--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/unwind-dw2-fde-glibc.c	Fri Jul 17 14:47:48 2009 +0900
@@ -0,0 +1,437 @@
+/* Copyright (C) 2001, 2002, 2003, 2004, 2005, 2009 Free Software Foundation, Inc.
+   Contributed by Jakub Jelinek <jakub@redhat.com>.
+
+   This file is part of GCC.
+
+   GCC is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3, or (at your option)
+   any later version.
+
+   GCC is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   Under Section 7 of GPL version 3, you are granted additional
+   permissions described in the GCC Runtime Library Exception, version
+   3.1, as published by the Free Software Foundation.
+
+   You should have received a copy of the GNU General Public License and
+   a copy of the GCC Runtime Library Exception along with this program;
+   see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+   <http://www.gnu.org/licenses/>.  */
+
+/* Locate the FDE entry for a given address, using PT_GNU_EH_FRAME ELF
+   segment and dl_iterate_phdr to avoid register/deregister calls at
+   DSO load/unload.  */
+
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE 1
+#endif
+
+#include "tconfig.h"
+#include "tsystem.h"
+#ifndef inhibit_libc
+#include <link.h>
+#endif
+#include "coretypes.h"
+#include "tm.h"
+#include "dwarf2.h"
+#include "unwind.h"
+#define NO_BASE_OF_ENCODED_VALUE
+#include "unwind-pe.h"
+#include "unwind-dw2-fde.h"
+#include "unwind-compat.h"
+#include "gthr.h"
+
+#if !defined(inhibit_libc) && defined(HAVE_LD_EH_FRAME_HDR) \
+    && (__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ > 2) \
+	|| (__GLIBC__ == 2 && __GLIBC_MINOR__ == 2 && defined(DT_CONFIG)))
+
+#ifndef __RELOC_POINTER
+# define __RELOC_POINTER(ptr, base) ((ptr) + (base))
+#endif
+
+static const fde * _Unwind_Find_registered_FDE (void *pc, struct dwarf_eh_bases *bases);
+
+#define _Unwind_Find_FDE _Unwind_Find_registered_FDE
+#include "unwind-dw2-fde.c"
+#undef _Unwind_Find_FDE
+
+#ifndef PT_GNU_EH_FRAME
+#define PT_GNU_EH_FRAME (PT_LOOS + 0x474e550)
+#endif
+
+struct unw_eh_callback_data
+{
+  _Unwind_Ptr pc;
+  void *tbase;
+  void *dbase;
+  void *func;
+  const fde *ret;
+  int check_cache;
+};
+
+struct unw_eh_frame_hdr
+{
+  unsigned char version;
+  unsigned char eh_frame_ptr_enc;
+  unsigned char fde_count_enc;
+  unsigned char table_enc;
+};
+
+#define FRAME_HDR_CACHE_SIZE 8
+
+static struct frame_hdr_cache_element
+{
+  _Unwind_Ptr pc_low;
+  _Unwind_Ptr pc_high;
+  _Unwind_Ptr load_base;
+  const ElfW(Phdr) *p_eh_frame_hdr;
+  const ElfW(Phdr) *p_dynamic;
+  struct frame_hdr_cache_element *link;
+} frame_hdr_cache[FRAME_HDR_CACHE_SIZE];
+
+static struct frame_hdr_cache_element *frame_hdr_cache_head;
+
+/* Like base_of_encoded_value, but take the base from a struct
+   unw_eh_callback_data instead of an _Unwind_Context.  */
+
+static _Unwind_Ptr
+base_from_cb_data (unsigned char encoding, struct unw_eh_callback_data *data)
+{
+  if (encoding == DW_EH_PE_omit)
+    return 0;
+
+  switch (encoding & 0x70)
+    {
+    case DW_EH_PE_absptr:
+    case DW_EH_PE_pcrel:
+    case DW_EH_PE_aligned:
+      return 0;
+
+    case DW_EH_PE_textrel:
+      return (_Unwind_Ptr) data->tbase;
+    case DW_EH_PE_datarel:
+      return (_Unwind_Ptr) data->dbase;
+    default:
+      gcc_unreachable ();
+    }
+}
+
+static int
+_Unwind_IteratePhdrCallback (struct dl_phdr_info *info, size_t size, void *ptr)
+{
+  struct unw_eh_callback_data *data = (struct unw_eh_callback_data *) ptr;
+  const ElfW(Phdr) *phdr, *p_eh_frame_hdr, *p_dynamic;
+  long n, match;
+#ifdef __FRV_FDPIC__
+  struct elf32_fdpic_loadaddr load_base;
+#else
+  _Unwind_Ptr load_base;
+#endif
+  const unsigned char *p;
+  const struct unw_eh_frame_hdr *hdr;
+  _Unwind_Ptr eh_frame;
+  struct object ob;
+  
+  struct ext_dl_phdr_info
+    {
+      ElfW(Addr) dlpi_addr;
+      const char *dlpi_name;
+      const ElfW(Phdr) *dlpi_phdr;
+      ElfW(Half) dlpi_phnum;
+      unsigned long long int dlpi_adds;
+      unsigned long long int dlpi_subs;
+    };
+
+  match = 0;
+  phdr = info->dlpi_phdr;
+  load_base = info->dlpi_addr;
+  p_eh_frame_hdr = NULL;
+  p_dynamic = NULL;
+
+  struct frame_hdr_cache_element *prev_cache_entry = NULL,
+    *last_cache_entry = NULL;
+
+  if (data->check_cache && size >= sizeof (struct ext_dl_phdr_info))
+    {
+      static unsigned long long adds = -1ULL, subs;
+      struct ext_dl_phdr_info *einfo = (struct ext_dl_phdr_info *) info;
+
+      /* We use a least recently used cache replacement policy.  Also,
+	 the most recently used cache entries are placed at the head
+	 of the search chain.  */
+
+      if (einfo->dlpi_adds == adds && einfo->dlpi_subs == subs)
+	{
+	  /* Find data->pc in shared library cache.
+	     Set load_base, p_eh_frame_hdr and p_dynamic
+	     plus match from the cache and goto
+	     "Read .eh_frame_hdr header." below.  */
+
+	  struct frame_hdr_cache_element *cache_entry;
+
+	  for (cache_entry = frame_hdr_cache_head;
+	       cache_entry;
+	       cache_entry = cache_entry->link)
+	    {
+	      if (data->pc >= cache_entry->pc_low
+		  && data->pc < cache_entry->pc_high)
+		{
+		  load_base = cache_entry->load_base;
+		  p_eh_frame_hdr = cache_entry->p_eh_frame_hdr;
+		  p_dynamic = cache_entry->p_dynamic;
+
+		  /* And move the entry we're using to the head.  */
+		  if (cache_entry != frame_hdr_cache_head)
+		    {
+		      prev_cache_entry->link = cache_entry->link;
+		      cache_entry->link = frame_hdr_cache_head;
+		      frame_hdr_cache_head = cache_entry;
+		    }
+		  goto found;
+		}
+		  
+	      last_cache_entry = cache_entry;
+	      /* Exit early if we found an unused entry.  */
+	      if ((cache_entry->pc_low | cache_entry->pc_high) == 0)
+		break;
+	      if (cache_entry->link != NULL)
+		prev_cache_entry = cache_entry;		  
+	    }
+	}
+      else
+	{
+	  adds = einfo->dlpi_adds;
+	  subs = einfo->dlpi_subs;
+	  /* Initialize the cache.  Create a chain of cache entries,
+	     with the final one terminated by a NULL link.  */
+	  int i;
+	  for (i = 0; i < FRAME_HDR_CACHE_SIZE; i++)
+	    {
+	      frame_hdr_cache[i].pc_low = 0;
+	      frame_hdr_cache[i].pc_high = 0;
+	      frame_hdr_cache[i].link = &frame_hdr_cache[i+1];
+	    }
+	  frame_hdr_cache[i-1].link = NULL;
+	  frame_hdr_cache_head = &frame_hdr_cache[0];
+	  data->check_cache = 0;
+	}
+    }
+
+  /* Make sure struct dl_phdr_info is at least as big as we need.  */
+  if (size < offsetof (struct dl_phdr_info, dlpi_phnum)
+	     + sizeof (info->dlpi_phnum))
+    return -1;
+ 
+  _Unwind_Ptr pc_low = 0, pc_high = 0;
+
+  /* See if PC falls into one of the loaded segments.  Find the eh_frame
+     segment at the same time.  */
+  for (n = info->dlpi_phnum; --n >= 0; phdr++)
+    {
+      if (phdr->p_type == PT_LOAD)
+	{
+	  _Unwind_Ptr vaddr = (_Unwind_Ptr)
+	    __RELOC_POINTER (phdr->p_vaddr, load_base);
+	  if (data->pc >= vaddr && data->pc < vaddr + phdr->p_memsz)
+	    {
+	      match = 1;
+	      pc_low = vaddr;
+	      pc_high =  vaddr + phdr->p_memsz;
+	    }
+	}
+      else if (phdr->p_type == PT_GNU_EH_FRAME)
+	p_eh_frame_hdr = phdr;
+      else if (phdr->p_type == PT_DYNAMIC)
+	p_dynamic = phdr;
+    }
+  
+  if (!match)
+    return 0;
+
+  if (size >= sizeof (struct ext_dl_phdr_info))
+    {
+      /* Move the cache entry we're about to overwrite to the head of
+	 the list.  If either last_cache_entry or prev_cache_entry are
+	 NULL, that cache entry is already at the head.  */
+      if (last_cache_entry != NULL && prev_cache_entry != NULL)
+	{
+	  prev_cache_entry->link = last_cache_entry->link;
+	  last_cache_entry->link = frame_hdr_cache_head;
+	  frame_hdr_cache_head = last_cache_entry;
+	}
+
+      frame_hdr_cache_head->load_base = load_base;
+      frame_hdr_cache_head->p_eh_frame_hdr = p_eh_frame_hdr;
+      frame_hdr_cache_head->p_dynamic = p_dynamic;
+      frame_hdr_cache_head->pc_low = pc_low;
+      frame_hdr_cache_head->pc_high = pc_high;
+    }
+
+ found:
+
+  if (!p_eh_frame_hdr)
+    return 0;
+
+  /* Read .eh_frame_hdr header.  */
+  hdr = (const struct unw_eh_frame_hdr *)
+    __RELOC_POINTER (p_eh_frame_hdr->p_vaddr, load_base);
+  if (hdr->version != 1)
+    return 1;
+
+#ifdef CRT_GET_RFIB_DATA
+# ifdef __i386__
+  data->dbase = NULL;
+  if (p_dynamic)
+    {
+      /* For dynamically linked executables and shared libraries,
+	 DT_PLTGOT is the gp value for that object.  */
+      ElfW(Dyn) *dyn = (ElfW(Dyn) *)
+	__RELOC_POINTER (p_dynamic->p_vaddr, load_base);
+      for (; dyn->d_tag != DT_NULL ; dyn++)
+	if (dyn->d_tag == DT_PLTGOT)
+	  {
+	    /* On IA-32, _DYNAMIC is writable and GLIBC has relocated it.  */
+	    data->dbase = (void *) dyn->d_un.d_ptr;
+	    break;
+	  }
+    }
+# elif defined __FRV_FDPIC__ && defined __linux__
+  data->dbase = load_base.got_value;
+# else
+#  error What is DW_EH_PE_datarel base on this platform?
+# endif
+#endif
+
+  p = read_encoded_value_with_base (hdr->eh_frame_ptr_enc,
+				    base_from_cb_data (hdr->eh_frame_ptr_enc,
+						       data),
+				    (const unsigned char *) (hdr + 1),
+				    &eh_frame);
+
+  /* We require here specific table encoding to speed things up.
+     Also, DW_EH_PE_datarel here means using PT_GNU_EH_FRAME start
+     as base, not the processor specific DW_EH_PE_datarel.  */
+  if (hdr->fde_count_enc != DW_EH_PE_omit
+      && hdr->table_enc == (DW_EH_PE_datarel | DW_EH_PE_sdata4))
+    {
+      _Unwind_Ptr fde_count;
+
+      p = read_encoded_value_with_base (hdr->fde_count_enc,
+					base_from_cb_data (hdr->fde_count_enc,
+							   data),
+					p, &fde_count);
+      /* Shouldn't happen.  */
+      if (fde_count == 0)
+	return 1;
+      if ((((_Unwind_Ptr) p) & 3) == 0)
+	{
+	  struct fde_table {
+	    signed initial_loc __attribute__ ((mode (SI)));
+	    signed fde __attribute__ ((mode (SI)));
+	  };
+	  const struct fde_table *table = (const struct fde_table *) p;
+	  size_t lo, hi, mid;
+	  _Unwind_Ptr data_base = (_Unwind_Ptr) hdr;
+	  fde *f;
+	  unsigned int f_enc, f_enc_size;
+	  _Unwind_Ptr range;
+
+	  mid = fde_count - 1;
+	  if (data->pc < table[0].initial_loc + data_base)
+	    return 1;
+	  else if (data->pc < table[mid].initial_loc + data_base)
+	    {
+	      lo = 0;
+	      hi = mid;
+
+	      while (lo < hi)
+		{
+		  mid = (lo + hi) / 2;
+		  if (data->pc < table[mid].initial_loc + data_base)
+		    hi = mid;
+		  else if (data->pc >= table[mid + 1].initial_loc + data_base)
+		    lo = mid + 1;
+		  else
+		    break;
+		}
+
+	      gcc_assert (lo < hi);
+	    }
+
+	  f = (fde *) (table[mid].fde + data_base);
+	  f_enc = get_fde_encoding (f);
+	  f_enc_size = size_of_encoded_value (f_enc);
+	  read_encoded_value_with_base (f_enc & 0x0f, 0,
+					&f->pc_begin[f_enc_size], &range);
+	  if (data->pc < table[mid].initial_loc + data_base + range)
+	    data->ret = f;
+	  data->func = (void *) (table[mid].initial_loc + data_base);
+	  return 1;
+	}
+    }
+
+  /* We have no sorted search table, so need to go the slow way.
+     As soon as GLIBC will provide API so to notify that a library has been
+     removed, we could cache this (and thus use search_object).  */
+  ob.pc_begin = NULL;
+  ob.tbase = data->tbase;
+  ob.dbase = data->dbase;
+  ob.u.single = (fde *) eh_frame;
+  ob.s.i = 0;
+  ob.s.b.mixed_encoding = 1;  /* Need to assume worst case.  */
+  data->ret = linear_search_fdes (&ob, (fde *) eh_frame, (void *) data->pc);
+  if (data->ret != NULL)
+    {
+      _Unwind_Ptr func;
+      unsigned int encoding = get_fde_encoding (data->ret);
+      
+      read_encoded_value_with_base (encoding,
+				    base_from_cb_data (encoding, data),
+				    data->ret->pc_begin, &func);
+      data->func = (void *) func;
+    }
+  return 1;
+}
+
+const fde *
+_Unwind_Find_FDE (void *pc, struct dwarf_eh_bases *bases)
+{
+  struct unw_eh_callback_data data;
+  const fde *ret;
+
+  ret = _Unwind_Find_registered_FDE (pc, bases);
+  if (ret != NULL)
+    return ret;
+
+  data.pc = (_Unwind_Ptr) pc;
+  data.tbase = NULL;
+  data.dbase = NULL;
+  data.func = NULL;
+  data.ret = NULL;
+  data.check_cache = 1;
+
+  if (dl_iterate_phdr (_Unwind_IteratePhdrCallback, &data) < 0)
+    return NULL;
+
+  if (data.ret)
+    {
+      bases->tbase = data.tbase;
+      bases->dbase = data.dbase;
+      bases->func = data.func;
+    }
+  return data.ret;
+}
+
+#else
+/* Prevent multiple include of header files.  */
+#define _Unwind_Find_FDE _Unwind_Find_FDE
+#include "unwind-dw2-fde.c"
+#endif
+
+#if defined (USE_GAS_SYMVER) && defined (SHARED) && defined (USE_LIBUNWIND_EXCEPTIONS)
+alias (_Unwind_Find_FDE);
+#endif