[RFA] Kill SKIP_PROLOGUE_FRAMELESS_P

[RFA] Kill SKIP_PROLOGUE_FRAMELESS_P

[David S. Miller]

This is being done so that we don't have to multi-arch it.
It's existence is questionable at best.

Basically, it allowed a target to optimize SKIP_PROLOGUE()
if we just cared about whether the function was frameless or
not (ie. lacked any prologue at all).

PROLOGUE_FRAMELESS_P and it's gdbarch equivalent exist and allow
the target to perform this optimization equivalently.

So we kill SKIP_PROLOGUE_FRAMELESS_P, and for every target that
provided it we instead make them implement PROLOGUE_FRAMELESS_P.

Now we have one less thing to make multi-arch'able.

Ok to install?

2002-04-21  David S. Miller  <davem@redhat.com>

	* arch-utils.c (generic_prologue_frameless_p): Kill
	SKIP_PROLOGUE_FRAMELESS_P code.
	* config/arc/tm-arc.h (SKIP_PROLOGUE_FRAMELESS_P): Delete
	references.
	(PROLOGUE_FRAMELESS_P, arc_prologue_frameless_p): New.
	* arc-tdep.c (arc_prologue_frameless_p): Implement.
	* config/arc/tm-sparc.h (SKIP_PROLOGUE_FRAMELESS_P): Delete
	references.
	(PROLOGUE_FRAMELESS_P, sparc_prologue_frameless_p): New.
	* sparc-tdep.c (sparc_prologue_frameless_p): Implement.
	(sparc_gdbarch_init): Pass it to
	set_gdbarch_prologue_frameless_p.
	* config/sparc/tm-linux.h, config/sparc/tm-sp64linux.h
	(SKIP_PROLOGUE_FRAMELESS_P,
	sparc_linux_skip_prologue_frameless_p): Kill.
	* sparc-linux-tdep.c (sparc_prologue_frameless_p): Declare.
	(sparc_linux_skip_prologue_frameless_p): Rename to...
	(sparc_linux_prologue_frameless_p): And reimplement to return
	boolean.
	(sparc_linux_gdbarch_os_init): Pass it to
	set_gdbarch_prologue_frameless_p.
	
--- ./config/arc/tm-arc.h.~1~	Sun Jan 20 19:34:30 2002
+++ ./config/arc/tm-arc.h	Sun Apr 21 02:01:42 2002
@@ -29,14 +29,13 @@
 #define FUNCTION_START_OFFSET 0
 
 /* Advance PC across any function entry prologue instructions
-   to reach some "real" code.  SKIP_PROLOGUE_FRAMELESS_P advances
-   the PC past some of the prologue, but stops as soon as it
-   knows that the function has a frame.  Its result is equal
-   to its input PC if the function is frameless, unequal otherwise.  */
+   to reach some "real" code.  */
 
 #define SKIP_PROLOGUE(pc) (arc_skip_prologue (pc, 0))
-#define SKIP_PROLOGUE_FRAMELESS_P(pc) (arc_skip_prologue (pc, 1))
 extern CORE_ADDR arc_skip_prologue (CORE_ADDR, int);
+
+#define PROLOGUE_FRAMELESS_P(pc) arc_prologue_frameless_p(pc)
+extern int arc_prologue_frameless_p (CORE_ADDR);
 
 /* Sequence of bytes for breakpoint instruction.
    ??? The current value is "sr -1,[-1]" and is for the simulator only.
--- ./config/sparc/tm-sparc.h.~1~	Mon Jan 28 20:42:44 2002
+++ ./config/sparc/tm-sparc.h	Sun Apr 21 02:04:12 2002
@@ -248,10 +248,7 @@ extern int sparc_intreg_size (void);
 #define BELIEVE_PCC_PROMOTION 1
 
 /* Advance PC across any function entry prologue instructions
-   to reach some "real" code.  SKIP_PROLOGUE_FRAMELESS_P advances
-   the PC past some of the prologue, but stops as soon as it
-   knows that the function has a frame.  Its result is equal
-   to its input PC if the function is frameless, unequal otherwise.  */
+   to reach some "real" code.  */
 
 #define SKIP_PROLOGUE(PC) sparc_skip_prologue (PC, 0)
 
@@ -312,6 +309,10 @@ extern CORE_ADDR sparc32_stack_align (CO
      sparc_reg_struct_has_addr (GCC_P, TYPE)
 extern int sparc_reg_struct_has_addr (int, struct type *);
 
+/* Is the prologue at PC frameless?  */
+#define PROLOGUE_FRAMELESS_P(PC) sparc_prologue_frameless_p (PC)
+extern int sparc_prologue_frameless_p (CORE_ADDR);
+
 #endif /* GDB_MULTI_ARCH */
 
 #if defined (GDB_MULTI_ARCH) && (GDB_MULTI_ARCH > 0)
@@ -332,15 +333,6 @@ extern int sparc_y_regnum (void);
 
 #define PC_ADJUST(PC) sparc_pc_adjust (PC)
 extern CORE_ADDR sparc_pc_adjust (CORE_ADDR);
-
-/* Advance PC across any function entry prologue instructions to reach
-   some "real" code.  SKIP_PROLOGUE_FRAMELESS_P advances the PC past
-   some of the prologue, but stops as soon as it knows that the
-   function has a frame.  Its result is equal to its input PC if the
-   function is frameless, unequal otherwise.  */
-
-#define SKIP_PROLOGUE_FRAMELESS_P(PC) sparc_skip_prologue (PC, 1)
-extern CORE_ADDR sparc_skip_prologue (CORE_ADDR, int);
 
 /* If an argument is declared "register", Sun cc will keep it in a register,
    never saving it onto the stack.  So we better not believe the "p" symbol
--- ./config/sparc/tm-linux.h.~1~	Sun Apr 21 01:30:19 2002
+++ ./config/sparc/tm-linux.h	Sun Apr 21 01:57:42 2002
@@ -29,8 +29,4 @@
 
 #include "tm-linux.h"
 
-#undef SKIP_PROLOGUE_FRAMELESS_P
-#define SKIP_PROLOGUE_FRAMELESS_P(PC) sparc_linux_skip_prologue_frameless_p (PC)
-extern CORE_ADDR sparc_linux_skip_prologue_frameless_p (CORE_ADDR pc);
-
 #endif /* TM_SPARCLINUX_H */
--- ./config/sparc/tm-sp64linux.h.~1~	Sun Apr 21 01:30:27 2002
+++ ./config/sparc/tm-sp64linux.h	Sun Apr 21 01:57:47 2002
@@ -29,8 +29,4 @@ Foundation, Inc., 59 Temple Place - Suit
 
 #include "tm-linux.h"
 
-#undef SKIP_PROLOGUE_FRAMELESS_P
-#define SKIP_PROLOGUE_FRAMELESS_P(PC) sparc_linux_skip_prologue_frameless_p (PC)
-extern CORE_ADDR sparc_linux_skip_prologue_frameless_p (CORE_ADDR pc);
-
 #endif /* TM_SPARC_LIN64_H */
--- ./sparc-tdep.c.~1~	Sat Apr 20 20:21:56 2002
+++ ./sparc-tdep.c	Sun Apr 21 01:57:20 2002
@@ -626,6 +626,14 @@ sparc_skip_prologue (CORE_ADDR start_pc,
   return examine_prologue (start_pc, frameless_p, NULL, NULL);
 }
 
+/* Is the prologue at IP frameless?  */
+
+int
+sparc_prologue_frameless_p (CORE_ADDR ip)
+{
+  return ip == sparc_skip_prologue (ip, 1);
+}
+
 /* Check instruction at ADDR to see if it is a branch.
    All non-annulled instructions will go to NPC or will trap.
    Set *TARGET if we find a candidate branch; set to zero if not.
@@ -2709,10 +2717,7 @@ sparc64_register_byte (int regno)
 }
 
 /* Advance PC across any function entry prologue instructions to reach
-   some "real" code.  SKIP_PROLOGUE_FRAMELESS_P advances the PC past
-   some of the prologue, but stops as soon as it knows that the
-   function has a frame.  Its result is equal to its input PC if the
-   function is frameless, unequal otherwise.  */
+   some "real" code.  */
 
 static CORE_ADDR
 sparc_gdbarch_skip_prologue (CORE_ADDR ip)
@@ -3031,6 +3036,7 @@ sparc_gdbarch_init (struct gdbarch_info 
   set_gdbarch_reg_struct_has_addr (gdbarch, sparc_reg_struct_has_addr);
   set_gdbarch_return_value_on_stack (gdbarch, sparc_return_value_on_stack);
   set_gdbarch_saved_pc_after_call (gdbarch, sparc_saved_pc_after_call);
+  set_gdbarch_prologue_frameless_p (gdbarch, sparc_prologue_frameless_p);
   set_gdbarch_short_bit (gdbarch, 2 * TARGET_CHAR_BIT);
   set_gdbarch_skip_prologue (gdbarch, sparc_gdbarch_skip_prologue);
   set_gdbarch_sp_regnum (gdbarch, SPARC_SP_REGNUM);
--- ./sparc-linux-tdep.c.~1~	Sun Apr 21 01:30:03 2002
+++ ./sparc-linux-tdep.c	Sun Apr 21 01:58:17 2002
@@ -385,13 +385,13 @@ sparc_linux_skip_solib_resolver (CORE_AD
 			ret
 			 restore
 
-   is going to confuse SKIP_PROLOGUE_FRAMELESS_P.  It is hard to
-   formulate a generic fix for this that would not break on sibcalls.
+   is going to confuse sparc_prologue_frameless_p.  It is hard to
+   formulate a generic fix for this that would not break on sibcalls.  */
 
-   TODO Need to generically multi-arch this.  */
+extern int sparc_prologue_frameless_p (CORE_ADDR);
 
-CORE_ADDR
-sparc_linux_skip_prologue_frameless_p (CORE_ADDR pc)
+static int
+sparc_linux_prologue_frameless_p (CORE_ADDR pc)
 {
   struct objfile *objfile;
   struct minimal_symbol *resolver 
@@ -414,9 +414,9 @@ sparc_linux_skip_prologue_frameless_p (C
 	resolver_size = 0x100;
 
       if (pc >= rpc && pc < (rpc + resolver_size))
-	return pc + 4;
+	return 1;
     }
-  return sparc_skip_prologue (pc, 1);
+  return sparc_prologue_frameless_p (pc);
 }
 
 /* Fetch (and possibly build) an appropriate link_map_offsets
@@ -483,6 +483,7 @@ sparc_linux_gdbarch_os_init(struct gdbar
   set_gdbarch_saved_pc_after_call (gdbarch, sparc_linux_saved_pc_after_call);
   set_gdbarch_in_sigtramp (gdbarch, sparc_linux_in_sigtramp);
   set_gdbarch_skip_solib_resolver (gdbarch, sparc_linux_skip_solib_resolver);
+  set_gdbarch_prologue_frameless_p (gdbarch, sparc_linux_prologue_frameless_p);
 
   if (gdbarch_tdep (gdbarch)->intreg_size == 4)
     {
--- ./arch-utils.c.~1~	Sun Apr 21 01:20:26 2002
+++ ./arch-utils.c	Sun Apr 21 01:59:35 2002
@@ -166,11 +166,7 @@ generic_remote_translate_xfer_address (C
 int
 generic_prologue_frameless_p (CORE_ADDR ip)
 {
-#ifdef SKIP_PROLOGUE_FRAMELESS_P
-  return ip == SKIP_PROLOGUE_FRAMELESS_P (ip);
-#else
   return ip == SKIP_PROLOGUE (ip);
-#endif
 }
 
 /* New/multi-arched targets should use the correct gdbarch field
--- ./arc-tdep.c.~1~	Wed Feb 20 02:42:59 2002
+++ ./arc-tdep.c	Sun Apr 21 02:00:40 2002
@@ -296,6 +296,14 @@ arc_skip_prologue (CORE_ADDR pc, int fra
   return codestream_tell ();
 }
 
+/* Is the prologue at PC frameless?  */
+
+int
+arc_prologue_frameless_p (CORE_ADDR pc)
+{
+  return (pc == arc_skip_prologue (pc, 1);
+}
+
 /* Return the return address for a frame.
    This is used to implement FRAME_SAVED_PC.
    This is taken from frameless_look_for_prologue.  */

Re: [RFA] Kill SKIP_PROLOGUE_FRAMELESS_P

[Andrew Cagney]

> This is being done so that we don't have to multi-arch it.
> It's existence is questionable at best.

Good catch.

I don't think anyone expects SKIP_PROLOGUE_FRAMELESS_P to be 
multi-arched.  Instead, as the tm.h files (or entire architectures - 
arc) get deleted, all uses will disappear.  That letting the macro slip 
quietly off the table.

Giving the occasional macro a good swift shove never hurts.

> Basically, it allowed a target to optimize SKIP_PROLOGUE()
> if we just cared about whether the function was frameless or
> not (ie. lacked any prologue at all).
> 
> PROLOGUE_FRAMELESS_P and it's gdbarch equivalent exist and allow
> the target to perform this optimization equivalently.
> 
> So we kill SKIP_PROLOGUE_FRAMELESS_P, and for every target that
> provided it we instead make them implement PROLOGUE_FRAMELESS_P.
> 
> Now we have one less thing to make multi-arch'able.

As the patch stands, it is dependant on other changes.  Can you please 
revise this patch so that it is against the existing source base.  That 
would create an arc_... and sparc_... function,  but leave the 
sparc_linux_.. function for later.

enjoy,
Andrew

Re: [RFA] Kill SKIP_PROLOGUE_FRAMELESS_P

[David S. Miller]

   From: Andrew Cagney <ac131313@cygnus.com>
   Date: Sun, 21 Apr 2002 14:40:13 -0400

   As the patch stands, it is dependant on other changes.  Can you please 
   revise this patch so that it is against the existing source base.  That 
   would create an arc_... and sparc_... function,  but leave the 
   sparc_linux_.. function for later.

Here is the change I installed.

2002-04-21  David S. Miller  <davem@redhat.com>

	* arch-utils.c (generic_prologue_frameless_p): Kill
	SKIP_PROLOGUE_FRAMELESS_P code.
	* config/arc/tm-arc.h (SKIP_PROLOGUE_FRAMELESS_P): Delete
	references.
	(PROLOGUE_FRAMELESS_P, arc_prologue_frameless_p): New.
	* arc-tdep.c (arc_prologue_frameless_p): Implement.
	* config/arc/tm-sparc.h (SKIP_PROLOGUE_FRAMELESS_P): Delete
	references.
	(PROLOGUE_FRAMELESS_P, sparc_prologue_frameless_p): New.
	* sparc-tdep.c (sparc_prologue_frameless_p): Implement.
	(sparc_gdbarch_init): Pass it to
	set_gdbarch_prologue_frameless_p.
	
--- ./config/arc/tm-arc.h.~1~	Sun Jan 20 19:34:30 2002
+++ ./config/arc/tm-arc.h	Sun Apr 21 02:01:42 2002
@@ -29,14 +29,13 @@
 #define FUNCTION_START_OFFSET 0
 
 /* Advance PC across any function entry prologue instructions
-   to reach some "real" code.  SKIP_PROLOGUE_FRAMELESS_P advances
-   the PC past some of the prologue, but stops as soon as it
-   knows that the function has a frame.  Its result is equal
-   to its input PC if the function is frameless, unequal otherwise.  */
+   to reach some "real" code.  */
 
 #define SKIP_PROLOGUE(pc) (arc_skip_prologue (pc, 0))
-#define SKIP_PROLOGUE_FRAMELESS_P(pc) (arc_skip_prologue (pc, 1))
 extern CORE_ADDR arc_skip_prologue (CORE_ADDR, int);
+
+#define PROLOGUE_FRAMELESS_P(pc) arc_prologue_frameless_p(pc)
+extern int arc_prologue_frameless_p (CORE_ADDR);
 
 /* Sequence of bytes for breakpoint instruction.
    ??? The current value is "sr -1,[-1]" and is for the simulator only.
--- ./config/sparc/tm-sparc.h.~1~	Mon Jan 28 20:42:44 2002
+++ ./config/sparc/tm-sparc.h	Sun Apr 21 02:04:12 2002
@@ -248,10 +248,7 @@ extern int sparc_intreg_size (void);
 #define BELIEVE_PCC_PROMOTION 1
 
 /* Advance PC across any function entry prologue instructions
-   to reach some "real" code.  SKIP_PROLOGUE_FRAMELESS_P advances
-   the PC past some of the prologue, but stops as soon as it
-   knows that the function has a frame.  Its result is equal
-   to its input PC if the function is frameless, unequal otherwise.  */
+   to reach some "real" code.  */
 
 #define SKIP_PROLOGUE(PC) sparc_skip_prologue (PC, 0)
 
@@ -312,6 +309,10 @@ extern CORE_ADDR sparc32_stack_align (CO
      sparc_reg_struct_has_addr (GCC_P, TYPE)
 extern int sparc_reg_struct_has_addr (int, struct type *);
 
+/* Is the prologue at PC frameless?  */
+#define PROLOGUE_FRAMELESS_P(PC) sparc_prologue_frameless_p (PC)
+extern int sparc_prologue_frameless_p (CORE_ADDR);
+
 #endif /* GDB_MULTI_ARCH */
 
 #if defined (GDB_MULTI_ARCH) && (GDB_MULTI_ARCH > 0)
@@ -332,15 +333,6 @@ extern int sparc_y_regnum (void);
 
 #define PC_ADJUST(PC) sparc_pc_adjust (PC)
 extern CORE_ADDR sparc_pc_adjust (CORE_ADDR);
-
-/* Advance PC across any function entry prologue instructions to reach
-   some "real" code.  SKIP_PROLOGUE_FRAMELESS_P advances the PC past
-   some of the prologue, but stops as soon as it knows that the
-   function has a frame.  Its result is equal to its input PC if the
-   function is frameless, unequal otherwise.  */
-
-#define SKIP_PROLOGUE_FRAMELESS_P(PC) sparc_skip_prologue (PC, 1)
-extern CORE_ADDR sparc_skip_prologue (CORE_ADDR, int);
 
 /* If an argument is declared "register", Sun cc will keep it in a register,
    never saving it onto the stack.  So we better not believe the "p" symbol
--- ./sparc-tdep.c.~1~	Sat Apr 20 20:21:56 2002
+++ ./sparc-tdep.c	Sun Apr 21 01:57:20 2002
@@ -626,6 +626,14 @@ sparc_skip_prologue (CORE_ADDR start_pc,
   return examine_prologue (start_pc, frameless_p, NULL, NULL);
 }
 
+/* Is the prologue at IP frameless?  */
+
+int
+sparc_prologue_frameless_p (CORE_ADDR ip)
+{
+  return ip == sparc_skip_prologue (ip, 1);
+}
+
 /* Check instruction at ADDR to see if it is a branch.
    All non-annulled instructions will go to NPC or will trap.
    Set *TARGET if we find a candidate branch; set to zero if not.
@@ -2709,10 +2717,7 @@ sparc64_register_byte (int regno)
 }
 
 /* Advance PC across any function entry prologue instructions to reach
-   some "real" code.  SKIP_PROLOGUE_FRAMELESS_P advances the PC past
-   some of the prologue, but stops as soon as it knows that the
-   function has a frame.  Its result is equal to its input PC if the
-   function is frameless, unequal otherwise.  */
+   some "real" code.  */
 
 static CORE_ADDR
 sparc_gdbarch_skip_prologue (CORE_ADDR ip)
@@ -3031,6 +3036,7 @@ sparc_gdbarch_init (struct gdbarch_info 
   set_gdbarch_reg_struct_has_addr (gdbarch, sparc_reg_struct_has_addr);
   set_gdbarch_return_value_on_stack (gdbarch, sparc_return_value_on_stack);
   set_gdbarch_saved_pc_after_call (gdbarch, sparc_saved_pc_after_call);
+  set_gdbarch_prologue_frameless_p (gdbarch, sparc_prologue_frameless_p);
   set_gdbarch_short_bit (gdbarch, 2 * TARGET_CHAR_BIT);
   set_gdbarch_skip_prologue (gdbarch, sparc_gdbarch_skip_prologue);
   set_gdbarch_sp_regnum (gdbarch, SPARC_SP_REGNUM);
--- ./arch-utils.c.~1~	Sun Apr 21 01:20:26 2002
+++ ./arch-utils.c	Sun Apr 21 01:59:35 2002
@@ -166,11 +166,7 @@ generic_remote_translate_xfer_address (C
 int
 generic_prologue_frameless_p (CORE_ADDR ip)
 {
-#ifdef SKIP_PROLOGUE_FRAMELESS_P
-  return ip == SKIP_PROLOGUE_FRAMELESS_P (ip);
-#else
   return ip == SKIP_PROLOGUE (ip);
-#endif
 }
 
 /* New/multi-arched targets should use the correct gdbarch field
--- ./arc-tdep.c.~1~	Wed Feb 20 02:42:59 2002
+++ ./arc-tdep.c	Sun Apr 21 02:00:40 2002
@@ -296,6 +296,14 @@ arc_skip_prologue (CORE_ADDR pc, int fra
   return codestream_tell ();
 }
 
+/* Is the prologue at PC frameless?  */
+
+int
+arc_prologue_frameless_p (CORE_ADDR pc)
+{
+  return (pc == arc_skip_prologue (pc, 1);
+}
+
 /* Return the return address for a frame.
    This is used to implement FRAME_SAVED_PC.
    This is taken from frameless_look_for_prologue.  */

Re: [RFA] Kill SKIP_PROLOGUE_FRAMELESS_P

[David S. Miller]

   From: Andrew Cagney <ac131313@cygnus.com>
   Date: Sun, 21 Apr 2002 14:40:13 -0400
   
   As the patch stands, it is dependant on other changes.  Can you please 
   revise this patch so that it is against the existing source base.  That 
   would create an arc_... and sparc_... function,  but leave the 
   sparc_linux_.. function for later.

That is what I was going to do if you approved it before those
changes.  I'm assuming therefore that I can install the change
sans the sparc_linux_* bits.

Re: [RFA] Kill SKIP_PROLOGUE_FRAMELESS_P

[Andrew Cagney]

>  From: Andrew Cagney <ac131313@cygnus.com>
> Date: Sun, 21 Apr 2002 14:40:13 -0400
>    
>    As the patch stands, it is dependant on other changes.  Can you please 
>    revise this patch so that it is against the existing source base.  That 
>    would create an arc_... and sparc_... function,  but leave the 
>    sparc_linux_.. function for later.
> 
> That is what I was going to do if you approved it before those
> changes.  I'm assuming therefore that I can install the change
> sans the sparc_linux_* bits.

If you're unsure, ask.  If something is approved, it tends to be very clear.

Can you also please remember to create patches against current sources. 
  That way everyones life is easier (and in this case I could have 
reviewed it a lot quicker).

Anyway, can you please update the documentation (obvious) - it now 
refers to a non-existant macro.

Andrew

Re: [RFA] Kill SKIP_PROLOGUE_FRAMELESS_P

[David S. Miller]

   From: Andrew Cagney <ac131313@cygnus.com>
   Date: Sun, 21 Apr 2002 21:34:28 -0400

   Can you also please remember to create patches against current sources. 
     That way everyones life is easier (and in this case I could have 
   reviewed it a lot quicker).
   
Ok.

   Anyway, can you please update the documentation (obvious) - it now 
   refers to a non-existant macro.
   
Done, thusly.

2002-04-21  David S. Miller  <davem@redhat.com>

	* gdbint.texinfo (SKIP_PROLOGUE_FRAMELESS_P): Delete definition.

--- gdbint.texinfo.~1~	Sun Apr 21 08:52:35 2002
+++ gdbint.texinfo	Sun Apr 21 18:35:29 2002
@@ -3415,12 +3415,6 @@
 A C expression that returns the address of the ``real'' code beyond the
 function entry prologue found at @var{pc}.
 
-@item SKIP_PROLOGUE_FRAMELESS_P
-@findex SKIP_PROLOGUE_FRAMELESS_P
-A C expression that should behave similarly, but that can stop as soon
-as the function is known to have a frame.  If not defined,
-@code{SKIP_PROLOGUE} will be used instead.
-
 @item SKIP_TRAMPOLINE_CODE (@var{pc})
 @findex SKIP_TRAMPOLINE_CODE
 If the target machine has trampoline code that sits between callers and