Squashed commit of the following:

commit 77abb31cb8d55980ef92260917a7ecdd228b1a44
Author: Petr Machata <pmachata@redhat.com>
Date:   Mon Jun 8 15:46:16 2009 +0200

    Fix a bug in offset checking

commit b794eac4f8d3e08101b5d2924523b1259bbc1b17
Author: Petr Machata <pmachata@redhat.com>
Date:   Wed Jun 3 16:00:01 2009 +0200

    Cosmetic, get rid of defining several variables per line

commit a23938fe35d515a3d75a51f6204771f3cf6c9ec4
Author: Petr Machata <pmachata@redhat.com>
Date:   Wed Jun 3 15:50:03 2009 +0200

    Restructure the code to decrease the binary size

commit 7c301e3d4e8584dfb3174855fb6af3d5791dfeed
Author: Petr Machata <pmachata@redhat.com>
Date:   Mon Jun 1 19:43:28 2009 +0200

    Shuffle a couple pieces of code around to make the code smaller

commit 6325323482c2a3e17409d32c7feec9461be26614
Merge: 83ac53d... e94b1b2...
Author: Petr Machata <pmachata@redhat.com>
Date:   Fri May 22 08:49:07 2009 +0200

    Merge branch 'master' of ssh://pmachata@git.fedorahosted.org/git/elfutils into pmachata/reader_hooks

    Conflicts:
    	libdw/ChangeLog

commit 83ac53db400945c074e77ec9904efe550903a0e2
Author: Petr Machata <pmachata@redhat.com>
Date:   Fri May 22 08:40:25 2009 +0200

    Call reloc hook with the original address, not incremented

commit f1996388745566abc1ca1c1700b3b7eded208575
Author: Petr Machata <pmachata@redhat.com>
Date:   Wed May 6 16:53:03 2009 +0200

    Rewrite boundary checking logic so that it's immune to arithmetic overflow

    * ... also get rid of some code redundancy.

commit 0c1df732822d83548edd0d005f3450281ed1701b
Author: Petr Machata <pmachata@redhat.com>
Date:   Wed May 6 16:25:09 2009 +0200

    __libdw_read_offset* take extra argument for header size checks

    * also presence of debug data and buffer is checked in __libdw_in_section

commit 6fb192e360f842cacb34a90c03cd0524cccc3dec
Author: Petr Machata <pmachata@redhat.com>
Date:   Wed May 6 15:51:20 2009 +0200

    Check for presence of data before loading the offset

commit a2e7612b165d83dd241225f87075fa4f58d18781
Author: Petr Machata <pmachata@redhat.com>
Date:   Wed May 6 15:04:16 2009 +0200

    Cosmetic changes

commit 8b1aad2c2f6c8dc02b3e704e4f386c1827e385cb
Author: Petr Machata <pmachata@redhat.com>
Date:   Tue May 5 15:34:13 2009 +0200

    Improve reader hook functions a bit

    * ... so that they are closer match to what's need on call sites

commit 3854b7fbab2fe331711365f94a295af82164d0d2
Author: Petr Machata <pmachata@redhat.com>
Date:   Tue May 5 14:33:50 2009 +0200

    Fixes in use of reader hooks in __libdw_formptr and dwarf_formudata

    * and a bit more

commit 335075596b6acef6e59919155e2b087e690a572d
Author: Petr Machata <pmachata@redhat.com>
Date:   Tue May 5 14:32:39 2009 +0200

    Rename __libdw_read_udata_addr to __libdw_formptr

commit 8273a2adaf8cb2ee203926af2849e4f96f8a6eaf
Author: Petr Machata <pmachata@redhat.com>
Date:   Tue May 5 02:53:40 2009 +0200

    Introduce __libdw_read_udata_address

    * the use in dwarf_ranges is iffy, there's a functionality mismatch.
      Need to find some better way

commit 1c897f4abde1530038d332f4fc03a596a24f6aaf
Author: Petr Machata <pmachata@redhat.com>
Date:   Mon May 4 18:09:13 2009 +0200

    ChangeLog entries for previous commit

commit 90d7c39454468b91c0fd6514a4e8d821222d6adb
Author: Petr Machata <pmachata@redhat.com>
Date:   Mon May 4 18:07:54 2009 +0200

    Fix bugs, introduce __libdw_read_begin_end_pair_inc

commit 9b3923f5b69a3e56590769435c4693f057acdc1f
Merge: 6200ba6... 589b3d3...
Author: Petr Machata <pmachata@redhat.com>
Date:   Mon May 4 12:22:21 2009 +0200

    Merge branch 'master' of ssh://pmachata@git.fedorahosted.org/git/elfutils into pmachata/reader_hooks

commit 6200ba62aa9ea3cb9318f73a27181907a528dbe4
Author: Petr Machata <pmachata@redhat.com>
Date:   Wed Apr 29 15:31:28 2009 +0200

    dwarf_getlocation_addr uses read hooks

commit ecbb8cdd8b500e37dc34fc246b912f704fe31ca4
Author: Petr Machata <pmachata@redhat.com>
Date:   Wed Apr 29 15:16:09 2009 +0200

    dwarf_ranges and dwarf_formref use read hooks

commit cb8f67b29a896c2660c10aa1028a9dbb377553e9
Author: Petr Machata <pmachata@redhat.com>
Date:   Tue Apr 28 18:39:04 2009 +0200

    Convert several new functions to use read hooks

commit b130453eb16a8cf042915e312cc5f189b8b92c01
Author: Petr Machata <pmachata@redhat.com>
Date:   Tue Apr 28 18:38:27 2009 +0200

    Add length read hooks

commit bd885ff694817b965231d99f1ab867947998e734
Author: Petr Machata <pmachata@redhat.com>
Date:   Tue Apr 28 18:36:17 2009 +0200

    Constify read hook arguments

commit 66fe03f1e489a88b89a15c9e13f9bd33db2729b1
Author: Petr Machata <pmachata@redhat.com>
Date:   Tue Apr 28 16:11:05 2009 +0200

    Change type of return value of offset read hooks to Dwarf_Off

commit 22b36e00cc228f5a966f84ca3323e5d652923ce8
Merge: 5b3534b... a7cb532...
Author: Petr Machata <pmachata@redhat.com>
Date:   Mon Apr 27 19:05:25 2009 +0200

    Merge branch 'master' of ssh://pmachata@git.fedorahosted.org/git/elfutils into pmachata/reader_hooks

commit 5b3534b62cbd45fe4f11dd1be3e492237938cce0
Author: Petr Machata <pmachata@redhat.com>
Date:   Mon Apr 27 18:53:06 2009 +0200

    Rewrites in read hooks

    * Have the checking and reading logic itself in the header so that it gets
      optimized out/inlined.  Call external relocating hook from there, there
      will presumably be more work to do, and we presumably don't want to keep
      this in the header.

commit 9e265d71d0eb900e76d6fdb0196ef4fc6507f3a7
Merge: 1783089... 300f3a4...
Author: Petr Machata <pmachata@redhat.com>
Date:   Thu Apr 23 17:45:25 2009 +0200

    Merge branch 'master' of ssh://pmachata@git.fedorahosted.org/git/elfutils into pmachata/reader_hooks

commit 1783089b184ddea2081bbe5ac4e80420cb6b0803
Author: Petr Machata <pmachata@redhat.com>
Date:   Thu Apr 23 17:44:48 2009 +0200

    Use the new reader hooks in several places

commit 11c3d97a5b40ea15edf324092b03da3050610d01
Author: Petr Machata <pmachata@redhat.com>
Date:   Thu Apr 23 17:40:03 2009 +0200

    Introduce reader hooks

1 files changed, 30 insertions, 64 deletions

diff --git a/libdw/dwarf_getlocation.c b/libdw/dwarf_getlocation.c
index f680aa96..f829e72b 100644
--- a/libdw/dwarf_getlocation.c
+++ b/libdw/dwarf_getlocation.c
@@ -113,7 +113,7 @@ loc_compare (const void *p1, const void *p2)
 
 static int
 getlocation (struct Dwarf_CU *cu, const Dwarf_Block *block,
-	     Dwarf_Op **llbuf, size_t *listlen)
+	     Dwarf_Op **llbuf, size_t *listlen, int sec_index)
 {
   Dwarf *dbg = cu->dbg;
 
@@ -151,24 +151,9 @@ getlocation (struct Dwarf_CU *cu, const Dwarf_Block *block,
 	{
 	case DW_OP_addr:
 	  /* Address, depends on address size of CU.  */
-	  if (cu->address_size == 4)
-	    {
-	      if (unlikely (data + 4 > end_data))
-		{
-		invalid:
-		  __libdw_seterrno (DWARF_E_INVALID_DWARF);
-		  return -1;
-		}
-
-	      newloc->number = read_4ubyte_unaligned_inc (dbg, data);
-	    }
-	  else
-	    {
-	      if (unlikely (data + 8 > end_data))
-		goto invalid;
-
-	      newloc->number = read_8ubyte_unaligned_inc (dbg, data);
-	    }
+	  if (__libdw_read_address_inc (dbg, sec_index, (unsigned char **)&data,
+					cu->address_size, &newloc->number))
+	    return -1;
 	  break;
 
 	case DW_OP_deref:
@@ -211,7 +196,11 @@ getlocation (struct Dwarf_CU *cu, const Dwarf_Block *block,
 	case DW_OP_deref_size:
 	case DW_OP_xderef_size:
 	  if (unlikely (data >= end_data))
-	    goto invalid;
+	    {
+	    invalid:
+	      __libdw_seterrno (DWARF_E_INVALID_DWARF);
+	      return -1;
+	    }
 
 	  newloc->number = *data++;
 	  break;
@@ -352,7 +341,7 @@ dwarf_getlocation (attr, llbuf, listlen)
   if (INTUSE(dwarf_formblock) (attr, &block) != 0)
     return -1;
 
-  return getlocation (attr->cu, &block, llbuf, listlen);
+  return getlocation (attr->cu, &block, llbuf, listlen, IDX_debug_info);
 }
 
 int
@@ -376,7 +365,8 @@ dwarf_getlocation_addr (attr, address, llbufs, listlens, maxlocs)
       if (maxlocs == 0)
 	return 0;
       if (llbufs != NULL &&
-	  getlocation (attr->cu, &block, &llbufs[0], &listlens[0]) != 0)
+	  getlocation (attr->cu, &block, &llbufs[0], &listlens[0],
+		       IDX_debug_info) != 0)
 	return -1;
       return listlens[0] == 0 ? 0 : 1;
     }
@@ -388,25 +378,17 @@ dwarf_getlocation_addr (attr, address, llbufs, listlens, maxlocs)
       return -1;
     }
 
-  /* Must have the form data4 or data8 which act as an offset.  */
-  Dwarf_Word offset;
-  if (unlikely (INTUSE(dwarf_formudata) (attr, &offset) != 0))
+  unsigned char *endp;
+  unsigned char *readp = __libdw_formptr (attr, IDX_debug_loc,
+					  DWARF_E_NO_LOCLIST, &endp, NULL);
+  if (readp == NULL)
     return -1;
 
-  const Elf_Data *d = attr->cu->dbg->sectiondata[IDX_debug_loc];
-  if (unlikely (d == NULL))
-    {
-      __libdw_seterrno (DWARF_E_NO_LOCLIST);
-      return -1;
-    }
-
   Dwarf_Addr base = (Dwarf_Addr) -1;
-  unsigned char *readp = d->d_buf + offset;
   size_t got = 0;
   while (got < maxlocs)
     {
-      if ((unsigned char *) d->d_buf + d->d_size - readp
-	  < attr->cu->address_size * 2)
+      if (endp - readp < attr->cu->address_size * 2)
 	{
 	invalid:
 	  __libdw_seterrno (DWARF_E_INVALID_DWARF);
@@ -415,42 +397,25 @@ dwarf_getlocation_addr (attr, address, llbufs, listlens, maxlocs)
 
       Dwarf_Addr begin;
       Dwarf_Addr end;
-      if (attr->cu->address_size == 8)
-	{
-	  begin = read_8ubyte_unaligned_inc (attr->cu->dbg, readp);
-	  end = read_8ubyte_unaligned_inc (attr->cu->dbg, readp);
-
-	  if (begin == (Elf64_Addr) -1l) /* Base address entry.  */
-	    {
-	      base = end;
-	      if (unlikely (base == (Dwarf_Addr) -1))
-		goto invalid;
-	      continue;
-	    }
-	}
-      else
-	{
-	  begin = read_4ubyte_unaligned_inc (attr->cu->dbg, readp);
-	  end = read_4ubyte_unaligned_inc (attr->cu->dbg, readp);
-
-	  if (begin == (Elf32_Addr) -1) /* Base address entry.  */
-	    {
-	      base = end;
-	      continue;
-	    }
-	}
 
-      if (begin == 0 && end == 0) /* End of list entry.  */
+      int status
+	= __libdw_read_begin_end_pair_inc (attr->cu->dbg, IDX_debug_loc,
+					   &readp, attr->cu->address_size,
+					   &begin, &end, &base);
+      if (status == 2) /* End of list entry.  */
 	break;
+      else if (status == 1) /* Base address selected.  */
+	continue;
+      else if (status < 0)
+	return status;
 
-      if ((unsigned char *) d->d_buf + d->d_size - readp < 2)
+      if (endp - readp < 2)
 	goto invalid;
 
       /* We have a location expression.  */
       block.length = read_2ubyte_unaligned_inc (attr->cu->dbg, readp);
       block.data = readp;
-      if ((unsigned char *) d->d_buf + d->d_size - readp
-	  < (ptrdiff_t) block.length)
+      if (endp - readp < (ptrdiff_t) block.length)
 	goto invalid;
       readp += block.length;
 
@@ -486,7 +451,8 @@ dwarf_getlocation_addr (attr, address, llbufs, listlens, maxlocs)
 	  /* This one matches the address.  */
 	  if (llbufs != NULL
 	      && unlikely (getlocation (attr->cu, &block,
-					&llbufs[got], &listlens[got]) != 0))
+					&llbufs[got], &listlens[got],
+					IDX_debug_loc) != 0))
 	    return -1;
 	  ++got;
 	}