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-rw-r--r--elf/sprof.c937
1 files changed, 937 insertions, 0 deletions
diff --git a/elf/sprof.c b/elf/sprof.c
new file mode 100644
index 0000000000..0d50806126
--- /dev/null
+++ b/elf/sprof.c
@@ -0,0 +1,937 @@
+/* Read and display shared object profiling data.
+   Copyright (C) 1997, 1998 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#include <argp.h>
+#include <dlfcn.h>
+#include <elf.h>
+#include <endian.h>
+#include <error.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <libintl.h>
+#include <link.h>
+#include <locale.h>
+#include <obstack.h>
+#include <search.h>
+#include <stab.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/gmon.h>
+#include <sys/gmon_out.h>
+#include <sys/mman.h>
+#include <sys/param.h>
+#include <sys/stat.h>
+
+/* Undefine the following line line in the production version.  */
+/* #define _NDEBUG 1 */
+#include <assert.h>
+
+/* Get libc version number.  */
+#include "../version.h"
+
+#define PACKAGE _libc_intl_domainname
+
+
+#include <endian.h>
+#if BYTE_ORDER == BIG_ENDIAN
+#define byteorder ELFDATA2MSB
+#define byteorder_name "big-endian"
+#elif BYTE_ORDER == LITTLE_ENDIAN
+#define byteorder ELFDATA2LSB
+#define byteorder_name "little-endian"
+#else
+#error "Unknown BYTE_ORDER " BYTE_ORDER
+#define byteorder ELFDATANONE
+#endif
+
+
+extern int __profile_frequency __P ((void));
+
+/* Name and version of program.  */
+static void print_version (FILE *stream, struct argp_state *state);
+void (*argp_program_version_hook) (FILE *, struct argp_state *) = print_version;
+
+#define OPT_COUNT_TOTAL	1
+#define OPT_TEST 2
+
+/* Definitions of arguments for argp functions.  */
+static const struct argp_option options[] =
+{
+  { NULL, 0, NULL, 0, N_("Output selection:") },
+  { "count-total", OPT_COUNT_TOTAL, NULL, 0,
+    N_("print number of invocations for each function") },
+  { "test", OPT_TEST, NULL, OPTION_HIDDEN, NULL },
+  { NULL, 0, NULL, 0, NULL }
+};
+
+/* Short description of program.  */
+static const char doc[] = N_("Read and display shared object profiling data");
+
+/* Strings for arguments in help texts.  */
+static const char args_doc[] = N_("SHOBJ [PROFDATA]");
+
+/* Prototype for option handler.  */
+static error_t parse_opt (int key, char *arg, struct argp_state *state);
+
+/* Data structure to communicate with argp functions.  */
+static struct argp argp =
+{
+  options, parse_opt, args_doc, doc, NULL, NULL
+};
+
+
+/* Operation modes.  */
+static enum
+{
+  NONE = 0,
+  COUNT_TOTAL
+} mode;
+
+/* If nonzero the total number of invocations of a function is emitted.  */
+int count_total;
+
+/* Nozero for testing.  */
+int do_test;
+
+/* Strcuture describing calls.  */
+struct here_fromstruct
+  {
+    struct here_cg_arc_record volatile *here;
+    uint16_t link;
+  };
+
+/* We define a special type to address the elements of the arc table.
+   This is basically the `gmon_cg_arc_record' format but it includes
+   the room for the tag and it uses real types.  */
+struct here_cg_arc_record
+  {
+    uintptr_t from_pc;
+    uintptr_t self_pc;
+    uint32_t count;
+  } __attribute__ ((packed));
+
+/* Information about the stab debugging info.  This should be in a
+   head but it is not.  */
+#define STRDXOFF (0)
+#define TYPEOFF (4)
+#define OTHEROFF (5)
+#define DESCOFF (6)
+#define VALOFF (8)
+#define STABSIZE (12)
+
+
+struct known_symbol
+{
+  const char *name;
+  uintptr_t addr;
+  size_t size;
+};
+
+
+struct shobj
+{
+  const char *name;		/* User-provided name.  */
+
+  struct link_map *map;
+  const char *strtab;		/* String table of shared object.  */
+  const char *soname;		/* Soname of shared object.  */
+
+  uintptr_t lowpc;
+  uintptr_t highpc;
+  unsigned long int kcountsize;
+  size_t expected_size;		/* Expected size of profiling file.  */
+  size_t tossize;
+  size_t fromssize;
+  size_t fromlimit;
+  unsigned int hashfraction;
+  int s_scale;
+
+  void *stab_map;
+  size_t stab_mapsize;
+  const char *stab;
+  size_t stab_size;
+  const char *stabstr;
+  size_t stabstr_size;
+
+  struct obstack ob_str;
+  struct obstack ob_sym;
+};
+
+
+struct profdata
+{
+  void *addr;
+  off_t size;
+
+  char *hist;
+  uint16_t *kcount;
+  uint32_t narcs;		/* Number of arcs in toset.  */
+  struct here_cg_arc_record *data;
+  uint16_t *tos;
+  struct here_fromstruct *froms;
+};
+
+/* Search tree for symbols.  */
+void *symroot;
+static const struct known_symbol **sortsym;
+static size_t symidx;
+
+/* Prototypes for local functions.  */
+static struct shobj *load_shobj (const char *name);
+static void unload_shobj (struct shobj *shobj);
+static struct profdata *load_profdata (const char *name, struct shobj *shobj);
+static void unload_profdata (struct profdata *profdata);
+static void count_total_ticks (struct shobj *shobj, struct profdata *profdata);
+static void read_symbols (struct shobj *shobj);
+
+
+int
+main (int argc, char *argv[])
+{
+  const char *shobj;
+  const char *profdata;
+  struct shobj *shobj_handle;
+  struct profdata *profdata_handle;
+  int remaining;
+
+  setlocale (LC_ALL, "");
+
+  /* Initialize the message catalog.  */
+  textdomain (_libc_intl_domainname);
+
+  /* Parse and process arguments.  */
+  argp_parse (&argp, argc, argv, 0, &remaining, NULL);
+
+  if (argc - remaining == 0 || argc - remaining > 2)
+    {
+      /* We need exactly two non-option parameter.  */
+      argp_help (&argp, stdout, ARGP_HELP_SEE | ARGP_HELP_EXIT_ERR,
+                 program_invocation_short_name);
+      exit (1);
+    }
+
+  /* Get parameters.  */
+  shobj = argv[remaining];
+  if (argc - remaining == 2)
+    profdata = argv[remaining + 1];
+  else
+    /* No filename for the profiling data given.  We will determine it
+       from the soname of the shobj, later.  */
+    profdata = NULL;
+
+  /* First see whether we can load the shared object.  */
+  shobj_handle = load_shobj (shobj);
+  if (shobj_handle == NULL)
+    exit (1);
+
+  /* We can now determine the filename for the profiling data, if
+     nececessary.  */
+  if (profdata == NULL)
+    {
+      char *newp;
+
+      if (shobj_handle->soname == NULL)
+	{
+	  unload_shobj (shobj_handle);
+
+	  error (EXIT_FAILURE, 0, _("\
+no filename for profiling data given and shared object `%s' has no soname"),
+		 shobj);
+	}
+
+      newp = (char *) alloca (strlen (shobj_handle->soname)
+			      + sizeof ".profile");
+      stpcpy (stpcpy (newp, shobj_handle->soname), ".profile");
+      profdata = newp;
+    }
+
+  /* Now see whether the profiling data file matches the given object.   */
+  profdata_handle = load_profdata (profdata, shobj_handle);
+  if (profdata_handle == NULL)
+    {
+      unload_shobj (shobj_handle);
+
+      exit (1);
+    }
+
+  read_symbols (shobj_handle);
+
+  /* Do some work.  */
+  switch (mode)
+    {
+    case COUNT_TOTAL:
+      count_total_ticks (shobj_handle, profdata_handle);
+      break;
+    case NONE:
+      /* Do nothing.  */
+      break;
+    default:
+      assert (! "Internal error");
+    }
+
+  /* Free the resources.  */
+  unload_shobj (shobj_handle);
+  unload_profdata (profdata_handle);
+
+  return 0;
+}
+
+
+/* Handle program arguments.  */
+static error_t
+parse_opt (int key, char *arg, struct argp_state *state)
+{
+  switch (key)
+    {
+    case OPT_COUNT_TOTAL:
+      mode = COUNT_TOTAL;
+      break;
+    case OPT_TEST:
+      do_test = 1;
+      break;
+    default:
+      return ARGP_ERR_UNKNOWN;
+    }
+  return 0;
+}
+
+
+/* Print the version information.  */
+static void
+print_version (FILE *stream, struct argp_state *state)
+{
+  fprintf (stream, "sprof (GNU %s) %s\n", PACKAGE, VERSION);
+  fprintf (stream, gettext ("\
+Copyright (C) %s Free Software Foundation, Inc.\n\
+This is free software; see the source for copying conditions.  There is NO\n\
+warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n\
+"),
+	   "1997, 1998");
+  fprintf (stream, gettext ("Written by %s.\n"), "Ulrich Drepper");
+}
+
+
+/* Note that we must not use `dlopen' etc.  The shobj object must not
+   be loaded for use.  */
+static struct shobj *
+load_shobj (const char *name)
+{
+  struct link_map *map = NULL;
+  struct shobj *result;
+  ElfW(Addr) mapstart = ~((ElfW(Addr)) 0);
+  ElfW(Addr) mapend = 0;
+  const ElfW(Phdr) *ph;
+  size_t textsize;
+  unsigned int log_hashfraction;
+  ElfW(Ehdr) *ehdr;
+  int fd;
+  ElfW(Shdr) *shdr;
+  void *ptr;
+  size_t pagesize = getpagesize ();
+  const char *shstrtab;
+  int idx;
+  ElfW(Shdr) *stab_entry;
+  ElfW(Shdr) *stabstr_entry;
+
+  /* Since we use dlopen() we must be prepared to work around the sometimes
+     strange lookup rules for the shared objects.  If we have a file foo.so
+     in the current directory and the user specfies foo.so on the command
+     line (without specifying a directory) we should load the file in the
+     current directory even if a normal dlopen() call would read the other
+     file.  We do this by adding a directory portion to the name.  */
+  if (strchr (name, '/') == NULL)
+    {
+      char *load_name = (char *) alloca (strlen (name) + 3);
+      stpcpy (stpcpy (load_name, "./"), name);
+
+      map = (struct link_map *) dlopen (load_name, RTLD_LAZY);
+    }
+  if (map == NULL)
+    {
+      map = (struct link_map *) dlopen (name, RTLD_LAZY);
+      if (map == NULL)
+	{
+	  error (0, errno, _("failed to load shared object `%s'"), name);
+	  return NULL;
+	}
+    }
+
+  /* Prepare the result.  */
+  result = (struct shobj *) calloc (1, sizeof (struct shobj));
+  if (result == NULL)
+    {
+      error (0, errno, _("cannot create internal descriptors"));
+      dlclose (map);
+      return NULL;
+    }
+  result->name = name;
+  result->map = map;
+
+  /* Compute the size of the sections which contain program code.
+     This must match the code in dl-profile.c (_dl_start_profile).  */
+  for (ph = map->l_phdr; ph < &map->l_phdr[map->l_phnum]; ++ph)
+    if (ph->p_type == PT_LOAD && (ph->p_flags & PF_X))
+      {
+	ElfW(Addr) start = (ph->p_vaddr & ~(_dl_pagesize - 1));
+	ElfW(Addr) end = ((ph->p_vaddr + ph->p_memsz + _dl_pagesize - 1)
+			  & ~(_dl_pagesize - 1));
+
+	if (start < mapstart)
+	  mapstart = start;
+	if (end > mapend)
+	  mapend = end;
+      }
+
+  result->lowpc = ROUNDDOWN ((uintptr_t) (mapstart + map->l_addr),
+			     HISTFRACTION * sizeof (HISTCOUNTER));
+  result->highpc = ROUNDUP ((uintptr_t) (mapend + map->l_addr),
+			    HISTFRACTION * sizeof (HISTCOUNTER));
+  if (do_test)
+    printf ("load addr: %0#*" PRIxPTR "\n"
+	    "lower bound PC: %0#*" PRIxPTR "\n"
+	    "upper bound PC: %0#*" PRIxPTR "\n",
+	    __ELF_NATIVE_CLASS == 32 ? 10 : 18, map->l_addr,
+	    __ELF_NATIVE_CLASS == 32 ? 10 : 18, result->lowpc,
+	    __ELF_NATIVE_CLASS == 32 ? 10 : 18, result->highpc);
+
+  textsize = result->highpc - result->lowpc;
+  result->kcountsize = textsize / HISTFRACTION;
+  result->hashfraction = HASHFRACTION;
+  if ((HASHFRACTION & (HASHFRACTION - 1)) == 0)
+    /* If HASHFRACTION is a power of two, mcount can use shifting
+       instead of integer division.  Precompute shift amount.  */
+    log_hashfraction = __builtin_ffs (result->hashfraction
+				      * sizeof (struct here_fromstruct)) - 1;
+  else
+    log_hashfraction = -1;
+  if (do_test)
+    printf ("hashfraction = %d\ndivider = %d\n",
+	    result->hashfraction,
+	    result->hashfraction * sizeof (struct here_fromstruct));
+  result->tossize = textsize / HASHFRACTION;
+  result->fromlimit = textsize * ARCDENSITY / 100;
+  if (result->fromlimit < MINARCS)
+    result->fromlimit = MINARCS;
+  if (result->fromlimit > MAXARCS)
+    result->fromlimit = MAXARCS;
+  result->fromssize = result->fromlimit * sizeof (struct here_fromstruct);
+
+  result->expected_size = (sizeof (struct gmon_hdr)
+			   + 4 + sizeof (struct gmon_hist_hdr)
+			   + result->kcountsize
+			   + 4 + 4
+			   + (result->fromssize
+			      * sizeof (struct here_cg_arc_record)));
+
+  if (do_test)
+    {
+#define SCALE_1_TO_1	0x10000L
+
+      printf ("expected size: %Zd\n", result->expected_size);
+
+      if (result->kcountsize < result->highpc - result->lowpc)
+	{
+	  size_t range = result->highpc - result->lowpc;
+	  size_t quot = range / result->kcountsize;
+
+	  if (quot >= SCALE_1_TO_1)
+	    result->s_scale = 1;
+	  else if (quot >= SCALE_1_TO_1 / 256)
+	    result->s_scale = SCALE_1_TO_1 / quot;
+	  else if (range > ULONG_MAX / 256)
+	    result->s_scale = ((SCALE_1_TO_1 * 256)
+			       / (range / (result->kcountsize / 256)));
+	  else
+	    result->s_scale = ((SCALE_1_TO_1 * 256)
+			       / ((range * 256) / result->kcountsize));
+	}
+      else
+	result->s_scale = SCALE_1_TO_1;
+
+      printf ("s_scale: %d\n", result->s_scale);
+    }
+
+  /* Determine the string table.  */
+  if (map->l_info[DT_STRTAB] == NULL)
+    result->strtab = NULL;
+  else
+    result->strtab = (const char *) (map->l_addr
+				     + map->l_info[DT_STRTAB]->d_un.d_ptr);
+  if (do_test)
+    printf ("string table: %p\n", result->strtab);
+
+  /* Determine the soname.  */
+  if (map->l_info[DT_SONAME] == NULL)
+    result->soname = NULL;
+  else
+    result->soname = result->strtab + map->l_info[DT_SONAME]->d_un.d_val;
+  if (do_test)
+    printf ("soname: %s\n", result->soname);
+
+  /* Now the hard part, we have to load the debugging data.  For now
+     we support stabs only.
+
+     First load the section header table.  */
+  ehdr = (ElfW(Ehdr) *) map->l_addr;
+
+  /* Make sure we are on the right party.  */
+  if (ehdr->e_shentsize != sizeof (ElfW(Shdr)))
+    abort ();
+
+  /* And we need the shared object file descriptor again.  */
+  fd = open (map->l_name, O_RDONLY);
+  if (fd == -1)
+    /* Dooh, this really shouldn't happen.  We know the file is available.  */
+    error (EXIT_FAILURE, errno, _("Reopening shared object `%s' failed"));
+
+  /* Now map the section header.  */
+  ptr = mmap (NULL, (ehdr->e_phnum * sizeof (ElfW(Shdr))
+		     + (ehdr->e_shoff & (pagesize - 1))), PROT_READ,
+	      MAP_SHARED|MAP_FILE, fd, ehdr->e_shoff & ~(pagesize - 1));
+  if (ptr == MAP_FAILED)
+    error (EXIT_FAILURE, errno, _("mapping of section headers failed"));
+  shdr = (ElfW(Shdr) *) ((char *) ptr + (ehdr->e_shoff & (pagesize - 1)));
+
+  /* Get the section header string table.  */
+  ptr = mmap (NULL, (shdr[ehdr->e_shstrndx].sh_size
+		     + (shdr[ehdr->e_shstrndx].sh_offset & (pagesize - 1))),
+	      PROT_READ, MAP_SHARED|MAP_FILE, fd,
+	      shdr[ehdr->e_shstrndx].sh_offset & ~(pagesize - 1));
+  if (ptr == MAP_FAILED)
+    error (EXIT_FAILURE, errno,
+	   _("mapping of section header string table failed"));
+  shstrtab = ((const char *) ptr
+	      + (shdr[ehdr->e_shstrndx].sh_offset & (pagesize - 1)));
+
+  /* Search for the ".stab" and ".stabstr" section (and ".rel.stab" ?).  */
+  stab_entry = NULL;
+  stabstr_entry = NULL;
+  for (idx = 0; idx < ehdr->e_shnum; ++idx)
+    /* We only have to look for sections which are not loaded.  */
+    if (shdr[idx].sh_addr == 0)
+      {
+	if (strcmp (shstrtab + shdr[idx].sh_name, ".stab") == 0)
+	  stab_entry = &shdr[idx];
+	else if (strcmp (shstrtab + shdr[idx].sh_name, ".stabstr") == 0)
+	  stabstr_entry = &shdr[idx];
+      }
+
+  /* We don't need the sectin header string table anymore.  */
+  munmap (ptr, (shdr[ehdr->e_shstrndx].sh_size
+		+ (shdr[ehdr->e_shstrndx].sh_offset & (pagesize - 1))));
+
+  if (stab_entry == NULL || stabstr_entry == NULL)
+    {
+      fprintf (stderr, _("\
+*** The file `%s' is stripped: no detailed analysis possible\n"),
+	      name);
+      result->stab = NULL;
+      result->stabstr = NULL;
+    }
+  else
+    {
+      if (stab_entry->sh_offset + stab_entry->sh_size
+	  != stabstr_entry->sh_offset)
+	abort ();
+      if (stab_entry->sh_size % STABSIZE != 0)
+	abort ();
+
+      result->stab_map = mmap (NULL, (stab_entry->sh_size
+				      + stabstr_entry->sh_size
+				      + (stab_entry->sh_offset
+					 & (pagesize - 1))),
+			       PROT_READ, MAP_SHARED|MAP_FILE, fd,
+			       stab_entry->sh_offset & ~(pagesize - 1));
+      if (result->stab_map == NULL)
+	error (EXIT_FAILURE, errno, _("failed to load stab data:"));
+
+      result->stab = ((const char *) result->stab_map
+		      + (stab_entry->sh_offset & (pagesize - 1)));
+      result->stab_size = stab_entry->sh_size;
+      result->stabstr = result->stab + stab_entry->sh_size;
+      result->stabstr_size = stabstr_entry->sh_size;
+      result->stab_mapsize = (stab_entry->sh_size + stabstr_entry->sh_size
+			      + (stab_entry->sh_offset & (pagesize - 1)));
+    }
+
+  /* Now we also don't need the sectio header table anymore.  */
+  munmap ((char *) shdr - (ehdr->e_shoff & (pagesize - 1)),
+	  (ehdr->e_phnum * sizeof (ElfW(Shdr))
+	   + (ehdr->e_shoff & (pagesize - 1))));
+
+  /* Free the descriptor for the shared object.  */
+  close (fd);
+
+  return result;
+}
+
+
+static void
+unload_shobj (struct shobj *shobj)
+{
+  munmap (shobj->stab_map, shobj->stab_mapsize);
+  dlclose (shobj->map);
+}
+
+
+static struct profdata *
+load_profdata (const char *name, struct shobj *shobj)
+{
+  struct profdata *result;
+  int fd;
+  struct stat st;
+  void *addr;
+  struct gmon_hdr gmon_hdr;
+  struct gmon_hist_hdr hist_hdr;
+  uint32_t *narcsp;
+  size_t fromlimit;
+  struct here_cg_arc_record *data;
+  struct here_fromstruct *froms;
+  uint16_t *tos;
+  size_t fromidx;
+  size_t idx;
+
+  fd = open (name, O_RDONLY);
+  if (fd == -1)
+    {
+      char *ext_name;
+
+      if (errno != ENOENT || strchr (name, '/') != NULL)
+	/* The file exists but we are not allowed to read it or the
+	   file does not exist and the name includes a path
+	   specification..  */
+	return NULL;
+
+      /* A file with the given name does not exist in the current
+	 directory, try it in the default location where the profiling
+	 files are created.  */
+      ext_name = (char *) alloca (strlen (name) + sizeof "/var/tmp/");
+      stpcpy (stpcpy (ext_name, "/var/tmp/"), name);
+      name = ext_name;
+
+      fd = open (ext_name, O_RDONLY);
+      if (fd == -1)
+	{
+	  /* Even this file does not exist.  */
+	  error (0, errno, _("cannot load profiling data"));
+	  return NULL;
+	}
+    }
+
+  /* We have found the file, now make sure it is the right one for the
+     data file.  */
+  if (fstat (fd, &st) < 0)
+    {
+      error (0, errno, _("while stat'ing profiling data file"));
+      close (fd);
+      return NULL;
+    }
+
+  if (st.st_size != shobj->expected_size)
+    {
+      error (0, 0, _("profiling data file `%s' does match shared object `%s'"),
+	     name, shobj->name);
+      close (fd);
+      return NULL;
+    }
+
+  /* The data file is most probably the right one for our shared
+     object.  Map it now.  */
+  addr = mmap (NULL, st.st_size, PROT_READ, MAP_SHARED|MAP_FILE, fd, 0);
+  if (addr == MAP_FAILED)
+    {
+      error (0, errno, _("failed to mmap the profiling data file"));
+      close (fd);
+      return NULL;
+    }
+
+  /* We don't need the file desriptor anymore.  */
+  if (close (fd) < 0)
+    {
+      error (0, errno, _("error while closing the profiling data file"));
+      munmap (addr, st.st_size);
+      return NULL;
+    }
+
+  /* Prepare the result.  */
+  result = (struct profdata *) calloc (1, sizeof (struct profdata));
+  if (result == NULL)
+    {
+      error (0, errno, _("cannot create internal descriptor"));
+      munmap (addr, st.st_size);
+      return NULL;
+    }
+
+  /* Store the address and size so that we can later free the resources.  */
+  result->addr = addr;
+  result->size = st.st_size;
+
+  /* Pointer to data after the header.  */
+  result->hist = (char *) ((struct gmon_hdr *) addr + 1);
+  result->kcount = (uint16_t *) ((char *) result->hist + sizeof (uint32_t)
+				 + sizeof (struct gmon_hist_hdr));
+
+  /* Compute pointer to array of the arc information.  */
+  narcsp = (uint32_t *) ((char *) result->kcount + shobj->kcountsize
+			 + sizeof (uint32_t));
+  result->narcs = *narcsp;
+  result->data = (struct here_cg_arc_record *) ((char *) narcsp
+						+ sizeof (uint32_t));
+
+  /* Create the gmon_hdr we expect or write.  */
+  memset (&gmon_hdr, '\0', sizeof (struct gmon_hdr));
+  memcpy (&gmon_hdr.cookie[0], GMON_MAGIC, sizeof (gmon_hdr.cookie));
+  *(int32_t *) gmon_hdr.version = GMON_SHOBJ_VERSION;
+
+  /* Create the hist_hdr we expect or write.  */
+  *(char **) hist_hdr.low_pc = (char *) shobj->lowpc - shobj->map->l_addr;
+  *(char **) hist_hdr.high_pc = (char *) shobj->highpc - shobj->map->l_addr;
+  if (do_test)
+    printf ("low_pc = %p\nhigh_pc = %p\n",
+	    hist_hdr.low_pc, hist_hdr.high_pc);
+  *(int32_t *) hist_hdr.hist_size = shobj->kcountsize / sizeof (HISTCOUNTER);
+  *(int32_t *) hist_hdr.prof_rate = __profile_frequency ();
+  strncpy (hist_hdr.dimen, "seconds", sizeof (hist_hdr.dimen));
+  hist_hdr.dimen_abbrev = 's';
+
+  /* Test whether the header of the profiling data is ok.  */
+  if (memcmp (addr, &gmon_hdr, sizeof (struct gmon_hdr)) != 0
+      || *(uint32_t *) result->hist != GMON_TAG_TIME_HIST
+      || memcmp (result->hist + sizeof (uint32_t), &hist_hdr,
+		 sizeof (struct gmon_hist_hdr)) != 0
+      || narcsp[-1] != GMON_TAG_CG_ARC)
+    {
+      free (result);
+      error (0, 0, _("`%s' is no correct profile data file for `%s'"),
+	     name, shobj->name);
+      munmap (addr, st.st_size);
+      return NULL;
+    }
+
+  /* We are pretty sure now that this is a correct input file.  Set up
+     the remaining information in the result structure and return.  */
+  result->tos = (uint16_t *) calloc (shobj->tossize + shobj->fromssize, 1);
+  if (result->tos == NULL)
+    {
+      error (0, errno, _("cannot create internal descriptor"));
+      munmap (addr, st.st_size);
+      free (result);
+      return NULL;
+    }
+
+  result->froms = (struct here_fromstruct *) ((char *) result->tos
+					      + shobj->tossize);
+  fromidx = 0;
+
+  /* Now we have to process all the arc count entries.  */
+  fromlimit = shobj->fromlimit;
+  data = result->data;
+  froms = result->froms;
+  tos = result->tos;
+  for (idx = 0; idx < MIN (*narcsp, fromlimit); ++idx)
+    {
+      size_t to_index;
+      size_t newfromidx;
+      to_index = (data[idx].self_pc / (shobj->hashfraction * sizeof (*tos)));
+      newfromidx = fromidx++;
+      froms[newfromidx].here = &data[idx];
+      froms[newfromidx].link = tos[to_index];
+      tos[to_index] = newfromidx;
+    }
+
+  return result;
+}
+
+
+static void
+unload_profdata (struct profdata *profdata)
+{
+  free (profdata->tos);
+  munmap (profdata->addr, profdata->size);
+  free (profdata);
+}
+
+
+static void
+count_total_ticks (struct shobj *shobj, struct profdata *profdata)
+{
+  volatile uint16_t *kcount = profdata->kcount;
+  uint64_t sum = 0;
+  size_t idx;
+  size_t factor = 2 * (65536 / shobj->s_scale);
+
+  for (idx = shobj->kcountsize / sizeof (*kcount); idx > 0; )
+    {
+      --idx;
+      if (kcount[idx] != 0)
+	{
+	  size_t n;
+
+	  for (n = 0; n < symidx; ++n)
+	    if (sortsym[n]->addr <= factor * idx
+		&& sortsym[n]->addr + sortsym[n]->size > factor * idx)
+	      break;
+
+	  if (n < symidx)
+	    printf ("idx = %d, count = %d, name = %s\n", idx, kcount[idx],
+		    sortsym[n]->name);
+	  else
+	    printf ("idx = %d, N/A\n", idx);
+	}
+      sum += kcount[idx];
+    }
+
+  printf ("total ticks: %10" PRId64 "\n", sum);
+}
+
+
+static int
+symorder (const void *o1, const void *o2)
+{
+  const struct known_symbol *p1 = (struct known_symbol *) o1;
+  const struct known_symbol *p2 = (struct known_symbol *) o2;
+
+  return p1->addr - p2->addr;
+}
+
+
+static void
+printsym (const void *node, VISIT value, int level)
+{
+  if (value == leaf || value == postorder)
+    {
+      const struct known_symbol *sym = *(const struct known_symbol **) node;
+
+      printf ("Name: %30s, Start: %6x, Len: %5d\n",
+	      sym->name, sym->addr, sym->size);
+
+      sortsym[symidx++] = sym;
+    }
+}
+
+
+static void
+read_symbols (struct shobj *shobj)
+{
+  void *load_addr = (void *) shobj->map->l_addr;
+  int n = 0;
+  int idx;
+  const char *last_name = NULL;
+  uintptr_t last_addr = 0;
+
+  /* Initialize the obstacks.  */
+#define obstack_chunk_alloc malloc
+#define obstack_chunk_free free
+  obstack_init (&shobj->ob_str);
+  obstack_init (&shobj->ob_sym);
+
+  /* Process the stabs.  */
+  for (idx = 0; idx < shobj->stab_size; idx += 12)
+    if (*(shobj->stab + idx + TYPEOFF) == N_FUN)
+      {
+	const char *str = (shobj->stabstr
+			   + *((uint32_t *) (shobj->stab + idx + STRDXOFF)));
+
+	if (*str != '\0')
+	  {
+	    last_name = str;
+	    last_addr = *((uint32_t *) (shobj->stab + idx + VALOFF));
+	  }
+	else
+	  {
+	    const char *endp;
+	    char *name0;
+	    struct known_symbol *newsym;
+
+	    if (last_name == NULL)
+	      abort ();
+
+	    endp = strchr (last_name, ':');
+
+	    name0 = (char *) obstack_copy0 (&shobj->ob_str, last_name,
+					    endp - last_name);
+	    if (name0 != NULL)
+	      newsym =
+		(struct known_symbol *) obstack_alloc (&shobj->ob_sym,
+						       sizeof (*newsym));
+	    else
+	      /* Keep the stupid compiler happy.  */
+	      newsym = NULL;
+	    if (name0 == NULL || newsym == NULL)
+	      error (EXIT_FAILURE, errno, _("cannot allocate symbol data"));
+
+	    newsym->name = name0;
+	    newsym->addr = last_addr;
+	    newsym->size = *((uint32_t *) (shobj->stab + idx + VALOFF));
+
+	    tsearch (newsym, &symroot, symorder);
+	    ++n;
+
+	    last_name = NULL;
+	    last_addr = 0;
+	  }
+      }
+
+  if (shobj->stab == NULL)
+    {
+      /* Blarg, the binary is stripped.  We have to rely on the
+	 information contained in the dynamic section of the object.  */
+      const ElfW(Sym) *symtab = (load_addr
+				 + shobj->map->l_info[DT_SYMTAB]->d_un.d_ptr);
+      const char *strtab = (load_addr
+			    + shobj->map->l_info[DT_STRTAB]->d_un.d_ptr);
+
+      /* We assume that the string table follows the symbol table,
+	 because there is no way in ELF to know the size of the
+	 dynamic symbol table!!  */
+      while ((void *) symtab < (void *) strtab)
+	{
+	  if (/*(ELFW(ST_TYPE)(symtab->st_info) == STT_FUNC
+		|| ELFW(ST_TYPE)(symtab->st_info) == STT_NOTYPE)
+		&&*/ symtab->st_size != 0)
+	    {
+	      struct known_symbol *newsym;
+
+	      newsym =
+		(struct known_symbol *) obstack_alloc (&shobj->ob_sym,
+						       sizeof (*newsym));
+	      if (newsym == NULL)
+		error (EXIT_FAILURE, errno, _("cannot allocate symbol data"));
+
+	      newsym->name = &strtab[symtab->st_name];
+	      newsym->addr = symtab->st_value;
+	      newsym->size = symtab->st_size;
+
+	      tsearch (newsym, &symroot, symorder);
+	      ++n;
+	    }
+	}
+
+      ++symtab;
+    }
+
+  sortsym = malloc (n * sizeof (struct known_symbol *));
+  if (sortsym == NULL)
+    abort ();
+
+  twalk (symroot, printsym);
+}