Commit 2c4b9280 authored by Ian Rogers's avatar Ian Rogers Committed by Arnaldo Carvalho de Melo
Browse files

perf srcline: Support for llvm-addr2line 



The sentinel value differs for llvm-addr2line. Configure this once and
then detect when reading records.

Signed-off-by: default avatarIan Rogers <irogers@google.com>
Acked-by: default avatarNamhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tom Rix <trix@redhat.com>
Cc: llvm@lists.linux.dev
Link: https://lore.kernel.org/r/20230403184033.1836023-2-irogers@google.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent b3801e79

tools/perf/util/srcline.c

+67 −7
Original line number Diff line number Diff line
@@ -435,7 +435,50 @@ static struct child_process *addr2line_subprocess_init(const char *addr2line_pat 
	return a2l;

}



enum a2l_style {

	BROKEN,

	GNU_BINUTILS,

	LLVM,

};



static enum a2l_style addr2line_configure(struct child_process *a2l)

{

	static bool cached;

	static enum a2l_style style;



	if (!cached) {

		char buf[128];

		struct io io;

		int ch;



		if (write(a2l->in, ",\n", 2) != 2)

			return BROKEN;



		io__init(&io, a2l->out, buf, sizeof(buf));

		ch = io__get_char(&io);

		if (ch == ',') {

			style = LLVM;

			cached = true;

		} else if (ch == '?') {

			style = GNU_BINUTILS;

			cached = true;

		} else {

			style = BROKEN;

		}

		do {

			ch = io__get_char(&io);

		} while (ch > 0 && ch != '\n');

		if (style == GNU_BINUTILS) {

			do {

				ch = io__get_char(&io);

			} while (ch > 0 && ch != '\n');

		}

	}

	return style;

}



static int read_addr2line_record(struct io *io,

				 enum a2l_style style,

				 char **function,

				 char **filename,

				 unsigned int *line_nr)
@@ -462,6 +505,12 @@ static int read_addr2line_record(struct io *io, 


	if (io__getline(io, &line, &line_len) < 0 || !line_len)

		goto error;



	if (style == LLVM && line_len == 2 && line[0] == ',') {

		zfree(&line);

		return 0;

	}



	if (function != NULL)

		*function = strdup(strim(line));
@@ -471,7 +520,8 @@ static int read_addr2line_record(struct io *io, 
	if (io__getline(io, &line, &line_len) < 0 || !line_len)

		goto error;



	if (filename_split(line, line_nr == NULL ? &dummy_line_nr : line_nr) == 0) {

	if (filename_split(line, line_nr == NULL ? &dummy_line_nr : line_nr) == 0 &&

	    style == GNU_BINUTILS) {

		ret = 0;

		goto error;

	}
@@ -523,6 +573,7 @@ static int addr2line(const char *dso_name, u64 addr, 
	char buf[128];

	ssize_t written;

	struct io io;

	enum a2l_style a2l_style;



	if (!a2l) {

		if (!filename__has_section(dso_name, ".debug_line"))
@@ -538,15 +589,22 @@ static int addr2line(const char *dso_name, u64 addr, 
			pr_warning("%s %s: addr2line_subprocess_init failed\n", __func__, dso_name);

		goto out;

	}

	a2l_style = addr2line_configure(a2l);

	if (a2l_style == BROKEN) {

		if (!symbol_conf.disable_add2line_warn)

			pr_warning("%s: addr2line configuration failed\n", __func__);

		goto out;

	}



	/*

	 * Send our request and then *deliberately* send something that can't be interpreted as

	 * a valid address to ask addr2line about (namely, ","). This causes addr2line to first

	 * write out the answer to our request, in an unbounded/unknown number of records, and

	 * then to write out the lines "??" and "??:0", so that we can detect when it has

	 * finished giving us anything useful. We have to be careful about the first record,

	 * though, because it may be genuinely unknown, in which case we'll get two sets of

	 * "??"/"??:0" lines.

	 * then to write out the lines "??" and "??:0", for GNU binutils, or "," for

	 * llvm-addr2line, so that we can detect when it has finished giving us anything

	 * useful. With GNU binutils, we have to be careful about the first record, though,

	 * because it may be genuinely unknown, in which case we'll get two sets of "??"/"??:0"

	 * lines.

	 */

	len = snprintf(buf, sizeof(buf), "%016"PRIx64"\n,\n", addr);

	written = len > 0 ? write(a2l->in, buf, len) : -1;
@@ -557,7 +615,8 @@ static int addr2line(const char *dso_name, u64 addr, 
	}

	io__init(&io, a2l->out, buf, sizeof(buf));



	switch (read_addr2line_record(&io, &record_function, &record_filename, &record_line_nr)) {

	switch (read_addr2line_record(&io, a2l_style,

				      &record_function, &record_filename, &record_line_nr)) {

	case -1:

		if (!symbol_conf.disable_add2line_warn)

			pr_warning("%s %s: could not read first record\n", __func__, dso_name);
@@ -567,7 +626,7 @@ static int addr2line(const char *dso_name, u64 addr, 
		 * The first record was invalid, so return failure, but first read another

		 * record, since we asked a junk question and have to clear the answer out.

		 */

		switch (read_addr2line_record(&io, NULL, NULL, NULL)) {

		switch (read_addr2line_record(&io, a2l_style, NULL, NULL, NULL)) {

		case -1:

			if (!symbol_conf.disable_add2line_warn)

				pr_warning("%s %s: could not read delimiter record\n",
@@ -606,6 +665,7 @@ static int addr2line(const char *dso_name, u64 addr, 


	/* We have to read the records even if we don't care about the inline info. */

	while ((record_status = read_addr2line_record(&io,

						      a2l_style,

						      &record_function,

						      &record_filename,

						      &record_line_nr)) == 1) {