perf tools: Support --prefix/--prefix-strip

The objdump utility has useful --prefix / --prefix-strip options to
allow changing source code file names hardcoded into executables' debug
info. Add options to 'perf report', 'perf top' and 'perf annotate',
which are then passed to objdump.

  $ mkdir foo
  $ echo 'main() { for (;;); }' > foo/foo.c
  $ gcc -g foo/foo.c
  foo/foo.c:1:1: warning: return type defaults to ‘int’ [-Wimplicit-int]
      1 | main() { for (;;); }
        | ^~~~
  $ perf record ./a.out
  ^C[ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.230 MB perf.data (5721 samples) ]
  $ mv foo bar
  $ perf annotate
  <does not show source code>
  $ perf annotate --prefix=/home/ak/lsrc/git/bar --prefix-strip=5
  <does show source code>

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Tested-by: Jiri Olsa <jolsa@redhat.com>
LPU-Reference: 20200107210444.214071-1-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/Documentation/perf-annotate.txt

@@ -112,6 +112,12 @@ OPTIONS
 --objdump=<path>::
         Path to objdump binary.
 
+--prefix=PREFIX::
+--prefix-strip=N::
+	Remove first N entries from source file path names in executables
+	and add PREFIX. This allows to display source code compiled on systems
+	with different file system layout.
+
 --skip-missing::
 	Skip symbols that cannot be annotated.
 

tools/perf/Documentation/perf-report.txt

@@ -367,6 +367,12 @@ OPTIONS
 --objdump=<path>::
         Path to objdump binary.
 
+--prefix=PREFIX::
+--prefix-strip=N::
+	Remove first N entries from source file path names in executables
+	and add PREFIX. This allows to display source code compiled on systems
+	with different file system layout.
+
 --group::
 	Show event group information together. It forces group output also
 	if there are no groups defined in data file.

tools/perf/Documentation/perf-top.txt

@@ -158,6 +158,12 @@ Default is to monitor all CPUS.
 -M::
 --disassembler-style=:: Set disassembler style for objdump.
 
+--prefix=PREFIX::
+--prefix-strip=N::
+        Remove first N entries from source file path names in executables
+        and add PREFIX. This allows to display source code compiled on systems
+        with different file system layout.
+
 --source::
 	Interleave source code with assembly code. Enabled by default,
 	disable with --no-source.

tools/perf/builtin-annotate.c

@@ -535,6 +535,10 @@ int cmd_annotate(int argc, const char **argv)
 		    "Display raw encoding of assembly instructions (default)"),
 	OPT_STRING('M', "disassembler-style", &annotate.opts.disassembler_style, "disassembler style",
 		   "Specify disassembler style (e.g. -M intel for intel syntax)"),
+	OPT_STRING(0, "prefix", &annotate.opts.prefix, "prefix",
+		    "Add prefix to source file path names in programs (with --prefix-strip)"),
+	OPT_STRING(0, "prefix-strip", &annotate.opts.prefix_strip, "N",
+		    "Strip first N entries of source file path name in programs (with --prefix)"),
 	OPT_STRING(0, "objdump", &annotate.opts.objdump_path, "path",
 		   "objdump binary to use for disassembly and annotations"),
 	OPT_BOOLEAN(0, "group", &symbol_conf.event_group,
@@ -574,6 +578,9 @@ int cmd_annotate(int argc, const char **argv)
 		annotate.sym_hist_filter = argv[0];
 	}
 
+	if (annotate_check_args(&annotate.opts) < 0)
+		return -EINVAL;
+
 	if (symbol_conf.show_nr_samples && annotate.use_gtk) {
 		pr_err("--show-nr-samples is not available in --gtk mode at this time\n");
 		return ret;

tools/perf/builtin-report.c

@@ -1208,6 +1208,10 @@ int cmd_report(int argc, const char **argv)
 		    "Display raw encoding of assembly instructions (default)"),
 	OPT_STRING('M', "disassembler-style", &report.annotation_opts.disassembler_style, "disassembler style",
 		   "Specify disassembler style (e.g. -M intel for intel syntax)"),
+	OPT_STRING(0, "prefix", &report.annotation_opts.prefix, "prefix",
+		    "Add prefix to source file path names in programs (with --prefix-strip)"),
+	OPT_STRING(0, "prefix-strip", &report.annotation_opts.prefix_strip, "N",
+		    "Strip first N entries of source file path name in programs (with --prefix)"),
 	OPT_BOOLEAN(0, "show-total-period", &symbol_conf.show_total_period,
 		    "Show a column with the sum of periods"),
 	OPT_BOOLEAN_SET(0, "group", &symbol_conf.event_group, &report.group_set,
@@ -1287,6 +1291,9 @@ int cmd_report(int argc, const char **argv)
 		report.symbol_filter_str = argv[0];
 	}
 
+	if (annotate_check_args(&report.annotation_opts) < 0)
+		return -EINVAL;
+
 	if (report.mmaps_mode)
 		report.tasks_mode = true;
 

tools/perf/builtin-top.c

@@ -1512,6 +1512,10 @@ int cmd_top(int argc, const char **argv)
 		    "objdump binary to use for disassembly and annotations"),
 	OPT_STRING('M', "disassembler-style", &top.annotation_opts.disassembler_style, "disassembler style",
 		   "Specify disassembler style (e.g. -M intel for intel syntax)"),
+	OPT_STRING(0, "prefix", &top.annotation_opts.prefix, "prefix",
+		    "Add prefix to source file path names in programs (with --prefix-strip)"),
+	OPT_STRING(0, "prefix-strip", &top.annotation_opts.prefix_strip, "N",
+		    "Strip first N entries of source file path name in programs (with --prefix)"),
 	OPT_STRING('u', "uid", &target->uid_str, "user", "user to profile"),
 	OPT_CALLBACK(0, "percent-limit", &top, "percent",
 		     "Don't show entries under that percent", parse_percent_limit),
@@ -1582,6 +1586,9 @@ int cmd_top(int argc, const char **argv)
 	if (argc)
 		usage_with_options(top_usage, options);
 
+	if (annotate_check_args(&top.annotation_opts) < 0)
+		goto out_delete_evlist;
+
 	if (!top.evlist->core.nr_entries &&
 	    perf_evlist__add_default(top.evlist) < 0) {
 		pr_err("Not enough memory for event selector list\n");

tools/perf/util/annotate.c

@@ -1966,14 +1966,20 @@ static int symbol__disassemble(struct symbol *sym, struct annotate_args *args)
 	err = asprintf(&command,
 		 "%s %s%s --start-address=0x%016" PRIx64
 		 " --stop-address=0x%016" PRIx64
-		 " -l -d %s %s -C \"$1\"",
+		 " -l -d %s %s %s %c%s%c %s%s -C \"$1\"",
 		 opts->objdump_path ?: "objdump",
 		 opts->disassembler_style ? "-M " : "",
 		 opts->disassembler_style ?: "",
 		 map__rip_2objdump(map, sym->start),
 		 map__rip_2objdump(map, sym->end),
 		 opts->show_asm_raw ? "" : "--no-show-raw-insn",
-		 opts->annotate_src ? "-S" : "");
+		 opts->annotate_src ? "-S" : "",
+		 opts->prefix ? "--prefix " : "",
+		 opts->prefix ? '"' : ' ',
+		 opts->prefix ?: "",
+		 opts->prefix ? '"' : ' ',
+		 opts->prefix_strip ? "--prefix-strip=" : "",
+		 opts->prefix_strip ?: "");
 
 	if (err < 0) {
 		pr_err("Failure allocating memory for the command to run\n");
@@ -3204,3 +3210,12 @@ int annotate_parse_percent_type(const struct option *opt, const char *_str,
 	free(str1);
 	return err;
 }
+
+int annotate_check_args(struct annotation_options *args)
+{
+	if (args->prefix_strip && !args->prefix) {
+		pr_err("--prefix-strip requires --prefix\n");
+		return -1;
+	}
+	return 0;
+}

tools/perf/util/annotate.h

@@ -94,6 +94,8 @@ struct annotation_options {
 	int  context;
 	const char *objdump_path;
 	const char *disassembler_style;
+	const char *prefix;
+	const char *prefix_strip;
 	unsigned int percent_type;
 };
 
@@ -415,4 +417,7 @@ void annotation_config__init(void);
 
 int annotate_parse_percent_type(const struct option *opt, const char *_str,
 				int unset);
+
+int annotate_check_args(struct annotation_options *args);
+
 #endif	/* __PERF_ANNOTATE_H */