Add support for producing genksyms-style symtypes files. Process
die_map to find the longest expansions for each type, and use symtypes
references in type definitions. The basic file format is similar to
genksyms, with two notable exceptions:
1. Type names with spaces (common with Rust) in references are
wrapped in single quotes. E.g.:
s#'core::result::Result<u8, core::num::error::ParseIntError>'
2. The actual type definition is the simple parsed DWARF format we
output with --dump-dies, not the preprocessed C-style format
genksyms produces.
Signed-off-by: Sami Tolvanen <samitolva...@google.com>
---
scripts/gendwarfksyms/Makefile | 1 +
scripts/gendwarfksyms/die.c | 13 +
scripts/gendwarfksyms/dwarf.c | 14 +-
scripts/gendwarfksyms/gendwarfksyms.c | 28 +-
scripts/gendwarfksyms/gendwarfksyms.h | 21 +-
scripts/gendwarfksyms/symbols.c | 11 +-
scripts/gendwarfksyms/types.c | 439 ++++++++++++++++++++++++++
7 files changed, 517 insertions(+), 10 deletions(-)
create mode 100644 scripts/gendwarfksyms/types.c
diff --git a/scripts/gendwarfksyms/Makefile b/scripts/gendwarfksyms/Makefile
index 681b42441840..4866a2fd0e46 100644
--- a/scripts/gendwarfksyms/Makefile
+++ b/scripts/gendwarfksyms/Makefile
@@ -5,6 +5,7 @@ gendwarfksyms-objs += cache.o
gendwarfksyms-objs += die.o
gendwarfksyms-objs += dwarf.o
gendwarfksyms-objs += symbols.o
+gendwarfksyms-objs += types.o
HOST_EXTRACFLAGS := -I $(srctree)/tools/include
HOSTLDLIBS_gendwarfksyms := -ldw -lelf
diff --git a/scripts/gendwarfksyms/die.c b/scripts/gendwarfksyms/die.c
index fdd52df88fdd..e40f04b70f7f 100644
--- a/scripts/gendwarfksyms/die.c
+++ b/scripts/gendwarfksyms/die.c
@@ -85,6 +85,19 @@ static void reset_die(struct die *cd)
cd->list = NULL;
}
+int die_map_for_each(die_map_callback_t func, void *arg)
+{
+ struct die *cd;
+ struct hlist_node *tmp;
+ int i;
+
+ hash_for_each_safe(die_map, i, tmp, cd, hash) {
+ check(func(cd, arg));
+ }
+
+ return 0;
+}
+
void die_map_free(void)
{
struct hlist_node *tmp;
diff --git a/scripts/gendwarfksyms/dwarf.c b/scripts/gendwarfksyms/dwarf.c
index 9bca21a71639..62241cc97a76 100644
--- a/scripts/gendwarfksyms/dwarf.c
+++ b/scripts/gendwarfksyms/dwarf.c
@@ -60,11 +60,11 @@ static bool is_export_symbol(struct state *state, Dwarf_Die
*die)
if (get_ref_die_attr(die, DW_AT_abstract_origin, &origin))
source = &origin;
- state->sym = symbol_get(get_name(die));
+ state->sym = symbol_get_unprocessed(get_name(die));
/* Look up using the origin name if there are no matches. */
if (!state->sym && source != die)
- state->sym = symbol_get(get_name(source));
+ state->sym = symbol_get_unprocessed(get_name(source));
state->die = *source;
return !!state->sym;
@@ -384,6 +384,7 @@ static int process_subroutine_type(struct state *state,
struct die *cache,
return check(__process_subroutine_type(state, cache, die,
"subroutine_type"));
}
+
static int process_variant_type(struct state *state, struct die *cache,
Dwarf_Die *die)
{
@@ -695,14 +696,16 @@ static int process_type(struct state *state, struct die
*parent, Dwarf_Die *die)
static int process_subprogram(struct state *state, Dwarf_Die *die)
{
check(__process_subroutine_type(state, NULL, die, "subprogram"));
- return check(process(state, NULL, ";\n"));
+ state->sym->state = MAPPED;
+ return 0;
}
static int process_variable(struct state *state, Dwarf_Die *die)
{
check(process(state, NULL, "variable "));
check(process_type_attr(state, NULL, die));
- return check(process(state, NULL, ";\n"));
+ state->sym->state = MAPPED;
+ return 0;
}
static int process_symbol_ptr(struct state *state, Dwarf_Die *die)
@@ -757,6 +760,9 @@ static int process_exported_symbols(struct state *state,
struct die *cache,
else
check(process_variable(state, &state->die));
+ if (dump_dies)
+ fputs("\n", stderr);
+
cache_clear_expanded(&state->expansion_cache);
return 0;
default:
diff --git a/scripts/gendwarfksyms/gendwarfksyms.c
b/scripts/gendwarfksyms/gendwarfksyms.c
index 1349e592783b..6a219a54c342 100644
--- a/scripts/gendwarfksyms/gendwarfksyms.c
+++ b/scripts/gendwarfksyms/gendwarfksyms.c
@@ -20,6 +20,11 @@ bool debug;
bool dump_dies;
/* Print out inline debugging information about die_map changes */
bool dump_die_map;
+/* Print out type_map contents */
+bool dump_types;
+/* Produce a symtypes file */
+bool symtypes;
+static const char *symtypes_file;
static const struct {
const char *arg;
@@ -29,6 +34,8 @@ static const struct {
{ "--debug", &debug, NULL },
{ "--dump-dies", &dump_dies, NULL },
{ "--dump-die-map", &dump_die_map, NULL },
+ { "--dump-types", &dump_types, NULL },
+ { "--symtypes", &symtypes, &symtypes_file },
};
static int usage(void)
@@ -79,6 +86,7 @@ static int process_modules(Dwfl_Module *mod, void **userdata,
const char *name,
Dwarf_Die cudie;
Dwarf_CU *cu = NULL;
Dwarf *dbg;
+ FILE *symfile = arg;
int res;
debug("%s", name);
@@ -100,6 +108,10 @@ static int process_modules(Dwfl_Module *mod, void
**userdata, const char *name,
check(process_module(mod, dbg, &cudie));
} while (cu);
+ /*
+ * Use die_map to expand type strings and write them to `symfile`.
+ */
+ check(generate_symtypes(symfile));
die_map_free();
return DWARF_CB_OK;
@@ -112,6 +124,7 @@ static const Dwfl_Callbacks callbacks = {
int main(int argc, const char **argv)
{
+ FILE *symfile = NULL;
unsigned int n;
if (parse_options(argc, argv) < 0)
@@ -122,6 +135,16 @@ int main(int argc, const char **argv)
check(symbol_read_exports(stdin));
+ if (symtypes_file) {
+ symfile = fopen(symtypes_file, "w+");
+
+ if (!symfile) {
+ error("fopen failed for '%s': %s", symtypes_file,
+ strerror(errno));
+ return -1;
+ }
+ }
+
for (n = 0; n < object_count; n++) {
Dwfl *dwfl;
int fd;
@@ -151,7 +174,7 @@ int main(int argc, const char **argv)
dwfl_report_end(dwfl, NULL, NULL);
- if (dwfl_getmodules(dwfl, &process_modules, NULL, 0)) {
+ if (dwfl_getmodules(dwfl, &process_modules, symfile, 0)) {
error("dwfl_getmodules failed for '%s'",
object_files[n]);
return -1;
@@ -161,5 +184,8 @@ int main(int argc, const char **argv)
close(fd);
}
+ if (symfile)
+ fclose(symfile);
+
return 0;
}
diff --git a/scripts/gendwarfksyms/gendwarfksyms.h
b/scripts/gendwarfksyms/gendwarfksyms.h
index 7cd907e3d5e3..6edbd6478e0f 100644
--- a/scripts/gendwarfksyms/gendwarfksyms.h
+++ b/scripts/gendwarfksyms/gendwarfksyms.h
@@ -22,6 +22,8 @@
extern bool debug;
extern bool dump_dies;
extern bool dump_die_map;
+extern bool dump_types;
+extern bool symtypes;
#define MAX_INPUT_FILES 128
@@ -89,6 +91,12 @@ extern bool dump_die_map;
#define SYMBOL_PTR_PREFIX "__gendwarfksyms_ptr_"
#define SYMBOL_PTR_PREFIX_LEN (sizeof(SYMBOL_PTR_PREFIX) - 1)
+/* See dwarf.c:is_declaration */
+#define SYMBOL_DECLONLY_PREFIX "__gendwarfksyms_declonly_"
+#define SYMBOL_DECLONLY_PREFIX_LEN (sizeof(SYMBOL_DECLONLY_PREFIX) - 1)
+
+enum symbol_state { UNPROCESSED, MAPPED };
+
struct symbol_addr {
uint32_t section;
Elf64_Addr address;
@@ -109,12 +117,14 @@ struct symbol {
struct symbol_addr addr;
struct hlist_node addr_hash;
struct hlist_node name_hash;
+ enum symbol_state state;
+ uintptr_t die_addr;
};
extern bool is_symbol_ptr(const char *name);
extern int symbol_read_exports(FILE *file);
extern int symbol_read_symtab(int fd);
-extern struct symbol *symbol_get(const char *name);
+extern struct symbol *symbol_get_unprocessed(const char *name);
/*
* die.c
@@ -157,12 +167,15 @@ struct die {
struct hlist_node hash;
};
+typedef int (*die_map_callback_t)(struct die *, void *arg);
+
extern int __die_map_get(uintptr_t addr, enum die_state state,
struct die **res);
extern int die_map_get(Dwarf_Die *die, enum die_state state, struct die **res);
extern int die_map_add_string(struct die *pd, const char *str);
extern int die_map_add_linebreak(struct die *pd, int linebreak);
extern int die_map_add_die(struct die *pd, struct die *child);
+extern int die_map_for_each(die_map_callback_t func, void *arg);
extern void die_map_free(void);
/*
@@ -222,4 +235,10 @@ extern int process_die_container(struct state *state,
struct die *cache,
extern int process_module(Dwfl_Module *mod, Dwarf *dbg, Dwarf_Die *cudie);
+/*
+ * types.c
+ */
+
+extern int generate_symtypes(FILE *file);
+
#endif /* __GENDWARFKSYMS_H */
diff --git a/scripts/gendwarfksyms/symbols.c b/scripts/gendwarfksyms/symbols.c
index d6d016458ae1..8cc04e6295a7 100644
--- a/scripts/gendwarfksyms/symbols.c
+++ b/scripts/gendwarfksyms/symbols.c
@@ -117,6 +117,7 @@ int symbol_read_exports(FILE *file)
sym->name = name;
sym->addr.section = SHN_UNDEF;
+ sym->state = UNPROCESSED;
name = NULL;
hash_add(symbol_names, &sym->name_hash, name_hash(sym->name));
@@ -132,19 +133,21 @@ int symbol_read_exports(FILE *file)
return 0;
}
-static int get_symbol(struct symbol *sym, void *arg)
+static int get_unprocessed(struct symbol *sym, void *arg)
{
struct symbol **res = arg;
- *res = sym;
+ if (sym->state == UNPROCESSED)
+ *res = sym;
+
return 0;
}
-struct symbol *symbol_get(const char *name)
+struct symbol *symbol_get_unprocessed(const char *name)
{
struct symbol *sym = NULL;
- for_each(name, false, get_symbol, &sym);
+ for_each(name, false, get_unprocessed, &sym);
return sym;
}
diff --git a/scripts/gendwarfksyms/types.c b/scripts/gendwarfksyms/types.c
new file mode 100644
index 000000000000..7b9997d8322d
--- /dev/null
+++ b/scripts/gendwarfksyms/types.c
@@ -0,0 +1,439 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2024 Google LLC
+ */
+
+#include "gendwarfksyms.h"
+#include "crc32.h"
+
+static struct expansion_cache expansion_cache;
+
+/*
+ * A simple linked list of shared or owned strings to avoid copying strings
+ * around when not necessary.
+ */
+struct type_list {
+ const char *str;
+ void *owned;
+ struct type_list *next;
+};
+
+static struct type_list *type_list_alloc(void)
+{
+ struct type_list *list;
+
+ list = calloc(1, sizeof(struct type_list));
+ if (!list)
+ error("calloc failed");
+
+ return list;
+}
+
+static void type_list_free(struct type_list *list)
+{
+ struct type_list *tmp;
+
+ while (list) {
+ if (list->owned)
+ free(list->owned);
+
+ tmp = list;
+ list = list->next;
+ free(tmp);
+ }
+}
+
+static int type_list_append(struct type_list *list, const char *s, void *owned)
+{
+ if (!list || !s)
+ return 0;
+
+ while (list->next)
+ list = list->next;
+
+ if (list->str) {
+ list->next = type_list_alloc();
+
+ if (!list->next) {
+ error("type_list_alloc failed");
+ return -1;
+ }
+
+ list = list->next;
+ }
+
+ list->str = s;
+ list->owned = owned;
+
+ return strlen(list->str);
+}
+
+static int type_list_write(struct type_list *list, FILE *file)
+{
+ while (list) {
+ if (list->str)
+ checkp(fputs(list->str, file));
+ list = list->next;
+ }
+
+ return 0;
+}
+
+/*
+ * An expanded type string in symtypes format.
+ */
+struct type_expansion {
+ char *name;
+ struct type_list *expanded;
+ struct type_list *last;
+ size_t len;
+ struct hlist_node hash;
+};
+
+static int type_expansion_init(struct type_expansion *type, bool alloc)
+{
+ memset(type, 0, sizeof(struct type_expansion));
+ if (alloc) {
+ type->expanded = type_list_alloc();
+ if (!type->expanded)
+ return -1;
+
+ type->last = type->expanded;
+ }
+ return 0;
+}
+
+static inline void type_expansion_free(struct type_expansion *type)
+{
+ free(type->name);
+ type_list_free(type->expanded);
+ type_expansion_init(type, false);
+}
+
+static int type_expansion_append(struct type_expansion *type, const char *s,
+ void *owned)
+{
+ type->len += checkp(type_list_append(type->last, s, owned));
+
+ if (type->last->next)
+ type->last = type->last->next;
+
+ return 0;
+}
+
+/*
+ * type_map -- the longest expansions for each type.
+ *
+ * const char *name -> struct type_expansion *
+ */
+#define TYPE_HASH_BITS 16
+static DEFINE_HASHTABLE(type_map, TYPE_HASH_BITS);
+
+static int type_map_get(const char *name, struct type_expansion **res)
+{
+ struct type_expansion *e;
+
+ hash_for_each_possible(type_map, e, hash, name_hash(name)) {
+ if (!strcmp(name, e->name)) {
+ *res = e;
+ return 0;
+ }
+ }
+
+ return -1;
+}
+
+static int type_map_add(const char *name, struct type_expansion *type)
+{
+ struct type_expansion *e;
+
+ if (type_map_get(name, &e)) {
+ e = malloc(sizeof(struct type_expansion));
+ if (!e) {
+ error("malloc failed");
+ return -1;
+ }
+
+ type_expansion_init(e, false);
+
+ e->name = strdup(name);
+ if (!e->name) {
+ error("strdup failed");
+ return -1;
+ }
+
+ hash_add(type_map, &e->hash, name_hash(e->name));
+
+ if (dump_types)
+ debug("adding %s", e->name);
+ } else {
+ /* Use the longest available expansion */
+ if (type->len <= e->len)
+ return 0;
+
+ type_list_free(e->expanded);
+
+ if (dump_types)
+ debug("replacing %s", e->name);
+ }
+
+ /* Take ownership of type->expanded */
+ e->expanded = type->expanded;
+ e->last = type->last;
+ e->len = type->len;
+ type->expanded = NULL;
+ type->last = NULL;
+ type->len = 0;
+
+ if (dump_types) {
+ fputs(e->name, stderr);
+ fputs(" ", stderr);
+ type_list_write(e->expanded, stderr);
+ fputs("\n", stderr);
+ }
+
+ return 0;
+}
+
+static int type_map_write(FILE *file)
+{
+ struct type_expansion *e;
+ struct hlist_node *tmp;
+ int i;
+
+ if (!file)
+ return 0;
+
+ hash_for_each_safe(type_map, i, tmp, e, hash) {
+ checkp(fputs(e->name, file));
+ checkp(fputs(" ", file));
+ type_list_write(e->expanded, file);
+ checkp(fputs("\n", file));
+ }
+
+ return 0;
+}
+
+static void type_map_free(void)
+{
+ struct type_expansion *e;
+ struct hlist_node *tmp;
+ int i;
+
+ hash_for_each_safe(type_map, i, tmp, e, hash) {
+ type_expansion_free(e);
+ free(e);
+ }
+
+ hash_init(type_map);
+}
+
+/*
+ * Type reference format: <prefix>#<name>, where prefix:
+ * s -> structure
+ * u -> union
+ * e -> enum
+ * t -> typedef
+ *
+ * Names with spaces are additionally wrapped in single quotes.
+ */
+static inline bool is_type_prefix(const char *s)
+{
+ return (s[0] == 's' || s[0] == 'u' || s[0] == 'e' || s[0] == 't') &&
+ s[1] == '#';
+}
+
+static char get_type_prefix(int tag)
+{
+ switch (tag) {
+ case DW_TAG_class_type:
+ case DW_TAG_structure_type:
+ return 's';
+ case DW_TAG_union_type:
+ return 'u';
+ case DW_TAG_enumeration_type:
+ return 'e';
+ case DW_TAG_typedef_type:
+ return 't';
+ default:
+ return 0;
+ }
+}
+
+static char *get_type_name(struct die *cache)
+{
+ const char *format;
+ char prefix;
+ char *name;
+ size_t len;
+
+ if (cache->state == INCOMPLETE) {
+ warn("found incomplete cache entry: %p", cache);
+ return NULL;
+ }
+ if (!cache->fqn)
+ return NULL;
+
+ prefix = get_type_prefix(cache->tag);
+ if (!prefix)
+ return NULL;
+
+ /* <prefix>#<type_name>\0 */
+ len = 2 + strlen(cache->fqn) + 1;
+
+ /* Wrap names with spaces in single quotes */
+ if (strstr(cache->fqn, " ")) {
+ format = "%c#'%s'";
+ len += 2;
+ } else {
+ format = "%c#%s";
+ }
+
+ name = malloc(len);
+ if (!name) {
+ error("malloc failed");
+ return NULL;
+ }
+
+ if (snprintf(name, len, format, prefix, cache->fqn) >= len) {
+ error("snprintf failed for '%s' (length %zu)", cache->fqn,
+ len);
+ free(name);
+ return NULL;
+ }
+
+ return name;
+}
+
+static int __type_expand(struct die *cache, struct type_expansion *type,
+ bool recursive);
+
+static int type_expand_child(struct die *cache, struct type_expansion *type,
+ bool recursive)
+{
+ struct type_expansion child;
+ char *name;
+
+ name = get_type_name(cache);
+ if (!name)
+ return check(__type_expand(cache, type, recursive));
+
+ if (recursive && !__cache_was_expanded(&expansion_cache, cache->addr)) {
+ check(__cache_mark_expanded(&expansion_cache, cache->addr));
+ check(type_expansion_init(&child, true));
+ check(__type_expand(cache, &child, true));
+ check(type_map_add(name, &child));
+ type_expansion_free(&child);
+ }
+
+ check(type_expansion_append(type, name, name));
+ return 0;
+}
+
+static int __type_expand(struct die *cache, struct type_expansion *type,
+ bool recursive)
+{
+ struct die_fragment *df = cache->list;
+ struct die *child;
+
+ while (df) {
+ switch (df->type) {
+ case STRING:
+ check(type_expansion_append(type, df->data.str, NULL));
+ break;
+ case DIE:
+ /* Use a complete die_map expansion if available */
+ if (__die_map_get(df->data.addr, COMPLETE, &child) &&
+ __die_map_get(df->data.addr, UNEXPANDED, &child)) {
+ error("unknown child: %" PRIxPTR,
+ df->data.addr);
+ return -1;
+ }
+
+ check(type_expand_child(child, type, recursive));
+ break;
+ case LINEBREAK:
+ /*
+ * Keep whitespace in the symtypes format, but avoid
+ * repeated spaces.
+ */
+ if (!df->next || df->next->type != LINEBREAK)
+ check(type_expansion_append(type, " ", NULL));
+ break;
+ default:
+ error("empty die_fragment in %p", cache);
+ return -1;
+ }
+
+ df = df->next;
+ }
+
+ return 0;
+}
+
+static int type_expand(struct die *cache, struct type_expansion *type,
+ bool recursive)
+{
+ check(type_expansion_init(type, true));
+ check(__type_expand(cache, type, recursive));
+ cache_clear_expanded(&expansion_cache);
+ return 0;
+}
+
+static int expand_type(struct die *cache, void *arg)
+{
+ struct type_expansion type;
+ char *name;
+
+ /*
+ * Skip unexpanded die_map entries if there's a complete
+ * expansion available for this DIE.
+ */
+ if (cache->state == UNEXPANDED)
+ __die_map_get(cache->addr, COMPLETE, &cache);
+
+ if (cache->mapped)
+ return 0;
+
+ cache->mapped = true;
+
+ name = get_type_name(cache);
+ if (!name)
+ return 0;
+
+ debug("%s", name);
+ check(type_expand(cache, &type, true));
+ check(type_map_add(name, &type));
+
+ type_expansion_free(&type);
+ free(name);
+
+ return 0;
+}
+
+int generate_symtypes(FILE *file)
+{
+ hash_init(expansion_cache.cache);
+
+ /*
+ * die_map processing:
+ *
+ * 1. die_map contains all types referenced in exported symbol
+ * signatures, but can contain duplicates just like the original
+ * DWARF, and some references may not be fully expanded depending
+ * on how far we processed the DIE tree for that specific symbol.
+ *
+ * For each die_map entry, find the longest available expansion,
+ * and add it to type_map.
+ */
+ check(die_map_for_each(expand_type, NULL));
+
+ /*
+ * 2. If a symtypes file is requested, write type_map contents to
+ * the file.
+ */
+ check(type_map_write(file));
+ type_map_free();
+
+ return 0;
+}
--
2.46.0.184.g6999bdac58-goog
