diff mbox

[6/8] const-fy regcache::m_aspace

Message ID 86d152xrl0.fsf@gmail.com
State New
Headers show

Commit Message

Yao Qi Nov. 1, 2017, 9:42 a.m. UTC
Simon Marchi <simon.marchi@ericsson.com> writes:

> I don't really understand what this patch tries to achieve.  From the
> description above, I thought you wanted to make the m_aspace field const,
> not the pointed object.
>

I want to achieve both, the field m_aspace is a const, and the pointed
object is const too.

   /* The address space of this register cache (for registers where it
      makes sense, like PC or SP).  */
-  struct address_space *m_aspace;
+  const address_space * const m_aspace;

> If constifying the pointed address_space object is really what you meant to
> do, I find having the const_cast more confusing than anything else.  I think
> we should constify all the way (removing const_casts, putting more consts
> where needed) or not at all.

OK, const_cast is removed in the updated patch, what do you think?

Comments

Simon Marchi Nov. 1, 2017, 1:59 p.m. UTC | #1
On 2017-11-01 05:42, Yao Qi wrote:
> Simon Marchi <simon.marchi@ericsson.com> writes:
> 
>> I don't really understand what this patch tries to achieve.  From the
>> description above, I thought you wanted to make the m_aspace field 
>> const,
>> not the pointed object.
>> 
> 
> I want to achieve both, the field m_aspace is a const, and the pointed
> object is const too.
> 
>    /* The address space of this register cache (for registers where it
>       makes sense, like PC or SP).  */
> -  struct address_space *m_aspace;
> +  const address_space * const m_aspace;

Ah ok I had missed that there was two consts added.

>> If constifying the pointed address_space object is really what you 
>> meant to
>> do, I find having the const_cast more confusing than anything else.  I 
>> think
>> we should constify all the way (removing const_casts, putting more 
>> consts
>> where needed) or not at all.
> 
> OK, const_cast is removed in the updated patch, what do you think?

LGTM!
Yao Qi Nov. 1, 2017, 2:35 p.m. UTC | #2
On Wed, Nov 1, 2017 at 1:59 PM, Simon Marchi <simon.marchi@polymtl.ca> wrote:
>>
>> I want to achieve both, the field m_aspace is a const, and the pointed
>> object is const too.
>>
>>    /* The address space of this register cache (for registers where it
>>       makes sense, like PC or SP).  */
>> -  struct address_space *m_aspace;
>> +  const address_space * const m_aspace;
>
>
> Ah ok I had missed that there was two consts added.
>

The 2nd const was added in the updated patch.  It was missed in the
the first version.
diff mbox

Patch

diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
index ada72e0..98cedb4 100644
--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -14572,7 +14572,7 @@  insert_single_step_breakpoints (struct gdbarch *gdbarch)
   if (!next_pcs.empty ())
     {
       struct frame_info *frame = get_current_frame ();
-      struct address_space *aspace = get_frame_address_space (frame);
+      const address_space *aspace = get_frame_address_space (frame);
 
       for (CORE_ADDR pc : next_pcs)
 	insert_single_step_breakpoint (gdbarch, aspace, pc);
diff --git a/gdb/frame.c b/gdb/frame.c
index 5380c7d..e40685f 100644
--- a/gdb/frame.c
+++ b/gdb/frame.c
@@ -99,7 +99,7 @@  struct frame_info
   struct program_space *pspace;
 
   /* The frame's address space.  */
-  struct address_space *aspace;
+  const address_space *aspace;
 
   /* The frame's low-level unwinder and corresponding cache.  The
      low-level unwinder is responsible for unwinding register values
@@ -1020,7 +1020,7 @@  do_frame_register_read (void *src, int regnum, gdb_byte *buf)
 std::unique_ptr<struct regcache>
 frame_save_as_regcache (struct frame_info *this_frame)
 {
-  struct address_space *aspace = get_frame_address_space (this_frame);
+  const address_space *aspace = get_frame_address_space (this_frame);
   std::unique_ptr<struct regcache> regcache
     (new struct regcache (get_frame_arch (this_frame), aspace));
 
@@ -2643,7 +2643,7 @@  frame_unwind_program_space (struct frame_info *this_frame)
   return this_frame->pspace;
 }
 
-struct address_space *
+const address_space *
 get_frame_address_space (struct frame_info *frame)
 {
   return frame->aspace;
diff --git a/gdb/frame.h b/gdb/frame.h
index 190ce76..c751002 100644
--- a/gdb/frame.h
+++ b/gdb/frame.h
@@ -494,8 +494,10 @@  extern struct program_space *get_frame_program_space (struct frame_info *);
 /* Unwind THIS frame's program space from the NEXT frame.  */
 extern struct program_space *frame_unwind_program_space (struct frame_info *);
 
+class address_space;
+
 /* Return the frame's address space.  */
-extern struct address_space *get_frame_address_space (struct frame_info *);
+extern const address_space *get_frame_address_space (struct frame_info *);
 
 /* For frames where we can not unwind further, describe why.  */
 
diff --git a/gdb/infrun.c b/gdb/infrun.c
index 0e31dbc..ef5a505 100644
--- a/gdb/infrun.c
+++ b/gdb/infrun.c
@@ -1289,7 +1289,7 @@  struct step_over_info
      and address of the instruction the breakpoint is set at.  We'll
      skip inserting all breakpoints here.  Valid iff ASPACE is
      non-NULL.  */
-  struct address_space *aspace;
+  const address_space *aspace;
   CORE_ADDR address;
 
   /* The instruction being stepped over triggers a nonsteppable
@@ -1332,7 +1332,7 @@  static struct step_over_info step_over_info;
    because when we need the info later the thread may be running.  */
 
 static void
-set_step_over_info (struct address_space *aspace, CORE_ADDR address,
+set_step_over_info (const address_space *aspace, CORE_ADDR address,
 		    int nonsteppable_watchpoint_p,
 		    int thread)
 {
@@ -1760,7 +1760,7 @@  displaced_step_prepare_throw (ptid_t ptid)
   struct thread_info *tp = find_thread_ptid (ptid);
   struct regcache *regcache = get_thread_regcache (ptid);
   struct gdbarch *gdbarch = regcache->arch ();
-  struct address_space *aspace = regcache->aspace ();
+  const address_space *aspace = regcache->aspace ();
   CORE_ADDR original, copy;
   ULONGEST len;
   struct displaced_step_closure *closure;
@@ -2388,7 +2388,7 @@  resume (enum gdb_signal sig)
   struct gdbarch *gdbarch = regcache->arch ();
   struct thread_info *tp = inferior_thread ();
   CORE_ADDR pc = regcache_read_pc (regcache);
-  struct address_space *aspace = regcache->aspace ();
+  const address_space *aspace = regcache->aspace ();
   ptid_t resume_ptid;
   /* This represents the user's step vs continue request.  When
      deciding whether "set scheduler-locking step" applies, it's the
@@ -2983,7 +2983,6 @@  proceed (CORE_ADDR addr, enum gdb_signal siggnal)
   struct gdbarch *gdbarch;
   struct thread_info *tp;
   CORE_ADDR pc;
-  struct address_space *aspace;
   ptid_t resume_ptid;
   struct execution_control_state ecss;
   struct execution_control_state *ecs = &ecss;
@@ -3007,7 +3006,8 @@  proceed (CORE_ADDR addr, enum gdb_signal siggnal)
 
   regcache = get_current_regcache ();
   gdbarch = regcache->arch ();
-  aspace = regcache->aspace ();
+  const address_space *aspace = regcache->aspace ();
+
   pc = regcache_read_pc (regcache);
   tp = inferior_thread ();
 
@@ -4070,7 +4070,6 @@  adjust_pc_after_break (struct thread_info *thread,
 {
   struct regcache *regcache;
   struct gdbarch *gdbarch;
-  struct address_space *aspace;
   CORE_ADDR breakpoint_pc, decr_pc;
 
   /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP.  If
@@ -4150,7 +4149,7 @@  adjust_pc_after_break (struct thread_info *thread,
   if (decr_pc == 0)
     return;
 
-  aspace = regcache->aspace ();
+  const address_space *aspace = regcache->aspace ();
 
   /* Find the location where (if we've hit a breakpoint) the
      breakpoint would be.  */
@@ -4385,7 +4384,6 @@  static void
 save_waitstatus (struct thread_info *tp, struct target_waitstatus *ws)
 {
   struct regcache *regcache;
-  struct address_space *aspace;
 
   if (debug_infrun)
     {
@@ -4404,7 +4402,7 @@  save_waitstatus (struct thread_info *tp, struct target_waitstatus *ws)
   tp->suspend.waitstatus_pending_p = 1;
 
   regcache = get_thread_regcache (tp->ptid);
-  aspace = regcache->aspace ();
+  const address_space *aspace = regcache->aspace ();
 
   if (ws->kind == TARGET_WAITKIND_STOPPED
       && ws->value.sig == GDB_SIGNAL_TRAP)
@@ -5776,11 +5774,11 @@  handle_signal_stop (struct execution_control_state *ecs)
   if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
     {
       struct regcache *regcache;
-      struct address_space *aspace;
       CORE_ADDR pc;
 
       regcache = get_thread_regcache (ecs->ptid);
-      aspace = regcache->aspace ();
+      const address_space *aspace = regcache->aspace ();
+
       pc = regcache_read_pc (regcache);
 
       /* However, before doing so, if this single-step breakpoint was
@@ -5871,7 +5869,7 @@  handle_signal_stop (struct execution_control_state *ecs)
      inline function call sites).  */
   if (ecs->event_thread->control.step_range_end != 1)
     {
-      struct address_space *aspace = 
+      const address_space *aspace =
 	get_thread_regcache (ecs->ptid)->aspace ();
 
       /* skip_inline_frames is expensive, so we avoid it if we can
diff --git a/gdb/jit.c b/gdb/jit.c
index a2d1f6d..b70f87c 100644
--- a/gdb/jit.c
+++ b/gdb/jit.c
@@ -1186,7 +1186,6 @@  jit_frame_sniffer (const struct frame_unwind *self,
   struct jit_unwind_private *priv_data;
   struct gdb_unwind_callbacks callbacks;
   struct gdb_reader_funcs *funcs;
-  struct address_space *aspace;
   struct gdbarch *gdbarch;
 
   callbacks.reg_get = jit_unwind_reg_get_impl;
@@ -1200,7 +1199,8 @@  jit_frame_sniffer (const struct frame_unwind *self,
 
   gdb_assert (!*cache);
 
-  aspace = get_frame_address_space (this_frame);
+  const address_space *aspace = get_frame_address_space (this_frame);
+
   gdbarch = get_frame_arch (this_frame);
 
   *cache = XCNEW (struct jit_unwind_private);
diff --git a/gdb/mips-tdep.c b/gdb/mips-tdep.c
index 4b19896..20bd5d3 100644
--- a/gdb/mips-tdep.c
+++ b/gdb/mips-tdep.c
@@ -6598,7 +6598,6 @@  mips_single_step_through_delay (struct gdbarch *gdbarch,
 {
   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
   CORE_ADDR pc = get_frame_pc (frame);
-  struct address_space *aspace;
   enum mips_isa isa;
   ULONGEST insn;
   int status;
@@ -6616,7 +6615,9 @@  mips_single_step_through_delay (struct gdbarch *gdbarch,
   /* _has_delay_slot above will have validated the read.  */
   insn = mips_fetch_instruction (gdbarch, isa, pc, NULL);
   size = mips_insn_size (isa, insn);
-  aspace = get_frame_address_space (frame);
+
+  const address_space *aspace = get_frame_address_space (frame);
+
   return breakpoint_here_p (aspace, pc + size) != no_breakpoint_here;
 }
 
diff --git a/gdb/ppc-linux-tdep.c b/gdb/ppc-linux-tdep.c
index 67d8305..d01cff8 100644
--- a/gdb/ppc-linux-tdep.c
+++ b/gdb/ppc-linux-tdep.c
@@ -1362,7 +1362,7 @@  ppu2spu_sniffer (const struct frame_unwind *self,
 	  struct ppu2spu_cache *cache
 	    = FRAME_OBSTACK_CALLOC (1, struct ppu2spu_cache);
 
-	  struct address_space *aspace = get_frame_address_space (this_frame);
+	  const address_space *aspace = get_frame_address_space (this_frame);
 	  std::unique_ptr<struct regcache> regcache
 	    (new struct regcache (data.gdbarch, aspace));
 	  regcache_save (regcache.get (), ppu2spu_unwind_register, &data);
diff --git a/gdb/record-full.c b/gdb/record-full.c
index 0488b71..6fc29d6 100644
--- a/gdb/record-full.c
+++ b/gdb/record-full.c
@@ -1098,7 +1098,6 @@  record_full_wait_1 (struct target_ops *ops,
 		  && status->value.sig == GDB_SIGNAL_TRAP)
 		{
 		  struct regcache *regcache;
-		  struct address_space *aspace;
 		  enum target_stop_reason *stop_reason_p
 		    = &record_full_stop_reason;
 
@@ -1109,7 +1108,7 @@  record_full_wait_1 (struct target_ops *ops,
 		  registers_changed ();
 		  regcache = get_current_regcache ();
 		  tmp_pc = regcache_read_pc (regcache);
-		  aspace = regcache->aspace ();
+		  const struct address_space *aspace = regcache->aspace ();
 
 		  if (target_stopped_by_watchpoint ())
 		    {
@@ -1172,7 +1171,7 @@  record_full_wait_1 (struct target_ops *ops,
     {
       struct regcache *regcache = get_current_regcache ();
       struct gdbarch *gdbarch = regcache->arch ();
-      struct address_space *aspace = regcache->aspace ();
+      const struct address_space *aspace = regcache->aspace ();
       int continue_flag = 1;
       int first_record_full_end = 1;
       struct cleanup *old_cleanups
diff --git a/gdb/regcache.c b/gdb/regcache.c
index 6985dc9..2cffb70 100644
--- a/gdb/regcache.c
+++ b/gdb/regcache.c
@@ -181,7 +181,7 @@  regcache_register_size (const struct regcache *regcache, int n)
   return register_size (regcache->arch (), n);
 }
 
-regcache::regcache (gdbarch *gdbarch, address_space *aspace_,
+regcache::regcache (gdbarch *gdbarch, const address_space *aspace_,
 		    bool readonly_p_)
   : m_aspace (aspace_), m_readonly_p (readonly_p_)
 {
diff --git a/gdb/regcache.h b/gdb/regcache.h
index 2360e27..cea76fb 100644
--- a/gdb/regcache.h
+++ b/gdb/regcache.h
@@ -232,7 +232,7 @@  typedef struct cached_reg
 class regcache
 {
 public:
-  regcache (gdbarch *gdbarch, address_space *aspace_)
+  regcache (gdbarch *gdbarch, const address_space *aspace_)
     : regcache (gdbarch, aspace_, true)
   {}
 
@@ -254,7 +254,7 @@  public:
   gdbarch *arch () const;
 
   /* Return REGCACHE's address space.  */
-  address_space *aspace () const
+  const address_space *aspace () const
   {
     return m_aspace;
   }
@@ -338,7 +338,7 @@  public:
 
   static void regcache_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid);
 protected:
-  regcache (gdbarch *gdbarch, address_space *aspace_, bool readonly_p_);
+  regcache (gdbarch *gdbarch, const address_space *aspace_, bool readonly_p_);
 
   static std::forward_list<regcache *> current_regcache;
 
@@ -362,7 +362,7 @@  private:
 
   /* The address space of this register cache (for registers where it
      makes sense, like PC or SP).  */
-  struct address_space *m_aspace;
+  const address_space * const m_aspace;
 
   /* The register buffers.  A read-only register cache can hold the
      full [0 .. gdbarch_num_regs + gdbarch_num_pseudo_regs) while a read/write