public inbox for gdb-cvs@sourceware.org
help / color / mirror / Atom feed
* [binutils-gdb] gdb: change value_of_register and value_of_register_lazy to take the next frame
@ 2023-12-14 16:21 Simon Marchi
  0 siblings, 0 replies; only message in thread
From: Simon Marchi @ 2023-12-14 16:21 UTC (permalink / raw)
  To: gdb-cvs

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=a7952927db56b6adca3c1f58398f61dcd8f32d36

commit a7952927db56b6adca3c1f58398f61dcd8f32d36
Author: Simon Marchi <simon.marchi@efficios.com>
Date:   Fri Dec 1 11:27:21 2023 -0500

    gdb: change value_of_register and value_of_register_lazy to take the next frame
    
    Some functions related to the handling of registers in frames accept
    "this frame", for which we want to read or write the register values,
    while other functions accept "the next frame", which is the frame next
    to that.  The later is needed because we sometimes need to read register
    values for a frame that does not exist yet (usually when trying to
    unwind that frame-to-be).
    
    value_of_register and value_of_register_lazy both take "this frame",
    even if what they ultimately want internally is "the next frame".  This
    is annoying if you are in a spot that currently has "the next frame" and
    need to call one of these functions (which happens later in this
    series).  You need to get the previous frame only for those functions to
    get the next frame again.  This is more manipulations, more chances of
    mistake.
    
    I propose to change these functions (and a few more functions in the
    subsequent patches) to operate on "the next frame".  Things become a bit
    less awkward when all these functions agree on which frame they take.
    
    So, in this patch, change value_of_register_lazy and value_of_register
    to take "the next frame" instead of "this frame".  This adds a lot of
    get_next_frame_sentinel_okay, but if we convert the user registers API
    to also use "the next frame" instead of "this frame", it will get simple
    again.
    
    Change-Id: Iaa24815e648fbe5ae3c214c738758890a91819cd
    Reviewed-By: John Baldwin <jhb@FreeBSD.org>

Diff:
---
 gdb/aarch64-tdep.c     |  3 +--
 gdb/arm-tdep.c         |  4 ++--
 gdb/eval.c             |  3 ++-
 gdb/findvar.c          | 34 ++++++++++++----------------------
 gdb/frame-unwind.c     |  3 ++-
 gdb/guile/scm-frame.c  |  3 ++-
 gdb/infcmd.c           |  6 +++---
 gdb/loongarch-tdep.c   |  3 ++-
 gdb/mi/mi-main.c       |  3 ++-
 gdb/mips-tdep.c        |  2 +-
 gdb/nds32-tdep.c       |  5 +++--
 gdb/python/py-frame.c  |  3 ++-
 gdb/python/py-unwind.c |  4 ++--
 gdb/riscv-tdep.c       |  4 ++--
 gdb/s12z-tdep.c        |  2 +-
 gdb/std-regs.c         | 11 +++++++----
 gdb/value.h            |  9 +++++++--
 17 files changed, 53 insertions(+), 49 deletions(-)

diff --git a/gdb/aarch64-tdep.c b/gdb/aarch64-tdep.c
index 4a7ce68e85a..b0aee191d71 100644
--- a/gdb/aarch64-tdep.c
+++ b/gdb/aarch64-tdep.c
@@ -3449,9 +3449,8 @@ value_of_aarch64_user_reg (frame_info_ptr frame, const void *baton)
 {
   const int *reg_p = (const int *) baton;
 
-  return value_of_register (*reg_p, frame);
+  return value_of_register (*reg_p, get_next_frame_sentinel_okay (frame));
 }
-\f
 
 /* Implement the "software_single_step" gdbarch method, needed to
    single step through atomic sequences on AArch64.  */
diff --git a/gdb/arm-tdep.c b/gdb/arm-tdep.c
index 83fce2abd50..1ee8bdf4615 100644
--- a/gdb/arm-tdep.c
+++ b/gdb/arm-tdep.c
@@ -9954,9 +9954,9 @@ static struct value *
 value_of_arm_user_reg (frame_info_ptr frame, const void *baton)
 {
   const int *reg_p = (const int *) baton;
-  return value_of_register (*reg_p, frame);
+  return value_of_register (*reg_p, get_next_frame_sentinel_okay (frame));
 }
-\f
+
 static enum gdb_osabi
 arm_elf_osabi_sniffer (bfd *abfd)
 {
diff --git a/gdb/eval.c b/gdb/eval.c
index 8192aeba364..e075cc3138d 100644
--- a/gdb/eval.c
+++ b/gdb/eval.c
@@ -1134,7 +1134,8 @@ eval_op_register (struct type *expect_type, struct expression *exp,
       && regno < gdbarch_num_cooked_regs (exp->gdbarch))
     val = value::zero (register_type (exp->gdbarch, regno), not_lval);
   else
-    val = value_of_register (regno, get_selected_frame (NULL));
+    val = value_of_register
+      (regno, get_next_frame_sentinel_okay (get_selected_frame ()));
   if (val == NULL)
     error (_("Value of register %s not available."), name);
   else
diff --git a/gdb/findvar.c b/gdb/findvar.c
index 8f016f5756b..e6dedf0aadf 100644
--- a/gdb/findvar.c
+++ b/gdb/findvar.c
@@ -243,42 +243,32 @@ copy_integer_to_size (gdb_byte *dest, int dest_size, const gdb_byte *source,
     }
 }
 
-/* Return a `value' with the contents of (virtual or cooked) register
-   REGNUM as found in the specified FRAME.  The register's type is
-   determined by register_type ().  */
+/* See value.h.  */
 
-struct value *
-value_of_register (int regnum, frame_info_ptr frame)
+value *
+value_of_register (int regnum, frame_info_ptr next_frame)
 {
-  struct gdbarch *gdbarch = get_frame_arch (frame);
-  struct value *reg_val;
+  gdbarch *gdbarch = frame_unwind_arch (next_frame);
 
   /* User registers lie completely outside of the range of normal
      registers.  Catch them early so that the target never sees them.  */
   if (regnum >= gdbarch_num_cooked_regs (gdbarch))
-    return value_of_user_reg (regnum, frame);
+    return value_of_user_reg (regnum, get_prev_frame_always (next_frame));
 
-  reg_val = value_of_register_lazy (frame, regnum);
+  value *reg_val = value_of_register_lazy (next_frame, regnum);
   reg_val->fetch_lazy ();
   return reg_val;
 }
 
-/* Return a `value' with the contents of (virtual or cooked) register
-   REGNUM as found in the specified FRAME.  The register's type is
-   determined by register_type ().  The value is not fetched.  */
+/* See value.h.  */
 
-struct value *
-value_of_register_lazy (frame_info_ptr frame, int regnum)
+value *
+value_of_register_lazy (frame_info_ptr next_frame, int regnum)
 {
-  struct gdbarch *gdbarch = get_frame_arch (frame);
-  struct value *reg_val;
-  frame_info_ptr next_frame;
+  gdbarch *gdbarch = frame_unwind_arch (next_frame);
 
   gdb_assert (regnum < gdbarch_num_cooked_regs (gdbarch));
-
-  gdb_assert (frame != NULL);
-
-  next_frame = get_next_frame_sentinel_okay (frame);
+  gdb_assert (next_frame != nullptr);
 
   /* In some cases NEXT_FRAME may not have a valid frame-id yet.  This can
      happen if we end up trying to unwind a register as part of the frame
@@ -291,7 +281,7 @@ value_of_register_lazy (frame_info_ptr frame, int regnum)
   /* We should have a valid next frame.  */
   gdb_assert (frame_id_p (get_frame_id (next_frame)));
 
-  reg_val = value::allocate_lazy (register_type (gdbarch, regnum));
+  value *reg_val = value::allocate_lazy (register_type (gdbarch, regnum));
   reg_val->set_lval (lval_register);
   VALUE_REGNUM (reg_val) = regnum;
   VALUE_NEXT_FRAME_ID (reg_val) = get_frame_id (next_frame);
diff --git a/gdb/frame-unwind.c b/gdb/frame-unwind.c
index 927b6256b0b..89ae3d70b20 100644
--- a/gdb/frame-unwind.c
+++ b/gdb/frame-unwind.c
@@ -278,7 +278,8 @@ struct value *
 frame_unwind_got_register (frame_info_ptr frame,
 			   int regnum, int new_regnum)
 {
-  return value_of_register_lazy (frame, new_regnum);
+  return value_of_register_lazy (get_next_frame_sentinel_okay (frame),
+				 new_regnum);
 }
 
 /* Return a value which indicates that FRAME saved REGNUM in memory at
diff --git a/gdb/guile/scm-frame.c b/gdb/guile/scm-frame.c
index 45863c587c1..830acb8b53e 100644
--- a/gdb/guile/scm-frame.c
+++ b/gdb/guile/scm-frame.c
@@ -835,7 +835,8 @@ gdbscm_frame_read_register (SCM self, SCM register_scm)
 						register_str,
 						strlen (register_str));
 	  if (regnum >= 0)
-	    value = value_of_register (regnum, frame);
+	    value = value_of_register (regnum,
+				       get_next_frame_sentinel_okay (frame));
 	}
     }
   catch (const gdb_exception &ex)
diff --git a/gdb/infcmd.c b/gdb/infcmd.c
index c420fa15abf..511cf5fb997 100644
--- a/gdb/infcmd.c
+++ b/gdb/infcmd.c
@@ -2280,9 +2280,9 @@ default_print_registers_info (struct gdbarch *gdbarch,
       if (*(gdbarch_register_name (gdbarch, i)) == '\0')
 	continue;
 
-      default_print_one_register_info (file,
-				       gdbarch_register_name (gdbarch, i),
-				       value_of_register (i, frame));
+      default_print_one_register_info
+	(file, gdbarch_register_name (gdbarch, i),
+	 value_of_register (i, get_next_frame_sentinel_okay (frame)));
     }
 }
 
diff --git a/gdb/loongarch-tdep.c b/gdb/loongarch-tdep.c
index f7d08c60a58..12865b99e13 100644
--- a/gdb/loongarch-tdep.c
+++ b/gdb/loongarch-tdep.c
@@ -392,7 +392,8 @@ loongarch_software_single_step (struct regcache *regcache)
 static struct value *
 value_of_loongarch_user_reg (frame_info_ptr frame, const void *baton)
 {
-  return value_of_register ((long long) baton, frame);
+  return value_of_register ((long long) baton,
+			    get_next_frame_sentinel_okay (frame));
 }
 
 /* Implement the frame_align gdbarch method.  */
diff --git a/gdb/mi/mi-main.c b/gdb/mi/mi-main.c
index 487b0a92025..21f2c72cfb9 100644
--- a/gdb/mi/mi-main.c
+++ b/gdb/mi/mi-main.c
@@ -1101,7 +1101,8 @@ output_register (frame_info_ptr frame, int regnum, int format,
 		 int skip_unavailable)
 {
   struct ui_out *uiout = current_uiout;
-  struct value *val = value_of_register (regnum, frame);
+  value *val
+    = value_of_register (regnum, get_next_frame_sentinel_okay (frame));
   struct value_print_options opts;
 
   if (skip_unavailable && !val->entirely_available ())
diff --git a/gdb/mips-tdep.c b/gdb/mips-tdep.c
index 16edfdb0f1b..adaa091bda1 100644
--- a/gdb/mips-tdep.c
+++ b/gdb/mips-tdep.c
@@ -8074,7 +8074,7 @@ static struct value *
 value_of_mips_user_reg (frame_info_ptr frame, const void *baton)
 {
   const int *reg_p = (const int *) baton;
-  return value_of_register (*reg_p, frame);
+  return value_of_register (*reg_p, get_next_frame_sentinel_okay (frame));
 }
 
 static struct gdbarch *
diff --git a/gdb/nds32-tdep.c b/gdb/nds32-tdep.c
index a81b5fd1fae..7618a81fc25 100644
--- a/gdb/nds32-tdep.c
+++ b/gdb/nds32-tdep.c
@@ -267,9 +267,10 @@ static const struct
 static struct value *
 value_of_nds32_reg (frame_info_ptr frame, const void *baton)
 {
-  return value_of_register ((int) (intptr_t) baton, frame);
+  return value_of_register ((int) (intptr_t) baton,
+			    get_next_frame_sentinel_okay (frame));
 }
-\f
+
 /* Implement the "frame_align" gdbarch method.  */
 
 static CORE_ADDR
diff --git a/gdb/python/py-frame.c b/gdb/python/py-frame.c
index 0a7e10f09ff..f38bf5d8237 100644
--- a/gdb/python/py-frame.c
+++ b/gdb/python/py-frame.c
@@ -260,7 +260,8 @@ frapy_read_register (PyObject *self, PyObject *args, PyObject *kw)
 	return nullptr;
 
       gdb_assert (regnum >= 0);
-      struct value *val = value_of_register (regnum, frame);
+      value *val
+	= value_of_register (regnum, get_next_frame_sentinel_okay (frame));
 
       if (val == NULL)
 	PyErr_SetString (PyExc_ValueError, _("Can't read register."));
diff --git a/gdb/python/py-unwind.c b/gdb/python/py-unwind.c
index ee50c51b531..f1162f22290 100644
--- a/gdb/python/py-unwind.c
+++ b/gdb/python/py-unwind.c
@@ -467,8 +467,8 @@ pending_framepy_read_register (PyObject *self, PyObject *args, PyObject *kw)
 	 which maps to a real register.  In the past,
 	 get_frame_register_value() was used here, which did not
 	 handle the user register case.  */
-      struct value *val = value_of_register (regnum,
-					     pending_frame->frame_info);
+      value *val = value_of_register
+        (regnum, get_next_frame_sentinel_okay (pending_frame->frame_info));
       if (val == NULL)
 	PyErr_Format (PyExc_ValueError,
 		      "Cannot read register %d from frame.",
diff --git a/gdb/riscv-tdep.c b/gdb/riscv-tdep.c
index 2b4b9e2a02a..8110a8deedb 100644
--- a/gdb/riscv-tdep.c
+++ b/gdb/riscv-tdep.c
@@ -168,7 +168,7 @@ static struct value *
 value_of_riscv_user_reg (frame_info_ptr frame, const void *baton)
 {
   const int *reg_p = (const int *) baton;
-  return value_of_register (*reg_p, frame);
+  return value_of_register (*reg_p, get_next_frame_sentinel_okay (frame));
 }
 
 /* Information about a register alias that needs to be set up for this
@@ -1149,7 +1149,7 @@ riscv_print_one_register_info (struct gdbarch *gdbarch,
 
   try
     {
-      val = value_of_register (regnum, frame);
+      val = value_of_register (regnum, get_next_frame_sentinel_okay (frame));
       regtype = val->type ();
     }
   catch (const gdb_exception_error &ex)
diff --git a/gdb/s12z-tdep.c b/gdb/s12z-tdep.c
index 4781eab083e..42fd1fb1d6c 100644
--- a/gdb/s12z-tdep.c
+++ b/gdb/s12z-tdep.c
@@ -494,7 +494,7 @@ s12z_print_ccw_info (struct gdbarch *gdbarch,
 		     frame_info_ptr frame,
 		     int reg)
 {
-  struct value *v = value_of_register (reg, frame);
+  value *v = value_of_register (reg, get_next_frame_sentinel_okay (frame));
   const char *name = gdbarch_register_name (gdbarch, reg);
   uint32_t ccw = value_as_long (v);
   gdb_puts (name, file);
diff --git a/gdb/std-regs.c b/gdb/std-regs.c
index 54cf9018e42..221b15f1de9 100644
--- a/gdb/std-regs.c
+++ b/gdb/std-regs.c
@@ -39,7 +39,7 @@ value_of_builtin_frame_fp_reg (frame_info_ptr frame, const void *baton)
        register can do so by adding "fp" to register name table (mind
        you, doing this is probably a dangerous thing).  */
     return value_of_register (gdbarch_deprecated_fp_regnum (gdbarch),
-			      frame);
+			      get_next_frame_sentinel_okay (frame));
   else
     {
       struct type *data_ptr_type = builtin_type (gdbarch)->builtin_data_ptr;
@@ -58,7 +58,8 @@ value_of_builtin_frame_pc_reg (frame_info_ptr frame, const void *baton)
   struct gdbarch *gdbarch = get_frame_arch (frame);
 
   if (gdbarch_pc_regnum (gdbarch) >= 0)
-    return value_of_register (gdbarch_pc_regnum (gdbarch), frame);
+    return value_of_register (gdbarch_pc_regnum (gdbarch),
+			      get_next_frame_sentinel_okay (frame));
   else
     {
       struct type *func_ptr_type = builtin_type (gdbarch)->builtin_func_ptr;
@@ -77,7 +78,8 @@ value_of_builtin_frame_sp_reg (frame_info_ptr frame, const void *baton)
   struct gdbarch *gdbarch = get_frame_arch (frame);
 
   if (gdbarch_sp_regnum (gdbarch) >= 0)
-    return value_of_register (gdbarch_sp_regnum (gdbarch), frame);
+    return value_of_register (gdbarch_sp_regnum (gdbarch),
+			      get_next_frame_sentinel_okay (frame));
   error (_("Standard register ``$sp'' is not available for this target"));
 }
 
@@ -87,7 +89,8 @@ value_of_builtin_frame_ps_reg (frame_info_ptr frame, const void *baton)
   struct gdbarch *gdbarch = get_frame_arch (frame);
 
   if (gdbarch_ps_regnum (gdbarch) >= 0)
-    return value_of_register (gdbarch_ps_regnum (gdbarch), frame);
+    return value_of_register (gdbarch_ps_regnum (gdbarch),
+			      get_next_frame_sentinel_okay (frame));
   error (_("Standard register ``$ps'' is not available for this target"));
 }
 
diff --git a/gdb/value.h b/gdb/value.h
index 6d91e8eee7a..3f9b35b589b 100644
--- a/gdb/value.h
+++ b/gdb/value.h
@@ -1123,9 +1123,14 @@ extern struct value *value_of_variable (struct symbol *var,
 extern struct value *address_of_variable (struct symbol *var,
 					  const struct block *b);
 
-extern struct value *value_of_register (int regnum, frame_info_ptr frame);
+/* Return a value with the contents of register REGNUM as found in the frame
+   previous to NEXT_FRAME.  */
 
-struct value *value_of_register_lazy (frame_info_ptr frame, int regnum);
+extern value *value_of_register (int regnum, frame_info_ptr next_frame);
+
+/* Same as the above, but the value is not fetched.  */
+
+extern value *value_of_register_lazy (frame_info_ptr next_frame, int regnum);
 
 /* Return the symbol's reading requirement.  */

^ permalink raw reply	[flat|nested] only message in thread

only message in thread, other threads:[~2023-12-14 16:21 UTC | newest]

Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-12-14 16:21 [binutils-gdb] gdb: change value_of_register and value_of_register_lazy to take the next frame Simon Marchi

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).