From: Douglas Raillard <douglas.raillard@xxxxxxx>
Print forward declaration for types supporting it. This allows creating
a self-contained header where it is guaranteed that union and struct
pointers will compile correctly regardless of their declaration order.
Signed-off-by: Douglas Raillard <douglas.raillard@xxxxxxx>
---
dwarves.h | 4 ++++
dwarves_fprintf.c | 5 +----
pahole.c | 22 ++++++++++++++++++++++
3 files changed, 27 insertions(+), 4 deletions(-)
diff --git a/dwarves.h b/dwarves.h
index 0967e5c..3f4b31b 100644
--- a/dwarves.h
+++ b/dwarves.h
@@ -1046,6 +1046,10 @@ struct type {
void __type__init(struct type *type);
+size_t type__fprintf(struct tag *type, const struct cu *cu,
+ const char *name, const struct conf_fprintf *conf,
+ FILE *fp);
+
size_t tag__natural_alignment(struct tag *tag, const struct cu *cu);
static inline struct class *type__class(const struct type *type)
diff --git a/dwarves_fprintf.c b/dwarves_fprintf.c
index 2c5dce6..c116184 100644
--- a/dwarves_fprintf.c
+++ b/dwarves_fprintf.c
@@ -199,9 +199,6 @@ size_t tag__fprintf_decl_info(const struct tag *tag,
static size_t __class__fprintf(struct class *class, const struct cu *cu,
const struct conf_fprintf *conf, FILE *fp);
-static size_t type__fprintf(struct tag *type, const struct cu *cu,
- const char *name, const struct conf_fprintf *conf,
- FILE *fp);
static size_t array_type__fprintf(const struct tag *tag,
const struct cu *cu, const char *name,
@@ -637,7 +634,7 @@ static size_t type__fprintf_stats(struct type *type, const struct cu *cu,
static size_t union__fprintf(struct type *type, const struct cu *cu,
const struct conf_fprintf *conf, FILE *fp);
-static size_t type__fprintf(struct tag *type, const struct cu *cu,
+size_t type__fprintf(struct tag *type, const struct cu *cu,
const char *name, const struct conf_fprintf *conf,
FILE *fp)
{
diff --git a/pahole.c b/pahole.c
index e828c31..73579f5 100644
--- a/pahole.c
+++ b/pahole.c
@@ -59,6 +59,8 @@ static size_t cu__exclude_prefix_len;
static char *decl_exclude_prefix;
static size_t decl_exclude_prefix_len;
+static bool print_forward_decl;
+
static uint16_t nr_holes;
static uint16_t nr_bit_holes;
static uint16_t hole_size_ge;
@@ -1128,6 +1130,7 @@ ARGP_PROGRAM_VERSION_HOOK_DEF = dwarves_print_version;
#define ARGP_skip_missing 332
#define ARGP_skip_encoding_btf_type_tag 333
#define ARGP_expanded_prefix 334
+#define ARGP_forward_decl 335
static const struct argp_option pahole__options[] = {
{
@@ -1241,6 +1244,11 @@ static const struct argp_option pahole__options[] = {
.arg = "NAME_PREFIX",
.doc = "Add prefix to all the nested types displayed with --expand_types",
},
+ {
+ .name = "forward_decl",
+ .key = ARGP_forward_decl,
+ .doc = "Print a forward declaration for types that support it",
+ },
{
.name = "nr_members",
.key = 'n',
@@ -1675,6 +1683,8 @@ static error_t pahole__options_parser(int key, char *arg,
conf_load.skip_encoding_btf_type_tag = true; break;
case ARGP_expanded_prefix:
conf.name_prefix = arg; break;
+ case ARGP_forward_decl:
+ print_forward_decl = true; break;
default:
return ARGP_ERR_UNKNOWN;
}
@@ -2898,6 +2908,10 @@ out_btf:
bool skip;
const char *prefix = conf_load->conf_fprintf->name_prefix;
const size_t prefix_len = prefix ? strlen(prefix) : 0;
+
+ struct conf_fprintf pconf = *conf_load->conf_fprintf;
+ pconf.expand_types = false;
+
cu__for_each_type(cu, id, pos) {
if (tag__is_type(pos)) {
const char *name = type__name(tag__type(pos));
@@ -2917,6 +2931,14 @@ out_btf:
}
}
}
+ if (print_forward_decl && (tag__is_union(pos) || tag__is_struct(pos))) {
+ const char *name = type__name(tag__type(pos));
+ if (name) {
+ type__fprintf(pos, cu, NULL, &pconf, stdout);
+ pos->printed = false;
+ printf(";\n");
+ }
+ }
}
list_for_each_entry_safe(prototype, n, &class_names, node) {
--
2.25.1
