perf annotate: Don't pipe objdump output through 'expand' command

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.

Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: clang-built-linux@googlegroups.com
Link: http://lore.kernel.org/lkml/20191010183649.23768-5-irogers@google.com
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 0e052e2..efc5bfe 100644 (file)
--- a/tools/perf/util/annotate.c
+++ b/tools/perf/util/annotate.c
@@ -1492,35 +1492,24 @@ 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);
 
@@ -1528,7 +1517,7 @@ 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;
@@ -1854,6 +1843,67 @@ 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;
@@ -1916,7 +1966,7 @@ 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 ?: "",
@@ -1963,6 +2013,7 @@ 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;
@@ -1972,13 +2023,19 @@ 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++;
        }