#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "target.h"
#include "memmodel.h"
#include "tm_p.h"
#include "output.h"
#include "dwarf2asm.h"
#include "debug.h"
#include "ctfc.h"
#include "diagnostic-core.h"
#include "cgraph.h"
#include "varasm.h"
#include "stringpool.h"
#include "attribs.h"
#include "dwarf2out.h"
#include "gt-btfout.h"

Include dependency graph for btfout.cc:

Data Structures
struct	btf_datasec_entry
struct	btf_datasec
struct	btf_fixup

Macros
#define	BTF_INFO_SECTION_NAME ".BTF"
#define	BTF_INFO_SECTION_FLAGS (SECTION_DEBUG)
#define	MAX_BTF_LABEL_BYTES 40
#define	BTF_INFO_SECTION_LABEL "Lbtf"
#define	BTF_INVALID_TYPEID 0xFFFFFFFF

Typedefs
typedef struct btf_datasec	btf_datasec_t

Functions
static const char *	btf_kind_name (uint32_t btf_kind)
static uint32_t	get_btf_kind (uint32_t ctf_kind)
uint32_t	btf_dtd_kind (ctf_dtdef_ref dtd)
static const char *	get_btf_type_name (ctf_dtdef_ref dtd)
static bool	btf_emit_type_p (ctf_dtdef_ref dtd)
static bool	btf_fwd_to_enum_p (ctf_dtdef_ref dtd)
static uint64_t	btf_calc_num_vbytes (ctf_dtdef_ref dtd)
void	init_btf_sections (void)
static const char *	get_section_name (symtab_node *node)
static bool	btf_dmd_representable_bitfield_p (ctf_dmdef_t *dmd)
static void	btf_asm_type_ref (const char *prefix, ctf_dtdef_ref dtd)
static void	btf_asm_type (ctf_dtdef_ref dtd)
static void	btf_asm_array (ctf_arinfo_t arr)
static void	btf_asm_varent (ctf_dvdef_ref var)
static void	btf_asm_sou_member (ctf_dmdef_t *dmd, unsigned int idx)
static void	btf_asm_enum_const (unsigned int size, ctf_dmdef_t *dmd, unsigned int idx)
static void	btf_asm_func_arg (ctf_func_arg_t *farg, size_t stroffset)
static void	btf_asm_func_type (ctf_dtdef_ref dtd)
static void	btf_asm_datasec_entry (struct btf_datasec_entry entry)
static void	btf_asm_datasec_type (btf_datasec_t ds)
static void	output_btf_header (ctf_container_ref ctfc)
static void	output_btf_vars (ctf_container_ref ctfc)
static void	output_btf_strs (ctf_container_ref ctfc)
static void	output_asm_btf_sou_fields (ctf_dtdef_ref dtd)
static void	output_asm_btf_enum_list (ctf_dtdef_ref dtd)
static void	output_asm_btf_func_args_list (ctf_container_ref ctfc, ctf_dtdef_ref dtd)
static void	output_asm_btf_vlen_bytes (ctf_container_ref ctfc, ctf_dtdef_ref dtd)
static void	output_asm_btf_type (ctf_container_ref ctfc, ctf_dtdef_ref type)
static void	output_btf_types (ctf_container_ref ctfc)
static void	output_btf_func_types (void)
static void	output_btf_tags (ctf_container_ref ctfc)
static void	output_btf_datasec_types (void)
void	btf_output (ctf_container_ref ctfc)
static void	btf_add_const_void (ctf_container_ref ctfc)
static void	btf_add_func_records (ctf_container_ref ctfc)
static ctf_dtdef_ref	btf_add_used_type_1 (ctf_container_ref ctfc, ctf_dtdef_ref dtd, bool check_ptr, bool seen_ptr, bool create_fixups)
static ctf_dtdef_ref	btf_add_used_type (ctf_container_ref ctfc, ctf_dtdef_ref dtd)
void	btf_early_finish (void)
static void	btf_datasec_push_entry (ctf_container_ref ctfc, const char *secname, struct btf_datasec_entry entry)
static void	btf_datasec_add_func (ctf_container_ref ctfc, cgraph_node *func, ctf_dtdef_ref func_dtd)
static void	btf_datasec_add_var (ctf_container_ref ctfc, varpool_node *var, ctf_dvdef_ref dvd)
static void	btf_add_func_datasec_entries (ctf_container_ref ctfc)
static bool	btf_emit_variable_p (ctf_container_ref ctfc, varpool_node var, ctf_dvdef_ref pdvd)
static void	btf_add_vars (ctf_container_ref ctfc)
static int	btf_type_list_cb (ctf_dtdef_ref *slot, ctf_container_ref ctfc)
static void	btf_collect_translated_types (ctf_container_ref ctfc)
static void	btf_assign_func_ids (ctf_container_ref ctfc)
static void	btf_assign_var_ids (ctf_container_ref ctfc)
static void	btf_assign_tag_ids (ctf_container_ref ctfc)
static void	btf_assign_datasec_ids (ctf_container_ref ctfc)
void	btf_mark_type_used (tree t)
static bool	btf_used_type_list_cb (const ctf_dtdef_ref &dtd, ctf_container_ref ctfc)
static void	btf_collect_pruned_types (ctf_container_ref ctfc)
void	btf_finish (void)
void	btf_finalize (void)
bool	traverse_btf_func_types (funcs_traverse_callback callback, void *data)

Variables
static int	btf_label_num
static section *	btf_info_section
static char	btf_info_section_label [MAX_BTF_LABEL_BYTES]
static vec< btf_datasec_t >	datasecs
static vec< ctf_dtdef_ref, va_gc > *	funcs
static hash_map< ctf_dtdef_ref, ctf_dtdef_ref > *	func_map
static ctf_id_t	max_translated_id = 0
static const char *const	btf_kind_names []
static hash_set< ctf_dtdef_ref > *	btf_used_types
static vec< struct btf_fixup >	fixups
static vec< ctf_dtdef_ref, va_gc > *	forwards

Macro Definition Documentation

◆ BTF_INFO_SECTION_FLAGS

#define BTF_INFO_SECTION_FLAGS (SECTION_DEBUG)

Referenced by init_btf_sections().

◆ BTF_INFO_SECTION_LABEL

#define BTF_INFO_SECTION_LABEL "Lbtf"

Referenced by init_btf_sections().

◆ BTF_INFO_SECTION_NAME

#define BTF_INFO_SECTION_NAME ".BTF"

BTF debug info section.

Referenced by init_btf_sections().

◆ BTF_INVALID_TYPEID

#define BTF_INVALID_TYPEID 0xFFFFFFFF

Referenced by btf_collect_translated_types().

◆ MAX_BTF_LABEL_BYTES

#define MAX_BTF_LABEL_BYTES 40

Maximum size (in bytes) for an artificially generated BTF label.

Typedef Documentation

◆ btf_datasec_t

typedef struct btf_datasec btf_datasec_t

Internal representation of a BTF_KIND_DATASEC record.

Function Documentation

◆ btf_add_const_void()

void btf_add_const_void ( ctf_container_ref ctfc )

static

Workaround for 'const void' variables.  These variables are sometimes used
in eBPF programs to address kernel symbols.  DWARF does not generate const
qualifier on void type, so we would incorrectly emit these variables
without the const qualifier.  Find any such variables, and update them to
refer to a new 'const' modifier type for void.

References btf_add_const_void(), ctf_add_reftype(), CTF_ADD_ROOT, ctf_dvd_lookup(), symtab_node::decl, ctf_dvdef::dvd_type, FOR_EACH_VARIABLE, lookup_decl_die(), NULL, TREE_TYPE, TYPE_READONLY, and VOID_TYPE_P.

Referenced by btf_add_const_void(), and btf_early_finish().

◆ btf_add_func_datasec_entries()

void btf_add_func_datasec_entries ( ctf_container_ref ctfc )

static

Add datasec entries for functions to CTFC.

References btf_add_func_datasec_entries(), btf_datasec_add_func(), ctf_dtd_lookup(), symtab_node::decl, DECL_EXTERNAL, FOR_EACH_FUNCTION, func_map, lookup_decl_die(), and NULL.

Referenced by btf_add_func_datasec_entries(), and btf_finish().

◆ btf_add_func_records()

void btf_add_func_records ( ctf_container_ref ctfc )

static

Functions actually get two type records: a BTF_KIND_FUNC_PROTO, and also a
BTF_KIND_FUNC.  But the CTF container only allocates one type per function,
which matches closely with BTF_KIND_FUNC_PROTO.  For each such function,
construct a BTF_KIND_FUNC entry.  This is done early, because we want FUNC
records even for functions which are later inlined by optimizations.

References btf_add_func_records(), ctf_dtd_lookup(), symtab_node::decl, DECL_ATTRIBUTES, DECL_EXTERNAL, ctf_dtdef::dtd_data, ctf_dtdef::dtd_name, FOR_EACH_FUNCTION, func_map, funcs, ggc_cleared_alloc(), ctf_dtdef::linkage, lookup_attribute(), lookup_decl_die(), NULL, NULL_TREE, ctf_dtdef::ref_type, and vec_safe_push().

Referenced by btf_add_func_records(), and btf_early_finish().

◆ btf_add_used_type()

ctf_dtdef_ref btf_add_used_type	(	ctf_container_ref	ctfc,
		ctf_dtdef_ref	dtd )

static

Recursively add type DTD and any types it references to the used set.
Return a type that should be used for references to DTD - usually DTD itself,
but may be NULL if DTD corresponds to a type which will not be emitted.

References btf_add_used_type(), and btf_add_used_type_1().

Referenced by btf_add_used_type(), btf_add_vars(), btf_collect_pruned_types(), and btf_mark_type_used().

◆ btf_add_used_type_1()

ctf_dtdef_ref btf_add_used_type_1	(	ctf_container_ref	ctfc,
		ctf_dtdef_ref	dtd,
		bool	check_ptr,
		bool	seen_ptr,
		bool	create_fixups )

static

Implementation of btf_add_used_type.
Recursively add type DTD and any types it references to the used set.
Return a type that should be used for references to DTD - usually DTD itself,
but may be NULL if DTD corresponds to a type which will not be emitted.
CHECK_PTR is true if one of the predecessors in recursive calls is a struct
or union member.  SEEN_PTR is true if CHECK_PTR is true AND one of the
predecessors was a pointer type.  These two flags are used to avoid chasing
pointers to struct/union only used from pointer members.  For such types, we
will emit a forward instead of the full type information, unless
CREATE_FIXUPS is false.

References btf_add_used_type_1(), btf_calc_num_vbytes(), btf_dtd_kind(), btf_used_types, ctf_add_string(), ctf_dmd_list_next, ctf_farg_list_next, CTF_STRTAB, ctf_arinfo::ctr_contents, ctf_arinfo::ctr_index, ctf_dmdef::dmd_name, ctf_dmdef::dmd_name_offset, ctf_dmdef::dmd_type, ctf_func_arg::farg_type, fixups, gcc_assert, gcc_unreachable, get_btf_kind(), i, NULL, and btf_fixup::pointer_dtd.

Referenced by btf_add_used_type(), and btf_add_used_type_1().

◆ btf_add_vars()

void btf_add_vars ( ctf_container_ref ctfc )

static

Add BTF_KIND_VAR records for variables.

References btf_add_used_type(), btf_add_vars(), btf_datasec_add_var(), btf_dtd_kind(), btf_emit_variable_p(), ctf_dmd_list_next, ctf_container::ctfc_vars, ctf_container::ctfc_vars_list, ctf_container::ctfc_vars_list_count, symtab_node::decl, DECL_EXTERNAL, ctf_dmdef::dmd_type, ctf_dvdef::dvd_type, ctf_dvdef::dvd_visibility, hash_table< Descriptor, Lazy, Allocator >::elements(), FOR_EACH_VARIABLE, symtab_node::get_section(), ggc_vec_alloc(), and NULL.

Referenced by btf_add_vars(), and btf_finish().

◆ btf_asm_array()

void btf_asm_array ( ctf_arinfo_t arr )

static

Asm'out the variable information following a BTF_KIND_ARRAY.

References btf_asm_array(), btf_asm_type_ref(), ctf_arinfo::ctr_contents, ctf_arinfo::ctr_index, ctf_arinfo::ctr_nelems, and dw2_asm_output_data().

Referenced by btf_asm_array(), and output_asm_btf_vlen_bytes().

◆ btf_asm_datasec_entry()

void btf_asm_datasec_entry ( struct btf_datasec_entry entry )

static

Asm'out a variable entry following a BTF_KIND_DATASEC.

References btf_asm_datasec_entry(), btf_asm_type_ref(), btf_with_core_debuginfo_p(), dw2_asm_output_data(), dw2_asm_output_offset(), btf_datasec_entry::is_var, NULL, and btf_datasec_entry::size.

Referenced by btf_asm_datasec_entry(), and btf_asm_datasec_type().

◆ btf_asm_datasec_type()

void btf_asm_datasec_type ( btf_datasec_t ds )

static

Asm'out a whole BTF_KIND_DATASEC, including its variable entries.

References btf_asm_datasec_entry(), btf_asm_datasec_type(), dw2_asm_output_data(), btf_datasec::entries, i, btf_datasec::id, btf_datasec::name, btf_datasec::name_offset, and PRIu64.

Referenced by btf_asm_datasec_type(), and output_btf_datasec_types().

◆ btf_asm_enum_const()

void btf_asm_enum_const	(	unsigned int	size,
		ctf_dmdef_t *	dmd,
		unsigned int	idx )

static

Asm'out an enum constant following a BTF_KIND_ENUM{,64}.

References btf_asm_enum_const(), ctf_dmdef::dmd_name, ctf_dmdef::dmd_name_offset, ctf_dmdef::dmd_value, and dw2_asm_output_data().

Referenced by btf_asm_enum_const(), and output_asm_btf_enum_list().

◆ btf_asm_func_arg()

void btf_asm_func_arg	(	ctf_func_arg_t *	farg,
		size_t	stroffset )

static

Asm'out a function parameter description following a BTF_KIND_FUNC_PROTO.

References btf_asm_func_arg(), btf_asm_type_ref(), dw2_asm_output_data(), ctf_func_arg::farg_name, ctf_func_arg::farg_name_offset, ctf_func_arg::farg_type, and NULL.

Referenced by btf_asm_func_arg(), and output_asm_btf_func_args_list().

◆ btf_asm_func_type()

void btf_asm_func_type ( ctf_dtdef_ref dtd )

static

Asm'out a BTF_KIND_FUNC type.

References btf_asm_func_type(), btf_asm_type_ref(), dw2_asm_output_data(), get_btf_type_name(), and PRIu64.

Referenced by btf_asm_func_type(), and output_btf_func_types().

◆ btf_asm_sou_member()

void btf_asm_sou_member	(	ctf_dmdef_t *	dmd,
		unsigned int	idx )

static

Asm'out a member description following a BTF_KIND_STRUCT or
BTF_KIND_UNION.

References btf_asm_sou_member(), btf_asm_type_ref(), btf_dmd_representable_bitfield_p(), ctf_itype::ctti_info, ctf_dmdef::dmd_name, ctf_dmdef::dmd_name_offset, ctf_dmdef::dmd_offset, ctf_dmdef::dmd_type, ctf_dtdef::dtd_data, ctf_dtdef::dtd_u, dw2_asm_output_data(), and NULL.

Referenced by btf_asm_sou_member(), and output_asm_btf_sou_fields().

◆ btf_asm_type()

void btf_asm_type ( ctf_dtdef_ref dtd )

static

Asm'out a BTF type. This routine is responsible for the bulk of the task
of converting CTF types to their BTF representation.

References btf_asm_type(), btf_asm_type_ref(), btf_dmd_representable_bitfield_p(), btf_dtd_kind(), btf_kind_name(), ctf_dmd_list_next, ctf_dvdef::dvd_id, ctf_dvdef::dvd_name, dw2_asm_output_data(), gcc_assert, get_btf_type_name(), NULL, and PRIu64.

Referenced by btf_asm_type(), and output_asm_btf_type().

◆ btf_asm_type_ref()

void btf_asm_type_ref	(	const char *	prefix,
		ctf_dtdef_ref	dtd )

static

BTF asm helper routines.

Asm'out a reference to another BTF type.

References btf_asm_type_ref(), btf_dtd_kind(), btf_emit_type_p(), btf_fwd_to_enum_p(), btf_kind_name(), dw2_asm_output_data(), get_btf_type_name(), and max_translated_id.

Referenced by btf_asm_array(), btf_asm_datasec_entry(), btf_asm_func_arg(), btf_asm_func_type(), btf_asm_sou_member(), btf_asm_type(), btf_asm_type_ref(), and btf_asm_varent().

◆ btf_asm_varent()

void btf_asm_varent ( ctf_dvdef_ref var )

static

Asm'out a BTF_KIND_VAR.

References btf_asm_type_ref(), btf_asm_varent(), ctf_dvdef::dvd_id, ctf_dvdef::dvd_name, ctf_dvdef::dvd_name_offset, ctf_dvdef::dvd_type, ctf_dvdef::dvd_visibility, dw2_asm_output_data(), and PRIu64.

Referenced by btf_asm_varent(), and output_btf_vars().

◆ btf_assign_datasec_ids()

void btf_assign_datasec_ids ( ctf_container_ref ctfc )

static

Assign BTF IDs for datasec records and account for their size.

References btf_assign_datasec_ids(), CTF_STRTAB, ctfc_get_strtab_len(), ctf_container::ctfc_nextid, ctf_container::ctfc_num_types, ctf_container::ctfc_num_vlen_bytes, datasecs, and i.

Referenced by btf_assign_datasec_ids(), and btf_finish().

◆ btf_assign_func_ids()

void btf_assign_func_ids ( ctf_container_ref ctfc )

static

Assign BTF IDs for FUNC records and account for their size.

References btf_assign_func_ids(), ctf_container::ctfc_nextid, ctf_container::ctfc_num_types, FOR_EACH_VEC_ELT, funcs, and i.

Referenced by btf_assign_func_ids(), and btf_finish().

◆ btf_assign_tag_ids()

void btf_assign_tag_ids ( ctf_container_ref ctfc )

static

Assign BTF IDs for type and decl tags and account for their size.

References btf_assign_tag_ids(), btf_calc_num_vbytes(), CTF_STRTAB, ctfc_get_strtab_len(), ctf_container::ctfc_nextid, ctf_container::ctfc_num_types, ctf_container::ctfc_num_vlen_bytes, ctf_container::ctfc_tags, FOR_EACH_VEC_ELT, func_map, gcc_assert, i, NULL, and vec_safe_length().

Referenced by btf_assign_tag_ids(), and btf_finish().

◆ btf_assign_var_ids()

void btf_assign_var_ids ( ctf_container_ref ctfc )

static

Assign BTF IDs for variables and account for their size.

References btf_assign_var_ids(), ctf_container::ctfc_nextid, ctf_container::ctfc_num_types, ctf_container::ctfc_num_vlen_bytes, ctf_container::ctfc_vars_list, ctf_container::ctfc_vars_list_count, ctf_dvdef::dvd_id, gcc_assert, and i.

Referenced by btf_assign_var_ids(), and btf_finish().

◆ btf_calc_num_vbytes()

uint64_t btf_calc_num_vbytes ( ctf_dtdef_ref dtd )

static

Each BTF type can be followed additional, variable-length information
completing the description of the type. Calculate the number of bytes
of variable information required to encode a given type.

References btf_calc_num_vbytes(), and btf_dtd_kind().

Referenced by btf_add_used_type_1(), btf_assign_tag_ids(), btf_calc_num_vbytes(), btf_collect_pruned_types(), and btf_collect_translated_types().

◆ btf_collect_pruned_types()

void btf_collect_pruned_types ( ctf_container_ref ctfc )

static

Collect the set of types reachable from global variables and functions.
This is the minimal set of types, used when generating pruned BTF.

References btf_add_used_type(), btf_calc_num_vbytes(), btf_collect_pruned_types(), btf_dtd_kind(), btf_used_type_list_cb(), btf_used_types, ctf_add_string(), CTF_STRTAB, ctf_container::ctfc_nextid, ctf_container::ctfc_num_types, ctf_container::ctfc_num_vlen_bytes, ctf_container::ctfc_tags, ctf_container::ctfc_types_list, ctf_container::ctfc_vars_list, ctf_container::ctfc_vars_list_count, ctf_itype::ctti_info, ctf_itype::ctti_name, ctf_dtdef::dtd_data, ctf_dtdef::dtd_name, ctf_dtdef::dtd_type, ctf_dvdef::dvd_name, ctf_dvdef::dvd_name_offset, ctf_dvdef::dvd_type, fixups, FOR_EACH_VEC_ELT, forwards, func_map, funcs, gcc_assert, ggc_cleared_alloc(), ggc_vec_alloc(), i, max_translated_id, NULL, btf_fixup::pointee_dtd, btf_fixup::pointer_dtd, ctf_dtdef::ref_type, vec_alloc(), vec_safe_length(), and vec_safe_push().

Referenced by btf_collect_pruned_types(), and btf_finish().

◆ btf_collect_translated_types()

void btf_collect_translated_types ( ctf_container_ref ctfc )

static

Construct the initial type list and assign BTF IDs for all types translated
from CTF.

References btf_calc_num_vbytes(), btf_collect_translated_types(), btf_emit_type_p(), BTF_INVALID_TYPEID, btf_type_list_cb(), ctf_container::ctfc_nextid, ctf_container::ctfc_num_types, ctf_container::ctfc_num_vlen_bytes, ctf_container::ctfc_types, ctf_container::ctfc_types_list, hash_table< Descriptor, Lazy, Allocator >::elements(), ggc_vec_alloc(), i, max_translated_id, and hash_table< Descriptor, Lazy, Allocator >::traverse().

Referenced by btf_collect_translated_types(), and btf_finish().

◆ btf_datasec_add_func()

void btf_datasec_add_func	(	ctf_container_ref	ctfc,
		cgraph_node *	func,
		ctf_dtdef_ref	func_dtd )

static

Create a datasec entry for a function, and insert it into the datasec
record for the appropriate section.  Create the record if it does not
yet exist.

References btf_datasec_add_func(), btf_datasec_push_entry(), gcc_assert, get_section_name(), btf_datasec_entry::is_var, NULL, and btf_datasec_entry::size.

Referenced by btf_add_func_datasec_entries(), and btf_datasec_add_func().

◆ btf_datasec_add_var()

void btf_datasec_add_var	(	ctf_container_ref	ctfc,
		varpool_node *	var,
		ctf_dvdef_ref	dvd )

static

Create a datasec entry for a variable, and insert it into the datasec
record for the appropriate section.  Create the record if it does not
yet exist.

References btf_datasec_add_var(), btf_datasec_push_entry(), symtab_node::decl, DECL_EXTERNAL, DECL_SIZE_UNIT, gcc_assert, symtab_node::get_section(), get_section_name(), btf_datasec_entry::is_var, NULL, btf_datasec_entry::size, tree_fits_uhwi_p(), tree_to_uhwi(), TREE_TYPE, and VOID_TYPE_P.

Referenced by btf_add_vars(), and btf_datasec_add_var().

◆ btf_datasec_push_entry()

void btf_datasec_push_entry	(	ctf_container_ref	ctfc,
		const char *	secname,
		struct btf_datasec_entry	entry )

static

Push a BTF datasec entry ENTRY into the datasec named SECNAME,
creating the datasec record if it does not already exist.

References btf_datasec_push_entry(), ctf_add_string(), CTF_AUX_STRTAB, ctf_container::ctfc_aux_strlen, datasecs, btf_datasec::entries, i, btf_datasec::name, btf_datasec::name_offset, and NULL.

Referenced by btf_datasec_add_func(), btf_datasec_add_var(), and btf_datasec_push_entry().

◆ btf_dmd_representable_bitfield_p()

bool btf_dmd_representable_bitfield_p ( ctf_dmdef_t * dmd )

static

Return true iff DMD is a member description of a bit-field which can be
validly represented in BTF.

References btf_dmd_representable_bitfield_p(), ctf_itype::ctti_info, ctf_dmdef::dmd_offset, ctf_dmdef::dmd_type, ctf_dtdef::dtd_data, and ctf_dtdef::dtd_u.

Referenced by btf_asm_sou_member(), btf_asm_type(), and btf_dmd_representable_bitfield_p().

◆ btf_dtd_kind()

uint32_t btf_dtd_kind ( ctf_dtdef_ref dtd )

Convenience wrapper around get_btf_kind for the common case.

References btf_dtd_kind(), and get_btf_kind().

Referenced by btf_add_used_type_1(), btf_add_vars(), btf_asm_type(), btf_asm_type_ref(), btf_calc_num_vbytes(), btf_collect_pruned_types(), btf_dtd_kind(), btf_emit_type_p(), btf_fwd_to_enum_p(), and output_asm_btf_vlen_bytes().

◆ btf_early_finish()

void btf_early_finish ( void )

Initial entry point of BTF generation, called at early_finish () after
CTF information has possibly been output.  Translate all CTF information
to BTF, and do any processing that must be done early, such as creating
BTF_KIND_FUNC records.

References btf_add_const_void(), btf_add_func_records(), btf_early_finish(), btf_used_types, hash_map< KeyId, Value, Traits >::create_ggc(), hash_set< KeyId, Lazy, Traits >::create_ggc(), ctf_get_tu_ctfc(), ctfc_delete_strtab(), ctf_container::ctfc_nextid, ctf_container::ctfc_num_types, ctf_container::ctfc_num_vlen_bytes, ctf_container::ctfc_strlen, ctf_container::ctfc_strtable, ctf_container::ctfc_types, ctf_container::ctfc_vars_list_count, hash_table< Descriptor, Lazy, Allocator >::elements(), fixups, func_map, funcs, init_ctf_strtable(), tu_ctfc, and vec_alloc().

Referenced by btf_early_finish(), and ctf_debug_early_finish().

◆ btf_emit_type_p()

bool btf_emit_type_p ( ctf_dtdef_ref dtd )

static

References btf_dtd_kind(), and btf_emit_type_p().

Referenced by btf_asm_type_ref(), btf_collect_translated_types(), btf_emit_type_p(), btf_emit_variable_p(), and output_asm_btf_type().

◆ btf_emit_variable_p()

bool btf_emit_variable_p	(	ctf_container_ref	ctfc,
		varpool_node *	var,
		ctf_dvdef_ref *	pdvd )

static

Helper function used to determine whether or not a BTF_KIND_VAR record
for the variable VAR shall be emitted.

References btf_emit_type_p(), btf_emit_variable_p(), ctf_dvd_ignore_lookup(), ctf_dvd_lookup(), symtab_node::decl, ctf_dvdef::dvd_key, ctf_dvdef::dvd_type, lookup_decl_die(), and NULL.

Referenced by btf_add_vars(), and btf_emit_variable_p().

◆ btf_finalize()

void btf_finalize ( void )

Reset all state for BTF generation so that we can rerun the compiler within
the same process.

References btf_finalize(), btf_info_section, btf_used_types, ctf_get_tu_ctfc(), ctfc_delete_container(), datasecs, fixups, forwards, func_map, funcs, i, max_translated_id, NULL, and tu_ctfc.

Referenced by btf_finalize(), and btf_finish().

◆ btf_finish()

void btf_finish ( void )

Late entry point for BTF generation, called from dwarf2out_finish ().
Complete and emit BTF information.

References btf_add_func_datasec_entries(), btf_add_vars(), btf_assign_datasec_ids(), btf_assign_func_ids(), btf_assign_tag_ids(), btf_assign_var_ids(), btf_collect_pruned_types(), btf_collect_translated_types(), btf_finalize(), btf_finish(), btf_output(), btf_with_core_debuginfo_p(), ctf_get_tu_ctfc(), datasecs, init_btf_sections(), and tu_ctfc.

Referenced by btf_finish(), ctf_debug_early_finish(), and ctf_debug_finish().

◆ btf_fwd_to_enum_p()

bool btf_fwd_to_enum_p ( ctf_dtdef_ref dtd )

static

Return true if DTD is a forward-declared enum.  The BTF representation
of forward declared enums is not formally defined.

References btf_dtd_kind(), and btf_fwd_to_enum_p().

Referenced by btf_asm_type_ref(), and btf_fwd_to_enum_p().

◆ btf_kind_name()

const char * btf_kind_name ( uint32_t btf_kind )

static

Return a name string for the given BTF_KIND.

References btf_kind_name(), and btf_kind_names.

Referenced by btf_asm_type(), btf_asm_type_ref(), and btf_kind_name().

◆ btf_mark_type_used()

void btf_mark_type_used ( tree t )

Manually mark that type T is used to ensure it will not be pruned.
Used by the BPF backend when generating BPF CO-RE to mark types used
in CO-RE relocations.

References btf_add_used_type(), btf_mark_type_used(), ctf_get_tu_ctfc(), ctf_lookup_tree_type(), gcc_assert, and TYPE_P.

Referenced by btf_mark_type_used().

◆ btf_output()

void btf_output ( ctf_container_ref ctfc )

Write out all BTF debug info.

References btf_output(), output_btf_datasec_types(), output_btf_func_types(), output_btf_header(), output_btf_strs(), output_btf_tags(), output_btf_types(), and output_btf_vars().

Referenced by btf_finish(), and btf_output().

◆ btf_type_list_cb()

int btf_type_list_cb	(	ctf_dtdef_ref *	slot,
		ctf_container_ref	ctfc )

static

Callback used by btf_assign_type_ids to insert types into their initial
positions in the type list.

References btf_type_list_cb(), and ctf_container::ctfc_types_list.

Referenced by btf_collect_translated_types(), and btf_type_list_cb().

◆ btf_used_type_list_cb()

bool btf_used_type_list_cb	(	const ctf_dtdef_ref &	dtd,
		ctf_container_ref	ctfc )

static

Callback used for assembling the only-used-types list.  Note that this is
the same as btf_type_list_cb above, but the hash_set traverse requires a
different function signature.

References btf_used_type_list_cb(), and ctf_container::ctfc_types_list.

Referenced by btf_collect_pruned_types(), and btf_used_type_list_cb().

◆ get_btf_kind()

uint32_t get_btf_kind ( uint32_t ctf_kind )

static

Map a CTF type kind to the corresponding BTF type kind.

References get_btf_kind().

Referenced by btf_add_used_type_1(), btf_dtd_kind(), and get_btf_kind().

◆ get_btf_type_name()

const char * get_btf_type_name ( ctf_dtdef_ref dtd )

static

Some BTF types, like BTF_KIND_FUNC_PROTO, are anonymous.  The machinery
in btfout to emit BTF, may reset dtd_data->ctti_name, but does not update
the name in the ctf_dtdef_ref type object (deliberate choice).  This
interface helps abstract out that state of affairs, while giving access to
the name of the type as intended.

References get_btf_type_name().

Referenced by btf_asm_func_type(), btf_asm_type(), btf_asm_type_ref(), and get_btf_type_name().

◆ get_section_name()

const char * get_section_name ( symtab_node * node )

static

Return the section name, as of interest to btf_collect_datasec, for the
given symtab node.  Note that this deliberately returns NULL for objects
which do not go in a section btf_collect_datasec cares about.

References categorize_decl_for_section(), get_section_name(), NULL, SECCAT_BSS, SECCAT_DATA, and SECCAT_RODATA.

Referenced by btf_datasec_add_func(), btf_datasec_add_var(), and get_section_name().

◆ init_btf_sections()

void init_btf_sections ( void )

Initialize BTF section (.BTF) for output.

References btf_info_section, BTF_INFO_SECTION_FLAGS, BTF_INFO_SECTION_LABEL, btf_info_section_label, BTF_INFO_SECTION_NAME, btf_label_num, get_section(), init_btf_sections(), and NULL.

Referenced by btf_finish(), and init_btf_sections().

◆ output_asm_btf_enum_list()

void output_asm_btf_enum_list ( ctf_dtdef_ref dtd )

static

Output all enumerator constants following a BTF_KIND_ENUM{,64}.

References btf_asm_enum_const(), ctf_dmd_list_next, NULL, and output_asm_btf_enum_list().

Referenced by output_asm_btf_enum_list(), and output_asm_btf_vlen_bytes().

◆ output_asm_btf_func_args_list()

void output_asm_btf_func_args_list	(	ctf_container_ref	ctfc,
		ctf_dtdef_ref	dtd )

static

Output all function arguments following a BTF_KIND_FUNC_PROTO.

References btf_asm_func_arg(), ctf_farg_list_next, CTF_STRTAB, ctfc_get_strtab_len(), NULL, and output_asm_btf_func_args_list().

Referenced by output_asm_btf_func_args_list(), and output_asm_btf_vlen_bytes().

◆ output_asm_btf_sou_fields()

void output_asm_btf_sou_fields ( ctf_dtdef_ref dtd )

static

Output all (representable) members of a BTF_KIND_STRUCT or
BTF_KIND_UNION type.

References btf_asm_sou_member(), ctf_dmd_list_next, NULL, and output_asm_btf_sou_fields().

Referenced by output_asm_btf_sou_fields(), and output_asm_btf_vlen_bytes().

◆ output_asm_btf_type()

void output_asm_btf_type	(	ctf_container_ref	ctfc,
		ctf_dtdef_ref	type )

static

Output a whole BTF type record for TYPE, including the fixed and variable
data portions.

References btf_asm_type(), btf_emit_type_p(), output_asm_btf_type(), and output_asm_btf_vlen_bytes().

Referenced by output_asm_btf_type(), output_btf_tags(), and output_btf_types().

◆ output_asm_btf_vlen_bytes()

void output_asm_btf_vlen_bytes	(	ctf_container_ref	ctfc,
		ctf_dtdef_ref	dtd )

static

Output the variable portion of a BTF type record. The information depends
on the kind of the type.

References btf_asm_array(), btf_dtd_kind(), dw2_asm_output_data(), gcc_unreachable, output_asm_btf_enum_list(), output_asm_btf_func_args_list(), output_asm_btf_sou_fields(), and output_asm_btf_vlen_bytes().

Referenced by output_asm_btf_type(), and output_asm_btf_vlen_bytes().

◆ output_btf_datasec_types()

void output_btf_datasec_types ( void )

static

Output all BTF_KIND_DATASEC records.

References btf_asm_datasec_type(), datasecs, i, and output_btf_datasec_types().

Referenced by btf_output(), and output_btf_datasec_types().

◆ output_btf_func_types()

void output_btf_func_types ( void )

static

Output all BTF_KIND_FUNC type records.

References btf_asm_func_type(), FOR_EACH_VEC_ELT, funcs, i, and output_btf_func_types().

Referenced by btf_output(), and output_btf_func_types().

◆ output_btf_header()

void output_btf_header ( ctf_container_ref ctfc )

static

Compute and output the header information for a .BTF section.

References asm_out_file, ASM_OUTPUT_LABEL, btf_info_section, btf_info_section_label, ctfc_is_empty_container(), ctf_container::ctfc_num_types, ctf_container::ctfc_num_vlen_bytes, dw2_asm_output_data(), output_btf_header(), and switch_to_section().

Referenced by btf_output(), and output_btf_header().

◆ output_btf_strs()

void output_btf_strs ( ctf_container_ref ctfc )

static

Output BTF string records. The BTF strings section is a concatenation
of the standard and auxiliary string tables in the ctf container.

References ctf_container::ctfc_aux_strtable, ctf_container::ctfc_strtable, ctf_string::cts_next, ctf_string::cts_str, ctf_strtable::ctstab_head, dw2_asm_output_nstring(), and output_btf_strs().

Referenced by btf_output(), and output_btf_strs().

◆ output_btf_tags()

void output_btf_tags ( ctf_container_ref ctfc )

static

References ctf_container::ctfc_tags, FOR_EACH_VEC_ELT, i, output_asm_btf_type(), and output_btf_tags().

Referenced by btf_output(), and output_btf_tags().

◆ output_btf_types()

void output_btf_types ( ctf_container_ref ctfc )

static

Output all BTF types in the container. This does not include synthesized
types: BTF_KIND_VAR, BTF_KIND_FUNC, nor BTF_KIND_DATASEC.

References ctf_container::ctfc_types, ctf_container::ctfc_types_list, hash_table< Descriptor, Lazy, Allocator >::elements(), i, max_translated_id, output_asm_btf_type(), and output_btf_types().

Referenced by btf_output(), and output_btf_types().

◆ output_btf_vars()

void output_btf_vars ( ctf_container_ref ctfc )

static

Output all BTF_KIND_VARs in CTFC.

References btf_asm_varent(), ctf_container::ctfc_vars_list, ctf_container::ctfc_vars_list_count, i, and output_btf_vars().

Referenced by btf_output(), and output_btf_vars().

◆ traverse_btf_func_types()

bool traverse_btf_func_types	(	funcs_traverse_callback	callback,
		void *	data )

Traversal function for all BTF_KIND_FUNC type records.

References FOR_EACH_VEC_ELT, funcs, i, and traverse_btf_func_types().

Referenced by traverse_btf_func_types().

Variable Documentation

◆ btf_info_section

section* btf_info_section

static

Referenced by btf_finalize(), init_btf_sections(), and output_btf_header().

◆ btf_info_section_label

char btf_info_section_label[MAX_BTF_LABEL_BYTES]

static

Referenced by init_btf_sections(), and output_btf_header().

◆ btf_kind_names

const char* const btf_kind_names[]

static

Initial value:

                                     =
{
  "UNKN", "INT", "PTR", "ARRAY", "STRUCT", "UNION", "ENUM", "FWD",
  "TYPEDEF", "VOLATILE", "CONST", "RESTRICT", "FUNC", "FUNC_PROTO",
  "VAR", "DATASEC", "FLOAT", "DECL_TAG", "TYPE_TAG", "ENUM64"
}

Name strings for BTF kinds.
Note: the indices here must match the type defines in btf.h.

Referenced by btf_kind_name().

◆ btf_label_num

int btf_label_num

static

Output BTF format from GCC.
   Copyright (C) 2021-2026 Free Software Foundation, Inc.

This file is part of GCC.

GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.

GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3.  If not see
<http://www.gnu.org/licenses/>.

This file contains routines to output the BPF Type Format (BTF). The BTF
debug format is very similar to CTF; as a result, the structure of this file
closely resembles that of ctfout.cc, and the same CTF container objects are
used.

Referenced by init_btf_sections().

◆ btf_used_types

hash_set<ctf_dtdef_ref>* btf_used_types

static

The set of types used directly in the source program, and any types manually
marked as used.  This is the set of types which will be emitted when
flag_prune_btf is set.

Referenced by btf_add_used_type_1(), btf_collect_pruned_types(), btf_early_finish(), and btf_finalize().

◆ datasecs

vec<btf_datasec_t> datasecs

static

One BTF_KIND_DATASEC record is created for each output data section which
will hold at least one variable.

Referenced by btf_assign_datasec_ids(), btf_datasec_push_entry(), btf_finalize(), btf_finish(), and output_btf_datasec_types().

◆ fixups

vec<struct btf_fixup> fixups

static

Stores fixups while processing types.

Referenced by btf_add_used_type_1(), btf_collect_pruned_types(), btf_early_finish(), and btf_finalize().

◆ forwards

vec<ctf_dtdef_ref, va_gc>* forwards

static

For fixups where the underlying type is not used in the end, a BTF_KIND_FWD
is created and emitted.  This vector stores them.

Referenced by btf_collect_pruned_types(), and btf_finalize().

◆ func_map

hash_map<ctf_dtdef_ref, ctf_dtdef_ref>* func_map

static

Maps BTF_KIND_FUNC_PROTO to the BTF_KIND_FUNC record for it.  Used when
creating DATASEC entries.

Referenced by btf_add_func_datasec_entries(), btf_add_func_records(), btf_assign_tag_ids(), btf_collect_pruned_types(), btf_early_finish(), and btf_finalize().

◆ funcs

vec<ctf_dtdef_ref, va_gc>* funcs

static

Functions in BTF have two separate type records - one for the prototype
(BTF_KIND_FUNC_PROTO), as well as a BTF_KIND_FUNC. CTF_K_FUNCTION types
map closely to BTF_KIND_FUNC_PROTO, but the BTF_KIND_FUNC records must be
created. This vector holds them.

Referenced by btf_add_func_records(), btf_assign_func_ids(), btf_collect_pruned_types(), btf_early_finish(), btf_finalize(), output_btf_func_types(), and traverse_btf_func_types().

◆ max_translated_id

ctf_id_t max_translated_id = 0

static

Highest BTF ID assigned to any regular type translated from CTF.
Does not include BTF_KIND_{VAR,FUNC,DATASEC} types.

Referenced by btf_asm_type_ref(), btf_collect_pruned_types(), btf_collect_translated_types(), btf_finalize(), and output_btf_types().

Data Structures

Macros

Typedefs

Functions

Variables

Macro Definition Documentation

◆ BTF_INFO_SECTION_FLAGS

◆ BTF_INFO_SECTION_LABEL

◆ BTF_INFO_SECTION_NAME

◆ BTF_INVALID_TYPEID

◆ MAX_BTF_LABEL_BYTES

Typedef Documentation

◆ btf_datasec_t

Function Documentation

◆ btf_add_const_void()

◆ btf_add_func_datasec_entries()

◆ btf_add_func_records()

◆ btf_add_used_type()

◆ btf_add_used_type_1()

◆ btf_add_vars()

◆ btf_asm_array()

◆ btf_asm_datasec_entry()

◆ btf_asm_datasec_type()

◆ btf_asm_enum_const()

◆ btf_asm_func_arg()

◆ btf_asm_func_type()

◆ btf_asm_sou_member()

◆ btf_asm_type()

◆ btf_asm_type_ref()

◆ btf_asm_varent()

◆ btf_assign_datasec_ids()

◆ btf_assign_func_ids()

◆ btf_assign_tag_ids()

◆ btf_assign_var_ids()

◆ btf_calc_num_vbytes()

◆ btf_collect_pruned_types()

◆ btf_collect_translated_types()

◆ btf_datasec_add_func()

◆ btf_datasec_add_var()

◆ btf_datasec_push_entry()

◆ btf_dmd_representable_bitfield_p()

◆ btf_dtd_kind()

◆ btf_early_finish()

◆ btf_emit_type_p()

◆ btf_emit_variable_p()

◆ btf_finalize()

◆ btf_finish()

◆ btf_fwd_to_enum_p()

◆ btf_kind_name()

◆ btf_mark_type_used()

◆ btf_output()

◆ btf_type_list_cb()

◆ btf_used_type_list_cb()

◆ get_btf_kind()

◆ get_btf_type_name()

◆ get_section_name()

◆ init_btf_sections()

◆ output_asm_btf_enum_list()

◆ output_asm_btf_func_args_list()

◆ output_asm_btf_sou_fields()

◆ output_asm_btf_type()

◆ output_asm_btf_vlen_bytes()

◆ output_btf_datasec_types()

◆ output_btf_func_types()

◆ output_btf_header()

◆ output_btf_strs()

◆ output_btf_tags()

◆ output_btf_types()

◆ output_btf_vars()

◆ traverse_btf_func_types()

Variable Documentation

◆ btf_info_section

◆ btf_info_section_label

◆ btf_kind_names

◆ btf_label_num

◆ btf_used_types

◆ datasecs

◆ fixups

◆ forwards

◆ func_map