From: Arnaldo Carvalho de Melo <acme@redhat.com>
Date: Tue, 21 Mar 2017 19:00:50 +0000 (-0300)
Subject: perf annotate: Add comment clarifying how the source code line is parsed
X-Git-Tag: v4.12-rc1~152^2~34^2~13
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=ed7b339fb570749042332169e62541b208fc4296;p=karo-tx-linux.git

perf annotate: Add comment clarifying how the source code line is parsed

The source code line number (lineno) needs to be kept in accross calls
to symbol__parse_objdump_line() when parsing the output of 'objdump -l
-dS', so that it can associate it with the instructions till the next
line.

See disasm_line__new() and struct disasm_line::line_nr.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Taeung Song <treeze.taeung@gmail.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-7hpx8f8ybdpiujceysaj229w@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---

diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
index 4d325cdcb732..22cd1dbe724b 100644
--- a/tools/perf/util/annotate.c
+++ b/tools/perf/util/annotate.c
@@ -1482,6 +1482,12 @@ int symbol__disassemble(struct symbol *sym, struct map *map, const char *arch_na
 
 	nline = 0;
 	while (!feof(file)) {
+		/*
+		 * The source code line number (lineno) needs to be kept in
+		 * accross calls to symbol__parse_objdump_line(), so that it
+		 * can associate it with the instructions till the next one.
+		 * See disasm_line__new() and struct disasm_line::line_nr.
+		 */
 		if (symbol__parse_objdump_line(sym, map, arch, file, privsize,
 			    &lineno) < 0)
 			break;