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#include "dwarves.h"
#include "libbtf.h"
#include "btf.h"
#include "hash.h"
#include "elf_symtab.h"
#include "btf_encoder.h"
#include <inttypes.h>
static int tag__check_id_drift(const struct tag *tag,
uint32_t core_id, uint32_t btf_type_id)
{
if (btf_type_id != core_id) {
fprintf(stderr, "%s: %s id drift, core_id: %u, btf_type_id: %u\n",
__func__, dwarf_tag_name(tag->tag),
core_id, btf_type_id);
return -1;
}
return 0;
}
static int32_t structure_type__encode(struct btf *btf, struct tag *tag)
{
struct type *type = tag__type(tag);
struct class_member *pos;
int32_t type_id;
uint8_t kind;
kind = (tag->tag == DW_TAG_union_type) ?
BTF_KIND_UNION : BTF_KIND_STRUCT;
type_id = btf__add_struct(btf, kind, type->namespace.name,
type->size, type->nr_members);
if (type_id < 0)
return type_id;
type__for_each_data_member(type, pos)
if (btf__add_member(btf, pos->name, pos->tag.type,
pos->bit_offset))
return -1;
return type_id;
}
static uint32_t array_type__nelems(struct tag *tag)
{
int i;
uint32_t nelem = 1;
struct array_type *array = tag__array_type(tag);
for (i = array->dimensions - 1; i >= 0; --i)
nelem *= array->nr_entries[i];
return nelem;
}
static int32_t enumeration_type__encode(struct btf *btf, struct tag *tag)
{
struct type *etype = tag__type(tag);
struct enumerator *pos;
int32_t type_id;
type_id = btf__add_enum(btf, etype->namespace.name,
etype->size, etype->nr_members);
if (type_id < 0)
return type_id;
type__for_each_enumerator(etype, pos)
if (btf__add_enum_val(btf, pos->name, pos->value))
return -1;
return type_id;
}
static int tag__encode_btf(struct tag *tag, uint32_t core_id, struct btf *btf,
uint32_t array_index_id)
{
switch (tag->tag) {
case DW_TAG_base_type:
return btf__add_base_type(btf, tag__base_type(tag));
case DW_TAG_const_type:
return btf__add_ref_type(btf, BTF_KIND_CONST, tag->type, 0);
case DW_TAG_pointer_type:
return btf__add_ref_type(btf, BTF_KIND_PTR, tag->type, 0);
case DW_TAG_restrict_type:
return btf__add_ref_type(btf, BTF_KIND_RESTRICT, tag->type, 0);
case DW_TAG_volatile_type:
return btf__add_ref_type(btf, BTF_KIND_VOLATILE, tag->type, 0);
case DW_TAG_typedef:
return btf__add_ref_type(btf, BTF_KIND_TYPEDEF, tag->type,
tag__namespace(tag)->name);
case DW_TAG_structure_type:
case DW_TAG_union_type:
case DW_TAG_class_type:
if (tag__type(tag)->declaration)
return btf__add_ref_type(btf, BTF_KIND_FWD, 0,
tag__namespace(tag)->name);
else
return structure_type__encode(btf, tag);
case DW_TAG_array_type:
return btf__add_array(btf, tag->type, array_index_id,
/*TODO: Encode one dimension
* at a time.
*/
array_type__nelems(tag));
case DW_TAG_enumeration_type:
return enumeration_type__encode(btf, tag);
case DW_TAG_subroutine_type:
/* A dummy void * to avoid a shift in btf->type_index */
btf_verbose_log("Filling unsupported DW_TAG_%s(0x%x) with void *\n",
dwarf_tag_name(tag->tag), tag->tag);
return btf__add_ref_type(btf, BTF_KIND_PTR, 0, 0);
default:
fprintf(stderr, "Unsupported DW_TAG_%s(0x%x)\n",
dwarf_tag_name(tag->tag), tag->tag);
return -1;
}
}
/*
* FIXME: Its in the DWARF loader, we have to find a better handoff
* mechanizm...
*/
extern struct strings *strings;
int cu__encode_btf(struct cu *cu, int verbose)
{
struct btf *btf = btf__new(cu->filename, cu->elf);
struct tag *pos;
uint32_t core_id, array_index_id;
uint16_t id;
int err;
btf_verbose = verbose;
if (btf == NULL)
return -1;
btf__set_strings(btf, &strings->gb);
/* cu__find_base_type_by_name() takes "uint16_t *id" */
if (!cu__find_base_type_by_name(cu, "int", &id))
id = cu->types_table.nr_entries;
array_index_id = id;
cu__for_each_type(cu, core_id, pos) {
int32_t btf_type_id = tag__encode_btf(pos, core_id, btf,
array_index_id);
if (btf_type_id < 0 ||
tag__check_id_drift(pos, core_id, btf_type_id)) {
err = -1;
goto out;
}
id = btf_type_id;
}
if (array_index_id == cu->types_table.nr_entries) {
struct base_type bt = {};
bt.name = 0;
bt.bit_size = 32;
btf__add_base_type(btf, &bt);
}
err = btf__encode(btf, 0);
out:
btf__free(btf);
if (err)
fprintf(stderr, "Failed to encode BTF\n");
return err;
}
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