gendwarfksyms: Add die_map debugging
authorSami Tolvanen <samitolvanen@google.com>
Fri, 3 Jan 2025 20:45:32 +0000 (20:45 +0000)
committerMasahiro Yamada <masahiroy@kernel.org>
Fri, 10 Jan 2025 16:25:25 +0000 (01:25 +0900)
Debugging the DWARF processing can be somewhat challenging, so add
more detailed debugging output for die_map operations. Add the
--dump-die-map flag, which adds color coded tags to the output for
die_map changes.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
scripts/gendwarfksyms/dwarf.c
scripts/gendwarfksyms/gendwarfksyms.c
scripts/gendwarfksyms/gendwarfksyms.h

index 6b30e45a4e8204ec8bf75c3dd71985827ab4f9f4..364ff4892d5c82702d21f14534912984244b62c5 100644 (file)
@@ -146,6 +146,8 @@ static void process(struct die *cache, const char *s)
        if (dump_dies)
                fputs(s, stderr);
 
+       if (cache)
+               die_debug_r("cache %p string '%s'", cache, s);
        die_map_add_string(cache, s);
 }
 
@@ -594,6 +596,8 @@ static void process_cached(struct state *state, struct die *cache,
        list_for_each_entry(df, &cache->fragments, list) {
                switch (df->type) {
                case FRAGMENT_STRING:
+                       die_debug_b("cache %p STRING '%s'", cache,
+                                   df->data.str);
                        process(NULL, df->data.str);
                        break;
                case FRAGMENT_LINEBREAK:
@@ -603,6 +607,8 @@ static void process_cached(struct state *state, struct die *cache,
                        if (!dwarf_die_addr_die(dwarf_cu_getdwarf(die->cu),
                                                (void *)df->data.addr, &child))
                                error("dwarf_die_addr_die failed");
+                       die_debug_b("cache %p DIE addr %" PRIxPTR " tag %x",
+                                   cache, df->data.addr, dwarf_tag(&child));
                        check(process_type(state, NULL, &child));
                        break;
                default:
@@ -671,6 +677,9 @@ static int process_type(struct state *state, struct die *parent, Dwarf_Die *die)
        cache = die_map_get(die, want_state);
 
        if (cache->state == want_state) {
+               die_debug_g("cached addr %p tag %x -- %s", die->addr, tag,
+                           die_state_name(cache->state));
+
                process_cached(state, cache, die);
                die_map_add_die(parent, cache);
 
@@ -678,6 +687,9 @@ static int process_type(struct state *state, struct die *parent, Dwarf_Die *die)
                return 0;
        }
 
+       die_debug_g("addr %p tag %x -- %s -> %s", die->addr, tag,
+                   die_state_name(cache->state), die_state_name(want_state));
+
        switch (tag) {
        /* Type modifiers */
        PROCESS_TYPE(atomic)
@@ -713,6 +725,9 @@ static int process_type(struct state *state, struct die *parent, Dwarf_Die *die)
                error("unexpected type: %x", tag);
        }
 
+       die_debug_r("parent %p cache %p die addr %p tag %x", parent, cache,
+                   die->addr, tag);
+
        /* Update cache state and append to the parent (if any) */
        cache->tag = tag;
        cache->state = want_state;
index 3809db840c06fbc2564670607b5ae18af0b163e5..bf282e33e00ce806422d6012f654e5c4f9c3e267 100644 (file)
@@ -19,6 +19,8 @@
 int debug;
 /* Dump DIE contents */
 int dump_dies;
+/* Print debugging information about die_map changes */
+int dump_die_map;
 
 static void usage(void)
 {
@@ -26,6 +28,7 @@ static void usage(void)
              "Options:\n"
              "  -d, --debug          Print debugging information\n"
              "      --dump-dies      Dump DWARF DIE contents\n"
+             "      --dump-die-map   Print debugging information about die_map changes\n"
              "  -h, --help           Print this message\n"
              "\n",
              stderr);
@@ -75,6 +78,7 @@ int main(int argc, char **argv)
        static const struct option opts[] = {
                { "debug", 0, NULL, 'd' },
                { "dump-dies", 0, &dump_dies, 1 },
+               { "dump-die-map", 0, &dump_die_map, 1 },
                { "help", 0, NULL, 'h' },
                { 0, 0, NULL, 0 }
        };
@@ -95,6 +99,9 @@ int main(int argc, char **argv)
                }
        }
 
+       if (dump_die_map)
+               dump_dies = 1;
+
        if (optind >= argc) {
                usage();
                error("no input files?");
index 941c4134da8ed1bb0161e6ba9ec86d0c10f8cda5..251832dac59979986b752bf1854c3900d7dc8ed7 100644 (file)
@@ -21,6 +21,7 @@
  */
 extern int debug;
 extern int dump_dies;
+extern int dump_die_map;
 
 /*
  * Output helpers
@@ -43,6 +44,18 @@ extern int dump_dies;
                exit(1);                                     \
        } while (0)
 
+#define __die_debug(color, format, ...)                                 \
+       do {                                                            \
+               if (dump_dies && dump_die_map)                          \
+                       fprintf(stderr,                                 \
+                               "\033[" #color "m<" format ">\033[39m", \
+                               __VA_ARGS__);                           \
+       } while (0)
+
+#define die_debug_r(format, ...) __die_debug(91, format, __VA_ARGS__)
+#define die_debug_g(format, ...) __die_debug(92, format, __VA_ARGS__)
+#define die_debug_b(format, ...) __die_debug(94, format, __VA_ARGS__)
+
 /*
  * Error handling helpers
  */