Document gcov-io (PR gcov-profile/84735).

2018-03-08  Martin Liska  <mliska@suse.cz>

	PR gcov-profile/84735
	* doc/gcov.texi: Document usage of profile files.
	* gcov-io.h: Document changes in the format.

From-SVN: r258360

gcc/ChangeLog

+2018-03-08  Martin Liska  <mliska@suse.cz>
+
+	PR gcov-profile/84735
+	* doc/gcov.texi: Document usage of profile files.
+	* gcov-io.h: Document changes in the format.
+
 2018-03-08  Alexandre Oliva <aoliva@redhat.com>
 
 	PR debug/84404

gcc/doc/gcov.texi

@@ -816,9 +816,9 @@ A separate @file{.gcda} file is created for each object file compiled with
 this option.  It contains arc transition counts, value profile counts, and
 some summary information.
 
-The full details of the file format is specified in @file{gcov-io.h},
-and functions provided in that header file should be used to access the
-coverage files.
+It is not recommended to access the coverage files directly.
+Consumers should use the intermediate format that is provided
+by @command{gcov} tool via @option{--intermediate-format} option.
 
 @node Cross-profiling
 @section Data File Relocation to Support Cross-Profiling

gcc/gcov-io.h

@@ -48,7 +48,11 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 	padding: | char:0 | char:0 char:0 | char:0 char:0 char:0
 	item: int32 | int64 | string
 
-   The basic format of the files is
+   The basic format of the notes file is
+
+	file : int32:magic int32:version int32:stamp int32:support_unexecuted_blocks record*
+
+   The basic format of the data file is
 
    	file : int32:magic int32:version int32:stamp record*
 
@@ -104,7 +108,7 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 	function-graph: announce_function basic_blocks {arcs | lines}*
 	announce_function: header int32:ident
 		int32:lineno_checksum int32:cfg_checksum
-		string:name string:source int32:lineno
+		string:name string:source int32:start_lineno int32:start_column int32:end_lineno
 	basic_block: header int32:flags*
 	arcs: header int32:block_no arc*
 	arc:  int32:dest_block int32:flags