mirror of
https://github.com/frida/tinycc
synced 2024-11-24 00:29:38 +03:00
1353ccd9e2
this is enough to let me link a tcctest.c compiled by GCC using some current debian sid riscv64 system. It needs linking against libgcc.a for various floating point TFmode routines. The result runs.
252 lines
6.9 KiB
C
252 lines
6.9 KiB
C
#ifdef TARGET_DEFS_ONLY
|
|
|
|
#define EM_TCC_TARGET EM_386
|
|
|
|
/* relocation type for 32 bit data relocation */
|
|
#define R_DATA_32 R_386_32
|
|
#define R_DATA_PTR R_386_32
|
|
#define R_JMP_SLOT R_386_JMP_SLOT
|
|
#define R_GLOB_DAT R_386_GLOB_DAT
|
|
#define R_COPY R_386_COPY
|
|
#define R_RELATIVE R_386_RELATIVE
|
|
|
|
#define R_NUM R_386_NUM
|
|
|
|
#define ELF_START_ADDR 0x08048000
|
|
#define ELF_PAGE_SIZE 0x1000
|
|
|
|
#define PCRELATIVE_DLLPLT 0
|
|
#define RELOCATE_DLLPLT 0
|
|
|
|
#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_386_RELATIVE:
|
|
case R_386_16:
|
|
case R_386_32:
|
|
case R_386_GOTPC:
|
|
case R_386_GOTOFF:
|
|
case R_386_GOT32:
|
|
case R_386_GOT32X:
|
|
case R_386_GLOB_DAT:
|
|
case R_386_COPY:
|
|
return 0;
|
|
|
|
case R_386_PC16:
|
|
case R_386_PC32:
|
|
case R_386_PLT32:
|
|
case R_386_JMP_SLOT:
|
|
return 1;
|
|
}
|
|
|
|
tcc_error ("Unknown relocation type: %d", reloc_type);
|
|
return -1;
|
|
}
|
|
|
|
/* Returns an enumerator to describe whether 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_386_RELATIVE:
|
|
case R_386_16:
|
|
case R_386_GLOB_DAT:
|
|
case R_386_JMP_SLOT:
|
|
case R_386_COPY:
|
|
return NO_GOTPLT_ENTRY;
|
|
|
|
case R_386_32:
|
|
/* This relocations shouldn't normally need GOT or PLT
|
|
slots if it weren't for simplicity in the code generator.
|
|
See our caller for comments. */
|
|
return AUTO_GOTPLT_ENTRY;
|
|
|
|
case R_386_PC16:
|
|
case R_386_PC32:
|
|
return AUTO_GOTPLT_ENTRY;
|
|
|
|
case R_386_GOTPC:
|
|
case R_386_GOTOFF:
|
|
return BUILD_GOT_ONLY;
|
|
|
|
case R_386_GOT32:
|
|
case R_386_GOT32X:
|
|
case R_386_PLT32:
|
|
return ALWAYS_GOTPLT_ENTRY;
|
|
}
|
|
|
|
tcc_error ("Unknown relocation type: %d", reloc_type);
|
|
return -1;
|
|
}
|
|
|
|
ST_FUNC unsigned create_plt_entry(TCCState *s1, unsigned got_offset, struct sym_attr *attr)
|
|
{
|
|
Section *plt = s1->plt;
|
|
uint8_t *p;
|
|
int modrm;
|
|
unsigned plt_offset, relofs;
|
|
|
|
/* on i386 if we build a DLL, we add a %ebx offset */
|
|
if (s1->output_type == TCC_OUTPUT_DLL)
|
|
modrm = 0xa3;
|
|
else
|
|
modrm = 0x25;
|
|
|
|
/* empty PLT: create PLT0 entry that pushes the library identifier
|
|
(GOT + PTR_SIZE) and jumps to ld.so resolution routine
|
|
(GOT + 2 * PTR_SIZE) */
|
|
if (plt->data_offset == 0) {
|
|
p = section_ptr_add(plt, 16);
|
|
p[0] = 0xff; /* pushl got + PTR_SIZE */
|
|
p[1] = modrm + 0x10;
|
|
write32le(p + 2, PTR_SIZE);
|
|
p[6] = 0xff; /* jmp *(got + PTR_SIZE * 2) */
|
|
p[7] = modrm;
|
|
write32le(p + 8, PTR_SIZE * 2);
|
|
}
|
|
plt_offset = plt->data_offset;
|
|
|
|
/* The PLT slot refers to the relocation entry it needs via offset.
|
|
The reloc entry is created below, so its offset is the current
|
|
data_offset */
|
|
relofs = s1->got->reloc ? s1->got->reloc->data_offset : 0;
|
|
|
|
/* Jump to GOT entry where ld.so initially put the address of ip + 4 */
|
|
p = section_ptr_add(plt, 16);
|
|
p[0] = 0xff; /* jmp *(got + x) */
|
|
p[1] = modrm;
|
|
write32le(p + 2, got_offset);
|
|
p[6] = 0x68; /* push $xxx */
|
|
write32le(p + 7, relofs);
|
|
p[11] = 0xe9; /* jmp plt_start */
|
|
write32le(p + 12, -(plt->data_offset));
|
|
return plt_offset;
|
|
}
|
|
|
|
/* relocate the PLT: compute addresses and offsets in the PLT now that final
|
|
address for PLT and GOT are known (see fill_program_header) */
|
|
ST_FUNC void relocate_plt(TCCState *s1)
|
|
{
|
|
uint8_t *p, *p_end;
|
|
|
|
if (!s1->plt)
|
|
return;
|
|
|
|
p = s1->plt->data;
|
|
p_end = p + s1->plt->data_offset;
|
|
|
|
if (p < p_end) {
|
|
add32le(p + 2, s1->got->sh_addr);
|
|
add32le(p + 8, s1->got->sh_addr);
|
|
p += 16;
|
|
while (p < p_end) {
|
|
add32le(p + 2, s1->got->sh_addr);
|
|
p += 16;
|
|
}
|
|
}
|
|
}
|
|
|
|
static ElfW_Rel *qrel; /* ptr to next reloc entry reused */
|
|
|
|
void relocate_init(Section *sr)
|
|
{
|
|
qrel = (ElfW_Rel *) sr->data;
|
|
}
|
|
|
|
void relocate_fini(Section *sr)
|
|
{
|
|
}
|
|
|
|
void relocate(TCCState *s1, ElfW_Rel *rel, int type, unsigned 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_386_32:
|
|
if (s1->output_type == TCC_OUTPUT_DLL) {
|
|
esym_index = get_sym_attr(s1, sym_index, 0)->dyn_index;
|
|
qrel->r_offset = rel->r_offset;
|
|
if (esym_index) {
|
|
qrel->r_info = ELFW(R_INFO)(esym_index, R_386_32);
|
|
qrel++;
|
|
return;
|
|
} else {
|
|
qrel->r_info = ELFW(R_INFO)(0, R_386_RELATIVE);
|
|
qrel++;
|
|
}
|
|
}
|
|
add32le(ptr, val);
|
|
return;
|
|
case R_386_PC32:
|
|
if (s1->output_type == TCC_OUTPUT_DLL) {
|
|
/* DLL relocation */
|
|
esym_index = get_sym_attr(s1, sym_index, 0)->dyn_index;
|
|
if (esym_index) {
|
|
qrel->r_offset = rel->r_offset;
|
|
qrel->r_info = ELFW(R_INFO)(esym_index, R_386_PC32);
|
|
qrel++;
|
|
return;
|
|
}
|
|
}
|
|
add32le(ptr, val - addr);
|
|
return;
|
|
case R_386_PLT32:
|
|
add32le(ptr, val - addr);
|
|
return;
|
|
case R_386_GLOB_DAT:
|
|
case R_386_JMP_SLOT:
|
|
write32le(ptr, val);
|
|
return;
|
|
case R_386_GOTPC:
|
|
add32le(ptr, s1->got->sh_addr - addr);
|
|
return;
|
|
case R_386_GOTOFF:
|
|
add32le(ptr, val - s1->got->sh_addr);
|
|
return;
|
|
case R_386_GOT32:
|
|
case R_386_GOT32X:
|
|
/* we load the got offset */
|
|
add32le(ptr, get_sym_attr(s1, sym_index, 0)->got_offset);
|
|
return;
|
|
case R_386_16:
|
|
if (s1->output_format != TCC_OUTPUT_FORMAT_BINARY) {
|
|
output_file:
|
|
tcc_error("can only produce 16-bit binary files");
|
|
}
|
|
write16le(ptr, read16le(ptr) + val);
|
|
return;
|
|
case R_386_PC16:
|
|
if (s1->output_format != TCC_OUTPUT_FORMAT_BINARY)
|
|
goto output_file;
|
|
write16le(ptr, read16le(ptr) + val - addr);
|
|
return;
|
|
case R_386_RELATIVE:
|
|
#ifdef TCC_TARGET_PE
|
|
add32le(ptr, val - s1->pe_imagebase);
|
|
#endif
|
|
/* do nothing */
|
|
return;
|
|
case R_386_COPY:
|
|
/* This relocation must copy initialized data from the library
|
|
to the program .bss segment. Currently made like for ARM
|
|
(to remove noise of default case). Is this true?
|
|
*/
|
|
return;
|
|
default:
|
|
fprintf(stderr,"FIXME: handle reloc type %d at %x [%p] to %x\n",
|
|
type, (unsigned)addr, ptr, (unsigned)val);
|
|
return;
|
|
}
|
|
}
|
|
|
|
#endif /* !TARGET_DEFS_ONLY */
|