[PATCH RFA] Zap EXTRA_FRAME_INFO for ARM target

[Kevin Buettner <kevinb at redhat dot com>]

The patch below represents a small step on the way to multiarching the
ARM target.  It eliminates the use of the deprecated EXTRA_FRAME_INFO
macro for describing a frame.  Instead, it now uses the ``extra_info''
and ``saved_regs'' members in the frame_info struct.

This patch is intended to be applied on top of two other patches that
I'm waiting for approval on.  These are:

    http://sources.redhat.com/ml/gdb-patches/2001-11/msg00484.html
    http://sources.redhat.com/ml/gdb-patches/2001-12/msg00349.html

Okay to commit?

	* tm-arm.h (EXTRA_FRAME_INFO): Delete definition.
	(arm_frame_init_saved_regs): Declare.
	(FRAME_INIT_SAVED_REGS): Define.
	(arm_frame_find_saved_regs): Delete declaration.
	(FRAME_FIND_SAVED_REGS): Delete definition.
	* arm-tdep.c (gdb_assert.h): Include.
	(struct frame_extra_info): Delete fsr member.
	(thumb_scan_prologue, check_prologue_cache, save_prologue_cache)
	(arm_scan_prologue, arm_find_callers_reg, arm_frame_chain)
	(arm_init_extra_frame_info, arm_push_dummy_frame): Use
	``saved_regs'' in place of ``fsr.regs''.  Use
	``extra_info->framesize'' in place of just ``framesize''.
	Likewise for ``frameoffset'' and ``framereg''.
	(arm_frame_init_saved_regs): New function.
	(arm_frame_find_saved_regs): Delete.
	(_initialize_arm_tdep): Allocate ``extra_info'' and ``saved_regs''
	structs for the prologue cache.
	(arm_frame_chain): Likewise for the hand created caller's
	frame_info struct.
	(arm_init_extra_frame_info): Likewise for the frame_info struct
	undergoing initialization.

diff -upr ../../../sourceware-arm1+2/src/gdb/arm-tdep.c ./arm-tdep.c
--- ../../../sourceware-arm1+2/src/gdb/arm-tdep.c	Sat Dec 15 00:13:02 2001
+++ ./arm-tdep.c	Sat Dec 15 00:30:34 2001
@@ -33,6 +33,7 @@
 #include "doublest.h"
 #include "value.h"
 #include "solib-svr4.h"
+#include "gdb_assert.h"
 
 /* Each OS has a different mechanism for accessing the various
    registers stored in the sigcontext structure.
@@ -108,7 +109,6 @@ static void convert_from_extended (void 
 
 struct frame_extra_info
   {
-    struct frame_saved_regs fsr;
     int framesize;
     int frameoffset;
     int framereg;
@@ -534,7 +534,7 @@ thumb_scan_prologue (struct frame_info *
      frame pointer, adjust the stack pointer, and save registers.
      Do this until all basic prolog instructions are found.  */
 
-  fi->framesize = 0;
+  fi->extra_info->framesize = 0;
   for (current_pc = prologue_start;
        (current_pc < prologue_end) && ((findmask & 7) != 7);
        current_pc += 2)
@@ -557,8 +557,8 @@ thumb_scan_prologue (struct frame_info *
 	  for (regno = LR_REGNUM; regno >= 0; regno--)
 	    if (mask & (1 << regno))
 	      {
-		fi->framesize += 4;
-		fi->fsr.regs[saved_reg[regno]] = -(fi->framesize);
+		fi->extra_info->framesize += 4;
+		fi->saved_regs[saved_reg[regno]] = -(fi->extra_info->framesize);
 		saved_reg[regno] = regno;	/* reset saved register map */
 	      }
 	}
@@ -572,22 +572,22 @@ thumb_scan_prologue (struct frame_info *
 	  offset = (insn & 0x7f) << 2;	/* get scaled offset */
 	  if (insn & 0x80)	/* is it signed? (==subtracting) */
 	    {
-	      fi->frameoffset += offset;
+	      fi->extra_info->frameoffset += offset;
 	      offset = -offset;
 	    }
-	  fi->framesize -= offset;
+	  fi->extra_info->framesize -= offset;
 	}
       else if ((insn & 0xff00) == 0xaf00)	/* add r7, sp, #imm */
 	{
 	  findmask |= 2;  /* setting of r7 found */
-	  fi->framereg = THUMB_FP_REGNUM;
-	  fi->frameoffset = (insn & 0xff) << 2;		/* get scaled offset */
+	  fi->extra_info->framereg = THUMB_FP_REGNUM;
+	  fi->extra_info->frameoffset = (insn & 0xff) << 2;		/* get scaled offset */
 	}
       else if (insn == 0x466f)			/* mov r7, sp */
 	{
 	  findmask |= 2;  /* setting of r7 found */
-	  fi->framereg = THUMB_FP_REGNUM;
-	  fi->frameoffset = 0;
+	  fi->extra_info->framereg = THUMB_FP_REGNUM;
+	  fi->extra_info->frameoffset = 0;
 	  saved_reg[THUMB_FP_REGNUM] = SP_REGNUM;
 	}
       else if ((insn & 0xffc0) == 0x4640)	/* mov r0-r7, r8-r15 */
@@ -627,11 +627,11 @@ check_prologue_cache (struct frame_info 
 
   if (fi->pc == prologue_cache.pc)
     {
-      fi->framereg = prologue_cache.framereg;
-      fi->framesize = prologue_cache.framesize;
-      fi->frameoffset = prologue_cache.frameoffset;
+      fi->extra_info->framereg = prologue_cache.extra_info->framereg;
+      fi->extra_info->framesize = prologue_cache.extra_info->framesize;
+      fi->extra_info->frameoffset = prologue_cache.extra_info->frameoffset;
       for (i = 0; i < NUM_REGS; i++)
-	fi->fsr.regs[i] = prologue_cache.fsr.regs[i];
+	fi->saved_regs[i] = prologue_cache.saved_regs[i];
       return 1;
     }
   else
@@ -647,12 +647,12 @@ save_prologue_cache (struct frame_info *
   int i;
 
   prologue_cache.pc = fi->pc;
-  prologue_cache.framereg = fi->framereg;
-  prologue_cache.framesize = fi->framesize;
-  prologue_cache.frameoffset = fi->frameoffset;
+  prologue_cache.extra_info->framereg = fi->extra_info->framereg;
+  prologue_cache.extra_info->framesize = fi->extra_info->framesize;
+  prologue_cache.extra_info->frameoffset = fi->extra_info->frameoffset;
 
   for (i = 0; i < NUM_REGS; i++)
-    prologue_cache.fsr.regs[i] = fi->fsr.regs[i];
+    prologue_cache.saved_regs[i] = fi->saved_regs[i];
 }
 
 
@@ -734,9 +734,9 @@ arm_scan_prologue (struct frame_info *fi
     return;
 
   /* Assume there is no frame until proven otherwise.  */
-  fi->framereg = SP_REGNUM;
-  fi->framesize = 0;
-  fi->frameoffset = 0;
+  fi->extra_info->framereg = SP_REGNUM;
+  fi->extra_info->framesize = 0;
+  fi->extra_info->frameoffset = 0;
 
   /* Check for Thumb prologue.  */
   if (arm_pc_is_thumb (fi->pc))
@@ -835,7 +835,7 @@ arm_scan_prologue (struct frame_info *fi
 	    if (mask & (1 << regno))
 	      {
 		sp_offset -= 4;
-		fi->fsr.regs[regno] = sp_offset;
+		fi->saved_regs[regno] = sp_offset;
 	      }
 	}
       else if ((insn & 0xfffff000) == 0xe24cb000)	/* sub fp, ip #n */
@@ -844,7 +844,7 @@ arm_scan_prologue (struct frame_info *fi
 	  unsigned rot = (insn & 0xf00) >> 7;	/* rotate amount */
 	  imm = (imm >> rot) | (imm << (32 - rot));
 	  fp_offset = -imm;
-	  fi->framereg = FP_REGNUM;
+	  fi->extra_info->framereg = FP_REGNUM;
 	}
       else if ((insn & 0xfffff000) == 0xe24dd000)	/* sub sp, sp #n */
 	{
@@ -857,7 +857,7 @@ arm_scan_prologue (struct frame_info *fi
 	{
 	  sp_offset -= 12;
 	  regno = F0_REGNUM + ((insn >> 12) & 0x07);
-	  fi->fsr.regs[regno] = sp_offset;
+	  fi->saved_regs[regno] = sp_offset;
 	}
       else if ((insn & 0xffbf0fff) == 0xec2d0200)	/* sfmfd f0, 4, [sp!] */
 	{
@@ -884,7 +884,7 @@ arm_scan_prologue (struct frame_info *fi
 	  for (; fp_start_reg < fp_bound_reg; fp_start_reg++)
 	    {
 	      sp_offset -= 12;
-	      fi->fsr.regs[fp_start_reg++] = sp_offset;
+	      fi->saved_regs[fp_start_reg++] = sp_offset;
 	    }
 	}
       else if ((insn & 0xf0000000) != 0xe0000000)
@@ -900,11 +900,11 @@ arm_scan_prologue (struct frame_info *fi
   /* The frame size is just the negative of the offset (from the original SP)
      of the last thing thing we pushed on the stack.  The frame offset is
      [new FP] - [new SP].  */
-  fi->framesize = -sp_offset;
-  if (fi->framereg == FP_REGNUM)
-    fi->frameoffset = fp_offset - sp_offset;
+  fi->extra_info->framesize = -sp_offset;
+  if (fi->extra_info->framereg == FP_REGNUM)
+    fi->extra_info->frameoffset = fp_offset - sp_offset;
   else
-    fi->frameoffset = 0;
+    fi->extra_info->frameoffset = 0;
 
   save_prologue_cache (fi);
 }
@@ -926,8 +926,8 @@ arm_find_callers_reg (struct frame_info 
       return generic_read_register_dummy (fi->pc, fi->frame, regnum);
     else
 #endif
-    if (fi->fsr.regs[regnum] != 0)
-      return read_memory_integer (fi->fsr.regs[regnum],
+    if (fi->saved_regs[regnum] != 0)
+      return read_memory_integer (fi->saved_regs[regnum],
 				  REGISTER_RAW_SIZE (regnum));
   return read_register (regnum);
 }
@@ -970,8 +970,7 @@ arm_frame_chain (struct frame_info *fi)
       return 0;			/* in _start fn, don't chain further */
 #endif
   CORE_ADDR caller_pc, fn_start;
-  struct frame_info caller_fi;
-  int framereg = fi->framereg;
+  int framereg = fi->extra_info->framereg;
 
   if (fi->pc < LOWEST_PC)
     return 0;
@@ -988,10 +987,25 @@ arm_frame_chain (struct frame_info *fi)
      frame register number. */
   if (arm_pc_is_thumb (caller_pc) != arm_pc_is_thumb (fi->pc))
     {
+      struct frame_info caller_fi;
+      struct cleanup *old_chain;
+
+      /* Create a temporary frame suitable for scanning the caller's
+         prologue.  (Ugh.)  */
       memset (&caller_fi, 0, sizeof (caller_fi));
+      caller_fi.saved_regs = (CORE_ADDR *) xcalloc (1, SIZEOF_FRAME_SAVED_REGS);
+      old_chain = make_cleanup (xfree, caller_fi.saved_regs);
+      caller_fi.extra_info = xcalloc (1, sizeof (struct frame_extra_info));
+      make_cleanup (xfree, caller_fi.extra_info);
+
+      /* Now, scan the prologue and obtain the frame register.  */
       caller_fi.pc = caller_pc;
       arm_scan_prologue (&caller_fi);
-      framereg = caller_fi.framereg;
+      framereg = caller_fi.extra_info->framereg;
+
+      /* Deallocate the storage associated with the temporary frame
+         created above.  */
+      do_cleanups (old_chain);
     }
 
   /* If the caller used a frame register, return its value.
@@ -999,7 +1013,7 @@ arm_frame_chain (struct frame_info *fi)
   if (framereg == FP_REGNUM || framereg == THUMB_FP_REGNUM)
     return arm_find_callers_reg (fi, framereg);
   else
-    return fi->frame + fi->framesize;
+    return fi->frame + fi->extra_info->framesize;
 }
 
 /* This function actually figures out the frame address for a given pc
@@ -1017,19 +1031,22 @@ arm_init_extra_frame_info (int fromleaf,
   int reg;
   CORE_ADDR sp;
 
+  fi->extra_info = (struct frame_extra_info *)
+    frame_obstack_alloc (sizeof (struct frame_extra_info));
+
+  frame_saved_regs_zalloc (fi);
+
   if (fi->next)
     fi->pc = FRAME_SAVED_PC (fi->next);
 
-  memset (fi->fsr.regs, '\000', sizeof fi->fsr.regs);
-
 #if 0				/* FIXME: enable this code if we convert to new call dummy scheme.  */
   if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame))
     {
       /* We need to setup fi->frame here because run_stack_dummy gets it wrong
          by assuming it's always FP.  */
       fi->frame = generic_read_register_dummy (fi->pc, fi->frame, SP_REGNUM);
-      fi->framesize = 0;
-      fi->frameoffset = 0;
+      fi->extra_info->framesize = 0;
+      fi->extra_info->frameoffset = 0;
       return;
     }
   else
@@ -1040,7 +1057,7 @@ arm_init_extra_frame_info (int fromleaf,
   if (!fi->next)
     sp = read_sp();
   else
-    sp = fi->next->frame - fi->next->frameoffset + fi->next->framesize;
+    sp = fi->next->frame - fi->next->extra_info->frameoffset + fi->next->extra_info->framesize;
 
   /* Determine whether or not we're in a sigtramp frame. 
      Unfortunately, it isn't sufficient to test
@@ -1058,14 +1075,14 @@ arm_init_extra_frame_info (int fromleaf,
       && (fi->signal_handler_caller || IN_SIGTRAMP (fi->pc, 0)))
     {
       for (reg = 0; reg < NUM_REGS; reg++)
-	fi->fsr.regs[reg] = SIGCONTEXT_REGISTER_ADDRESS (sp, fi->pc, reg);
+	fi->saved_regs[reg] = SIGCONTEXT_REGISTER_ADDRESS (sp, fi->pc, reg);
 
       /* FIXME: What about thumb mode? */
-      fi->framereg = SP_REGNUM;
-      fi->frame = read_memory_integer (fi->fsr.regs[fi->framereg],
-                                       REGISTER_RAW_SIZE (fi->framereg));
-      fi->framesize = 0;
-      fi->frameoffset = 0;
+      fi->extra_info->framereg = SP_REGNUM;
+      fi->frame = read_memory_integer (fi->saved_regs[fi->extra_info->framereg],
+                                       REGISTER_RAW_SIZE (fi->extra_info->framereg));
+      fi->extra_info->framesize = 0;
+      fi->extra_info->frameoffset = 0;
 
     }
   else if (PC_IN_CALL_DUMMY (fi->pc, sp, fi->frame))
@@ -1077,19 +1094,19 @@ arm_init_extra_frame_info (int fromleaf,
       rp = fi->frame - REGISTER_SIZE;
 
       /* Fill in addresses of saved registers.  */
-      fi->fsr.regs[PS_REGNUM] = rp;
+      fi->saved_regs[PS_REGNUM] = rp;
       rp -= REGISTER_RAW_SIZE (PS_REGNUM);
       for (reg = PC_REGNUM; reg >= 0; reg--)
 	{
-	  fi->fsr.regs[reg] = rp;
+	  fi->saved_regs[reg] = rp;
 	  rp -= REGISTER_RAW_SIZE (reg);
 	}
 
-      callers_sp = read_memory_integer (fi->fsr.regs[SP_REGNUM],
+      callers_sp = read_memory_integer (fi->saved_regs[SP_REGNUM],
                                         REGISTER_RAW_SIZE (SP_REGNUM));
-      fi->framereg = FP_REGNUM;
-      fi->framesize = callers_sp - sp;
-      fi->frameoffset = fi->frame - sp;
+      fi->extra_info->framereg = FP_REGNUM;
+      fi->extra_info->framesize = callers_sp - sp;
+      fi->extra_info->frameoffset = fi->frame - sp;
     }
   else
     {
@@ -1097,14 +1114,14 @@ arm_init_extra_frame_info (int fromleaf,
 
       if (!fi->next)
 	/* this is the innermost frame? */
-	fi->frame = read_register (fi->framereg);
-      else if (fi->framereg == FP_REGNUM || fi->framereg == THUMB_FP_REGNUM)
+	fi->frame = read_register (fi->extra_info->framereg);
+      else if (fi->extra_info->framereg == FP_REGNUM || fi->extra_info->framereg == THUMB_FP_REGNUM)
 	{
 	  /* not the innermost frame */
 	  /* If we have an FP, the callee saved it. */
-	  if (fi->next->fsr.regs[fi->framereg] != 0)
+	  if (fi->next->saved_regs[fi->extra_info->framereg] != 0)
 	    fi->frame =
-	      read_memory_integer (fi->next->fsr.regs[fi->framereg], 4);
+	      read_memory_integer (fi->next->saved_regs[fi->extra_info->framereg], 4);
 	  else if (fromleaf)
 	    /* If we were called by a frameless fn.  then our frame is
 	       still in the frame pointer register on the board... */
@@ -1114,11 +1131,19 @@ arm_init_extra_frame_info (int fromleaf,
       /* Calculate actual addresses of saved registers using offsets
          determined by arm_scan_prologue.  */
       for (reg = 0; reg < NUM_REGS; reg++)
-	if (fi->fsr.regs[reg] != 0)
-	  fi->fsr.regs[reg] += fi->frame + fi->framesize - fi->frameoffset;
+	if (fi->saved_regs[reg] != 0)
+	  fi->saved_regs[reg] += fi->frame + fi->extra_info->framesize - fi->extra_info->frameoffset;
     }
 }
 
+/* Initialize the saved register addresses.  There's nothing to do
+   here since these addresses were already computed by
+   arm_init_extra_frame_info().  */
+void
+arm_frame_init_saved_regs (struct frame_info *fi)
+{
+  gdb_assert (fi->extra_info != NULL && fi->saved_regs != NULL);
+}
 
 /* Find the caller of this frame.  We do this by seeing if LR_REGNUM
    is saved in the stack anywhere, otherwise we get it from the
@@ -1136,9 +1161,9 @@ arm_frame_saved_pc (struct frame_info *f
     return generic_read_register_dummy (fi->pc, fi->frame, PC_REGNUM);
   else
 #endif
-  if (PC_IN_CALL_DUMMY (fi->pc, fi->frame - fi->frameoffset, fi->frame))
+  if (PC_IN_CALL_DUMMY (fi->pc, fi->frame - fi->extra_info->frameoffset, fi->frame))
     {
-      return read_memory_integer (fi->fsr.regs[PC_REGNUM], REGISTER_RAW_SIZE (PC_REGNUM));
+      return read_memory_integer (fi->saved_regs[PC_REGNUM], REGISTER_RAW_SIZE (PC_REGNUM));
     }
   else
     {
@@ -1159,15 +1184,6 @@ arm_target_read_fp (void)
     return read_register (FP_REGNUM);	/* R11 if ARM */
 }
 
-/* Calculate the frame offsets of the saved registers (ARM version).  */
-
-void
-arm_frame_find_saved_regs (struct frame_info *fi,
-			   struct frame_saved_regs *regaddr)
-{
-  memcpy (regaddr, &fi->fsr, sizeof (struct frame_saved_regs));
-}
-
 void
 arm_push_dummy_frame (void)
 {
@@ -1419,12 +1435,12 @@ arm_pop_frame (void)
 {
   int regnum;
   struct frame_info *frame = get_current_frame ();
-  CORE_ADDR old_SP = frame->frame - frame->frameoffset + frame->framesize;
+  CORE_ADDR old_SP = frame->frame - frame->extra_info->frameoffset + frame->extra_info->framesize;
 
   for (regnum = 0; regnum < NUM_REGS; regnum++)
-    if (frame->fsr.regs[regnum] != 0)
+    if (frame->saved_regs[regnum] != 0)
       write_register (regnum,
-		  read_memory_integer (frame->fsr.regs[regnum],
+		  read_memory_integer (frame->saved_regs[regnum],
 				       REGISTER_RAW_SIZE (regnum)));
 
   write_register (PC_REGNUM, FRAME_SAVED_PC (frame));
@@ -2209,6 +2225,10 @@ The valid values are:\n");
 
   add_com ("othernames", class_obscure, arm_othernames,
 	   "Switch to the next set of register names.");
+
+  /* Allocate extra_info and saved_regs fields in the prologue cache.  */
+  prologue_cache.extra_info = xcalloc (1, sizeof (struct frame_extra_info));
+  prologue_cache.saved_regs = xcalloc (1, SIZEOF_FRAME_SAVED_REGS);
 }
 
 /* Test whether the coff symbol specific value corresponds to a Thumb
diff -upr ../../../sourceware-arm1+2/src/gdb/config/arm/tm-arm.h ./config/arm/tm-arm.h
--- ../../../sourceware-arm1+2/src/gdb/config/arm/tm-arm.h	Fri Nov 16 10:03:27 2001
+++ ./config/arm/tm-arm.h	Sat Dec 15 00:30:34 2001
@@ -318,22 +318,13 @@ extern void convert_to_extended (void *d
 #define VARIABLES_INSIDE_BLOCK(desc, gcc_p) (!(gcc_p))
 
 
-/* Define other aspects of the stack frame.  We keep the offsets of
-   all saved registers, 'cause we need 'em a lot!  We also keep the
-   current size of the stack frame, and the offset of the frame
-   pointer from the stack pointer (for frameless functions, and when
-   we're still in the prologue of a function with a frame) */
-
-#define EXTRA_FRAME_INFO  	\
-  struct frame_saved_regs fsr;	\
-  int framesize;		\
-  int frameoffset;		\
-  int framereg;
-
 extern void arm_init_extra_frame_info (int fromleaf, struct frame_info * fi);
 #define INIT_EXTRA_FRAME_INFO(fromleaf, fi) \
 	arm_init_extra_frame_info ((fromleaf), (fi))
 
+extern void arm_frame_init_saved_regs (struct frame_info *fi);
+#define FRAME_INIT_SAVED_REGS(fi) arm_frame_init_saved_regs (fi)
+
 /* Return the frame address.  On ARM, it is R11; on Thumb it is R7.  */
 CORE_ADDR arm_target_read_fp (void);
 #define TARGET_READ_FP() arm_target_read_fp ()
@@ -393,20 +384,6 @@ extern CORE_ADDR arm_frame_saved_pc (str
 /* Return number of bytes at start of arglist that are not really args. */
 
 #define FRAME_ARGS_SKIP 0
-
-/* Put here the code to store, into a struct frame_saved_regs, the
-   addresses of the saved registers of frame described by FRAME_INFO.
-   This includes special registers such as pc and fp saved in special
-   ways in the stack frame.  sp is even more special: the address we
-   return for it IS the sp for the next frame.  */
-
-struct frame_saved_regs;
-struct frame_info;
-void arm_frame_find_saved_regs (struct frame_info * fi,
-				struct frame_saved_regs * fsr);
-
-#define FRAME_FIND_SAVED_REGS(frame_info, frame_saved_regs) \
-	arm_frame_find_saved_regs (frame_info, &(frame_saved_regs));
 
 /* Things needed for making the inferior call functions.  */