third_party/ulib/musl/src/internal/dynlink.h

#pragma once

#include <elf.h>
#include <features.h>
#include <link.h>
#include <stddef.h>
#include <stdint.h>

typedef Elf64_Ehdr Ehdr;
typedef Elf64_Phdr Phdr;
typedef Elf64_Sym Sym;
#define R_TYPE(x) ((x)&0x7fffffff)
#define R_SYM(x) ((x) >> 32)
#define R_INFO ELF64_R_INFO

/* These enum constants provide unmatchable default values for
 * any relocation type the arch does not use. */
enum {
    REL_NONE = 0,
    REL_SYMBOLIC = -100,
    REL_GOT,
    REL_PLT,
    REL_RELATIVE,
    REL_OFFSET,
    REL_OFFSET32,
    REL_COPY,
    REL_DTPMOD,
    REL_DTPOFF,
    REL_TPOFF,
    REL_TPOFF_NEG,
    REL_TLSDESC,
    REL_FUNCDESC,
    REL_FUNCDESC_VAL,
};

#include "reloc.h"

#ifndef DT_DEBUG_INDIRECT
#define DT_DEBUG_INDIRECT 0
#endif

#define DYN_CNT 32

// This is the return value of the dynamic linker startup functions.
// They return all the way back to _start so as to pop their stack
// frames.  The DL_START_ASM code at _start then receives these two
// values and jumps to the entry point with the argument in place for
// the C ABI and return address/frame pointer cleared so it's the base
// of the call stack.
#ifndef DL_START_RETURN
typedef struct {
    void* arg;
    void* entry;
} dl_start_return_t;
#define DL_START_RETURN(entry, arg) \
    (dl_start_return_t) { (arg), (entry) }
#endif

dl_start_return_t _dl_start(void* start_arg, void* vdso)
    __attribute__((__visibility__("hidden")));
dl_start_return_t __dls2(void* start_arg, void* vdso)
    __attribute__((visibility("hidden")));

// We can access these with simple PC-relative relocs.
// Both of these symbols are defined automagically by the linker.
// Since we use a standard 0-based DSO layout, __ehdr_start matches
// the lowest address in the DSO image.
extern const ElfW(Ehdr) __ehdr_start[] __attribute__((visibility("hidden")));
extern ElfW(Dyn) _DYNAMIC[] __attribute__((visibility("hidden")));

void _dl_log_unlogged(void) __attribute__((__visibility__("hidden")));