Attachment 230151 Details for Bug 140532 – Another backport part

[patch] Another backport part

bz140532c22.patch (text/plain), 6.34 KB, created by Jan Kratochvil on 2007-10-17 18:26:30 UTC

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Creator: Jan Kratochvil

Created: 2007-10-17 18:26:30 UTC

Size: 6.34 KB

patch

obsolete

>2007-03-13  Daniel Jacobowitz  <dan@codesourcery.com>
>
>	* rs6000-tdep.c (rs6000_skip_prologue): Use skip_prologue_using_sal.
>	(rs6000_in_function_epilogue_p): Use extract_unsigned_integer.
>	(refine_prologue_limit): Delete.
>	(skip_prologue): Don't call it.  Use extract_unsigned_integer.
>	Assume lim_pc is set.  Correct check for incomplete prologues.
>	Do not skip clobbers of the frame pointer.
>	* symtab.c (skip_prologue_using_sal): Fail if there is only one
>	sal.
>
>[ Backported for GDB-6.3. ]
>
>diff -u -X /root/jkratoch/.diffi.list -rup gdb-6.3-orig/gdb/rs6000-tdep.c gdb-6.3/gdb/rs6000-tdep.c
>--- gdb-6.3-orig/gdb/rs6000-tdep.c	2007-10-17 09:37:18.000000000 -0400
>+++ gdb-6.3/gdb/rs6000-tdep.c	2007-10-17 12:58:10.000000000 -0400
>@@ -500,7 +500,29 @@ static CORE_ADDR
> rs6000_skip_prologue (CORE_ADDR pc)
> {
>   struct rs6000_framedata frame;
>-  pc = skip_prologue (pc, 0, &frame);
>+  CORE_ADDR limit_pc, func_addr;
>+
>+  /* See if we can determine the end of the prologue via the symbol table.
>+     If so, then return either PC, or the PC after the prologue, whichever
>+     is greater.  */
>+  if (find_pc_partial_function (pc, NULL, &func_addr, NULL))
>+    {
>+      CORE_ADDR post_prologue_pc = skip_prologue_using_sal (func_addr);
>+      if (post_prologue_pc != 0)
>+	return max (pc, post_prologue_pc);
>+    }
>+
>+  /* Can't determine prologue from the symbol table, need to examine
>+     instructions.  */
>+
>+  /* Find an upper limit on the function prologue using the debug
>+     information.  If the debug information could not be used to provide
>+     that bound, then use an arbitrary large number as the upper bound.  */
>+  limit_pc = skip_prologue_using_sal (pc);
>+  if (limit_pc == 0)
>+    limit_pc = pc + 100;          /* Magic.  */
>+
>+  pc = skip_prologue (pc, limit_pc, &frame);
>   return pc;
> }
> 
>@@ -783,57 +805,6 @@ rs6000_software_single_step (struct regc
>    of the prologue is expensive.  */
> static int max_skip_non_prologue_insns = 10;
> 
>-/* Given PC representing the starting address of a function, and
>-   LIM_PC which is the (sloppy) limit to which to scan when looking
>-   for a prologue, attempt to further refine this limit by using
>-   the line data in the symbol table.  If successful, a better guess
>-   on where the prologue ends is returned, otherwise the previous
>-   value of lim_pc is returned.  */
>-
>-/* FIXME: cagney/2004-02-14: This function and logic have largely been
>-   superseded by skip_prologue_using_sal.  */
>-
>-static CORE_ADDR
>-refine_prologue_limit (CORE_ADDR pc, CORE_ADDR lim_pc)
>-{
>-  struct symtab_and_line prologue_sal;
>-
>-  prologue_sal = find_pc_line (pc, 0);
>-  if (prologue_sal.line != 0)
>-    {
>-      int i;
>-      CORE_ADDR addr = prologue_sal.end;
>-
>-      /* Handle the case in which compiler's optimizer/scheduler
>-         has moved instructions into the prologue.  We scan ahead
>-	 in the function looking for address ranges whose corresponding
>-	 line number is less than or equal to the first one that we
>-	 found for the function.  (It can be less than when the
>-	 scheduler puts a body instruction before the first prologue
>-	 instruction.)  */
>-      for (i = 2 * max_skip_non_prologue_insns; 
>-           i > 0 && (lim_pc == 0 || addr < lim_pc);
>-	   i--)
>-        {
>-	  struct symtab_and_line sal;
>-
>-	  sal = find_pc_line (addr, 0);
>-	  if (sal.line == 0)
>-	    break;
>-	  if (sal.line <= prologue_sal.line 
>-	      && sal.symtab == prologue_sal.symtab)
>-	    {
>-	      prologue_sal = sal;
>-	    }
>-	  addr = sal.end;
>-	}
>-
>-      if (lim_pc == 0 || prologue_sal.end < lim_pc)
>-	lim_pc = prologue_sal.end;
>-    }
>-  return lim_pc;
>-}
>-
> /* Return nonzero if the given instruction OP can be part of the prologue
>    of a function and saves a parameter on the stack.  FRAMEP should be
>    set if one of the previous instructions in the function has set the
>@@ -953,21 +924,6 @@ skip_prologue (CORE_ADDR pc, CORE_ADDR l
>   int r0_contains_arg = 0;
>   const struct bfd_arch_info *arch_info = gdbarch_bfd_arch_info (current_gdbarch);
>   struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
>-  
>-  /* Attempt to find the end of the prologue when no limit is specified.
>-     Note that refine_prologue_limit() has been written so that it may
>-     be used to "refine" the limits of non-zero PC values too, but this
>-     is only safe if we 1) trust the line information provided by the
>-     compiler and 2) iterate enough to actually find the end of the
>-     prologue.  
>-     
>-     It may become a good idea at some point (for both performance and
>-     accuracy) to unconditionally call refine_prologue_limit().  But,
>-     until we can make a clear determination that this is beneficial,
>-     we'll play it safe and only use it to obtain a limit when none
>-     has been specified.  */
>-  if (lim_pc == 0)
>-    lim_pc = refine_prologue_limit (pc, lim_pc);
> 
>   memset (fdata, 0, sizeof (struct rs6000_framedata));
>   fdata->func_start = pc;
>@@ -989,7 +945,7 @@ skip_prologue (CORE_ADDR pc, CORE_ADDR l
> 	last_prologue_pc = pc;
> 
>       /* Stop scanning if we've hit the limit.  */
>-      if (lim_pc != 0 && pc >= lim_pc)
>+      if (pc >= lim_pc)
> 	break;
> 
>       prev_insn_was_prologue_insn = 1;
>@@ -997,7 +953,7 @@ skip_prologue (CORE_ADDR pc, CORE_ADDR l
>       /* Fetch the instruction and convert it to an integer.  */
>       if (target_read_memory (pc, buf, 4))
> 	break;
>-      op = extract_signed_integer (buf, 4);
>+      op = extract_unsigned_integer (buf, 4);
> 
>       /* A PPC64 GNU/Linux system call function is split into two
> 	 sub-functions: a non-threaded fast-path (__NAME_nocancel)
>@@ -1263,9 +1219,11 @@ skip_prologue (CORE_ADDR pc, CORE_ADDR l
> 	  offset = fdata->offset;
> 	  continue;
> 	}
>-      /* Load up minimal toc pointer */
>+      /* Load up minimal toc pointer.  Do not treat an epilogue restore
>+	 of r31 as a minimal TOC load.  */
>       else if (((op >> 22) == 0x20f	||	/* l r31,... or l r30,... */
> 	       (op >> 22) == 0x3af)		/* ld r31,... or ld r30,... */
>+	       && !framep
> 	       && !minimal_toc_loaded)
> 	{
> 	  minimal_toc_loaded = 1;
>@@ -1488,8 +1446,7 @@ skip_prologue (CORE_ADDR pc, CORE_ADDR l
> 	     Handle optimizer code motions into the prologue by continuing
> 	     the search if we have no valid frame yet or if the return
> 	     address is not yet saved in the frame.  */
>-	  if (fdata->frameless == 0
>-	      && (lr_reg == -1 || fdata->nosavedpc == 0))
>+	  if (fdata->frameless == 0 && fdata->nosavedpc == 0)
> 	    break;
> 
> 	  if (op == 0x4e800020		/* blr */

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Attachments on bug 140532: 144612 | 144613 | 145505 | 145506 | 145513 | 230151