tinycc/x86_64-link.c

#ifdef TARGET_DEFS_ONLY

#define EM_TCC_TARGET EM_X86_64

/* relocation type for 32 bit data relocation */
#define R_DATA_32   R_X86_64_32
#define R_DATA_PTR  R_X86_64_64
#define R_JMP_SLOT  R_X86_64_JUMP_SLOT
#define R_GLOB_DAT  R_X86_64_GLOB_DAT
#define R_COPY      R_X86_64_COPY

#define R_NUM       R_X86_64_NUM

#define ELF_START_ADDR 0x400000
#define ELF_PAGE_SIZE  0x200000

#define HAVE_SECTION_RELOC
#define PCRELATIVE_DLLPLT 1

#else /* !TARGET_DEFS_ONLY */

#include "tcc.h"

/* Returns 1 for a code relocation, 0 for a data relocation. For unknown
   relocations, returns -1. */
int code_reloc (int reloc_type)
{
    switch (reloc_type) {
        case R_X86_64_32:
        case R_X86_64_32S:
        case R_X86_64_64:
        case R_X86_64_GOTPCREL:
        case R_X86_64_GOTPCRELX:
        case R_X86_64_REX_GOTPCRELX:
        case R_X86_64_GOTTPOFF:
        case R_X86_64_GOT32:
        case R_X86_64_GLOB_DAT:
        case R_X86_64_COPY:
            return 0;

        case R_X86_64_PC32:
        case R_X86_64_PLT32:
        case R_X86_64_JUMP_SLOT:
            return 1;
    }

    tcc_error ("Unknown relocation type: %d", reloc_type);
    return -1;
}

/* Returns an enumerator to describe wether and when the relocation needs a
   GOT and/or PLT entry to be created. See tcc.h for a description of the
   different values. */
int gotplt_entry_type (int reloc_type)
{
    switch (reloc_type) {
        case R_X86_64_GLOB_DAT:
        case R_X86_64_JUMP_SLOT:
        case R_X86_64_COPY:
            return NO_GOTPLT_ENTRY;

        case R_X86_64_32:
        case R_X86_64_32S:
        case R_X86_64_64:
        case R_X86_64_PC32:
            return AUTO_GOTPLT_ENTRY;

        case R_X86_64_GOTTPOFF:
            return BUILD_GOT_ONLY;

        case R_X86_64_GOT32:
        case R_X86_64_GOTPCREL:
        case R_X86_64_GOTPCRELX:
	case R_X86_64_REX_GOTPCRELX:
        case R_X86_64_PLT32:
            return ALWAYS_GOTPLT_ENTRY;
    }

    tcc_error ("Unknown relocation type: %d", reloc_type);
    return -1;
}

static ElfW_Rel *qrel; /* ptr to next reloc entry reused */

void relocate_init(Section *sr)
{
    qrel = (ElfW_Rel *) sr->data;
}

void relocate(TCCState *s1, ElfW_Rel *rel, int type, char *ptr, addr_t addr, addr_t val)
{
    int sym_index, esym_index;

    sym_index = ELFW(R_SYM)(rel->r_info);

    switch (type) {
        case R_X86_64_64:
            if (s1->output_type == TCC_OUTPUT_DLL) {
                esym_index = s1->symtab_to_dynsym[sym_index];
                qrel->r_offset = rel->r_offset;
                if (esym_index) {
                    qrel->r_info = ELFW(R_INFO)(esym_index, R_X86_64_64);
		    qrel->r_addend = rel->r_addend;
                    qrel++;
                    break;
                } else {
		    qrel->r_info = ELFW(R_INFO)(0, R_X86_64_RELATIVE);
		    qrel->r_addend = read64le(ptr) + val;
                    qrel++;
                }
            }
            add64le(ptr, val);
            break;
        case R_X86_64_32:
        case R_X86_64_32S:
            if (s1->output_type == TCC_OUTPUT_DLL) {
                /* XXX: this logic may depend on TCC's codegen
                   now TCC uses R_X86_64_32 even for a 64bit pointer */
                qrel->r_info = ELFW(R_INFO)(0, R_X86_64_RELATIVE);
                /* Use sign extension! */
                qrel->r_addend = (int)read32le(ptr) + val;
                qrel++;
            }
            add32le(ptr, val);
            break;

        case R_X86_64_PC32:
            if (s1->output_type == TCC_OUTPUT_DLL) {
                /* DLL relocation */
                esym_index = s1->symtab_to_dynsym[sym_index];
                if (esym_index) {
                    qrel->r_offset = rel->r_offset;
                    qrel->r_info = ELFW(R_INFO)(esym_index, R_X86_64_PC32);
                    /* Use sign extension! */
                    qrel->r_addend = (int)read32le(ptr) + rel->r_addend;
                    qrel++;
                    break;
                }
            }
            goto plt32pc32;

        case R_X86_64_PLT32:
	    /* fallthrough: val already holds the PLT slot address */

	plt32pc32:
	{
            long long diff;
            diff = (long long)val - addr;
            if (diff < -2147483648LL || diff > 2147483647LL) {
                tcc_error("internal error: relocation failed");
            }
            add32le(ptr, diff);
        }
            break;
        case R_X86_64_GLOB_DAT:
        case R_X86_64_JUMP_SLOT:
            /* They don't need addend */
            write64le(ptr, val - rel->r_addend);
            break;
        case R_X86_64_GOTPCREL:
	case R_X86_64_GOTPCRELX:
	case R_X86_64_REX_GOTPCRELX:
            add32le(ptr, s1->got->sh_addr - addr +
                         s1->sym_attrs[sym_index].got_offset - 4);
            break;
        case R_X86_64_GOTTPOFF:
            add32le(ptr, val - s1->got->sh_addr);
            break;
        case R_X86_64_GOT32:
            /* we load the got offset */
            add32le(ptr, s1->sym_attrs[sym_index].got_offset);
            break;
    }
}

#endif /* !TARGET_DEFS_ONLY */