The patch re-factors libgcov.c to make it better modulelized.

2013-11-12  Rong Xu  <xur@google.com>

The patch re-factors libgcov.c to make it better modulelized.
It contains two pieces of work:
1. break gcov_exit() into the following structure:
   gcov_exit()
      --> gcov_exit_compute_summary()
      --> allocate_filename_struct()
          for gi_ptr in gcov_list
            --> gcov_exit_dump_gcov()
                   --> gcov_exit_open_gcda_file()
                   --> gcov_exit_merge_gcda ()
                   --> gcov_exit_merge_summary ()
                   --> gcov_exit_write_gcda ()
2. split libgcov.c into the following files:
     libgcov-profiler.c
     libgcov-merge.c
     libgcov-interface.c
     libgcov-driver.c
       libgcov-driver-system.c (source included into libgcov-driver.c)

	* libgcc/libgcov.c: Delete as part of re-factoring.
	* gcc/gcov-io.h (__gcov_indirect_call_profiler): Add the decl to
        avoid warning.
	* libgcc/libgcov-interface.c (init_mx): Moved from libgcov.c.
	(init_mx_once): Ditto.
	(__gcov_flush): Ditto.
	(__gcov_reset): Ditto.
	(__gcov_dump): Ditto.
	(__gcov_fork): Ditto.
	(__gcov_execl): Ditto.
	(__gcov_execlp): Ditto.
	(__gcov_execle): Ditto.
	(__gcov_execv): Ditto.
	(__gcov_execvp): Ditto.
	(__gcov_execve): Ditto.
        * libgcc/libgcov-merge.c (__gcov_merge_time_profile): Moved from
        libgcov.c.
	(__gcov_merge_add): Ditto.
	(__gcov_merge_ior): Ditto.
	(__gcov_merge_single): Ditto.
	(__gcov_merge_delta): Ditto.
	* libgcc/libgcov-profiler.c 
	(__gcov_interval_profiler): Ditto.
	(__gcov_pow2_profiler): Ditto.
	(__gcov_one_value_profiler_body): Ditto.
	(__gcov_one_value_profiler): Ditto.
	(__gcov_indirect_call_profiler): Ditto.
	(__gcov_indirect_call_profiler_v2): Ditto.
	(__gcov_time_profiler): Ditto.
	(__gcov_average_profiler): Ditto.
	(__gcov_ior_profiler): Ditto.
	* libgcc/libgcov-driver.c (set_gcov_list): New.
	(get_gcov_dump_complete): Ditto.
	(set_gcov_dump_complete):Ditto.
	(reset_gcov_dump_complete):Ditto.
	(gcov_exit_compute_summary): New function split from gcov_exit().
	(gcov_exit_merge_gcda): Ditto.
	(gcov_exit_write_gcda): Ditto.
	(gcov_exit_merge_summary): Ditto.
	(gcov_exit_dump_gcov): Ditto.
	(struct gcov_fn_buffer): Moved from libgcov.c
	(struct gcov_summary_buffer): Ditto.
	(free_fn_data): Ditto.
	(buffer_fn_data): Ditto.
	(crc32_unsigned): Ditto.
	(gcov_version): Ditto.
	(gcov_histogram_insert): Ditto.
	(gcov_compute_histogram): Ditto.
	(gcov_exit): Ditto.
	(gcov_clear): Ditto.
	(__gcov_init): Ditto.
        (this_prg): Make it file scope static variable.
        (all_prg): Ditto.
        (crc32): Ditto.
        (gi_filename): Ditto.
        (fn_buffer): Ditto.
        (sum_buffer): Ditto.
        (struct gcov_filename_aux): New types to store auxiliary information
        for gi_filename.
	* libgcc/libgcov-driver-system.c (gcov_error): New utility function.
	(allocate_filename_struct): New function split from gcov_exit().
	(gcov_exit_open_gcda_file): Ditto.
	(create_file_directory): Moved from libgcov.c
	* libgcc/Makefile.in: Change to build newly added files.

From-SVN: r204730

gcc/gcov-io.h

@@ -519,6 +519,8 @@ extern void __gcov_merge_time_profile (gcov_type *, unsigned) ATTRIBUTE_HIDDEN;
 extern void __gcov_interval_profiler (gcov_type *, gcov_type, int, unsigned);
 extern void __gcov_pow2_profiler (gcov_type *, gcov_type);
 extern void __gcov_one_value_profiler (gcov_type *, gcov_type);
+extern void __gcov_indirect_call_profiler (gcov_type*, gcov_type,
+                                           void*, void*);
 extern void __gcov_indirect_call_profiler_v2 (gcov_type, void *);
 extern void __gcov_average_profiler (gcov_type *, gcov_type);
 extern void __gcov_ior_profiler (gcov_type *, gcov_type);

libgcc/Makefile.in

@@ -852,18 +852,31 @@ include $(iterator)
 
 # Build libgcov components.
 
-# Defined in libgcov.c, included only in gcov library
-LIBGCOV = _gcov _gcov_merge_add _gcov_merge_single _gcov_merge_delta \
-    _gcov_fork _gcov_execl _gcov_execlp _gcov_execle \
-    _gcov_execv _gcov_execvp _gcov_execve _gcov_reset _gcov_dump \
-    _gcov_interval_profiler _gcov_pow2_profiler _gcov_one_value_profiler \
+LIBGCOV_MERGE = _gcov_merge_add _gcov_merge_single _gcov_merge_delta _gcov_merge_ior \
+     _gcov_merge_time_profile
+LIBGCOV_PROFILER = _gcov_interval_profiler _gcov_pow2_profiler _gcov_one_value_profiler \
     _gcov_indirect_call_profiler _gcov_average_profiler _gcov_ior_profiler \
-    _gcov_merge_ior _gcov_time_profiler _gcov_indirect_call_profiler_v2 _gcov_merge_time_profile
-
-libgcov-objects = $(patsubst %,%$(objext),$(LIBGCOV))
-
-$(libgcov-objects): %$(objext): $(srcdir)/libgcov.c
-	$(gcc_compile) -DL$* -c $(srcdir)/libgcov.c
+    _gcov_indirect_call_profiler_v2 _gcov_time_profiler
+LIBGCOV_INTERFACE = _gcov_flush _gcov_fork _gcov_execl _gcov_execlp _gcov_execle \
+    _gcov_execv _gcov_execvp _gcov_execve _gcov_reset _gcov_dump
+LIBGCOV_DRIVER = _gcov 
+
+libgcov-merge-objects = $(patsubst %,%$(objext),$(LIBGCOV_MERGE))
+libgcov-profiler-objects = $(patsubst %,%$(objext),$(LIBGCOV_PROFILER))
+libgcov-interface-objects = $(patsubst %,%$(objext),$(LIBGCOV_INTERFACE))
+libgcov-driver-objects = $(patsubst %,%$(objext),$(LIBGCOV_DRIVER))
+libgcov-objects = $(libgcov-merge-objects) $(libgcov-profiler-objects) \
+                 $(libgcov-interface-objects) $(libgcov-driver-objects)
+
+$(libgcov-merge-objects): %$(objext): $(srcdir)/libgcov-merge.c
+	$(gcc_compile) -DL$* -c $(srcdir)/libgcov-merge.c
+$(libgcov-profiler-objects): %$(objext): $(srcdir)/libgcov-profiler.c
+	$(gcc_compile) -DL$* -c $(srcdir)/libgcov-profiler.c
+$(libgcov-interface-objects): %$(objext): $(srcdir)/libgcov-interface.c
+	$(gcc_compile) -DL$* -c $(srcdir)/libgcov-interface.c
+$(libgcov-driver-objects): %$(objext): $(srcdir)/libgcov-driver.c \
+  $(srcdir)/libgcov-driver-system.c
+	$(gcc_compile) -DL$* -c $(srcdir)/libgcov-driver.c
 
 
 # Static libraries.

libgcc/libgcov-driver-system.c

+/* Routines required for instrumenting a program.  */
+/* Compile this one with gcc.  */
+/* Copyright (C) 1989-2013 Free Software Foundation, Inc.
+
+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/>.  */
+
+/* A utility function for outputing errors.  */
+
+static int __attribute__((format(printf, 1, 2)))
+gcov_error (const char *fmt, ...)
+{
+  int ret;
+  va_list argp;
+  va_start (argp, fmt);
+  ret = vfprintf (stderr, fmt, argp);
+  va_end (argp);
+  return ret;
+}
+
+/* Make sure path component of the given FILENAME exists, create
+   missing directories. FILENAME must be writable.
+   Returns zero on success, or -1 if an error occurred.  */
+
+static int
+create_file_directory (char *filename)
+{
+#if !defined(TARGET_POSIX_IO) && !defined(_WIN32)
+  (void) filename;
+  return -1;
+#else
+  char *s;
+
+  s = filename;
+
+  if (HAS_DRIVE_SPEC(s))
+    s += 2;
+  if (IS_DIR_SEPARATOR(*s))
+    ++s;
+  for (; *s != '\0'; s++)
+    if (IS_DIR_SEPARATOR(*s))
+      {
+        char sep = *s;
+        *s  = '\0';
+
+        /* Try to make directory if it doesn't already exist.  */
+        if (access (filename, F_OK) == -1
+#ifdef TARGET_POSIX_IO
+            && mkdir (filename, 0755) == -1
+#else
+            && mkdir (filename) == -1
+#endif
+            /* The directory might have been made by another process.  */
+            && errno != EEXIST)
+          {
+            gcov_error ("profiling:%s:Cannot create directory\n", filename);
+            *s = sep;
+            return -1;
+          };
+
+        *s = sep;
+      };
+  return 0;
+#endif
+}
+
+static void
+allocate_filename_struct (struct gcov_filename_aux *gf)
+{
+  const char *gcov_prefix;
+  int gcov_prefix_strip = 0;
+  size_t prefix_length;
+  char *gi_filename_up;
+
+  gcc_assert (gf);
+  {
+    /* Check if the level of dirs to strip off specified. */
+    char *tmp = getenv("GCOV_PREFIX_STRIP");
+    if (tmp)
+      {
+        gcov_prefix_strip = atoi (tmp);
+        /* Do not consider negative values. */
+        if (gcov_prefix_strip < 0)
+          gcov_prefix_strip = 0;
+      }
+  }
+
+  /* Get file name relocation prefix.  Non-absolute values are ignored. */
+  gcov_prefix = getenv("GCOV_PREFIX");
+  if (gcov_prefix)
+    {
+      prefix_length = strlen(gcov_prefix);
+
+      /* Remove an unnecessary trailing '/' */
+      if (IS_DIR_SEPARATOR (gcov_prefix[prefix_length - 1]))
+        prefix_length--;
+    }
+  else
+    prefix_length = 0;
+
+  /* If no prefix was specified and a prefix stip, then we assume
+     relative.  */
+  if (gcov_prefix_strip != 0 && prefix_length == 0)
+    {
+      gcov_prefix = ".";
+      prefix_length = 1;
+    }
+  /* Allocate and initialize the filename scratch space plus one.  */
+  gi_filename = (char *) malloc (prefix_length + gcov_max_filename + 2);
+  if (prefix_length)
+    memcpy (gi_filename, gcov_prefix, prefix_length);
+  gi_filename_up = gi_filename + prefix_length;
+
+  gf->gi_filename_up = gi_filename_up;
+  gf->prefix_length = prefix_length;
+  gf->gcov_prefix_strip = gcov_prefix_strip;
+}
+
+/* Open a gcda file specified by GI_FILENAME.
+   Return -1 on error.  Return 0 on success.  */
+
+static int
+gcov_exit_open_gcda_file (struct gcov_info *gi_ptr, struct gcov_filename_aux *gf)
+{
+  int gcov_prefix_strip;
+  size_t prefix_length;
+  char *gi_filename_up;
+  const char *fname, *s;
+
+  gcov_prefix_strip = gf->gcov_prefix_strip;
+  gi_filename_up = gf->gi_filename_up;
+  prefix_length = gf->prefix_length;
+  fname = gi_ptr->filename;
+
+  /* Avoid to add multiple drive letters into combined path.  */
+  if (prefix_length != 0 && HAS_DRIVE_SPEC(fname))
+    fname += 2;
+
+  /* Build relocated filename, stripping off leading
+     directories from the initial filename if requested. */
+  if (gcov_prefix_strip > 0)
+    {
+      int level = 0;
+
+      s = fname;
+      if (IS_DIR_SEPARATOR(*s))
+        ++s;
+
+      /* Skip selected directory levels. */
+      for (; (*s != '\0') && (level < gcov_prefix_strip); s++)
+        if (IS_DIR_SEPARATOR(*s))
+          {
+            fname = s;
+            level++;
+          }
+    }
+
+  /* Update complete filename with stripped original. */
+  if (prefix_length != 0 && !IS_DIR_SEPARATOR (*fname))
+    {
+      /* If prefix is given, add directory separator.  */
+      strcpy (gi_filename_up, "/");
+      strcpy (gi_filename_up + 1, fname);
+    }
+  else
+    strcpy (gi_filename_up, fname);
+
+  if (!gcov_open (gi_filename))
+    {
+      /* Open failed likely due to missed directory.
+         Create directory and retry to open file. */
+      if (create_file_directory (gi_filename))
+        {
+          fprintf (stderr, "profiling:%s:Skip\n", gi_filename);
+          return -1;
+        }
+      if (!gcov_open (gi_filename))
+        {
+          fprintf (stderr, "profiling:%s:Cannot open\n", gi_filename);
+          return -1;
+        }
+    }
+
+  return 0;
+}

libgcc/libgcov.c → libgcc/libgcov-driver.c

@@ -28,7 +28,6 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 #include "coretypes.h"
 #include "tm.h"
 #include "libgcc_tm.h"
-#include "gthr.h"
 
 #if defined(inhibit_libc)
 #define IN_LIBGCOV (-1)
@@ -43,35 +42,11 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 #if defined(inhibit_libc)
 /* If libc and its header files are not available, provide dummy functions.  */
 
-#ifdef L_gcov
+#if defined(L_gcov)
 void __gcov_init (struct gcov_info *p __attribute__ ((unused))) {}
-void __gcov_flush (void) {}
-#endif
-
-#ifdef L_gcov_reset
-void __gcov_reset (void) {}
-#endif
-
-#ifdef L_gcov_dump
-void __gcov_dump (void) {}
-#endif
-
-#ifdef L_gcov_merge_add
-void __gcov_merge_add (gcov_type *counters  __attribute__ ((unused)),
-		       unsigned n_counters __attribute__ ((unused))) {}
-#endif
-
-#ifdef L_gcov_merge_single
-void __gcov_merge_single (gcov_type *counters  __attribute__ ((unused)),
-			  unsigned n_counters __attribute__ ((unused))) {}
-#endif
-
-#ifdef L_gcov_merge_delta
-void __gcov_merge_delta (gcov_type *counters  __attribute__ ((unused)),
-			 unsigned n_counters __attribute__ ((unused))) {}
 #endif
 
-#else
+#else /* inhibit_libc */
 
 #include <string.h>
 #if GCOV_LOCKED
@@ -80,14 +55,17 @@ void __gcov_merge_delta (gcov_type *counters  __attribute__ ((unused)),
 #include <sys/stat.h>
 #endif
 
-extern gcov_type function_counter ATTRIBUTE_HIDDEN;
-extern void gcov_clear (void) ATTRIBUTE_HIDDEN;
-extern void gcov_exit (void) ATTRIBUTE_HIDDEN;
-extern int gcov_dump_complete ATTRIBUTE_HIDDEN;
-
 #ifdef L_gcov
 #include "gcov-io.c"
 
+/* The following functions can be called from outside of this file.  */
+extern void gcov_clear (void) ATTRIBUTE_HIDDEN;
+extern void gcov_exit (void) ATTRIBUTE_HIDDEN;
+extern void set_gcov_dump_complete (void) ATTRIBUTE_HIDDEN;
+extern void reset_gcov_dump_complete (void) ATTRIBUTE_HIDDEN;
+extern int get_gcov_dump_complete (void) ATTRIBUTE_HIDDEN;
+extern void set_gcov_list (struct gcov_info *) ATTRIBUTE_HIDDEN;
+
 struct gcov_fn_buffer
 {
   struct gcov_fn_buffer *next;
@@ -105,66 +83,55 @@ struct gcov_summary_buffer
 /* Chain of per-object gcov structures.  */
 static struct gcov_info *gcov_list;
 
+/* Set the head of gcov_list.  */
+void
+set_gcov_list (struct gcov_info *head)
+{
+  gcov_list = head;
+}
+
 /* Size of the longest file name. */
 static size_t gcov_max_filename = 0;
 
 /* Flag when the profile has already been dumped via __gcov_dump().  */
-int gcov_dump_complete = 0;
+static int gcov_dump_complete;
 
-/* Make sure path component of the given FILENAME exists, create
-   missing directories. FILENAME must be writable.
-   Returns zero on success, or -1 if an error occurred.  */
+/* A global functino that get the vaule of gcov_dump_complete.  */
 
-static int
-create_file_directory (char *filename)
+int
+get_gcov_dump_complete (void)
 {
-#if !defined(TARGET_POSIX_IO) && !defined(_WIN32)
-  (void) filename;
-  return -1;
-#else
-  char *s;
-
-  s = filename;
-
-  if (HAS_DRIVE_SPEC(s))
-    s += 2;
-  if (IS_DIR_SEPARATOR(*s))
-    ++s;
-  for (; *s != '\0'; s++)
-    if (IS_DIR_SEPARATOR(*s))
-      {
-        char sep = *s;
-	*s  = '\0';
-
-        /* Try to make directory if it doesn't already exist.  */
-        if (access (filename, F_OK) == -1
-#ifdef TARGET_POSIX_IO
-            && mkdir (filename, 0755) == -1
-#else
-            && mkdir (filename) == -1
-#endif
-            /* The directory might have been made by another process.  */
-	    && errno != EEXIST)
-	  {
-            fprintf (stderr, "profiling:%s:Cannot create directory\n",
-		     filename);
-            *s = sep;
-	    return -1;
-	  };
-
-	*s = sep;
-      };
-  return 0;
-#endif
+  return gcov_dump_complete;
+}
+
+/* A global functino that set the vaule of gcov_dump_complete. Will
+   be used in __gcov_dump() in libgcov-interface.c.  */
+
+void
+set_gcov_dump_complete (void)
+{
+  gcov_dump_complete = 1;
 }
 
+/* A global functino that set the vaule of gcov_dump_complete. Will
+   be used in __gcov_reset() in libgcov-interface.c.  */
+
+void
+reset_gcov_dump_complete (void)
+{
+  gcov_dump_complete = 0;
+}
+
+/* A utility function for outputing errors.  */
+static int gcov_error (const char *, ...);
+
 static struct gcov_fn_buffer *
 free_fn_data (const struct gcov_info *gi_ptr, struct gcov_fn_buffer *buffer,
-	      unsigned limit)
+              unsigned limit)
 {
   struct gcov_fn_buffer *next;
   unsigned ix, n_ctr = 0;
-  
+
   if (!buffer)
     return 0;
   next = buffer->next;
@@ -175,10 +142,10 @@ free_fn_data (const struct gcov_info *gi_ptr, struct gcov_fn_buffer *buffer,
   free (buffer);
   return next;
 }
-  
+
 static struct gcov_fn_buffer **
 buffer_fn_data (const char *filename, const struct gcov_info *gi_ptr,
-		struct gcov_fn_buffer **end_ptr, unsigned fn_ix)
+                struct gcov_fn_buffer **end_ptr, unsigned fn_ix)
 {
   unsigned n_ctrs = 0, ix = 0;
   struct gcov_fn_buffer *fn_buffer;
@@ -193,7 +160,7 @@ buffer_fn_data (const char *filename, const struct gcov_info *gi_ptr,
 
   if (!fn_buffer)
     goto fail;
-  
+
   fn_buffer->next = 0;
   fn_buffer->fn_ix = fn_ix;
   fn_buffer->info.ident = gcov_read_unsigned ();
@@ -206,34 +173,34 @@ buffer_fn_data (const char *filename, const struct gcov_info *gi_ptr,
       gcov_type *values;
 
       if (!gi_ptr->merge[ix])
-	continue;
-      
+        continue;
+
       if (gcov_read_unsigned () != GCOV_TAG_FOR_COUNTER (ix))
-	{
-	  len = 0;
-	  goto fail;
-	}
+        {
+          len = 0;
+          goto fail;
+        }
 
       length = GCOV_TAG_COUNTER_NUM (gcov_read_unsigned ());
       len = length * sizeof (gcov_type);
       values = (gcov_type *)malloc (len);
       if (!values)
-	goto fail;
-      
+        goto fail;
+
       fn_buffer->info.ctrs[n_ctrs].num = length;
       fn_buffer->info.ctrs[n_ctrs].values = values;
 
       while (length--)
-	*values++ = gcov_read_counter ();
+        *values++ = gcov_read_counter ();
       n_ctrs++;
     }
-  
+
   *end_ptr = fn_buffer;
   return &fn_buffer->next;
 
- fail:
-  fprintf (stderr, "profiling:%s:Function %u %s %u \n", filename, fn_ix,
-	   len ? "cannot allocate" : "counter mismatch", len ? len : ix);
+fail:
+  gcov_error ("profiling:%s:Function %u %s %u \n", filename, fn_ix,
+              len ? "cannot allocate" : "counter mismatch", len ? len : ix);
 
   return (struct gcov_fn_buffer **)free_fn_data (gi_ptr, fn_buffer, ix);
 }
@@ -264,7 +231,7 @@ crc32_unsigned (gcov_unsigned_t crc32, gcov_unsigned_t value)
 
 static int
 gcov_version (struct gcov_info *ptr, gcov_unsigned_t version,
-	      const char *filename)
+              const char *filename)
 {
   if (version != GCOV_VERSION)
     {
@@ -273,9 +240,8 @@ gcov_version (struct gcov_info *ptr, gcov_unsigned_t version,
       GCOV_UNSIGNED2STRING (v, version);
       GCOV_UNSIGNED2STRING (e, GCOV_VERSION);
 
-      fprintf (stderr,
-	       "profiling:%s:Version mismatch - expected %.4s got %.4s\n",
-	       filename? filename : ptr->filename, e, v);
+      gcov_error ("profiling:%s:Version mismatch - expected %.4s got %.4s\n",
+                  filename? filename : ptr->filename, e, v);
       return 0;
     }
   return 1;
@@ -351,41 +317,35 @@ gcov_compute_histogram (struct gcov_summary *sum)
     }
 }
 
+/* summary for program.  */
+static struct gcov_summary this_prg;
+#if !GCOV_LOCKED
+/* summary for all instances of program.  */
+static struct gcov_summary all_prg;
+#endif
+/* crc32 for this program.  */
+static gcov_unsigned_t crc32;
+/* gcda filename.  */
+static char *gi_filename;
+/* buffer for the fn_data from another program.  */
+static struct gcov_fn_buffer *fn_buffer;
+/* buffer for summary from other programs to be written out. */
+static struct gcov_summary_buffer *sum_buffer;
+
+/* This funtions computes the program level summary and the histo-gram.
+   It initializes ALL_PRG, computes CRC32, and stores the summary in
+   THIS_PRG. All these three variables are file statics.  */
 
-/* Counter for first visit of each function.  */
-gcov_type function_counter;
-
-/* Dump the coverage counts. We merge with existing counts when
-   possible, to avoid growing the .da files ad infinitum. We use this
-   program's checksum to make sure we only accumulate whole program
-   statistics to the correct summary. An object file might be embedded
-   in two separate programs, and we must keep the two program
-   summaries separate.  */
-
-void
-gcov_exit (void)
+static void
+gcov_exit_compute_summary (void)
 {
   struct gcov_info *gi_ptr;
   const struct gcov_fn_info *gfi_ptr;
-  struct gcov_summary this_prg; /* summary for program.  */
-#if !GCOV_LOCKED
-  struct gcov_summary all_prg;  /* summary for all instances of program.  */
-#endif
   struct gcov_ctr_summary *cs_ptr;
   const struct gcov_ctr_info *ci_ptr;
-  unsigned t_ix;
   int f_ix;
+  unsigned t_ix;
   gcov_unsigned_t c_num;
-  const char *gcov_prefix;
-  int gcov_prefix_strip = 0;
-  size_t prefix_length;
-  char *gi_filename, *gi_filename_up;
-  gcov_unsigned_t crc32 = 0;
-
-  /* Prevent the counters from being dumped a second time on exit when the
-     application already wrote out the profile using __gcov_dump().  */
-  if (gcov_dump_complete)
-    return;
 
 #if !GCOV_LOCKED
   memset (&all_prg, 0, sizeof (all_prg));
@@ -396,1017 +356,517 @@ gcov_exit (void)
     {
       crc32 = crc32_unsigned (crc32, gi_ptr->stamp);
       crc32 = crc32_unsigned (crc32, gi_ptr->n_functions);
-      
-      for (f_ix = 0; (unsigned)f_ix != gi_ptr->n_functions; f_ix++)
-	{
-	  gfi_ptr = gi_ptr->functions[f_ix];
-
-	  if (gfi_ptr && gfi_ptr->key != gi_ptr)
-	    gfi_ptr = 0;
-	  
-	  crc32 = crc32_unsigned (crc32, gfi_ptr ? gfi_ptr->cfg_checksum : 0);
-	  crc32 = crc32_unsigned (crc32,
-				  gfi_ptr ? gfi_ptr->lineno_checksum : 0);
-	  if (!gfi_ptr)
-	    continue;
-
-	  ci_ptr = gfi_ptr->ctrs;
-	  for (t_ix = 0; t_ix != GCOV_COUNTERS_SUMMABLE; t_ix++)
-	    {
-	      if (!gi_ptr->merge[t_ix])
-		continue;
-
-	      cs_ptr = &this_prg.ctrs[t_ix];
-	      cs_ptr->num += ci_ptr->num;
-	      crc32 = crc32_unsigned (crc32, ci_ptr->num);
-	      
-	      for (c_num = 0; c_num < ci_ptr->num; c_num++)
-		{
-		  cs_ptr->sum_all += ci_ptr->values[c_num];
-		  if (cs_ptr->run_max < ci_ptr->values[c_num])
-		    cs_ptr->run_max = ci_ptr->values[c_num];
-		}
-	      ci_ptr++;
-	    }
-	}
-    }
-  gcov_compute_histogram (&this_prg);
 
-  {
-    /* Check if the level of dirs to strip off specified. */
-    char *tmp = getenv("GCOV_PREFIX_STRIP");
-    if (tmp)
-      {
-	gcov_prefix_strip = atoi (tmp);
-	/* Do not consider negative values. */
-	if (gcov_prefix_strip < 0)
-	  gcov_prefix_strip = 0;
-      }
-  }
-
-  /* Get file name relocation prefix.  Non-absolute values are ignored. */
-  gcov_prefix = getenv("GCOV_PREFIX");
-  if (gcov_prefix)
-    {
-      prefix_length = strlen(gcov_prefix);
+      for (f_ix = 0; (unsigned)f_ix != gi_ptr->n_functions; f_ix++)
+        {
+          gfi_ptr = gi_ptr->functions[f_ix];
 
-      /* Remove an unnecessary trailing '/' */
-      if (IS_DIR_SEPARATOR (gcov_prefix[prefix_length - 1]))
-	prefix_length--;
-    }
-  else
-    prefix_length = 0;
+          if (gfi_ptr && gfi_ptr->key != gi_ptr)
+            gfi_ptr = 0;
 
-  /* If no prefix was specified and a prefix stip, then we assume
-     relative.  */
-  if (gcov_prefix_strip != 0 && prefix_length == 0)
-    {
-      gcov_prefix = ".";
-      prefix_length = 1;
-    }
-  /* Allocate and initialize the filename scratch space plus one.  */
-  gi_filename = (char *) alloca (prefix_length + gcov_max_filename + 2);
-  if (prefix_length)
-    memcpy (gi_filename, gcov_prefix, prefix_length);
-  gi_filename_up = gi_filename + prefix_length;
+          crc32 = crc32_unsigned (crc32, gfi_ptr ? gfi_ptr->cfg_checksum : 0);
+          crc32 = crc32_unsigned (crc32,
+                                  gfi_ptr ? gfi_ptr->lineno_checksum : 0);
+          if (!gfi_ptr)
+            continue;
 
-  /* Now merge each file.  */
-  for (gi_ptr = gcov_list; gi_ptr; gi_ptr = gi_ptr->next)
-    {
-      unsigned n_counts;
-      struct gcov_summary prg; /* summary for this object over all
-				  program.  */
-      struct gcov_ctr_summary *cs_prg, *cs_tprg;
-#if !GCOV_LOCKED
-      struct gcov_ctr_summary *cs_all;
-#endif
-      int error = 0;
-      gcov_unsigned_t tag, length;
-      gcov_position_t summary_pos = 0;
-      gcov_position_t eof_pos = 0;
-      const char *fname, *s;
-      struct gcov_fn_buffer *fn_buffer = 0;
-      struct gcov_fn_buffer **fn_tail = &fn_buffer;
-      struct gcov_summary_buffer *next_sum_buffer, *sum_buffer = 0;
-      struct gcov_summary_buffer **sum_tail = &sum_buffer;
-
-      fname = gi_ptr->filename;
-
-      /* Avoid to add multiple drive letters into combined path.  */
-      if (prefix_length != 0 && HAS_DRIVE_SPEC(fname))
-        fname += 2;
-
-      /* Build relocated filename, stripping off leading
-         directories from the initial filename if requested. */
-      if (gcov_prefix_strip > 0)
-        {
-          int level = 0;
-          s = fname;
-          if (IS_DIR_SEPARATOR(*s))
-            ++s;
-
-          /* Skip selected directory levels. */
-	  for (; (*s != '\0') && (level < gcov_prefix_strip); s++)
-	    if (IS_DIR_SEPARATOR(*s))
-	      {
-		fname = s;
-		level++;
-	      }
-        }
+          ci_ptr = gfi_ptr->ctrs;
+          for (t_ix = 0; t_ix != GCOV_COUNTERS_SUMMABLE; t_ix++)
+            {
+              if (!gi_ptr->merge[t_ix])
+                continue;
 
-      /* Update complete filename with stripped original. */
-      if (prefix_length != 0 && !IS_DIR_SEPARATOR (*fname))
-        {
-          /* If prefix is given, add directory separator.  */
-	  strcpy (gi_filename_up, "/");
-	  strcpy (gi_filename_up + 1, fname);
-	}
-      else
-        strcpy (gi_filename_up, fname);
-
-      if (!gcov_open (gi_filename))
-	{
-	  /* Open failed likely due to missed directory.
-	     Create directory and retry to open file. */
-          if (create_file_directory (gi_filename))
-	    {
-	      fprintf (stderr, "profiling:%s:Skip\n", gi_filename);
-	      continue;
-	    }
-	  if (!gcov_open (gi_filename))
-	    {
-              fprintf (stderr, "profiling:%s:Cannot open\n", gi_filename);
-	      continue;
-	    }
-	}
+              cs_ptr = &this_prg.ctrs[t_ix];
+              cs_ptr->num += ci_ptr->num;
+              crc32 = crc32_unsigned (crc32, ci_ptr->num);
 
-      tag = gcov_read_unsigned ();
-      if (tag)
-	{
-	  /* Merge data from file.  */
-	  if (tag != GCOV_DATA_MAGIC)
-	    {
-	      fprintf (stderr, "profiling:%s:Not a gcov data file\n",
-		       gi_filename);
-	      goto read_fatal;
-	    }
-	  length = gcov_read_unsigned ();
-	  if (!gcov_version (gi_ptr, length, gi_filename))
-	    goto read_fatal;
-
-	  length = gcov_read_unsigned ();
-	  if (length != gi_ptr->stamp)
-	    /* Read from a different compilation. Overwrite the file.  */
-	    goto rewrite;
-
-	  /* Look for program summary.  */
-	  for (f_ix = 0;;)
-	    {
-	      struct gcov_summary tmp;
-	      
-	      eof_pos = gcov_position ();
-	      tag = gcov_read_unsigned ();
-	      if (tag != GCOV_TAG_PROGRAM_SUMMARY)
-		break;
-
-	      f_ix--;
-	      length = gcov_read_unsigned ();
-	      gcov_read_summary (&tmp);
-	      if ((error = gcov_is_error ()))
-		goto read_error;
-	      if (summary_pos)
+              for (c_num = 0; c_num < ci_ptr->num; c_num++)
                 {
-                  /* Save all summaries after the one that will be
-                     merged into below. These will need to be rewritten
-                     as histogram merging may change the number of non-zero
-                     histogram entries that will be emitted, and thus the
-                     size of the merged summary.  */
-                  (*sum_tail) = (struct gcov_summary_buffer *)
-                      malloc (sizeof(struct gcov_summary_buffer));
-                  (*sum_tail)->summary = tmp;
-                  (*sum_tail)->next = 0;
-                  sum_tail = &((*sum_tail)->next);
-                  goto next_summary;
+                  cs_ptr->sum_all += ci_ptr->values[c_num];
+                  if (cs_ptr->run_max < ci_ptr->values[c_num])
+                    cs_ptr->run_max = ci_ptr->values[c_num];
                 }
-	      if (tmp.checksum != crc32)
-                goto next_summary;
-	      
-	      for (t_ix = 0; t_ix != GCOV_COUNTERS_SUMMABLE; t_ix++)
-		if (tmp.ctrs[t_ix].num != this_prg.ctrs[t_ix].num)
-                  goto next_summary;
-	      prg = tmp;
-	      summary_pos = eof_pos;
-
-	    next_summary:;
-	    }
-	  
-	  /* Merge execution counts for each function.  */
-	  for (f_ix = 0; (unsigned)f_ix != gi_ptr->n_functions;
-	       f_ix++, tag = gcov_read_unsigned ())
-	    {
-	      gfi_ptr = gi_ptr->functions[f_ix];
-
-	      if (tag != GCOV_TAG_FUNCTION)
-		goto read_mismatch;
-
-	      length = gcov_read_unsigned ();
-	      if (!length)
-		/* This function did not appear in the other program.
-		   We have nothing to merge.  */
-		continue;
-
-	      if (length != GCOV_TAG_FUNCTION_LENGTH)
-		goto read_mismatch;
-	      
-	      if (!gfi_ptr || gfi_ptr->key != gi_ptr)
-		{
-		  /* This function appears in the other program.  We
-		     need to buffer the information in order to write
-		     it back out -- we'll be inserting data before
-		     this point, so cannot simply keep the data in the
-		     file.  */
-		  fn_tail = buffer_fn_data (gi_filename,
-					    gi_ptr, fn_tail, f_ix);
-		  if (!fn_tail)
-		    goto read_mismatch;
-		  continue;
-		}
-
-	      length = gcov_read_unsigned ();
-	      if (length != gfi_ptr->ident)
-		goto read_mismatch;
-	      
-	      length = gcov_read_unsigned ();
-	      if (length != gfi_ptr->lineno_checksum)
-		goto read_mismatch;
-	      
-	      length = gcov_read_unsigned ();
-	      if (length != gfi_ptr->cfg_checksum)
-		goto read_mismatch;
-	      
-	      ci_ptr = gfi_ptr->ctrs;
-	      for (t_ix = 0; t_ix < GCOV_COUNTERS; t_ix++)
-		{
-		  gcov_merge_fn merge = gi_ptr->merge[t_ix];
-
-		  if (!merge)
-		    continue;
-
-		  tag = gcov_read_unsigned ();
-		  length = gcov_read_unsigned ();
-		  if (tag != GCOV_TAG_FOR_COUNTER (t_ix)
-		      || length != GCOV_TAG_COUNTER_LENGTH (ci_ptr->num))
-		    goto read_mismatch;
-		  (*merge) (ci_ptr->values, ci_ptr->num);
-		  ci_ptr++;
-		}
-	      if ((error = gcov_is_error ()))
-		goto read_error;
-	    }
-
-	  if (tag)
-	    {
-	    read_mismatch:;
-	      fprintf (stderr, "profiling:%s:Merge mismatch for %s %u\n",
-		       gi_filename, f_ix >= 0 ? "function" : "summary",
-		       f_ix < 0 ? -1 - f_ix : f_ix);
-	      goto read_fatal;
-	    }
-	}
-      goto rewrite;
-
-    read_error:;
-      fprintf (stderr, "profiling:%s:%s merging\n", gi_filename,
-	       error < 0 ? "Overflow": "Error");
-
-      goto read_fatal;
-
-    rewrite:;
-      gcov_rewrite ();
-      if (!summary_pos)
-	{
-	  memset (&prg, 0, sizeof (prg));
-	  summary_pos = eof_pos;
-	}
-
-      /* Merge the summaries.  */
-      for (t_ix = 0; t_ix < GCOV_COUNTERS_SUMMABLE; t_ix++)
-	{
-	  cs_prg = &prg.ctrs[t_ix];
-	  cs_tprg = &this_prg.ctrs[t_ix];
-
-	  if (gi_ptr->merge[t_ix])
-	    {
-	      if (!cs_prg->runs++)
-	        cs_prg->num = cs_tprg->num;
-	      cs_prg->sum_all += cs_tprg->sum_all;
-	      if (cs_prg->run_max < cs_tprg->run_max)
-		cs_prg->run_max = cs_tprg->run_max;
-	      cs_prg->sum_max += cs_tprg->run_max;
-              if (cs_prg->runs == 1)
-                memcpy (cs_prg->histogram, cs_tprg->histogram,
-                        sizeof (gcov_bucket_type) * GCOV_HISTOGRAM_SIZE);
-              else
-                gcov_histogram_merge (cs_prg->histogram, cs_tprg->histogram);
-	    }
-	  else if (cs_prg->runs)
-	    goto read_mismatch;
-
-#if !GCOV_LOCKED
-	  cs_all = &all_prg.ctrs[t_ix];
-	  if (!cs_all->runs && cs_prg->runs)
-            {
-              cs_all->num = cs_prg->num;
-              cs_all->runs = cs_prg->runs;
-              cs_all->sum_all = cs_prg->sum_all;
-              cs_all->run_max = cs_prg->run_max;
-              cs_all->sum_max = cs_prg->sum_max;
+              ci_ptr++;
             }
-	  else if (!all_prg.checksum
-                   /* Don't compare the histograms, which may have slight
-                      variations depending on the order they were updated
-                      due to the truncating integer divides used in the
-                      merge.  */
-                   && (cs_all->num != cs_prg->num
-                       || cs_all->runs != cs_prg->runs
-                       || cs_all->sum_all != cs_prg->sum_all
-                       || cs_all->run_max != cs_prg->run_max
-                       || cs_all->sum_max != cs_prg->sum_max))
-	    {
-	      fprintf (stderr,
-                       "profiling:%s:Data file mismatch - some data files may "
-                       "have been concurrently updated without locking support\n",
-		       gi_filename);
-	      all_prg.checksum = ~0u;
-	    }
-#endif
-	}
-
-      prg.checksum = crc32;
-
-      /* Write out the data.  */
-      if (!eof_pos)
-	{
-	  gcov_write_tag_length (GCOV_DATA_MAGIC, GCOV_VERSION);
-	  gcov_write_unsigned (gi_ptr->stamp);
-	}
-
-      if (summary_pos)
-	gcov_seek (summary_pos);
-
-      /* Generate whole program statistics.  */
-      gcov_write_summary (GCOV_TAG_PROGRAM_SUMMARY, &prg);
-
-      /* Rewrite all the summaries that were after the summary we merged
-         into. This is necessary as the merged summary may have a different
-         size due to the number of non-zero histogram entries changing after
-         merging.  */
-      
-      while (sum_buffer)
-        {
-          gcov_write_summary (GCOV_TAG_PROGRAM_SUMMARY, &sum_buffer->summary);
-          next_sum_buffer = sum_buffer->next;
-          free (sum_buffer);
-          sum_buffer = next_sum_buffer;
         }
-
-      /* Write execution counts for each function.  */
-      for (f_ix = 0; (unsigned)f_ix != gi_ptr->n_functions; f_ix++)
-	{
-	  unsigned buffered = 0;
-
-	  if (fn_buffer && fn_buffer->fn_ix == (unsigned)f_ix)
-	    {
-	      /* Buffered data from another program.  */
-	      buffered = 1;
-	      gfi_ptr = &fn_buffer->info;
-	      length = GCOV_TAG_FUNCTION_LENGTH;
-	    }
-	  else
-	    {
-	      gfi_ptr = gi_ptr->functions[f_ix];
-	      if (gfi_ptr && gfi_ptr->key == gi_ptr)
-		length = GCOV_TAG_FUNCTION_LENGTH;
-	      else
-		length = 0;
-	    }
-	  
-	  gcov_write_tag_length (GCOV_TAG_FUNCTION, length);
-	  if (!length)
-	    continue;
-	  
-	  gcov_write_unsigned (gfi_ptr->ident);
-	  gcov_write_unsigned (gfi_ptr->lineno_checksum);
-	  gcov_write_unsigned (gfi_ptr->cfg_checksum);
-
-	  ci_ptr = gfi_ptr->ctrs;
-	  for (t_ix = 0; t_ix < GCOV_COUNTERS; t_ix++)
-	    {
-	      if (!gi_ptr->merge[t_ix])
-		continue;
-
-	      n_counts = ci_ptr->num;
-	      gcov_write_tag_length (GCOV_TAG_FOR_COUNTER (t_ix),
-				     GCOV_TAG_COUNTER_LENGTH (n_counts));
-	      gcov_type *c_ptr = ci_ptr->values;
-	      while (n_counts--)
-		gcov_write_counter (*c_ptr++);
-	      ci_ptr++;
-	    }
-	  if (buffered)
-	    fn_buffer = free_fn_data (gi_ptr, fn_buffer, GCOV_COUNTERS);
-	}
-
-      gcov_write_unsigned (0);
-
-    read_fatal:;
-      while (fn_buffer)
-	fn_buffer = free_fn_data (gi_ptr, fn_buffer, GCOV_COUNTERS);
-
-      if ((error = gcov_close ()))
-	  fprintf (stderr, error  < 0 ?
-		   "profiling:%s:Overflow writing\n" :
-		   "profiling:%s:Error writing\n",
-		   gi_filename);
     }
+  gcov_compute_histogram (&this_prg);
 }
 
-/* Reset all counters to zero.  */
+/* A struct that bundles all the related information about the
+   gcda filename.  */
+struct gcov_filename_aux{
+  char *gi_filename_up;
+  int gcov_prefix_strip;
+  size_t prefix_length;
+};
 
-void
-gcov_clear (void)
-{
-  const struct gcov_info *gi_ptr;
+/* Including system dependent components. */
+#include "libgcov-driver-system.c"
 
-  for (gi_ptr = gcov_list; gi_ptr; gi_ptr = gi_ptr->next)
-    {
-      unsigned f_ix;
+/* This function merges counters in GI_PTR to an existing gcda file.
+   Return 0 on success.
+   Return -1 on error. In this case, caller will goto read_fatal.  */
 
-      for (f_ix = 0; f_ix < gi_ptr->n_functions; f_ix++)
-	{
-	  unsigned t_ix;
-	  const struct gcov_fn_info *gfi_ptr = gi_ptr->functions[f_ix];
-
-	  if (!gfi_ptr || gfi_ptr->key != gi_ptr)
-	    continue;
-	  const struct gcov_ctr_info *ci_ptr = gfi_ptr->ctrs;
-	  for (t_ix = 0; t_ix != GCOV_COUNTERS; t_ix++)
-	    {
-	      if (!gi_ptr->merge[t_ix])
-		continue;
-	      
-	      memset (ci_ptr->values, 0, sizeof (gcov_type) * ci_ptr->num);
-	      ci_ptr++;
-	    }
-	}
-    }
-}
+static int
+gcov_exit_merge_gcda (struct gcov_info *gi_ptr,
+                      struct gcov_summary *prg_p,
+                      gcov_position_t *summary_pos_p,
+                      gcov_position_t *eof_pos_p)
+{
+  gcov_unsigned_t tag, length;
+  unsigned t_ix;
+  int f_ix;
+  int error = 0;
+  struct gcov_fn_buffer **fn_tail = &fn_buffer;
+  struct gcov_summary_buffer **sum_tail = &sum_buffer;
 
-/* Add a new object file onto the bb chain.  Invoked automatically
-   when running an object file's global ctors.  */
+  length = gcov_read_unsigned ();
+  if (!gcov_version (gi_ptr, length, gi_filename))
+    return -1;
 
-void
-__gcov_init (struct gcov_info *info)
-{
-  if (!info->version || !info->n_functions)
-    return;
-  if (gcov_version (info, info->version, 0))
+  length = gcov_read_unsigned ();
+  if (length != gi_ptr->stamp)
+    /* Read from a different compilation. Overwrite the file.  */
+    return 0;
+
+  /* Look for program summary.  */
+  for (f_ix = 0;;)
     {
-      size_t filename_length = strlen(info->filename);
+      struct gcov_summary tmp;
 
-      /* Refresh the longest file name information */
-      if (filename_length > gcov_max_filename)
-        gcov_max_filename = filename_length;
+      *eof_pos_p = gcov_position ();
+      tag = gcov_read_unsigned ();
+      if (tag != GCOV_TAG_PROGRAM_SUMMARY)
+        break;
+
+      f_ix--;
+      length = gcov_read_unsigned ();
+      gcov_read_summary (&tmp);
+      if ((error = gcov_is_error ()))
+        goto read_error;
+      if (*summary_pos_p)
+        {
+          /* Save all summaries after the one that will be
+             merged into below. These will need to be rewritten
+             as histogram merging may change the number of non-zero
+             histogram entries that will be emitted, and thus the
+             size of the merged summary.  */
+          (*sum_tail) = (struct gcov_summary_buffer *)
+              malloc (sizeof(struct gcov_summary_buffer));
+          (*sum_tail)->summary = tmp;
+          (*sum_tail)->next = 0;
+          sum_tail = &((*sum_tail)->next);
+          goto next_summary;
+        }
+      if (tmp.checksum != crc32)
+        goto next_summary;
 
-      if (!gcov_list)
-	atexit (gcov_exit);
+      for (t_ix = 0; t_ix != GCOV_COUNTERS_SUMMABLE; t_ix++)
+        if (tmp.ctrs[t_ix].num != this_prg.ctrs[t_ix].num)
+          goto next_summary;
+      *prg_p = tmp;
+      *summary_pos_p = *eof_pos_p;
 
-      info->next = gcov_list;
-      gcov_list = info;
+    next_summary:;
     }
-  info->version = 0;
-}
-
-#ifdef __GTHREAD_MUTEX_INIT
-ATTRIBUTE_HIDDEN __gthread_mutex_t __gcov_flush_mx = __GTHREAD_MUTEX_INIT;
-#define init_mx_once()
-#else
-__gthread_mutex_t __gcov_flush_mx ATTRIBUTE_HIDDEN;
 
-static void
-init_mx (void)
-{
-  __GTHREAD_MUTEX_INIT_FUNCTION (&__gcov_flush_mx);
-}
-static void
-init_mx_once (void)
-{
-  static __gthread_once_t once = __GTHREAD_ONCE_INIT;
-  __gthread_once (&once, init_mx);
-}
-#endif
+  /* Merge execution counts for each function.  */
+  for (f_ix = 0; (unsigned)f_ix != gi_ptr->n_functions;
+       f_ix++, tag = gcov_read_unsigned ())
+    {
+      const struct gcov_ctr_info *ci_ptr;
+      const struct gcov_fn_info *gfi_ptr = gi_ptr->functions[f_ix];
 
-/* Called before fork or exec - write out profile information gathered so
-   far and reset it to zero.  This avoids duplication or loss of the
-   profile information gathered so far.  */
+      if (tag != GCOV_TAG_FUNCTION)
+        goto read_mismatch;
 
-void
-__gcov_flush (void)
-{
-  init_mx_once ();
-  __gthread_mutex_lock (&__gcov_flush_mx);
+      length = gcov_read_unsigned ();
+      if (!length)
+        /* This function did not appear in the other program.
+           We have nothing to merge.  */
+        continue;
 
-  gcov_exit ();
-  gcov_clear ();
+      if (length != GCOV_TAG_FUNCTION_LENGTH)
+        goto read_mismatch;
 
-  __gthread_mutex_unlock (&__gcov_flush_mx);
-}
+      if (!gfi_ptr || gfi_ptr->key != gi_ptr)
+        {
+          /* This function appears in the other program.  We
+             need to buffer the information in order to write
+             it back out -- we'll be inserting data before
+             this point, so cannot simply keep the data in the
+             file.  */
+          fn_tail = buffer_fn_data (gi_filename,
+                                    gi_ptr, fn_tail, f_ix);
+          if (!fn_tail)
+            goto read_mismatch;
+          continue;
+        }
 
-#endif /* L_gcov */
+      length = gcov_read_unsigned ();
+      if (length != gfi_ptr->ident)
+        goto read_mismatch;
 
-#ifdef L_gcov_reset
+      length = gcov_read_unsigned ();
+      if (length != gfi_ptr->lineno_checksum)
+        goto read_mismatch;
 
-/* Function that can be called from application to reset counters to zero,
-   in order to collect profile in region of interest.  */
+      length = gcov_read_unsigned ();
+      if (length != gfi_ptr->cfg_checksum)
+        goto read_mismatch;
 
-void
-__gcov_reset (void)
-{
-  gcov_clear ();
-  /* Re-enable dumping to support collecting profile in multiple regions
-     of interest.  */
-  gcov_dump_complete = 0;
-}
+      ci_ptr = gfi_ptr->ctrs;
+      for (t_ix = 0; t_ix < GCOV_COUNTERS; t_ix++)
+        {
+          gcov_merge_fn merge = gi_ptr->merge[t_ix];
 
-#endif /* L_gcov_reset */
+          if (!merge)
+            continue;
 
-#ifdef L_gcov_dump
+          tag = gcov_read_unsigned ();
+          length = gcov_read_unsigned ();
+          if (tag != GCOV_TAG_FOR_COUNTER (t_ix)
+              || length != GCOV_TAG_COUNTER_LENGTH (ci_ptr->num))
+            goto read_mismatch;
+          (*merge) (ci_ptr->values, ci_ptr->num);
+          ci_ptr++;
+        }
+      if ((error = gcov_is_error ()))
+        goto read_error;
+    }
 
-/* Function that can be called from application to write profile collected
-   so far, in order to collect profile in region of interest.  */
+  if (tag)
+    {
+    read_mismatch:;
+      gcov_error ("profiling:%s:Merge mismatch for %s %u\n",
+                  gi_filename, f_ix >= 0 ? "function" : "summary",
+                  f_ix < 0 ? -1 - f_ix : f_ix);
+      return -1;
+    }
+  return 0;
 
-void
-__gcov_dump (void)
-{
-  gcov_exit ();
-  /* Prevent profile from being dumped a second time on application exit.  */
-  gcov_dump_complete = 1;
+read_error:
+  gcov_error ("profiling:%s:%s merging\n", gi_filename,
+              error < 0 ? "Overflow": "Error");
+  return -1;
 }
 
-#endif /* L_gcov_dump */
+/* Write counters in GI_PTR and the summary in PRG to a gcda file. In
+   the case of appending to an existing file, SUMMARY_POS will be non-zero.
+   We will write the file starting from SUMMAY_POS.  */
 
-#ifdef L_gcov_merge_add
-/* The profile merging function that just adds the counters.  It is given
-   an array COUNTERS of N_COUNTERS old counters and it reads the same number
-   of counters from the gcov file.  */
-void
-__gcov_merge_add (gcov_type *counters, unsigned n_counters)
-{
-  for (; n_counters; counters++, n_counters--)
-    *counters += gcov_read_counter ();
-}
-#endif /* L_gcov_merge_add */
-
-#ifdef L_gcov_merge_ior
-/* The profile merging function that just adds the counters.  It is given
-   an array COUNTERS of N_COUNTERS old counters and it reads the same number
-   of counters from the gcov file.  */
-void
-__gcov_merge_ior (gcov_type *counters, unsigned n_counters)
+static void
+gcov_exit_write_gcda (const struct gcov_info *gi_ptr,
+                      const struct gcov_summary *prg_p,
+                      const gcov_position_t eof_pos,
+                      const gcov_position_t summary_pos)
 {
-  for (; n_counters; counters++, n_counters--)
-    *counters |= gcov_read_counter ();
-}
-#endif
+  unsigned f_ix;
+  struct gcov_summary_buffer *next_sum_buffer;
 
-/* Time profiles are merged so that minimum from all valid (greater than zero)
- * is stored. There could be a fork that creates new counters. To have
- * the profile stable, we chosen to pick the smallest function visit time.  */
+  /* Write out the data.  */
+  if (!eof_pos)
+    {
+      gcov_write_tag_length (GCOV_DATA_MAGIC, GCOV_VERSION);
+      gcov_write_unsigned (gi_ptr->stamp);
+    }
 
-#ifdef L_gcov_merge_time_profile
-void
-__gcov_merge_time_profile (gcov_type *counters, unsigned n_counters)
-{
-  unsigned int i;
-  gcov_type value;
+  if (summary_pos)
+    gcov_seek (summary_pos);
 
-  for (i = 0; i < n_counters; i++)
-  {
-    value = gcov_read_counter ();
+  /* Generate whole program statistics.  */
+  gcov_write_summary (GCOV_TAG_PROGRAM_SUMMARY, prg_p);
 
-    if (value && (!counters[i] || value < counters[i]))
-      counters[i] = value;
-  }
-}
-#endif /* L_gcov_merge_time_profile */
-
-#ifdef L_gcov_merge_single
-/* The profile merging function for choosing the most common value.
-   It is given an array COUNTERS of N_COUNTERS old counters and it
-   reads the same number of counters from the gcov file.  The counters
-   are split into 3-tuples where the members of the tuple have
-   meanings:
-
-   -- the stored candidate on the most common value of the measured entity
-   -- counter
-   -- total number of evaluations of the value  */
-void
-__gcov_merge_single (gcov_type *counters, unsigned n_counters)
-{
-  unsigned i, n_measures;
-  gcov_type value, counter, all;
+  /* Rewrite all the summaries that were after the summary we merged
+     into. This is necessary as the merged summary may have a different
+     size due to the number of non-zero histogram entries changing after
+     merging.  */
 
-  gcc_assert (!(n_counters % 3));
-  n_measures = n_counters / 3;
-  for (i = 0; i < n_measures; i++, counters += 3)
+  while (sum_buffer)
     {
-      value = gcov_read_counter ();
-      counter = gcov_read_counter ();
-      all = gcov_read_counter ();
-
-      if (counters[0] == value)
-	counters[1] += counter;
-      else if (counter > counters[1])
-	{
-	  counters[0] = value;
-	  counters[1] = counter - counters[1];
-	}
-      else
-	counters[1] -= counter;
-      counters[2] += all;
+      gcov_write_summary (GCOV_TAG_PROGRAM_SUMMARY, &sum_buffer->summary);
+      next_sum_buffer = sum_buffer->next;
+      free (sum_buffer);
+      sum_buffer = next_sum_buffer;
     }
-}
-#endif /* L_gcov_merge_single */
-
-#ifdef L_gcov_merge_delta
-/* The profile merging function for choosing the most common
-   difference between two consecutive evaluations of the value.  It is
-   given an array COUNTERS of N_COUNTERS old counters and it reads the
-   same number of counters from the gcov file.  The counters are split
-   into 4-tuples where the members of the tuple have meanings:
-
-   -- the last value of the measured entity
-   -- the stored candidate on the most common difference
-   -- counter
-   -- total number of evaluations of the value  */
-void
-__gcov_merge_delta (gcov_type *counters, unsigned n_counters)
-{
-  unsigned i, n_measures;
-  gcov_type value, counter, all;
 
-  gcc_assert (!(n_counters % 4));
-  n_measures = n_counters / 4;
-  for (i = 0; i < n_measures; i++, counters += 4)
+  /* Write execution counts for each function.  */
+  for (f_ix = 0; f_ix != gi_ptr->n_functions; f_ix++)
     {
-      /* last = */ gcov_read_counter ();
-      value = gcov_read_counter ();
-      counter = gcov_read_counter ();
-      all = gcov_read_counter ();
-
-      if (counters[1] == value)
-	counters[2] += counter;
-      else if (counter > counters[2])
-	{
-	  counters[1] = value;
-	  counters[2] = counter - counters[2];
-	}
-      else
-	counters[2] -= counter;
-      counters[3] += all;
-    }
-}
-#endif /* L_gcov_merge_delta */
-
-#ifdef L_gcov_interval_profiler
-/* If VALUE is in interval <START, START + STEPS - 1>, then increases the
-   corresponding counter in COUNTERS.  If the VALUE is above or below
-   the interval, COUNTERS[STEPS] or COUNTERS[STEPS + 1] is increased
-   instead.  */
+      unsigned buffered = 0;
+      const struct gcov_fn_info *gfi_ptr;
+      const struct gcov_ctr_info *ci_ptr;
+      gcov_unsigned_t length;
+      unsigned t_ix;
 
-void
-__gcov_interval_profiler (gcov_type *counters, gcov_type value,
-			  int start, unsigned steps)
-{
-  gcov_type delta = value - start;
-  if (delta < 0)
-    counters[steps + 1]++;
-  else if (delta >= steps)
-    counters[steps]++;
-  else
-    counters[delta]++;
-}
-#endif
+      if (fn_buffer && fn_buffer->fn_ix == f_ix)
+        {
+          /* Buffered data from another program.  */
+          buffered = 1;
+          gfi_ptr = &fn_buffer->info;
+          length = GCOV_TAG_FUNCTION_LENGTH;
+        }
+      else
+        {
+          gfi_ptr = gi_ptr->functions[f_ix];
+          if (gfi_ptr && gfi_ptr->key == gi_ptr)
+            length = GCOV_TAG_FUNCTION_LENGTH;
+          else
+                length = 0;
+        }
 
-#ifdef L_gcov_pow2_profiler
-/* If VALUE is a power of two, COUNTERS[1] is incremented.  Otherwise
-   COUNTERS[0] is incremented.  */
+      gcov_write_tag_length (GCOV_TAG_FUNCTION, length);
+      if (!length)
+        continue;
 
-void
-__gcov_pow2_profiler (gcov_type *counters, gcov_type value)
-{
-  if (value & (value - 1))
-    counters[0]++;
-  else
-    counters[1]++;
-}
-#endif
+      gcov_write_unsigned (gfi_ptr->ident);
+      gcov_write_unsigned (gfi_ptr->lineno_checksum);
+      gcov_write_unsigned (gfi_ptr->cfg_checksum);
 
-/* Tries to determine the most common value among its inputs.  Checks if the
-   value stored in COUNTERS[0] matches VALUE.  If this is the case, COUNTERS[1]
-   is incremented.  If this is not the case and COUNTERS[1] is not zero,
-   COUNTERS[1] is decremented.  Otherwise COUNTERS[1] is set to one and
-   VALUE is stored to COUNTERS[0].  This algorithm guarantees that if this
-   function is called more than 50% of the time with one value, this value
-   will be in COUNTERS[0] in the end.
+      ci_ptr = gfi_ptr->ctrs;
+      for (t_ix = 0; t_ix < GCOV_COUNTERS; t_ix++)
+        {
+          gcov_unsigned_t n_counts;
+          gcov_type *c_ptr;
 
-   In any case, COUNTERS[2] is incremented.  */
+          if (!gi_ptr->merge[t_ix])
+            continue;
 
-static inline void
-__gcov_one_value_profiler_body (gcov_type *counters, gcov_type value)
-{
-  if (value == counters[0])
-    counters[1]++;
-  else if (counters[1] == 0)
-    {
-      counters[1] = 1;
-      counters[0] = value;
+          n_counts = ci_ptr->num;
+          gcov_write_tag_length (GCOV_TAG_FOR_COUNTER (t_ix),
+                                 GCOV_TAG_COUNTER_LENGTH (n_counts));
+          c_ptr = ci_ptr->values;
+          while (n_counts--)
+            gcov_write_counter (*c_ptr++);
+          ci_ptr++;
+        }
+      if (buffered)
+        fn_buffer = free_fn_data (gi_ptr, fn_buffer, GCOV_COUNTERS);
     }
-  else
-    counters[1]--;
-  counters[2]++;
-}
-
-#ifdef L_gcov_one_value_profiler
-void
-__gcov_one_value_profiler (gcov_type *counters, gcov_type value)
-{
-  __gcov_one_value_profiler_body (counters, value);
-}
-#endif
 
-#ifdef L_gcov_indirect_call_profiler
-/* This function exist only for workaround of binutils bug 14342.
-   Once this compatibility hack is obsolette, it can be removed.  */
-
-/* By default, the C++ compiler will use function addresses in the
-   vtable entries.  Setting TARGET_VTABLE_USES_DESCRIPTORS to nonzero
-   tells the compiler to use function descriptors instead.  The value
-   of this macro says how many words wide the descriptor is (normally 2),
-   but it may be dependent on target flags.  Since we do not have access
-   to the target flags here we just check to see if it is set and use
-   that to set VTABLE_USES_DESCRIPTORS to 0 or 1.
-
-   It is assumed that the address of a function descriptor may be treated
-   as a pointer to a function.  */
-
-#ifdef TARGET_VTABLE_USES_DESCRIPTORS
-#define VTABLE_USES_DESCRIPTORS 1
-#else
-#define VTABLE_USES_DESCRIPTORS 0
-#endif
-
-/* Tries to determine the most common value among its inputs. */
-void
-__gcov_indirect_call_profiler (gcov_type* counter, gcov_type value,
-                               void* cur_func, void* callee_func)
-{
-  /* If the C++ virtual tables contain function descriptors then one
-     function may have multiple descriptors and we need to dereference
-     the descriptors to see if they point to the same function.  */
-  if (cur_func == callee_func
-      || (VTABLE_USES_DESCRIPTORS && callee_func
-          && *(void **) cur_func == *(void **) callee_func))
-    __gcov_one_value_profiler_body (counter, value);
+  gcov_write_unsigned (0);
 }
 
-#endif
-#ifdef L_gcov_indirect_call_profiler_v2
+/* Helper function for merging summary.
+   Return -1 on error. Return 0 on success.  */
 
-/* These two variables are used to actually track caller and callee.  Keep
-   them in TLS memory so races are not common (they are written to often).
-   The variables are set directly by GCC instrumented code, so declaration
-   here must match one in tree-profile.c  */
-
-#if defined(HAVE_CC_TLS) && !defined (USE_EMUTLS)
-__thread 
-#endif
-void * __gcov_indirect_call_callee;
-#if defined(HAVE_CC_TLS) && !defined (USE_EMUTLS) 
-__thread 
-#endif
-gcov_type * __gcov_indirect_call_counters;
-
-/* By default, the C++ compiler will use function addresses in the
-   vtable entries.  Setting TARGET_VTABLE_USES_DESCRIPTORS to nonzero
-   tells the compiler to use function descriptors instead.  The value
-   of this macro says how many words wide the descriptor is (normally 2),
-   but it may be dependent on target flags.  Since we do not have access
-   to the target flags here we just check to see if it is set and use
-   that to set VTABLE_USES_DESCRIPTORS to 0 or 1.
-
-   It is assumed that the address of a function descriptor may be treated
-   as a pointer to a function.  */
-
-#ifdef TARGET_VTABLE_USES_DESCRIPTORS
-#define VTABLE_USES_DESCRIPTORS 1
-#else
-#define VTABLE_USES_DESCRIPTORS 0
-#endif
-
-/* Tries to determine the most common value among its inputs. */
-void
-__gcov_indirect_call_profiler_v2 (gcov_type value, void* cur_func)
+static int
+gcov_exit_merge_summary (const struct gcov_info *gi_ptr, struct gcov_summary *prg)
 {
-  /* If the C++ virtual tables contain function descriptors then one
-     function may have multiple descriptors and we need to dereference
-     the descriptors to see if they point to the same function.  */
-  if (cur_func == __gcov_indirect_call_callee
-      || (VTABLE_USES_DESCRIPTORS && __gcov_indirect_call_callee
-	  && *(void **) cur_func == *(void **) __gcov_indirect_call_callee))
-    __gcov_one_value_profiler_body (__gcov_indirect_call_counters, value);
-}
+  struct gcov_ctr_summary *cs_prg, *cs_tprg;
+#if !GCOV_LOCKED
+  struct gcov_ctr_summary *cs_all;
 #endif
+  unsigned t_ix;
 
-#ifdef L_gcov_time_profiler
+  /* Merge the summaries.  */
+  for (t_ix = 0; t_ix < GCOV_COUNTERS_SUMMABLE; t_ix++)
+    {
+      cs_prg = &(prg->ctrs[t_ix]);
+      cs_tprg = &this_prg.ctrs[t_ix];
 
-/* Sets corresponding COUNTERS if there is no value.  */
+      if (gi_ptr->merge[t_ix])
+        {
+          if (!cs_prg->runs++)
+            cs_prg->num = cs_tprg->num;
+          cs_prg->sum_all += cs_tprg->sum_all;
+          if (cs_prg->run_max < cs_tprg->run_max)
+            cs_prg->run_max = cs_tprg->run_max;
+          cs_prg->sum_max += cs_tprg->run_max;
+          if (cs_prg->runs == 1)
+            memcpy (cs_prg->histogram, cs_tprg->histogram,
+                   sizeof (gcov_bucket_type) * GCOV_HISTOGRAM_SIZE);
+          else
+            gcov_histogram_merge (cs_prg->histogram, cs_tprg->histogram);
+        }
+      else if (cs_prg->runs)
+        {
+          gcov_error ("profiling:%s:Merge mismatch for summary.\n",
+                      gi_filename);
+          return -1;
+        }
 
-void
-__gcov_time_profiler (gcov_type* counters)
-{
-  if (!counters[0])
-    counters[0] = ++function_counter;
-}
+#if !GCOV_LOCKED
+      cs_all = &all_prg.ctrs[t_ix];
+      if (!cs_all->runs && cs_prg->runs)
+        {
+          cs_all->num = cs_prg->num;
+          cs_all->runs = cs_prg->runs;
+          cs_all->sum_all = cs_prg->sum_all;
+          cs_all->run_max = cs_prg->run_max;
+          cs_all->sum_max = cs_prg->sum_max;
+        }
+      else if (!all_prg.checksum
+               /* Don't compare the histograms, which may have slight
+                  variations depending on the order they were updated
+                  due to the truncating integer divides used in the
+                  merge.  */
+               && (cs_all->num != cs_prg->num
+                   || cs_all->runs != cs_prg->runs
+                   || cs_all->sum_all != cs_prg->sum_all
+                   || cs_all->run_max != cs_prg->run_max
+                   || cs_all->sum_max != cs_prg->sum_max))
+             {
+               gcov_error ("profiling:%s:Data file mismatch - some "
+                           "data files may have been concurrently "
+                           "updated without locking support\n", gi_filename);
+               all_prg.checksum = ~0u;
+             }
 #endif
+    }
 
-#ifdef L_gcov_average_profiler
-/* Increase corresponding COUNTER by VALUE.  FIXME: Perhaps we want
-   to saturate up.  */
+  prg->checksum = crc32;
 
-void
-__gcov_average_profiler (gcov_type *counters, gcov_type value)
-{
-  counters[0] += value;
-  counters[1] ++;
+  return 0;
 }
-#endif
 
-#ifdef L_gcov_ior_profiler
-/* Bitwise-OR VALUE into COUNTER.  */
+/* Dump the coverage counts for one gcov_info object. We merge with existing
+   counts when possible, to avoid growing the .da files ad infinitum. We use
+   this program's checksum to make sure we only accumulate whole program
+   statistics to the correct summary. An object file might be embedded
+   in two separate programs, and we must keep the two program
+   summaries separate.  */
 
-void
-__gcov_ior_profiler (gcov_type *counters, gcov_type value)
+static void
+gcov_exit_dump_gcov (struct gcov_info *gi_ptr, struct gcov_filename_aux *gf)
 {
-  *counters |= value;
-}
-#endif
+  struct gcov_summary prg; /* summary for this object over all program.  */
+  int error;
+  gcov_unsigned_t tag;
+  gcov_position_t summary_pos = 0;
+  gcov_position_t eof_pos = 0;
 
-#ifdef L_gcov_fork
-/* A wrapper for the fork function.  Flushes the accumulated profiling data, so
-   that they are not counted twice.  */
+  fn_buffer = 0;
+  sum_buffer = 0;
 
-pid_t
-__gcov_fork (void)
-{
-  pid_t pid;
-  extern __gthread_mutex_t __gcov_flush_mx;
-  __gcov_flush ();
-  pid = fork ();
-  if (pid == 0)
-    __GTHREAD_MUTEX_INIT_FUNCTION (&__gcov_flush_mx);
-  return pid;
-}
-#endif
+  error = gcov_exit_open_gcda_file (gi_ptr, gf);
+  if (error == -1)
+    return;
 
-#ifdef L_gcov_execl
-/* A wrapper for the execl function.  Flushes the accumulated profiling data, so
-   that they are not lost.  */
+  tag = gcov_read_unsigned ();
+  if (tag)
+    {
+      /* Merge data from file.  */
+      if (tag != GCOV_DATA_MAGIC)
+        {
+          gcov_error ("profiling:%s:Not a gcov data file\n", gi_filename);
+          goto read_fatal;
+        }
+      error = gcov_exit_merge_gcda (gi_ptr, &prg, &summary_pos, &eof_pos);
+      if (error == -1)
+        goto read_fatal;
+    }
 
-int
-__gcov_execl (const char *path, char *arg, ...)
-{
-  va_list ap, aq;
-  unsigned i, length;
-  char **args;
+  gcov_rewrite ();
 
-  __gcov_flush ();
+  if (!summary_pos)
+    {
+      memset (&prg, 0, sizeof (prg));
+      summary_pos = eof_pos;
+    }
 
-  va_start (ap, arg);
-  va_copy (aq, ap);
+  error = gcov_exit_merge_summary (gi_ptr, &prg);
+  if (error == -1)
+    goto read_fatal;
 
-  length = 2;
-  while (va_arg (ap, char *))
-    length++;
-  va_end (ap);
+  gcov_exit_write_gcda (gi_ptr, &prg, eof_pos, summary_pos);
+  /* fall through */
 
-  args = (char **) alloca (length * sizeof (void *));
-  args[0] = arg;
-  for (i = 1; i < length; i++)
-    args[i] = va_arg (aq, char *);
-  va_end (aq);
+read_fatal:;
+  while (fn_buffer)
+    fn_buffer = free_fn_data (gi_ptr, fn_buffer, GCOV_COUNTERS);
 
-  return execv (path, args);
+  if ((error = gcov_close ()))
+    gcov_error (error  < 0 ?
+                "profiling:%s:Overflow writing\n" :
+                "profiling:%s:Error writing\n",
+                gi_filename);
 }
-#endif
 
-#ifdef L_gcov_execlp
-/* A wrapper for the execlp function.  Flushes the accumulated profiling data, so
-   that they are not lost.  */
 
-int
-__gcov_execlp (const char *path, char *arg, ...)
+/* Dump all the coverage counts for the program. It first computes program
+   summary and then traverses gcov_list list and dumps the gcov_info
+   objects one by one.  */
+
+void
+gcov_exit (void)
 {
-  va_list ap, aq;
-  unsigned i, length;
-  char **args;
+  struct gcov_info *gi_ptr;
+  struct gcov_filename_aux gf;
 
-  __gcov_flush ();
+  /* Prevent the counters from being dumped a second time on exit when the
+     application already wrote out the profile using __gcov_dump().  */
+  if (gcov_dump_complete)
+    return;
 
-  va_start (ap, arg);
-  va_copy (aq, ap);
+  gcov_exit_compute_summary ();
 
-  length = 2;
-  while (va_arg (ap, char *))
-    length++;
-  va_end (ap);
+  allocate_filename_struct (&gf);
 
-  args = (char **) alloca (length * sizeof (void *));
-  args[0] = arg;
-  for (i = 1; i < length; i++)
-    args[i] = va_arg (aq, char *);
-  va_end (aq);
+  /* Now merge each file.  */
+  for (gi_ptr = gcov_list; gi_ptr; gi_ptr = gi_ptr->next)
+    gcov_exit_dump_gcov (gi_ptr, &gf);
 
-  return execvp (path, args);
+  if (gi_filename)
+    free (gi_filename);
 }
-#endif
 
-#ifdef L_gcov_execle
-/* A wrapper for the execle function.  Flushes the accumulated profiling data, so
-   that they are not lost.  */
+/* Reset all counters to zero.  */
 
-int
-__gcov_execle (const char *path, char *arg, ...)
+void
+gcov_clear (void)
 {
-  va_list ap, aq;
-  unsigned i, length;
-  char **args;
-  char **envp;
-
-  __gcov_flush ();
+  const struct gcov_info *gi_ptr;
 
-  va_start (ap, arg);
-  va_copy (aq, ap);
+  for (gi_ptr = gcov_list; gi_ptr; gi_ptr = gi_ptr->next)
+    {
+      unsigned f_ix;
 
-  length = 2;
-  while (va_arg (ap, char *))
-    length++;
-  va_end (ap);
+      for (f_ix = 0; f_ix < gi_ptr->n_functions; f_ix++)
+        {
+          unsigned t_ix;
+          const struct gcov_fn_info *gfi_ptr = gi_ptr->functions[f_ix];
 
-  args = (char **) alloca (length * sizeof (void *));
-  args[0] = arg;
-  for (i = 1; i < length; i++)
-    args[i] = va_arg (aq, char *);
-  envp = va_arg (aq, char **);
-  va_end (aq);
+          if (!gfi_ptr || gfi_ptr->key != gi_ptr)
+            continue;
+          const struct gcov_ctr_info *ci_ptr = gfi_ptr->ctrs;
+          for (t_ix = 0; t_ix != GCOV_COUNTERS; t_ix++)
+            {
+              if (!gi_ptr->merge[t_ix])
+                continue;
 
-  return execve (path, args, envp);
+              memset (ci_ptr->values, 0, sizeof (gcov_type) * ci_ptr->num);
+              ci_ptr++;
+            }
+        }
+    }
 }
-#endif
 
-#ifdef L_gcov_execv
-/* A wrapper for the execv function.  Flushes the accumulated profiling data, so
-   that they are not lost.  */
+/* Add a new object file onto the bb chain.  Invoked automatically
+  when running an object file's global ctors.  */
 
-int
-__gcov_execv (const char *path, char *const argv[])
+void
+__gcov_init (struct gcov_info *info)
 {
-  __gcov_flush ();
-  return execv (path, argv);
-}
-#endif
-
-#ifdef L_gcov_execvp
-/* A wrapper for the execvp function.  Flushes the accumulated profiling data, so
-   that they are not lost.  */
+  if (!info->version || !info->n_functions)
+    return;
+  if (gcov_version (info, info->version, 0))
+    {
+      size_t filename_length = strlen(info->filename);
 
-int
-__gcov_execvp (const char *path, char *const argv[])
-{
-  __gcov_flush ();
-  return execvp (path, argv);
-}
-#endif
+      /* Refresh the longest file name information */
+      if (filename_length > gcov_max_filename)
+        gcov_max_filename = filename_length;
 
-#ifdef L_gcov_execve
-/* A wrapper for the execve function.  Flushes the accumulated profiling data, so
-   that they are not lost.  */
+      if (!gcov_list)
+        atexit (gcov_exit);
 
-int
-__gcov_execve (const char *path, char *const argv[], char *const envp[])
-{
-  __gcov_flush ();
-  return execve (path, argv, envp);
+      info->next = gcov_list;
+      gcov_list = info;
+    }
+  info->version = 0;
 }
-#endif
+
+#endif /* L_gcov */
 #endif /* inhibit_libc */

libgcc/libgcov-interface.c

+/* Routines required for instrumenting a program.  */
+/* Compile this one with gcc.  */
+/* Copyright (C) 1989-2013 Free Software Foundation, Inc.
+
+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/>.  */
+
+#include "tconfig.h"
+#include "tsystem.h"
+#include "coretypes.h"
+#include "tm.h"
+#include "libgcc_tm.h"
+#include "gthr.h"
+
+#if defined(inhibit_libc)
+#define IN_LIBGCOV (-1)
+#else
+#define IN_LIBGCOV 1
+#endif
+#include "gcov-io.h"
+
+#if defined(inhibit_libc)
+
+#ifdef L_gcov_flush
+void __gcov_flush (void) {}
+#endif
+
+#ifdef L_gcov_reset
+void __gcov_reset (void) {}
+#endif
+
+#ifdef L_gcov_dump
+void __gcov_dump (void) {}
+#endif
+
+#else
+
+extern void gcov_clear (void) ATTRIBUTE_HIDDEN;
+extern void gcov_exit (void) ATTRIBUTE_HIDDEN;
+extern void set_gcov_dump_complete (void) ATTRIBUTE_HIDDEN;
+extern void reset_gcov_dump_complete (void) ATTRIBUTE_HIDDEN;
+
+#ifdef L_gcov_flush
+
+#ifdef __GTHREAD_MUTEX_INIT
+ATTRIBUTE_HIDDEN __gthread_mutex_t __gcov_flush_mx = __GTHREAD_MUTEX_INIT;
+#define init_mx_once()
+#else
+__gthread_mutex_t __gcov_flush_mx ATTRIBUTE_HIDDEN;
+
+static void
+init_mx (void)
+{
+  __GTHREAD_MUTEX_INIT_FUNCTION (&__gcov_flush_mx);
+}
+static void
+init_mx_once (void)
+{
+  static __gthread_once_t once = __GTHREAD_ONCE_INIT;
+  __gthread_once (&once, init_mx);
+}
+#endif
+
+/* Called before fork or exec - write out profile information gathered so
+   far and reset it to zero.  This avoids duplication or loss of the
+   profile information gathered so far.  */
+
+void
+__gcov_flush (void)
+{
+  init_mx_once ();
+  __gthread_mutex_lock (&__gcov_flush_mx);
+
+  gcov_exit ();
+  gcov_clear ();
+
+  __gthread_mutex_unlock (&__gcov_flush_mx);
+}
+
+#endif /* L_gcov_flush */
+
+#ifdef L_gcov_reset
+
+/* Function that can be called from application to reset counters to zero,
+   in order to collect profile in region of interest.  */
+
+void
+__gcov_reset (void)
+{
+  gcov_clear ();
+  /* Re-enable dumping to support collecting profile in multiple regions
+     of interest.  */
+  reset_gcov_dump_complete ();
+}
+
+#endif /* L_gcov_reset */
+
+#ifdef L_gcov_dump
+
+/* Function that can be called from application to write profile collected
+   so far, in order to collect profile in region of interest.  */
+
+void
+__gcov_dump (void)
+{
+  gcov_exit ();
+  /* Prevent profile from being dumped a second time on application exit.  */
+  set_gcov_dump_complete ();
+}
+
+#endif /* L_gcov_dump */
+
+
+#ifdef L_gcov_fork
+/* A wrapper for the fork function.  Flushes the accumulated profiling data, so
+   that they are not counted twice.  */
+
+pid_t
+__gcov_fork (void)
+{
+  pid_t pid;
+  extern __gthread_mutex_t __gcov_flush_mx;
+  __gcov_flush ();
+  pid = fork ();
+  if (pid == 0)
+    __GTHREAD_MUTEX_INIT_FUNCTION (&__gcov_flush_mx);
+  return pid;
+}
+#endif
+
+#ifdef L_gcov_execl
+/* A wrapper for the execl function.  Flushes the accumulated profiling data, so
+   that they are not lost.  */
+
+int
+__gcov_execl (const char *path, char *arg, ...)
+{
+  va_list ap, aq;
+  unsigned i, length;
+  char **args;
+
+  __gcov_flush ();
+
+  va_start (ap, arg);
+  va_copy (aq, ap);
+
+  length = 2;
+  while (va_arg (ap, char *))
+    length++;
+  va_end (ap);
+
+  args = (char **) alloca (length * sizeof (void *));
+  args[0] = arg;
+  for (i = 1; i < length; i++)
+    args[i] = va_arg (aq, char *);
+  va_end (aq);
+
+  return execv (path, args);
+}
+#endif
+
+#ifdef L_gcov_execlp
+/* A wrapper for the execlp function.  Flushes the accumulated profiling data, so
+   that they are not lost.  */
+
+int
+__gcov_execlp (const char *path, char *arg, ...)
+{
+  va_list ap, aq;
+  unsigned i, length;
+  char **args;
+
+  __gcov_flush ();
+
+  va_start (ap, arg);
+  va_copy (aq, ap);
+
+  length = 2;
+  while (va_arg (ap, char *))
+    length++;
+  va_end (ap);
+
+  args = (char **) alloca (length * sizeof (void *));
+  args[0] = arg;
+  for (i = 1; i < length; i++)
+    args[i] = va_arg (aq, char *);
+  va_end (aq);
+
+  return execvp (path, args);
+}
+#endif
+
+#ifdef L_gcov_execle
+/* A wrapper for the execle function.  Flushes the accumulated profiling data, so
+   that they are not lost.  */
+
+int
+__gcov_execle (const char *path, char *arg, ...)
+{
+  va_list ap, aq;
+  unsigned i, length;
+  char **args;
+  char **envp;
+
+  __gcov_flush ();
+
+  va_start (ap, arg);
+  va_copy (aq, ap);
+
+  length = 2;
+  while (va_arg (ap, char *))
+    length++;
+  va_end (ap);
+
+  args = (char **) alloca (length * sizeof (void *));
+  args[0] = arg;
+  for (i = 1; i < length; i++)
+    args[i] = va_arg (aq, char *);
+  envp = va_arg (aq, char **);
+  va_end (aq);
+
+  return execve (path, args, envp);
+}
+#endif
+
+#ifdef L_gcov_execv
+/* A wrapper for the execv function.  Flushes the accumulated profiling data, so
+   that they are not lost.  */
+
+int
+__gcov_execv (const char *path, char *const argv[])
+{
+  __gcov_flush ();
+  return execv (path, argv);
+}
+#endif
+
+#ifdef L_gcov_execvp
+/* A wrapper for the execvp function.  Flushes the accumulated profiling data, so
+   that they are not lost.  */
+
+int
+__gcov_execvp (const char *path, char *const argv[])
+{
+  __gcov_flush ();
+  return execvp (path, argv);
+}
+#endif
+
+#ifdef L_gcov_execve
+/* A wrapper for the execve function.  Flushes the accumulated profiling data, so
+   that they are not lost.  */
+
+int
+__gcov_execve (const char *path, char *const argv[], char *const envp[])
+{
+  __gcov_flush ();
+  return execve (path, argv, envp);
+}
+#endif
+#endif /* inhibit_libc */

libgcc/libgcov-merge.c

+/* Routines required for instrumenting a program.  */
+/* Compile this one with gcc.  */
+/* Copyright (C) 1989-2013 Free Software Foundation, Inc.
+
+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/>.  */
+
+#include "tconfig.h"
+#include "tsystem.h"
+#include "coretypes.h"
+#include "tm.h"
+#include "libgcc_tm.h"
+
+#if defined(inhibit_libc)
+#define IN_LIBGCOV (-1)
+#else
+#define IN_LIBGCOV 1
+#endif
+
+#include "gcov-io.h"
+
+#if defined(inhibit_libc)
+/* If libc and its header files are not available, provide dummy functions.  */
+
+#ifdef L_gcov_merge_add
+void __gcov_merge_add (gcov_type *counters  __attribute__ ((unused)),
+                       unsigned n_counters __attribute__ ((unused))) {}
+#endif
+
+#ifdef L_gcov_merge_single
+void __gcov_merge_single (gcov_type *counters  __attribute__ ((unused)),
+                          unsigned n_counters __attribute__ ((unused))) {}
+#endif
+
+#ifdef L_gcov_merge_delta
+void __gcov_merge_delta (gcov_type *counters  __attribute__ ((unused)),
+                         unsigned n_counters __attribute__ ((unused))) {}
+#endif
+
+#else
+
+#ifdef L_gcov_merge_add
+/* The profile merging function that just adds the counters.  It is given
+   an array COUNTERS of N_COUNTERS old counters and it reads the same number
+   of counters from the gcov file.  */
+void
+__gcov_merge_add (gcov_type *counters, unsigned n_counters)
+{
+  for (; n_counters; counters++, n_counters--)
+    *counters += gcov_read_counter ();
+}
+#endif /* L_gcov_merge_add */
+
+#ifdef L_gcov_merge_ior
+/* The profile merging function that just adds the counters.  It is given
+   an array COUNTERS of N_COUNTERS old counters and it reads the same number
+   of counters from the gcov file.  */
+void
+__gcov_merge_ior (gcov_type *counters, unsigned n_counters)
+{
+  for (; n_counters; counters++, n_counters--)
+    *counters |= gcov_read_counter ();
+}
+#endif
+
+#ifdef L_gcov_merge_time_profile
+/* Time profiles are merged so that minimum from all valid (greater than zero)
+   is stored. There could be a fork that creates new counters. To have
+   the profile stable, we chosen to pick the smallest function visit time.  */
+void
+__gcov_merge_time_profile (gcov_type *counters, unsigned n_counters)
+{
+  unsigned int i;
+  gcov_type value;
+
+  for (i = 0; i < n_counters; i++)
+    {
+      value = gcov_read_counter ();
+
+      if (value && (!counters[i] || value < counters[i]))
+        counters[i] = value;
+    }
+}
+#endif /* L_gcov_merge_time_profile */
+
+#ifdef L_gcov_merge_single
+/* The profile merging function for choosing the most common value.
+   It is given an array COUNTERS of N_COUNTERS old counters and it
+   reads the same number of counters from the gcov file.  The counters
+   are split into 3-tuples where the members of the tuple have
+   meanings:
+
+   -- the stored candidate on the most common value of the measured entity
+   -- counter
+   -- total number of evaluations of the value  */
+void
+__gcov_merge_single (gcov_type *counters, unsigned n_counters)
+{
+  unsigned i, n_measures;
+  gcov_type value, counter, all;
+
+  gcc_assert (!(n_counters % 3));
+  n_measures = n_counters / 3;
+  for (i = 0; i < n_measures; i++, counters += 3)
+    {
+      value = gcov_read_counter ();
+      counter = gcov_read_counter ();
+      all = gcov_read_counter ();
+
+      if (counters[0] == value)
+        counters[1] += counter;
+      else if (counter > counters[1])
+        {
+          counters[0] = value;
+          counters[1] = counter - counters[1];
+        }
+      else
+        counters[1] -= counter;
+      counters[2] += all;
+    }
+}
+#endif /* L_gcov_merge_single */
+
+#ifdef L_gcov_merge_delta
+/* The profile merging function for choosing the most common
+   difference between two consecutive evaluations of the value.  It is
+   given an array COUNTERS of N_COUNTERS old counters and it reads the
+   same number of counters from the gcov file.  The counters are split
+   into 4-tuples where the members of the tuple have meanings:
+
+   -- the last value of the measured entity
+   -- the stored candidate on the most common difference
+   -- counter
+   -- total number of evaluations of the value  */
+void
+__gcov_merge_delta (gcov_type *counters, unsigned n_counters)
+{
+  unsigned i, n_measures;
+  gcov_type value, counter, all;
+
+  gcc_assert (!(n_counters % 4));
+  n_measures = n_counters / 4;
+  for (i = 0; i < n_measures; i++, counters += 4)
+    {
+      /* last = */ gcov_read_counter ();
+      value = gcov_read_counter ();
+      counter = gcov_read_counter ();
+      all = gcov_read_counter ();
+
+      if (counters[1] == value)
+        counters[2] += counter;
+      else if (counter > counters[2])
+        {
+          counters[1] = value;
+          counters[2] = counter - counters[2];
+        }
+      else
+        counters[2] -= counter;
+      counters[3] += all;
+    }
+}
+#endif /* L_gcov_merge_delta */
+#endif /* inhibit_libc */

libgcc/libgcov-profiler.c

+/* Routines required for instrumenting a program.  */
+/* Compile this one with gcc.  */
+/* Copyright (C) 1989-2013 Free Software Foundation, Inc.
+
+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/>.  */
+
+#include "tconfig.h"
+#include "tsystem.h"
+#include "coretypes.h"
+#include "tm.h"
+#include "libgcc_tm.h"
+
+#if !defined(inhibit_libc)
+#define IN_LIBGCOV 1
+#include "gcov-io.h"
+
+#ifdef L_gcov_interval_profiler
+/* If VALUE is in interval <START, START + STEPS - 1>, then increases the
+   corresponding counter in COUNTERS.  If the VALUE is above or below
+   the interval, COUNTERS[STEPS] or COUNTERS[STEPS + 1] is increased
+   instead.  */
+
+void
+__gcov_interval_profiler (gcov_type *counters, gcov_type value,
+                          int start, unsigned steps)
+{
+  gcov_type delta = value - start;
+  if (delta < 0)
+    counters[steps + 1]++;
+  else if (delta >= steps)
+    counters[steps]++;
+  else
+    counters[delta]++;
+}
+#endif
+
+#ifdef L_gcov_pow2_profiler
+/* If VALUE is a power of two, COUNTERS[1] is incremented.  Otherwise
+   COUNTERS[0] is incremented.  */
+
+void
+__gcov_pow2_profiler (gcov_type *counters, gcov_type value)
+{
+  if (value & (value - 1))
+    counters[0]++;
+  else
+    counters[1]++;
+}
+#endif
+
+/* Tries to determine the most common value among its inputs.  Checks if the
+   value stored in COUNTERS[0] matches VALUE.  If this is the case, COUNTERS[1]
+   is incremented.  If this is not the case and COUNTERS[1] is not zero,
+   COUNTERS[1] is decremented.  Otherwise COUNTERS[1] is set to one and
+   VALUE is stored to COUNTERS[0].  This algorithm guarantees that if this
+   function is called more than 50% of the time with one value, this value
+   will be in COUNTERS[0] in the end.
+
+   In any case, COUNTERS[2] is incremented.  */
+
+static inline void
+__gcov_one_value_profiler_body (gcov_type *counters, gcov_type value)
+{
+  if (value == counters[0])
+    counters[1]++;
+  else if (counters[1] == 0)
+    {
+      counters[1] = 1;
+      counters[0] = value;
+    }
+  else
+    counters[1]--;
+  counters[2]++;
+}
+
+#ifdef L_gcov_one_value_profiler
+void
+__gcov_one_value_profiler (gcov_type *counters, gcov_type value)
+{
+  __gcov_one_value_profiler_body (counters, value);
+}
+#endif
+
+#ifdef L_gcov_indirect_call_profiler
+/* This function exist only for workaround of binutils bug 14342.
+   Once this compatibility hack is obsolette, it can be removed.  */
+
+/* By default, the C++ compiler will use function addresses in the
+   vtable entries.  Setting TARGET_VTABLE_USES_DESCRIPTORS to nonzero
+   tells the compiler to use function descriptors instead.  The value
+   of this macro says how many words wide the descriptor is (normally 2),
+   but it may be dependent on target flags.  Since we do not have access
+   to the target flags here we just check to see if it is set and use
+   that to set VTABLE_USES_DESCRIPTORS to 0 or 1.
+
+   It is assumed that the address of a function descriptor may be treated
+   as a pointer to a function.  */
+
+#ifdef TARGET_VTABLE_USES_DESCRIPTORS
+#define VTABLE_USES_DESCRIPTORS 1
+#else
+#define VTABLE_USES_DESCRIPTORS 0
+#endif
+
+/* Tries to determine the most common value among its inputs. */
+void
+__gcov_indirect_call_profiler (gcov_type* counter, gcov_type value,
+                               void* cur_func, void* callee_func)
+{
+  /* If the C++ virtual tables contain function descriptors then one
+     function may have multiple descriptors and we need to dereference
+     the descriptors to see if they point to the same function.  */
+  if (cur_func == callee_func
+      || (VTABLE_USES_DESCRIPTORS && callee_func
+          && *(void **) cur_func == *(void **) callee_func))
+    __gcov_one_value_profiler_body (counter, value);
+}
+
+#endif
+#ifdef L_gcov_indirect_call_profiler_v2
+
+/* These two variables are used to actually track caller and callee.  Keep
+   them in TLS memory so races are not common (they are written to often).
+   The variables are set directly by GCC instrumented code, so declaration
+   here must match one in tree-profile.c  */
+
+#if defined(HAVE_CC_TLS) && !defined (USE_EMUTLS)
+__thread
+#endif
+void * __gcov_indirect_call_callee;
+#if defined(HAVE_CC_TLS) && !defined (USE_EMUTLS)
+__thread
+#endif
+gcov_type * __gcov_indirect_call_counters;
+
+/* By default, the C++ compiler will use function addresses in the
+   vtable entries.  Setting TARGET_VTABLE_USES_DESCRIPTORS to nonzero
+   tells the compiler to use function descriptors instead.  The value
+   of this macro says how many words wide the descriptor is (normally 2),
+   but it may be dependent on target flags.  Since we do not have access
+   to the target flags here we just check to see if it is set and use
+   that to set VTABLE_USES_DESCRIPTORS to 0 or 1.
+
+   It is assumed that the address of a function descriptor may be treated
+   as a pointer to a function.  */
+
+#ifdef TARGET_VTABLE_USES_DESCRIPTORS
+#define VTABLE_USES_DESCRIPTORS 1
+#else
+#define VTABLE_USES_DESCRIPTORS 0
+#endif
+
+/* Tries to determine the most common value among its inputs. */
+void
+__gcov_indirect_call_profiler_v2 (gcov_type value, void* cur_func)
+{
+  /* If the C++ virtual tables contain function descriptors then one
+     function may have multiple descriptors and we need to dereference
+     the descriptors to see if they point to the same function.  */
+  if (cur_func == __gcov_indirect_call_callee
+      || (VTABLE_USES_DESCRIPTORS && __gcov_indirect_call_callee
+          && *(void **) cur_func == *(void **) __gcov_indirect_call_callee))
+    __gcov_one_value_profiler_body (__gcov_indirect_call_counters, value);
+}
+#endif
+
+#ifdef L_gcov_time_profiler
+
+/* Counter for first visit of each function.  */
+static gcov_type function_counter;
+
+/* Sets corresponding COUNTERS if there is no value.  */
+
+void
+__gcov_time_profiler (gcov_type* counters)
+{
+  if (!counters[0])
+    counters[0] = ++function_counter;
+}
+#endif
+
+#ifdef L_gcov_average_profiler
+/* Increase corresponding COUNTER by VALUE.  FIXME: Perhaps we want
+   to saturate up.  */
+
+void
+__gcov_average_profiler (gcov_type *counters, gcov_type value)
+{
+  counters[0] += value;
+  counters[1] ++;
+}
+#endif
+
+#ifdef L_gcov_ior_profiler
+/* Bitwise-OR VALUE into COUNTER.  */
+
+void
+__gcov_ior_profiler (gcov_type *counters, gcov_type value)
+{
+  *counters |= value;
+}
+#endif
+
+#endif /* inhibit_libc */