Re: [PATCH 4/5] perf annotate: don't pipe objdump output through expand

Arnaldo Carvalho de Melo
2019-10-14T14:24:44Z

Em Thu, Oct 10, 2019 at 11:36:48AM -0700, Ian Rogers escreveu:
> Avoiding a pipe allows objdump command failures to surface.
> Move to the caller of symbol__parse_objdump_line the call to strim
> that removes leading and trailing tabs.
> Add a new expand_tabs function that if a tab is present allocate a new
> line in which tabs are expanded.
> In symbol__parse_objdump_line the line had no leading spaces, so
> simplify the line_ip processing.

Thanks, applied.

> Signed-off-by: Ian Rogers <irogers@google.com>
> ---
> tools/perf/util/annotate.c | 95 ++++++++++++++++++++++++++++++--------
> 1 file changed, 76 insertions(+), 19 deletions(-)
>
> diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
> index 0a7a6f3c55f4..3d5b9236576a 100644
> --- a/tools/perf/util/annotate.c
> +++ b/tools/perf/util/annotate.c
> @@ -1488,35 +1488,24 @@ annotation_line__print(struct annotation_line *al, struct symbol *sym, u64 start
> */
> static int symbol__parse_objdump_line(struct symbol *sym,
> struct annotate_args *args,
> - char *line, int *line_nr)
> + char *parsed_line, int *line_nr)
> {
> struct map *map = args->ms.map;
> struct annotation *notes = symbol__annotation(sym);
> struct disasm_line *dl;
> - char *parsed_line, *tmp, *tmp2;
> + char *tmp;
> s64 line_ip, offset = -1;
> regmatch_t match[2];
>
> - line_ip = -1;
> - parsed_line = strim(line);
> -
> /* /filename:linenr ? Save line number and ignore. */
> if (regexec(&file_lineno, parsed_line, 2, match, 0) == 0) {
> *line_nr = atoi(parsed_line + match[1].rm_so);
> return 0;
> }
>
> - tmp = skip_spaces(parsed_line);
> - if (*tmp) {
> - /*
> - * Parse hexa addresses followed by ':'
> - */
> - line_ip = strtoull(tmp, &tmp2, 16);
> - if (*tmp2 != ':' || tmp == tmp2 || tmp2[1] == '\0')
> - line_ip = -1;
> - }
> -
> - if (line_ip != -1) {
> + /* Process hex address followed by ':'. */
> + line_ip = strtoull(parsed_line, &tmp, 16);
> + if (parsed_line != tmp && tmp[0] == ':' && tmp[1] != '\0') {
> u64 start = map__rip_2objdump(map, sym->start),
> end = map__rip_2objdump(map, sym->end);
>
> @@ -1524,7 +1513,7 @@ static int symbol__parse_objdump_line(struct symbol *sym,
> if ((u64)line_ip < start || (u64)line_ip >= end)
> offset = -1;
> else
> - parsed_line = tmp2 + 1;
> + parsed_line = tmp + 1;
> }
>
> args->offset = offset;
> @@ -1833,6 +1822,67 @@ static int symbol__disassemble_bpf(struct symbol *sym __maybe_unused,
> }
> #endif // defined(HAVE_LIBBFD_SUPPORT) && defined(HAVE_LIBBPF_SUPPORT)
>
> +/*
> + * Possibly create a new version of line with tabs expanded. Returns the
> + * existing or new line, storage is updated if a new line is allocated. If
> + * allocation fails then NULL is returned.
> + */
> +static char *expand_tabs(char *line, char **storage, size_t *storage_len)
> +{
> + size_t i, src, dst, len, new_storage_len, num_tabs;
> + char *new_line;
> + size_t line_len = strlen(line);
> +
> + for (num_tabs = 0, i = 0; i < line_len; i++)
> + if (line[i] == '\t')
> + num_tabs++;
> +
> + if (num_tabs == 0)
> + return line;
> +
> + /*
> + * Space for the line and '\0', less the leading and trailing
> + * spaces. Each tab may introduce 7 additional spaces.
> + */
> + new_storage_len = line_len + 1 + (num_tabs * 7);
> +
> + new_line = malloc(new_storage_len);
> + if (new_line == NULL) {
> + pr_err("Failure allocating memory for tab expansion\n");
> + return NULL;
> + }
> +
> + /*
> + * Copy regions starting at src and expand tabs. If there are two
> + * adjacent tabs then 'src == i', the memcpy is of size 0 and the spaces
> + * are inserted.
> + */
> + for (i = 0, src = 0, dst = 0; i < line_len && num_tabs; i++) {
> + if (line[i] == '\t') {
> + len = i - src;
> + memcpy(&new_line[dst], &line[src], len);
> + dst += len;
> + new_line[dst++] = ' ';
> + while (dst % 8 != 0)
> + new_line[dst++] = ' ';
> + src = i + 1;
> + num_tabs--;
> + }
> + }
> +
> + /* Expand the last region. */
> + len = line_len + 1 - src;
> + memcpy(&new_line[dst], &line[src], len);
> + dst += len;
> + new_line[dst] = '\0';
> +
> + free(*storage);
> + *storage = new_line;
> + *storage_len = new_storage_len;
> + return new_line;
> +
> +}
> +
> static int symbol__disassemble(struct symbol *sym, struct annotate_args *args)
> {
> struct annotation_options *opts = args->options;
> @@ -1894,7 +1944,7 @@ 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\" 2>/dev/null|expand",
> + " -l -d %s %s -C \"$1\" 2>/dev/null",
> opts->objdump_path ?: "objdump",
> opts->disassembler_style ? "-M " : "",
> opts->disassembler_style ?: "",
> @@ -1941,6 +1991,7 @@ static int symbol__disassemble(struct symbol *sym, struct annotate_args *args)
> nline = 0;
> while (!feof(file)) {
> const char *match;
> + char *expanded_line;
>
> if (getline(&line, &line_len, file) < 0 || !line)
> break;
> @@ -1950,13 +2001,19 @@ static int symbol__disassemble(struct symbol *sym, struct annotate_args *args)
> if (match && match[strlen(symfs_filename)] == ':')
> continue;
>
> + expanded_line = strim(line);
> + expanded_line = expand_tabs(expanded_line, &line, &line_len);
> + if (!expanded_line)
> + break;
> +
> /*
> * The source code line number (lineno) needs to be kept in
> * across 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, args, line, &lineno) < 0)
> + if (symbol__parse_objdump_line(sym, args, expanded_line,
> + &lineno) < 0)
> break;
> nline++;
> }
> --
> 2.23.0.581.g78d2f28ef7-goog

--

- Arnaldo