Do not stream all zeros for gcda files.

gcc/ChangeLog:

	PR gcov-profile/95348
	* coverage.c (read_counts_file): Read only COUNTERS that are
	not all-zero.
	* gcov-dump.c (tag_function): Change signature from unsigned to
	signed integer.
	(tag_blocks): Likewise.
	(tag_arcs): Likewise.
	(tag_lines): Likewise.
	(tag_counters): Likewise.
	(tag_summary): Likewise.
	* gcov.c (read_count_file): Read all non-zero counters
	sensitively.

libgcc/ChangeLog:

	PR gcov-profile/95348
	* libgcov-driver.c (merge_one_data): Merge only profiles
	that are not of non-zero type.
	(write_one_data): Write counters only if there's one non-zero
	value.
	* libgcov-util.c (tag_function): Change signature from unsigned
	to int.
	(tag_blocks): Likewise.
	(tag_arcs): Likewise.
	(tag_counters): Likewise.
	(tag_summary): Likewise.
	(tag_lines): Read only if COUNTERS is non-zero.
	(read_gcda_file): Handle negative length for COUNTERS type.

1 files changed, 7 insertions, 2 deletions

diff --git a/gcc/gcov.c b/gcc/gcov.c
index b2d2fda..b302e21 100644
--- a/gcc/gcov.c
+++ b/gcc/gcov.c
@@ -1972,11 +1972,16 @@ read_count_file (void)
 	}
       else if (tag == GCOV_TAG_FOR_COUNTER (GCOV_COUNTER_ARCS) && fn)
 	{
+	  int read_length = (int)length;
+	  length = abs (read_length);
 	  if (length != GCOV_TAG_COUNTER_LENGTH (fn->counts.size ()))
 	    goto mismatch;
 
-	  for (ix = 0; ix != fn->counts.size (); ix++)
-	    fn->counts[ix] += gcov_read_counter ();
+	  if (read_length > 0)
+	    for (ix = 0; ix != fn->counts.size (); ix++)
+	      fn->counts[ix] += gcov_read_counter ();
+	  else
+	    length = 0;
 	}
       gcov_sync (base, length);
       if ((error = gcov_is_error ()))