Re: [RFA] ARM : prologue scan

[Jerome Guitton <guitton@act-europe.fr>]

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I have done some minor corrections on the previous patch, discard it.
In attachment, the new version. No regression, no fixed.

-- 
Jerome.

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2003-07-21  J. Guitton  <guitton@gnat.com>

	* arm-tdep.c (arm_skip_prologue): Add the handling of "sub ip, sp #n"
	and "add ip, sp #n", as these instructions can be found in a ATPCS
	compliant prologue.
	(arm_scan_prologue): Ditto.

Index: arm-tdep.c
===================================================================
RCS file: /cvs/src/src/gdb/arm-tdep.c,v
retrieving revision 1.143
diff -u -3 -p -r1.143 arm-tdep.c
--- arm-tdep.c	13 Jun 2003 14:15:51 -0000	1.143
+++ arm-tdep.c	22 Jul 2003 11:43:10 -0000
@@ -449,6 +449,12 @@ arm_skip_prologue (CORE_ADDR pc)
       if (inst == 0xe1a0c00d)			/* mov ip, sp */
 	continue;
 
+      if ((inst & 0xfffff000) == 0xe28dc000)    /* add ip, sp #n */
+	continue;
+
+      if ((inst & 0xfffff000) == 0xe24dc000)    /* sub ip, sp #n */
+	continue;
+
       /* Some prologues begin with "str lr, [sp, #-4]!".  */
       if (inst == 0xe52de004)			/* str lr, [sp, #-4]! */
 	continue;
@@ -708,7 +714,7 @@ thumb_scan_prologue (struct frame_info *
 static void
 arm_scan_prologue (struct frame_info *fi)
 {
-  int regno, sp_offset, fp_offset;
+  int regno, sp_offset, fp_offset, ip_offset;
   LONGEST return_value;
   CORE_ADDR prologue_start, prologue_end, current_pc;
 
@@ -799,7 +805,7 @@ arm_scan_prologue (struct frame_info *fi
      in which case it is often (but not always) replaced by
      "str lr, [sp, #-4]!".  - Michael Snyder, 2002-04-23]  */
 
-  sp_offset = fp_offset = 0;
+  sp_offset = fp_offset = ip_offset = 0;
 
   for (current_pc = prologue_start;
        current_pc < prologue_end;
@@ -809,6 +815,23 @@ arm_scan_prologue (struct frame_info *fi
 
       if (insn == 0xe1a0c00d)		/* mov ip, sp */
 	{
+	  ip_offset = 0;
+	  continue;
+	}
+      else if ((insn & 0xfffff000) == 0xe28dc000) /* add ip, sp #n */
+	{
+	  unsigned imm = insn & 0xff;                   /* immediate value */
+	  unsigned rot = (insn & 0xf00) >> 7;           /* rotate amount */
+	  imm = (imm >> rot) | (imm << (32 - rot));
+	  ip_offset = imm;
+	  continue;
+	}
+      else if ((insn & 0xfffff000) == 0xe24dc000) /* sub ip, sp #n */
+	{
+	  unsigned imm = insn & 0xff;                   /* immediate value */
+	  unsigned rot = (insn & 0xf00) >> 7;           /* rotate amount */
+	  imm = (imm >> rot) | (imm << (32 - rot));
+	  ip_offset = -imm;
 	  continue;
 	}
       else if (insn == 0xe52de004)	/* str lr, [sp, #-4]! */
@@ -850,7 +873,7 @@ arm_scan_prologue (struct frame_info *fi
 	  unsigned imm = insn & 0xff;			/* immediate value */
 	  unsigned rot = (insn & 0xf00) >> 7;		/* rotate amount */
 	  imm = (imm >> rot) | (imm << (32 - rot));
-	  fp_offset = -imm;
+	  fp_offset = -imm + ip_offset;
 	  get_frame_extra_info (fi)->framereg = ARM_FP_REGNUM;
 	}
       else if ((insn & 0xfffff000) == 0xe24dd000)	/* sub sp, sp #n */