[gcc r12-2777] gcov: Add __gcov_info_to_gdca()

[gcc r12-2777] gcov: Add __gcov_info_to_gdca()

[Sebastian Huber]

https://gcc.gnu.org/g:9124bbe1857f0d3a3015d6461d5f8d04f07cab85

commit r12-2777-g9124bbe1857f0d3a3015d6461d5f8d04f07cab85
Author: Sebastian Huber <sebastian.huber@embedded-brains.de>
Date:   Sat Nov 14 13:51:09 2020 +0100

    gcov: Add __gcov_info_to_gdca()
    
    Add __gcov_info_to_gcda() to libgcov to get the gcda data for a gcda info in a
    freestanding environment.  It is intended to be used with the
    -fprofile-info-section option.  A crude test program which doesn't use a linker
    script is (use "gcc -coverage -fprofile-info-section -lgcov test.c" to compile
    it):
    
      #include <gcov.h>
      #include <stdio.h>
      #include <stdlib.h>
    
      extern const struct gcov_info *my_info;
    
      static void
      filename (const char *f, void *arg)
      {
        printf("filename: %s\n", f);
      }
    
      static void
      dump (const void *d, unsigned n, void *arg)
      {
        const unsigned char *c = d;
    
        for (unsigned i = 0; i < n; ++i)
          printf ("%02x", c[i]);
      }
    
      static void *
      allocate (unsigned length, void *arg)
      {
        return malloc (length);
      }
    
      int main()
      {
        __asm__ volatile (".set my_info, .LPBX2");
        __gcov_info_to_gcda (my_info, filename, dump, allocate, NULL);
        return 0;
      }
    
    With this patch, <stdint.h> is included in libgcov-driver.c even if
    inhibit_libc is defined.  This header file should be also available for
    freestanding environments.  If this is not the case, then we have to define
    intptr_t somehow.
    
    The patch removes one use of memset() which makes the <string.h> include
    superfluous.
    
    gcc/
    
            * gcov-io.h (gcov_write): Declare.
            * gcov-io.c (gcov_write): New.
            (gcov_write_counter): Remove.
            (gcov_write_tag_length): Likewise.
            (gcov_write_summary): Replace gcov_write_tag_length() with calls to
            gcov_write_unsigned().
            * doc/invoke.texi (fprofile-info-section): Mention
            __gcov_info_to_gdca().
    
    gcc/testsuite/
    
            * gcc.dg/gcov-info-to-gcda.c: New test.
    
    libgcc/
    
            * Makefile.in (LIBGCOV_DRIVER): Add _gcov_info_to_gcda.
            * gcov.h (gcov_info): Declare.
            (__gcov_info_to_gdca): Likewise.
            * libgcov.h (gcov_write_counter): Remove.
            (gcov_write_tag_length): Likewise.
            * libgcov-driver.c (#include <stdint.h>): New.
            (#include <string.h>): Remove.
            (NEED_L_GCOV): Conditionally define.
            (NEED_L_GCOV_INFO_TO_GCDA): Likewise.
            (are_all_counters_zero): New.
            (gcov_dump_handler): Likewise.
            (gcov_allocate_handler): Likewise.
            (dump_unsigned): Likewise.
            (dump_counter): Likewise.
            (write_topn_counters): Add dump_fn, allocate_fn, and arg parameters.
            Use dump_unsigned() and dump_counter().
            (write_one_data): Add dump_fn, allocate_fn, and arg parameters.  Use
            dump_unsigned(), dump_counter(), and are_all_counters_zero().
            (__gcov_info_to_gcda): New.

Diff:
---
 gcc/doc/invoke.texi                      |  80 +++++++++++--
 gcc/gcov-io.c                            |  36 ++----
 gcc/gcov-io.h                            |   1 +
 gcc/testsuite/gcc.dg/gcov-info-to-gcda.c |  60 ++++++++++
 libgcc/Makefile.in                       |   2 +-
 libgcc/gcov.h                            |  19 ++++
 libgcc/libgcov-driver.c                  | 185 +++++++++++++++++++++++--------
 libgcc/libgcov.h                         |   5 -
 8 files changed, 302 insertions(+), 86 deletions(-)

diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 4efc8b757ec..a64cec5387e 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -14801,17 +14801,17 @@ To optimize the program based on the collected profile information, use
 Register the profile information in the specified section instead of using a
 constructor/destructor.  The section name is @var{name} if it is specified,
 otherwise the section name defaults to @code{.gcov_info}.  A pointer to the
-profile information generated by @option{-fprofile-arcs} or
-@option{-ftest-coverage} is placed in the specified section for each
-translation unit.  This option disables the profile information registration
-through a constructor and it disables the profile information processing
-through a destructor.  This option is not intended to be used in hosted
-environments such as GNU/Linux.  It targets systems with limited resources
-which do not support constructors and destructors.  The linker could collect
-the input sections in a continuous memory block and define start and end
-symbols.  The runtime support could dump the profiling information registered
-in this linker set during program termination to a serial line for example.  A
-GNU linker script example which defines a linker output section follows:
+profile information generated by @option{-fprofile-arcs} is placed in the
+specified section for each translation unit.  This option disables the profile
+information registration through a constructor and it disables the profile
+information processing through a destructor.  This option is not intended to be
+used in hosted environments such as GNU/Linux.  It targets free-standing
+environments (for example embedded systems) with limited resources which do not
+support constructors/destructors or the C library file I/O.
+
+The linker could collect the input sections in a continuous memory block and
+define start and end symbols.  A GNU linker script example which defines a
+linker output section follows:
 
 @smallexample
   .gcov_info      :
@@ -14822,6 +14822,64 @@ GNU linker script example which defines a linker output section follows:
   @}
 @end smallexample
 
+The program could dump the profiling information registered in this linker set
+for example like this:
+
+@smallexample
+#include <gcov.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+extern const struct gcov_info *__gcov_info_start[];
+extern const struct gcov_info *__gcov_info_end[];
+
+static void
+filename (const char *f, void *arg)
+@{
+  puts (f);
+@}
+
+static void
+dump (const void *d, unsigned n, void *arg)
+@{
+  const unsigned char *c = d;
+
+  for (unsigned i = 0; i < n; ++i)
+    printf ("%02x", c[i]);
+@}
+
+static void *
+allocate (unsigned length, void *arg)
+@{
+  return malloc (length);
+@}
+
+static void
+dump_gcov_info (void)
+@{
+  const struct gcov_info **info = __gcov_info_start;
+  const struct gcov_info **end = __gcov_info_end;
+
+  /* Obfuscate variable to prevent compiler optimizations.  */
+  __asm__ ("" : "+r" (info));
+
+  while (info != end)
+  @{
+    void *arg = NULL;
+    __gcov_info_to_gcda (*info, filename, dump, allocate, arg);
+    putchar ('\n');
+    ++info;
+  @}
+@}
+
+int
+main()
+@{
+  dump_gcov_info();
+  return 0;
+@}
+@end smallexample
+
 @item -fprofile-note=@var{path}
 @opindex fprofile-note
 
diff --git a/gcc/gcov-io.c b/gcc/gcov-io.c
index 7819593234a..d3e56afb0a5 100644
--- a/gcc/gcov-io.c
+++ b/gcc/gcov-io.c
@@ -229,30 +229,25 @@ gcov_magic (gcov_unsigned_t magic, gcov_unsigned_t expected)
 #endif
 
 #if !IN_GCOV
-/* Write unsigned VALUE to coverage file.  */
+/* Write DATA of LENGTH characters to coverage file.  */
 
 GCOV_LINKAGE void
-gcov_write_unsigned (gcov_unsigned_t value)
+gcov_write (const void *data, unsigned length)
 {
-  gcov_unsigned_t r = fwrite (&value, sizeof (value), 1, gcov_var.file);
+  gcov_unsigned_t r = fwrite (data, length, 1, gcov_var.file);
   if (r != 1)
     gcov_var.error = 1;
 }
 
-/* Write counter VALUE to coverage file.  Sets error flag
-   appropriately.  */
+/* Write unsigned VALUE to coverage file.  */
 
-#if IN_LIBGCOV
 GCOV_LINKAGE void
-gcov_write_counter (gcov_type value)
+gcov_write_unsigned (gcov_unsigned_t value)
 {
-  gcov_write_unsigned ((gcov_unsigned_t) value);
-  if (sizeof (value) > sizeof (gcov_unsigned_t))
-    gcov_write_unsigned ((gcov_unsigned_t) (value >> 32));
-  else
-    gcov_write_unsigned (0);
+  gcov_unsigned_t r = fwrite (&value, sizeof (value), 1, gcov_var.file);
+  if (r != 1)
+    gcov_var.error = 1;
 }
-#endif /* IN_LIBGCOV */
 
 #if !IN_LIBGCOV
 /* Write STRING to coverage file.  Sets error flag on file
@@ -349,22 +344,13 @@ gcov_write_length (gcov_position_t position)
 
 #else /* IN_LIBGCOV */
 
-/* Write a tag TAG and length LENGTH.  */
-
-GCOV_LINKAGE void
-gcov_write_tag_length (gcov_unsigned_t tag, gcov_unsigned_t length)
-{
-  gcov_write_unsigned (tag);
-  gcov_write_unsigned (length);
-}
-
-/* Write a summary structure to the gcov file.  Return nonzero on
-   overflow.  */
+/* Write a summary structure to the gcov file.  */
 
 GCOV_LINKAGE void
 gcov_write_summary (gcov_unsigned_t tag, const struct gcov_summary *summary)
 {
-  gcov_write_tag_length (tag, GCOV_TAG_SUMMARY_LENGTH);
+  gcov_write_unsigned (tag);
+  gcov_write_unsigned (GCOV_TAG_SUMMARY_LENGTH);
   gcov_write_unsigned (summary->runs);
   gcov_write_unsigned (summary->sum_max);
 }
diff --git a/gcc/gcov-io.h b/gcc/gcov-io.h
index 538bee81263..99e1964c109 100644
--- a/gcc/gcov-io.h
+++ b/gcc/gcov-io.h
@@ -367,6 +367,7 @@ char *mangle_path (char const *base);
 
 #if !IN_GCOV
 /* Available outside gcov */
+GCOV_LINKAGE void gcov_write (const void *, unsigned) ATTRIBUTE_HIDDEN;
 GCOV_LINKAGE void gcov_write_unsigned (gcov_unsigned_t) ATTRIBUTE_HIDDEN;
 #endif
 
diff --git a/gcc/testsuite/gcc.dg/gcov-info-to-gcda.c b/gcc/testsuite/gcc.dg/gcov-info-to-gcda.c
new file mode 100644
index 00000000000..a42a768326c
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/gcov-info-to-gcda.c
@@ -0,0 +1,60 @@
+/* { dg-do run } */
+/* { dg-skip-if "profile-info-section" { powerpc-ibm-aix* } } */
+/* { dg-options "-fprofile-arcs -fprofile-info-section" } */
+
+#define assert(expr)                                            \
+  ((expr)                                                       \
+   ? (void)0                                                    \
+   : (__builtin_printf ("%s:%i: Assertion `%s' failed.\n",      \
+                        __FILE__, __LINE__, #expr),             \
+      __builtin_abort ()))
+
+struct gcov_info;
+
+extern void
+__gcov_info_to_gcda (const struct gcov_info *__info,
+		     void (*__filename_fn) (const char *, void *),
+		     void (*__dump_fn) (const void *, unsigned, void *),
+		     void *(*__allocate_fn) (unsigned, void *),
+		     void *__arg);
+
+extern const struct gcov_info *my_info;
+
+static unsigned counter;
+
+static void
+filename (const char *f, void *arg)
+{
+  assert (arg == &counter);
+  assert (__builtin_strstr (f, "gcov-info-to-gcda.c") == 0);
+}
+
+static void
+dump (const void *d, unsigned n, void *arg)
+{
+  unsigned *m = (unsigned *)arg;
+  assert (arg == &counter);
+
+  if (*m == 0)
+  {
+    const unsigned *u = d;
+    assert (*u == 0x67636461);
+  }
+
+  *m += n;
+}
+
+static void *
+allocate (unsigned length, void *arg)
+{
+  assert (arg == &counter);
+  return __builtin_malloc (length);
+}
+
+int main()
+{
+  __asm__ volatile (".set my_info, .LPBX2");
+  __gcov_info_to_gcda (my_info, filename, dump, allocate, &counter);
+  assert (counter > 4);
+  return 0;
+}
diff --git a/libgcc/Makefile.in b/libgcc/Makefile.in
index 2c8be561eb5..7ec97584554 100644
--- a/libgcc/Makefile.in
+++ b/libgcc/Makefile.in
@@ -908,7 +908,7 @@ LIBGCOV_INTERFACE = _gcov_dump _gcov_fork				\
 	_gcov_execl _gcov_execlp					\
 	_gcov_execle _gcov_execv _gcov_execvp _gcov_execve _gcov_reset  \
 	_gcov_lock_unlock
-LIBGCOV_DRIVER = _gcov
+LIBGCOV_DRIVER = _gcov _gcov_info_to_gcda
 
 libgcov-merge-objects = $(patsubst %,%$(objext),$(LIBGCOV_MERGE))
 libgcov-profiler-objects = $(patsubst %,%$(objext),$(LIBGCOV_PROFILER))
diff --git a/libgcc/gcov.h b/libgcc/gcov.h
index e6492cdd31e..66d03bf4e5d 100644
--- a/libgcc/gcov.h
+++ b/libgcc/gcov.h
@@ -25,6 +25,8 @@
 #ifndef GCC_GCOV_H
 #define GCC_GCOV_H
 
+struct gcov_info;
+
 /* Set all counters to zero.  */
 
 extern void __gcov_reset (void);
@@ -33,4 +35,21 @@ extern void __gcov_reset (void);
 
 extern void __gcov_dump (void);
 
+/* Convert the gcov information referenced by INFO to a gcda data stream.
+   The FILENAME_FN callback is called exactly once with the filename associated
+   with the gcov information.  The filename may be NULL.  Afterwards, the
+   DUMP_FN callback is subsequently called with chunks (the begin and length of
+   the chunk are passed as the first two callback parameters) of the gcda data
+   stream.  The ALLOCATE_FN callback shall allocate memory with a size in
+   characters specified by the first callback parameter.  The ARG parameter is
+   a user-provided argument passed as the last argument to the callback
+   functions.  */
+
+extern void
+__gcov_info_to_gcda (const struct gcov_info *__info,
+		     void (*__filename_fn) (const char *, void *),
+		     void (*__dump_fn) (const void *, unsigned, void *),
+		     void *(*__allocate_fn) (unsigned, void *),
+		     void *__arg);
+
 #endif /* GCC_GCOV_H */
diff --git a/libgcc/libgcov-driver.c b/libgcc/libgcov-driver.c
index df7ccb23567..9d7bc9c7995 100644
--- a/libgcc/libgcov-driver.c
+++ b/libgcc/libgcov-driver.c
@@ -26,6 +26,20 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 #include "libgcov.h"
 #include "gcov-io.h"
 
+#include <stdint.h>
+
+/* Return 1, if all counter values are zero, otherwise 0. */
+
+static inline int
+are_all_counters_zero (const struct gcov_ctr_info *ci_ptr)
+{
+  for (unsigned i = 0; i < ci_ptr->num; i++)
+    if (ci_ptr->values[i] != 0)
+      return 0;
+
+  return 1;
+}
+
 #if defined(inhibit_libc)
 /* If libc and its header files are not available, provide dummy functions.  */
 
@@ -35,8 +49,6 @@ void __gcov_init (struct gcov_info *p __attribute__ ((unused))) {}
 
 #else /* inhibit_libc */
 
-#include <string.h>
-
 #if GCOV_LOCKED
 #include <fcntl.h>
 #include <errno.h>
@@ -51,8 +63,17 @@ void __gcov_init (struct gcov_info *p __attribute__ ((unused))) {}
 #include <sys/mman.h>
 #endif
 
-#ifdef L_gcov
+#endif /* inhibit_libc */
+
+#if defined(L_gcov) && !defined(inhibit_libc)
+#define NEED_L_GCOV
+#endif
+
+#if defined(L_gcov_info_to_gcda) && !IN_GCOV_TOOL
+#define NEED_L_GCOV_INFO_TO_GCDA
+#endif
 
+#ifdef NEED_L_GCOV
 /* A utility function for outputting errors.  */
 static int gcov_error (const char *, ...);
 
@@ -343,6 +364,51 @@ read_error:
   return -1;
 }
 
+/* Write the DATA of LENGTH characters to the gcov file.  */
+
+static void
+gcov_dump_handler (const void *data,
+		   unsigned length,
+		   void *arg ATTRIBUTE_UNUSED)
+{
+  gcov_write (data, length);
+}
+
+/* Allocate SIZE characters and return the address of the allocated memory.  */
+
+static void *
+gcov_allocate_handler (unsigned size, void *arg ATTRIBUTE_UNUSED)
+{
+  return xmalloc (size);
+}
+#endif /* NEED_L_GCOV */
+
+#if defined(NEED_L_GCOV) || defined(NEED_L_GCOV_INFO_TO_GCDA)
+/* Dump the WORD using the DUMP handler called with ARG.  */
+
+static inline void
+dump_unsigned (gcov_unsigned_t word,
+	       void (*dump_fn) (const void *, unsigned, void *),
+	       void *arg)
+{
+  (*dump_fn) (&word, sizeof (word), arg);
+}
+
+/* Dump the COUNTER using the DUMP handler called with ARG.  */
+
+static inline void
+dump_counter (gcov_type counter,
+	      void (*dump_fn) (const void *, unsigned, void *),
+	      void *arg)
+{
+  dump_unsigned ((gcov_unsigned_t)counter, dump_fn, arg);
+
+  if (sizeof (counter) > sizeof (gcov_unsigned_t))
+    dump_unsigned ((gcov_unsigned_t)(counter >> 32), dump_fn, arg);
+  else
+    dump_unsigned (0, dump_fn, arg);
+}
+
 #define MAX(X,Y) ((X) > (Y) ? (X) : (Y))
 
 /* Store all TOP N counters where each has a dynamic length.  */
@@ -350,7 +416,10 @@ read_error:
 static void
 write_topn_counters (const struct gcov_ctr_info *ci_ptr,
 		     unsigned t_ix,
-		     gcov_unsigned_t n_counts)
+		     gcov_unsigned_t n_counts,
+		     void (*dump_fn) (const void *, unsigned, void *),
+		     void *(*allocate_fn)(unsigned, void *),
+		     void *arg)
 {
   unsigned counters = n_counts / GCOV_TOPN_MEM_COUNTERS;
   gcc_assert (n_counts % GCOV_TOPN_MEM_COUNTERS == 0);
@@ -365,46 +434,49 @@ write_topn_counters (const struct gcov_ctr_info *ci_ptr,
   if (list_sizes == NULL || counters > list_size_length)
     {
       list_size_length = MAX (LIST_SIZE_MIN_LENGTH, 2 * counters);
-#if HAVE_SYS_MMAN_H
+#if !defined(inhibit_libc) && HAVE_SYS_MMAN_H
       list_sizes
 	= (unsigned *)malloc_mmap (list_size_length * sizeof (unsigned));
 #endif
 
       /* Malloc fallback.  */
       if (list_sizes == NULL)
-	list_sizes = (unsigned *)xmalloc (list_size_length * sizeof (unsigned));
+	list_sizes =
+	  (unsigned *)(*allocate_fn) (list_size_length * sizeof (unsigned),
+				      arg);
     }
 
-  memset (list_sizes, 0, counters * sizeof (unsigned));
   unsigned pair_total = 0;
 
   for (unsigned i = 0; i < counters; i++)
     {
       gcov_type start = ci_ptr->values[GCOV_TOPN_MEM_COUNTERS * i + 2];
+      unsigned sizes = 0;
+
       for (struct gcov_kvp *node = (struct gcov_kvp *)(intptr_t)start;
 	   node != NULL; node = node->next)
-	{
-	  ++pair_total;
-	  ++list_sizes[i];
-	}
+	++sizes;
+
+      pair_total += sizes;
+      list_sizes[i] = sizes;
     }
 
   unsigned disk_size = GCOV_TOPN_DISK_COUNTERS * counters + 2 * pair_total;
-  gcov_write_tag_length (GCOV_TAG_FOR_COUNTER (t_ix),
-			 GCOV_TAG_COUNTER_LENGTH (disk_size));
+  dump_unsigned (GCOV_TAG_FOR_COUNTER (t_ix), dump_fn, arg),
+  dump_unsigned (GCOV_TAG_COUNTER_LENGTH (disk_size), dump_fn, arg);
 
   for (unsigned i = 0; i < counters; i++)
     {
-      gcov_write_counter (ci_ptr->values[GCOV_TOPN_MEM_COUNTERS * i]);
-      gcov_write_counter (list_sizes[i]);
+      dump_counter (ci_ptr->values[GCOV_TOPN_MEM_COUNTERS * i], dump_fn, arg);
+      dump_counter (list_sizes[i], dump_fn, arg);
       gcov_type start = ci_ptr->values[GCOV_TOPN_MEM_COUNTERS * i + 2];
 
       unsigned j = 0;
       for (struct gcov_kvp *node = (struct gcov_kvp *)(intptr_t)start;
 	   j < list_sizes[i]; node = node->next, j++)
 	{
-	  gcov_write_counter (node->value);
-	  gcov_write_counter (node->count);
+	  dump_counter (node->value, dump_fn, arg);
+	  dump_counter (node->count, dump_fn, arg);
 	}
     }
 }
@@ -415,25 +487,34 @@ write_topn_counters (const struct gcov_ctr_info *ci_ptr,
 
 static void
 write_one_data (const struct gcov_info *gi_ptr,
-		const struct gcov_summary *prg_p)
+		const struct gcov_summary *prg_p ATTRIBUTE_UNUSED,
+		void (*dump_fn) (const void *, unsigned, void *),
+		void *(*allocate_fn) (unsigned, void *),
+		void *arg)
 {
   unsigned f_ix;
 
-  gcov_write_tag_length (GCOV_DATA_MAGIC, GCOV_VERSION);
-  gcov_write_unsigned (gi_ptr->stamp);
+  dump_unsigned (GCOV_DATA_MAGIC, dump_fn, arg);
+  dump_unsigned (GCOV_VERSION, dump_fn, arg);
+  dump_unsigned (gi_ptr->stamp, dump_fn, arg);
 
+#ifdef NEED_L_GCOV
   /* Generate whole program statistics.  */
   gcov_write_summary (GCOV_TAG_OBJECT_SUMMARY, prg_p);
+#endif
 
   /* Write execution counts for each function.  */
   for (f_ix = 0; f_ix != gi_ptr->n_functions; f_ix++)
     {
+#ifdef NEED_L_GCOV
       unsigned buffered = 0;
+#endif
       const struct gcov_fn_info *gfi_ptr;
       const struct gcov_ctr_info *ci_ptr;
       gcov_unsigned_t length;
       unsigned t_ix;
 
+#ifdef NEED_L_GCOV
       if (fn_buffer && fn_buffer->fn_ix == f_ix)
         {
           /* Buffered data from another program.  */
@@ -442,6 +523,7 @@ write_one_data (const struct gcov_info *gi_ptr,
           length = GCOV_TAG_FUNCTION_LENGTH;
         }
       else
+#endif
         {
           gfi_ptr = gi_ptr->functions[f_ix];
           if (gfi_ptr && gfi_ptr->key == gi_ptr)
@@ -450,13 +532,14 @@ write_one_data (const struct gcov_info *gi_ptr,
                 length = 0;
         }
 
-      gcov_write_tag_length (GCOV_TAG_FUNCTION, length);
+      dump_unsigned (GCOV_TAG_FUNCTION, dump_fn, arg);
+      dump_unsigned (length, dump_fn, arg);
       if (!length)
         continue;
 
-      gcov_write_unsigned (gfi_ptr->ident);
-      gcov_write_unsigned (gfi_ptr->lineno_checksum);
-      gcov_write_unsigned (gfi_ptr->cfg_checksum);
+      dump_unsigned (gfi_ptr->ident, dump_fn, arg);
+      dump_unsigned (gfi_ptr->lineno_checksum, dump_fn, arg);
+      dump_unsigned (gfi_ptr->cfg_checksum, dump_fn, arg);
 
       ci_ptr = gfi_ptr->ctrs;
       for (t_ix = 0; t_ix < GCOV_COUNTERS; t_ix++)
@@ -469,39 +552,37 @@ write_one_data (const struct gcov_info *gi_ptr,
 	  n_counts = ci_ptr->num;
 
 	  if (t_ix == GCOV_COUNTER_V_TOPN || t_ix == GCOV_COUNTER_V_INDIR)
-	    write_topn_counters (ci_ptr, t_ix, n_counts);
+	    write_topn_counters (ci_ptr, t_ix, n_counts, dump_fn, allocate_fn,
+				 arg);
 	  else
 	    {
-	      /* Do not stream when all counters are zero.  */
-	      int all_zeros = 1;
-	      for (unsigned i = 0; i < n_counts; i++)
-		if (ci_ptr->values[i] != 0)
-		  {
-		    all_zeros = 0;
-		    break;
-		  }
-
-	      if (all_zeros)
-		gcov_write_tag_length (GCOV_TAG_FOR_COUNTER (t_ix),
-				       GCOV_TAG_COUNTER_LENGTH (-n_counts));
+	      dump_unsigned (GCOV_TAG_FOR_COUNTER (t_ix), dump_fn, arg);
+	      if (are_all_counters_zero (ci_ptr))
+		/* Do not stream when all counters are zero.  */
+		dump_unsigned (GCOV_TAG_COUNTER_LENGTH (-n_counts),
+			       dump_fn, arg);
 	      else
 		{
-		  gcov_write_tag_length (GCOV_TAG_FOR_COUNTER (t_ix),
-					 GCOV_TAG_COUNTER_LENGTH (n_counts));
+		  dump_unsigned (GCOV_TAG_COUNTER_LENGTH (n_counts),
+				 dump_fn, arg);
 		  for (unsigned i = 0; i < n_counts; i++)
-		    gcov_write_counter (ci_ptr->values[i]);
+		    dump_counter (ci_ptr->values[i], dump_fn, arg);
 		}
 	    }
 
 	  ci_ptr++;
 	}
+#ifdef NEED_L_GCOV
       if (buffered)
         fn_buffer = free_fn_data (gi_ptr, fn_buffer, GCOV_COUNTERS);
+#endif
     }
 
-  gcov_write_unsigned (0);
+  dump_unsigned (0, dump_fn, arg);
 }
+#endif /* NEED_L_GCOV || NEED_L_GCOV_INFO_TO_GCDA */
 
+#ifdef NEED_L_GCOV
 /* 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
@@ -550,7 +631,8 @@ dump_one_gcov (struct gcov_info *gi_ptr, struct gcov_filename *gf,
   summary = gi_ptr->summary;
 #endif
 
-  write_one_data (gi_ptr, &summary);
+  write_one_data (gi_ptr, &summary, gcov_dump_handler, gcov_allocate_handler,
+		  NULL);
   /* fall through */
 
 read_fatal:;
@@ -680,5 +762,20 @@ __gcov_init (struct gcov_info *info)
     }
 }
 #endif /* !IN_GCOV_TOOL */
-#endif /* L_gcov */
-#endif /* inhibit_libc */
+#endif /* NEED_L_GCOV */
+
+#ifdef NEED_L_GCOV_INFO_TO_GCDA
+/* Convert the gcov info to a gcda data stream.  It is intended for
+   free-standing environments which do not support the C library file I/O.  */
+
+void
+__gcov_info_to_gcda (const struct gcov_info *gi_ptr,
+		     void (*filename_fn) (const char *, void *),
+		     void (*dump_fn) (const void *, unsigned, void *),
+		     void *(*allocate_fn) (unsigned, void *),
+		     void *arg)
+{
+  (*filename_fn) (gi_ptr->filename, arg);
+  write_one_data (gi_ptr, NULL, dump_fn, allocate_fn, arg);
+}
+#endif /* NEED_L_GCOV_INFO_TO_GCDA */
diff --git a/libgcc/libgcov.h b/libgcc/libgcov.h
index 8d323db0538..9c537253293 100644
--- a/libgcc/libgcov.h
+++ b/libgcc/libgcov.h
@@ -114,13 +114,11 @@ typedef unsigned gcov_type_unsigned __attribute__ ((mode (QI)));
 #define gcov_var __gcov_var
 #define gcov_open __gcov_open
 #define gcov_close __gcov_close
-#define gcov_write_tag_length __gcov_write_tag_length
 #define gcov_position __gcov_position
 #define gcov_seek __gcov_seek
 #define gcov_rewrite __gcov_rewrite
 #define gcov_is_error __gcov_is_error
 #define gcov_write_unsigned __gcov_write_unsigned
-#define gcov_write_counter __gcov_write_counter
 #define gcov_write_summary __gcov_write_summary
 #define gcov_read_unsigned __gcov_read_unsigned
 #define gcov_read_counter __gcov_read_counter
@@ -345,9 +343,6 @@ extern int __gcov_execve (const char *, char  *const [], char *const [])
 
 /* Functions that only available in libgcov.  */
 GCOV_LINKAGE int gcov_open (const char */*name*/) ATTRIBUTE_HIDDEN;
-GCOV_LINKAGE void gcov_write_counter (gcov_type) ATTRIBUTE_HIDDEN;
-GCOV_LINKAGE void gcov_write_tag_length (gcov_unsigned_t, gcov_unsigned_t)
-    ATTRIBUTE_HIDDEN;
 GCOV_LINKAGE void gcov_write_summary (gcov_unsigned_t /*tag*/,
                                       const struct gcov_summary *)
     ATTRIBUTE_HIDDEN;