NEWS updates

1 files changed, 449 insertions, 0 deletions

diff --git a/libdw/dwarf_getlocation.c b/libdw/dwarf_getlocation.c
new file mode 100644
index 00000000..4a75f97d
--- /dev/null
+++ b/libdw/dwarf_getlocation.c
@@ -0,0 +1,449 @@
+/* Return location expression list.
+   Copyright (C) 2000, 2001, 2002, 2004, 2005 Red Hat, Inc.
+   Written by Ulrich Drepper <drepper@redhat.com>, 2000.
+
+   This program is Open Source software; you can redistribute it and/or
+   modify it under the terms of the Open Software License version 1.0 as
+   published by the Open Source Initiative.
+
+   You should have received a copy of the Open Software License along
+   with this program; if not, you may obtain a copy of the Open Software
+   License version 1.0 from http://www.opensource.org/licenses/osl.php or
+   by writing the Open Source Initiative c/o Lawrence Rosen, Esq.,
+   3001 King Ranch Road, Ukiah, CA 95482.   */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <dwarf.h>
+#include <search.h>
+#include <stdlib.h>
+
+#include <libdwP.h>
+
+
+static bool
+attr_ok (Dwarf_Attribute *attr)
+{
+  if (attr == NULL)
+    return false;
+
+  /* Must be one of the attributes listed below.  */
+  switch (attr->code)
+    {
+    case DW_AT_location:
+    case DW_AT_data_member_location:
+    case DW_AT_vtable_elem_location:
+    case DW_AT_string_length:
+    case DW_AT_use_location:
+    case DW_AT_frame_base:
+    case DW_AT_return_addr:
+    case DW_AT_static_link:
+      break;
+
+    default:
+      __libdw_seterrno (DWARF_E_NO_LOCLIST);
+      return false;
+    }
+
+  return true;
+}
+
+
+struct loclist
+{
+  uint8_t atom;
+  Dwarf_Word number;
+  Dwarf_Word number2;
+  Dwarf_Word offset;
+  struct loclist *next;
+};
+
+
+static int
+loc_compare (const void *p1, const void *p2)
+{
+  const struct loc_s *l1 = (const struct loc_s *) p1;
+  const struct loc_s *l2 = (const struct loc_s *) p2;
+
+  if ((uintptr_t) l1->addr < (uintptr_t) l2->addr)
+    return -1;
+  if ((uintptr_t) l1->addr > (uintptr_t) l2->addr)
+    return 1;
+
+  return 0;
+}
+
+static int
+getlocation (struct Dwarf_CU *cu, const Dwarf_Block *block,
+	     Dwarf_Op **llbuf, size_t *listlen)
+{
+  Dwarf *dbg = cu->dbg;
+
+  /* Check whether we already looked at this list.  */
+  struct loc_s fake = { .addr = block->data };
+  struct loc_s **found = tfind (&fake, &cu->locs, loc_compare);
+  if (found != NULL)
+    {
+      /* We already saw it.  */
+      *llbuf = (*found)->loc;
+      *listlen = (*found)->nloc;
+
+      return 0;
+    }
+
+  const unsigned char *data = block->data;
+  const unsigned char *const end_data = data + block->length;
+
+  struct loclist *loclist = NULL;
+  unsigned int n = 0;
+  /* Decode the opcodes.  It is possible in some situations to have a
+     block of size zero.  */
+  while (data < end_data)
+    {
+      struct loclist *newloc;
+      newloc = (struct loclist *) alloca (sizeof (struct loclist));
+      newloc->number = 0;
+      newloc->number2 = 0;
+      newloc->offset = data - block->data;
+      newloc->next = loclist;
+      loclist = newloc;
+      ++n;
+
+      switch ((newloc->atom = *data++))
+	{
+	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);
+	    }
+	  break;
+
+	case DW_OP_deref:
+	case DW_OP_dup:
+	case DW_OP_drop:
+	case DW_OP_over:
+	case DW_OP_swap:
+	case DW_OP_rot:
+	case DW_OP_xderef:
+	case DW_OP_abs:
+	case DW_OP_and:
+	case DW_OP_div:
+	case DW_OP_minus:
+	case DW_OP_mod:
+	case DW_OP_mul:
+	case DW_OP_neg:
+	case DW_OP_not:
+	case DW_OP_or:
+	case DW_OP_plus:
+	case DW_OP_shl:
+	case DW_OP_shr:
+	case DW_OP_shra:
+	case DW_OP_xor:
+	case DW_OP_eq:
+	case DW_OP_ge:
+	case DW_OP_gt:
+	case DW_OP_le:
+	case DW_OP_lt:
+	case DW_OP_ne:
+	case DW_OP_lit0 ... DW_OP_lit31:
+	case DW_OP_reg0 ... DW_OP_reg31:
+	case DW_OP_nop:
+	case DW_OP_push_object_address:
+	case DW_OP_call_ref:
+	  /* No operand.  */
+	  break;
+
+	case DW_OP_const1u:
+	case DW_OP_pick:
+	case DW_OP_deref_size:
+	case DW_OP_xderef_size:
+	  if (unlikely (data >= end_data))
+	    goto invalid;
+
+	  newloc->number = *data++;
+	  break;
+
+	case DW_OP_const1s:
+	  if (unlikely (data >= end_data))
+	    goto invalid;
+
+	  newloc->number = *((int8_t *) data);
+	  ++data;
+	  break;
+
+	case DW_OP_const2u:
+	  if (unlikely (data + 2 > end_data))
+	    goto invalid;
+
+	  newloc->number = read_2ubyte_unaligned_inc (dbg, data);
+	  break;
+
+	case DW_OP_const2s:
+	case DW_OP_skip:
+	case DW_OP_bra:
+	case DW_OP_call2:
+	  if (unlikely (data + 2 > end_data))
+	    goto invalid;
+
+	  newloc->number = read_2sbyte_unaligned_inc (dbg, data);
+	  break;
+
+	case DW_OP_const4u:
+	  if (unlikely (data + 4 > end_data))
+	    goto invalid;
+
+	  newloc->number = read_4ubyte_unaligned_inc (dbg, data);
+	  break;
+
+	case DW_OP_const4s:
+	case DW_OP_call4:
+	  if (unlikely (data + 4 > end_data))
+	    goto invalid;
+
+	  newloc->number = read_4sbyte_unaligned_inc (dbg, data);
+	  break;
+
+	case DW_OP_const8u:
+	  if (unlikely (data + 8 > end_data))
+	    goto invalid;
+
+	  newloc->number = read_8ubyte_unaligned_inc (dbg, data);
+	  break;
+
+	case DW_OP_const8s:
+	  if (unlikely (data + 8 > end_data))
+	    goto invalid;
+
+	  newloc->number = read_8sbyte_unaligned_inc (dbg, data);
+	  break;
+
+	case DW_OP_constu:
+	case DW_OP_plus_uconst:
+	case DW_OP_regx:
+	case DW_OP_piece:
+	  /* XXX Check size.  */
+	  get_uleb128 (newloc->number, data);
+	  break;
+
+	case DW_OP_consts:
+	case DW_OP_breg0 ... DW_OP_breg31:
+	case DW_OP_fbreg:
+	  /* XXX Check size.  */
+	  get_sleb128 (newloc->number, data);
+	  break;
+
+	case DW_OP_bregx:
+	  /* XXX Check size.  */
+	  get_uleb128 (newloc->number, data);
+	  get_sleb128 (newloc->number2, data);
+	  break;
+
+	default:
+	  goto invalid;
+	}
+    }
+
+  if (unlikely (n == 0))
+    {
+      /* This is not allowed.
+
+	 XXX Is it?  */
+      goto invalid;
+    }
+
+  /* Allocate the array.  */
+  Dwarf_Op *result = libdw_alloc (dbg, Dwarf_Op, sizeof (Dwarf_Op), n);
+
+  /* Store the result.  */
+  *llbuf = result;
+  *listlen = n;
+
+  do
+    {
+      /* We populate the array from the back since the list is
+         backwards.  */
+      --n;
+      result[n].atom = loclist->atom;
+      result[n].number = loclist->number;
+      result[n].number2 = loclist->number2;
+      result[n].offset = loclist->offset;
+
+      loclist = loclist->next;
+    }
+  while (n > 0);
+
+  /* Insert a record in the search tree so that we can find it again
+     later.  */
+  struct loc_s *newp = libdw_alloc (dbg, struct loc_s, sizeof (struct loc_s),
+				    1);
+  newp->addr = block->data;
+  newp->loc = result;
+  newp->nloc = *listlen;
+  (void) tsearch (newp, &cu->locs, loc_compare);
+
+  /* We did it.  */
+  return 0;
+}
+
+int
+dwarf_getlocation (attr, llbuf, listlen)
+     Dwarf_Attribute *attr;
+     Dwarf_Op **llbuf;
+     size_t *listlen;
+{
+  if (! attr_ok (attr))
+    return -1;
+
+  /* If it has a block form, it's a single location expression.  */
+  Dwarf_Block block;
+  if (INTUSE(dwarf_formblock) (attr, &block) != 0)
+    return -1;
+
+  return getlocation (attr->cu, &block, llbuf, listlen);
+}
+
+int
+dwarf_getlocation_addr (attr, address, llbufs, listlens, maxlocs)
+     Dwarf_Attribute *attr;
+     Dwarf_Addr address;
+     Dwarf_Op **llbufs;
+     size_t *listlens;
+     size_t maxlocs;
+{
+  if (! attr_ok (attr))
+    return -1;
+
+  if (llbufs == NULL)
+    maxlocs = SIZE_MAX;
+
+  /* If it has a block form, it's a single location expression.  */
+  Dwarf_Block block;
+  if (INTUSE(dwarf_formblock) (attr, &block) == 0)
+    {
+      if (maxlocs == 0)
+	return 0;
+      if (llbufs != NULL &&
+	  getlocation (attr->cu, &block, &llbufs[0], &listlens[0]) != 0)
+	return -1;
+      return listlens[0] == 0 ? 0 : 1;
+    }
+
+  int error = INTUSE(dwarf_errno) ();
+  if (error != DWARF_E_NO_BLOCK)
+    {
+      __libdw_seterrno (error);
+      return -1;
+    }
+
+  /* Must have the form data4 or data8 which act as an offset.  */
+  Dwarf_Word offset;
+  if (INTUSE(dwarf_formudata) (attr, &offset) != 0)
+    return -1;
+
+  const Elf_Data *d = attr->cu->dbg->sectiondata[IDX_debug_loc];
+  if (d == NULL)
+    {
+      __libdw_seterrno (DWARF_E_NO_LOCLIST);
+      return -1;
+    }
+
+  /* Fetch the CU's base address.  */
+  Dwarf_Addr base;
+  Dwarf_Die cudie = CUDIE (attr->cu);
+
+  /* Find the base address of the compilation unit.  It will
+     normally be specified by DW_AT_low_pc.  In DWARF-3 draft 4,
+     the base address could be overridden by DW_AT_entry_pc.  It's
+     been removed, but GCC emits DW_AT_entry_pc and not DW_AT_lowpc
+     for compilation units with discontinuous ranges.  */
+  Dwarf_Attribute attr_mem;
+  if (INTUSE(dwarf_lowpc) (&cudie, &base) != 0
+      && INTUSE(dwarf_formaddr) (INTUSE(dwarf_attr) (&cudie, DW_AT_entry_pc,
+						     &attr_mem),
+				 &base) != 0)
+    return -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)
+	{
+	invalid:
+	  __libdw_seterrno (DWARF_E_INVALID_DWARF);
+	  return -1;
+	}
+
+      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;
+	      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.  */
+	break;
+
+      if ((unsigned char *) d->d_buf + d->d_size - readp < 2)
+	{
+	  __libdw_seterrno (DWARF_E_INVALID_DWARF);
+	  return -1;
+	}
+
+      /* 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)
+	goto invalid;
+      readp += block.length;
+
+      if (address >= base + begin && address < base + end)
+	{
+	  /* This one matches the address.  */
+	  if (llbufs != NULL
+	      && getlocation (attr->cu, &block,
+			      &llbufs[got], &listlens[got]) != 0)
+	    return -1;
+	  ++got;
+	}
+    }
+
+  return got;
+}