930a53..1ac763da7ede9d4b9f4bff1e8d71551b0c776fa1 100644
--- a/gdb/spu-tdep.c
+++ b/gdb/spu-tdep.c
@@ -1288,7 +1288,7 @@ static void
spu2ppu_dealloc_cache (struct frame_info *self, void *this_cache)
{
  struct spu2ppu_cache *cache = (struct spu2ppu_cache *) this_cache;
-  regcache_xfree (cache->regcache);
+  delete cache->regcache;
}

static const struct frame_unwind spu2ppu_unwind = {

Re: [PATCH 3/7]: Regcache: Remove xmalloc/xfree methods

[Yao Qi]

Alan Hayward <Alan.Hayward@arm.com> writes:

> Regcache is a class. There is no need for explicit xmalloc
> and xfree methods, it is much simpler to use new and delete.
>

new/delete isn't simpler than xmalloc/xfree, IMO.  We still need to take
care of releasing resources.

>
> diff --git a/gdb/frame.c b/gdb/frame.c
> index 30e4aeab7e2901074c289ac4d96ebda885805a29..7fd4b07a2e95f28b2eb6a18dea4d2071f0ece4e2 100644
> --- a/gdb/frame.c
> +++ b/gdb/frame.c
> @@ -1021,13 +1021,12 @@ struct regcache *
> frame_save_as_regcache (struct frame_info *this_frame)
> {
>   struct address_space *aspace = get_frame_address_space (this_frame);
> -  struct regcache *regcache = regcache_xmalloc (get_frame_arch (this_frame),
> -						aspace);
> -  struct cleanup *cleanups = make_cleanup_regcache_xfree (regcache);
> +  regcache *backup = new regcache (get_frame_arch (this_frame), aspace);
> +  struct cleanup *cleanups = make_cleanup_regcache_delete (backup);
>

It makes no sense to change make_cleanup_regcache_xfree to
make_cleanup_regcache_delete.  We still have to use cleanup.

> -  regcache_save (regcache, do_frame_register_read, this_frame);
> +  regcache_save (backup, do_frame_register_read, this_frame);
>   discard_cleanups (cleanups);
> -  return regcache;
> +  return backup;
> }
>
> void
> @@ -1063,7 +1062,7 @@ frame_pop (struct frame_info *this_frame)
>      trying to extract the old values from the current regcache while
>      at the same time writing new values into that same cache.  */
>   scratch = frame_save_as_regcache (prev_frame);
> -  cleanups = make_cleanup_regcache_xfree (scratch);
> +  cleanups = make_cleanup_regcache_delete (scratch);

scratch is only used within this function, so we can change it to a
local object (instead of a pointer), and call regcache_save here.  Then,
we can remove the cleanups.

> diff --git a/gdb/mi/mi-main.c b/gdb/mi/mi-main.c
> index 0bf587ffe702c68f538fe2877cce6114e64ee1bd..1edcf752c82230fc65669f675e10735ac8e4f654 100644
> --- a/gdb/mi/mi-main.c
> +++ b/gdb/mi/mi-main.c
> @@ -1051,7 +1051,7 @@ mi_cmd_data_list_changed_registers (const char *command, char **argv, int argc)
>
>   prev_regs = this_regs;
>   this_regs = frame_save_as_regcache (get_selected_frame (NULL));
> -  cleanup = make_cleanup_regcache_xfree (prev_regs);
> +  cleanup = make_cleanup_regcache_delete (prev_regs);

Why don't you do this? then, we don't need this make_cleanup_regcache_xfree.

std::unique_ptr<regcache> prev_regs (this_regs);

>
>   /* Note that the test for a valid register must include checking the
>      gdbarch_register_name because gdbarch_num_regs may be allocated
> diff --git a/gdb/ppc-linux-tdep.c b/gdb/ppc-linux-tdep.c
> index 324b29d90c1266a73f172da20a6015174189625f..42aff2cd1bf3834268b0b58dcf00dac1c52add96 100644
> --- a/gdb/ppc-linux-tdep.c
> +++ b/gdb/ppc-linux-tdep.c
> @@ -1364,13 +1364,13 @@ ppu2spu_sniffer (const struct frame_unwind *self,
> 	    = FRAME_OBSTACK_CALLOC (1, struct ppu2spu_cache);
>
> 	  struct address_space *aspace = get_frame_address_space (this_frame);
> -	  struct regcache *regcache = regcache_xmalloc (data.gdbarch, aspace);
> -	  struct cleanup *cleanups = make_cleanup_regcache_xfree (regcache);
> -	  regcache_save (regcache, ppu2spu_unwind_register, &data);
> +	  regcache *backup = new regcache (data.gdbarch, aspace);
> +	  struct cleanup *cleanups = make_cleanup_regcache_delete (backup);
> +	  regcache_save (backup, ppu2spu_unwind_register, &data);
> 	  discard_cleanups (cleanups);

We can use std::unique_ptr<regcache> too here.  After call
regcache_save, call .release () to return the raw pointer to cache->regcache.

>
> 	  cache->frame_id = frame_id_build (base, func);
> -	  cache->regcache = regcache;
> +	  cache->regcache = backup;
> 	  *this_prologue_cache = cache;
> 	  return 1;
> 	}
> @@ -1383,7 +1383,7 @@ static void
> ppu2spu_dealloc_cache (struct frame_info *self, void *this_cache)
> {
>   struct ppu2spu_cache *cache = (struct ppu2spu_cache *) this_cache;
> -  regcache_xfree (cache->regcache);
> +  delete cache->regcache;
> }
>
> static const struct frame_unwind ppu2spu_unwind = {
> diff --git a/gdb/regcache.h b/gdb/regcache.h
> index aeac54e8d7b91e2bcf6a3e1ce8e781c3f994306b..00b87db7d145205b74859c08ca5a9d852441a4aa 100644
> --- a/gdb/regcache.h
> +++ b/gdb/regcache.h
> @@ -36,10 +36,7 @@ extern target_regcache *get_thread_arch_aspace_regcache (ptid_t,
> 							 struct gdbarch *,
> 							 struct address_space *);
>
> -void regcache_xfree (struct regcache *regcache);
> -struct cleanup *make_cleanup_regcache_xfree (struct regcache *regcache);
> -struct regcache *regcache_xmalloc (struct gdbarch *gdbarch,
> -				   struct address_space *aspace);
> +struct cleanup *make_cleanup_regcache_delete (regcache *regcache);
>
> /* Return REGCACHE's ptid.  */
>
> @@ -261,12 +258,7 @@ public:
>   regcache (const regcache &) = delete;
>   void operator= (const regcache &) = delete;
>
> -  /* class regcache is only extended in unit test, so only mark it
> -     virtual when selftest is enabled.  */
> -#if GDB_SELF_TEST
> -  virtual
> -#endif
> -  ~regcache ()
> +  virtual ~regcache ()

This is not related to this patch.  It should be in patch #1.

-- 
Yao (齐尧)

Re: [PATCH 3/7]: Regcache: Remove xmalloc/xfree methods

[Alan Hayward]

> On 23 Aug 2017, at 10:32, Yao Qi <qiyaoltc@gmail.com> wrote:
> 
> Alan Hayward <Alan.Hayward@arm.com> writes:
> 
>> Regcache is a class. There is no need for explicit xmalloc
>> and xfree methods, it is much simpler to use new and delete.
>> 
> 
> new/delete isn't simpler than xmalloc/xfree, IMO.  We still need to take
> care of releasing resources.

Agreed, but I wanted to only have one way of doing the same thing.
We have to have a constructor/destructor.
regcache_xmalloc and regcache_xfree are (almost) one liners that call new/delete.

> 
>> 
>> diff --git a/gdb/frame.c b/gdb/frame.c
>> index 30e4aeab7e2901074c289ac4d96ebda885805a29..7fd4b07a2e95f28b2eb6a18dea4d2071f0ece4e2 100644
>> --- a/gdb/frame.c
>> +++ b/gdb/frame.c
>> @@ -1021,13 +1021,12 @@ struct regcache *
>> frame_save_as_regcache (struct frame_info *this_frame)
>> {
>>  struct address_space *aspace = get_frame_address_space (this_frame);
>> -  struct regcache *regcache = regcache_xmalloc (get_frame_arch (this_frame),
>> -						aspace);
>> -  struct cleanup *cleanups = make_cleanup_regcache_xfree (regcache);
>> +  regcache *backup = new regcache (get_frame_arch (this_frame), aspace);
>> +  struct cleanup *cleanups = make_cleanup_regcache_delete (backup);
>> 
> 
> It makes no sense to change make_cleanup_regcache_xfree to
> make_cleanup_regcache_delete.  We still have to use cleanup.

I made this change to keep the consistent with the other changes in this patch.
Using new together with something_xfree() sounds wrong.

If I make all the changes below, then I think we can remove this function.

> 
>> -  regcache_save (regcache, do_frame_register_read, this_frame);
>> +  regcache_save (backup, do_frame_register_read, this_frame);
>>  discard_cleanups (cleanups);
>> -  return regcache;
>> +  return backup;
>> }
>> 
>> void
>> @@ -1063,7 +1062,7 @@ frame_pop (struct frame_info *this_frame)
>>     trying to extract the old values from the current regcache while
>>     at the same time writing new values into that same cache.  */
>>  scratch = frame_save_as_regcache (prev_frame);
>> -  cleanups = make_cleanup_regcache_xfree (scratch);
>> +  cleanups = make_cleanup_regcache_delete (scratch);
> 
> scratch is only used within this function, so we can change it to a
> local object (instead of a pointer), and call regcache_save here.  Then,
> we can remove the cleanups.

Ok.

> 
>> diff --git a/gdb/mi/mi-main.c b/gdb/mi/mi-main.c
>> index 0bf587ffe702c68f538fe2877cce6114e64ee1bd..1edcf752c82230fc65669f675e10735ac8e4f654 100644
>> --- a/gdb/mi/mi-main.c
>> +++ b/gdb/mi/mi-main.c
>> @@ -1051,7 +1051,7 @@ mi_cmd_data_list_changed_registers (const char *command, char **argv, int argc)
>> 
>>  prev_regs = this_regs;
>>  this_regs = frame_save_as_regcache (get_selected_frame (NULL));
>> -  cleanup = make_cleanup_regcache_xfree (prev_regs);
>> +  cleanup = make_cleanup_regcache_delete (prev_regs);
> 
> Why don't you do this? then, we don't need this make_cleanup_regcache_xfree.
> 
> std::unique_ptr<regcache> prev_regs (this_regs);

This is new to me. Happy to use it.

> 
>> 
>>  /* Note that the test for a valid register must include checking the
>>     gdbarch_register_name because gdbarch_num_regs may be allocated
>> diff --git a/gdb/ppc-linux-tdep.c b/gdb/ppc-linux-tdep.c
>> index 324b29d90c1266a73f172da20a6015174189625f..42aff2cd1bf3834268b0b58dcf00dac1c52add96 100644
>> --- a/gdb/ppc-linux-tdep.c
>> +++ b/gdb/ppc-linux-tdep.c
>> @@ -1364,13 +1364,13 @@ ppu2spu_sniffer (const struct frame_unwind *self,
>> 	    = FRAME_OBSTACK_CALLOC (1, struct ppu2spu_cache);
>> 
>> 	  struct address_space *aspace = get_frame_address_space (this_frame);
>> -	  struct regcache *regcache = regcache_xmalloc (data.gdbarch, aspace);
>> -	  struct cleanup *cleanups = make_cleanup_regcache_xfree (regcache);
>> -	  regcache_save (regcache, ppu2spu_unwind_register, &data);
>> +	  regcache *backup = new regcache (data.gdbarch, aspace);
>> +	  struct cleanup *cleanups = make_cleanup_regcache_delete (backup);
>> +	  regcache_save (backup, ppu2spu_unwind_register, &data);
>> 	  discard_cleanups (cleanups);
> 
> We can use std::unique_ptr<regcache> too here.  After call
> regcache_save, call .release () to return the raw pointer to cache->regcache.

Ok.

> 
>> 
>> 	  cache->frame_id = frame_id_build (base, func);
>> -	  cache->regcache = regcache;
>> +	  cache->regcache = backup;
>> 	  *this_prologue_cache = cache;
>> 	  return 1;
>> 	}
>> @@ -1383,7 +1383,7 @@ static void
>> ppu2spu_dealloc_cache (struct frame_info *self, void *this_cache)
>> {
>>  struct ppu2spu_cache *cache = (struct ppu2spu_cache *) this_cache;
>> -  regcache_xfree (cache->regcache);
>> +  delete cache->regcache;
>> }
>> 
>> static const struct frame_unwind ppu2spu_unwind = {
>> diff --git a/gdb/regcache.h b/gdb/regcache.h
>> index aeac54e8d7b91e2bcf6a3e1ce8e781c3f994306b..00b87db7d145205b74859c08ca5a9d852441a4aa 100644
>> --- a/gdb/regcache.h
>> +++ b/gdb/regcache.h
>> @@ -36,10 +36,7 @@ extern target_regcache *get_thread_arch_aspace_regcache (ptid_t,
>> 							 struct gdbarch *,
>> 							 struct address_space *);
>> 
>> -void regcache_xfree (struct regcache *regcache);
>> -struct cleanup *make_cleanup_regcache_xfree (struct regcache *regcache);
>> -struct regcache *regcache_xmalloc (struct gdbarch *gdbarch,
>> -				   struct address_space *aspace);
>> +struct cleanup *make_cleanup_regcache_delete (regcache *regcache);
>> 
>> /* Return REGCACHE's ptid.  */
>> 
>> @@ -261,12 +258,7 @@ public:
>>  regcache (const regcache &) = delete;
>>  void operator= (const regcache &) = delete;
>> 
>> -  /* class regcache is only extended in unit test, so only mark it
>> -     virtual when selftest is enabled.  */
>> -#if GDB_SELF_TEST
>> -  virtual
>> -#endif
>> -  ~regcache ()
>> +  virtual ~regcache ()
> 
> This is not related to this patch.  It should be in patch #1.

Ok.

> 
> -- 
> Yao (齐尧)