Alien-TinyCC
view release on metacpan or search on metacpan
src/tccelf.c view on Meta::CPAN
*(int *)(p + 2) = 0;
*(addr_t *)(p + 6) = val;
return (addr_t)p;
}
static addr_t add_got_table(TCCState *s1, addr_t val)
{
addr_t *p = (addr_t *)(s1->runtime_plt_and_got + s1->runtime_plt_and_got_offset);
s1->runtime_plt_and_got_offset += sizeof(addr_t);
*p = val;
return (addr_t)p;
}
#elif defined TCC_TARGET_ARM
#define JMP_TABLE_ENTRY_SIZE 8
static addr_t add_jmp_table(TCCState *s1, int val)
{
uint32_t *p = (uint32_t *)(s1->runtime_plt_and_got + s1->runtime_plt_and_got_offset);
s1->runtime_plt_and_got_offset += JMP_TABLE_ENTRY_SIZE;
/* ldr pc, [pc, #-4] */
p[0] = 0xE51FF004;
p[1] = val;
return (addr_t)p;
}
#endif
#endif /* def TCC_HAS_RUNTIME_PLTGOT */
/* relocate a given section (CPU dependent) */
ST_FUNC void relocate_section(TCCState *s1, Section *s)
{
Section *sr;
ElfW_Rel *rel, *rel_end, *qrel;
ElfW(Sym) *sym;
int type, sym_index;
unsigned char *ptr;
addr_t val, addr;
#if defined TCC_TARGET_I386 || defined TCC_TARGET_X86_64
int esym_index;
#endif
sr = s->reloc;
rel_end = (ElfW_Rel *)(sr->data + sr->data_offset);
qrel = (ElfW_Rel *)sr->data;
for(rel = qrel;
rel < rel_end;
rel++) {
ptr = s->data + rel->r_offset;
sym_index = ELFW(R_SYM)(rel->r_info);
sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
val = sym->st_value;
#ifdef TCC_TARGET_X86_64
val += rel->r_addend;
#endif
type = ELFW(R_TYPE)(rel->r_info);
addr = s->sh_addr + rel->r_offset;
/* CPU specific */
switch(type) {
#if defined(TCC_TARGET_I386)
case R_386_32:
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_386_32);
qrel++;
break;
} else {
qrel->r_info = ELFW(R_INFO)(0, R_386_RELATIVE);
qrel++;
}
}
*(int *)ptr += val;
break;
case R_386_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_386_PC32);
qrel++;
break;
}
}
*(int *)ptr += val - addr;
break;
case R_386_PLT32:
*(int *)ptr += val - addr;
break;
case R_386_GLOB_DAT:
case R_386_JMP_SLOT:
*(int *)ptr = val;
break;
case R_386_GOTPC:
*(int *)ptr += s1->got->sh_addr - addr;
break;
case R_386_GOTOFF:
*(int *)ptr += val - s1->got->sh_addr;
break;
case R_386_GOT32:
/* we load the got offset */
*(int *)ptr += s1->sym_attrs[sym_index].got_offset;
break;
case R_386_16:
if (s1->output_format != TCC_OUTPUT_FORMAT_BINARY) {
output_file:
tcc_error("can only produce 16-bit binary files");
}
*(short *)ptr += val;
break;
case R_386_PC16:
if (s1->output_format != TCC_OUTPUT_FORMAT_BINARY)
goto output_file;
*(short *)ptr += val - addr;
break;
#elif defined(TCC_TARGET_ARM)
case R_ARM_PC24:
case R_ARM_CALL:
case R_ARM_JUMP24:
case R_ARM_PLT32:
{
int x, is_thumb, is_call, h, blx_avail;
x = (*(int *)ptr)&0xffffff;
(*(int *)ptr) &= 0xff000000;
if (x & 0x800000)
x -= 0x1000000;
x <<= 2;
blx_avail = (TCC_ARM_VERSION >= 5);
is_thumb = val & 1;
is_call = (type == R_ARM_CALL);
x += val - addr;
h = x & 2;
#ifdef TCC_HAS_RUNTIME_PLTGOT
if (s1->output_type == TCC_OUTPUT_MEMORY) {
if ((x & 3) || x >= 0x2000000 || x < -0x2000000)
if (!(x & 3) || !blx_avail || !is_call) {
x += add_jmp_table(s1, val) - val; /* add veneer */
is_thumb = 0; /* Veneer uses ARM instructions */
}
}
#endif
if ((x & 3) || x >= 0x2000000 || x < -0x2000000)
if (!(x & 3) || !blx_avail || !is_call)
tcc_error("can't relocate value at %x",addr);
x >>= 2;
x &= 0xffffff;
/* Only reached if blx is avail and it is a call */
if (is_thumb) {
x |= h << 24;
(*(int *)ptr) = 0xfa << 24; /* bl -> blx */
}
(*(int *)ptr) |= x;
}
break;
/* Since these relocations only concern Thumb-2 and blx instruction was
introduced before Thumb-2, we can assume blx is available and not
guard its use */
case R_ARM_THM_CALL:
case R_ARM_THM_JUMP24:
{
int x, hi, lo, s, j1, j2, i1, i2, imm10, imm11;
int to_thumb, is_call, to_plt, blx_bit = 1 << 12;
Section *plt;
/* weak reference */
if (sym->st_shndx == SHN_UNDEF &&
ELFW(ST_BIND)(sym->st_info) == STB_WEAK)
break;
/* Get initial offset */
hi = (*(uint16_t *)ptr);
lo = (*(uint16_t *)(ptr+2));
s = (hi >> 10) & 1;
j1 = (lo >> 13) & 1;
j2 = (lo >> 11) & 1;
i1 = (j1 ^ s) ^ 1;
i2 = (j2 ^ s) ^ 1;
imm10 = hi & 0x3ff;
imm11 = lo & 0x7ff;
x = (s << 24) | (i1 << 23) | (i2 << 22) |
(imm10 << 12) | (imm11 << 1);
if (x & 0x01000000)
x -= 0x02000000;
/* Relocation infos */
to_thumb = val & 1;
plt = s1->plt;
to_plt = (val >= plt->sh_addr) &&
(val < plt->sh_addr + plt->data_offset);
is_call = (type == R_ARM_THM_CALL);
/* Compute final offset */
if (to_plt && !is_call) /* Point to 1st instr of Thumb stub */
x -= 4;
src/tccelf.c view on Meta::CPAN
x += val - addr;
if((x^(x>>1))&0x40000000)
tcc_error("can't relocate value at %x",addr);
(*(int *)ptr) |= x & 0x7fffffff;
}
case R_ARM_ABS32:
*(int *)ptr += val;
break;
case R_ARM_REL32:
*(int *)ptr += val - addr;
break;
case R_ARM_BASE_PREL:
*(int *)ptr += s1->got->sh_addr - addr;
break;
case R_ARM_GOTOFF32:
*(int *)ptr += val - s1->got->sh_addr;
break;
case R_ARM_GOT_BREL:
/* we load the got offset */
*(int *)ptr += s1->sym_attrs[sym_index].got_offset;
break;
case R_ARM_COPY:
break;
case R_ARM_V4BX:
/* trade Thumb support for ARMv4 support */
if ((0x0ffffff0 & *(int*)ptr) == 0x012FFF10)
*(int*)ptr ^= 0xE12FFF10 ^ 0xE1A0F000; /* BX Rm -> MOV PC, Rm */
break;
default:
fprintf(stderr,"FIXME: handle reloc type %x at %x [%p] to %x\n",
type, (unsigned)addr, ptr, (unsigned)val);
break;
#elif defined(TCC_TARGET_C67)
case R_C60_32:
*(int *)ptr += val;
break;
case R_C60LO16:
{
uint32_t orig;
/* put the low 16 bits of the absolute address */
// add to what is already there
orig = ((*(int *)(ptr )) >> 7) & 0xffff;
orig |= (((*(int *)(ptr+4)) >> 7) & 0xffff) << 16;
//patch both at once - assumes always in pairs Low - High
*(int *) ptr = (*(int *) ptr & (~(0xffff << 7)) ) | (((val+orig) & 0xffff) << 7);
*(int *)(ptr+4) = (*(int *)(ptr+4) & (~(0xffff << 7)) ) | ((((val+orig)>>16) & 0xffff) << 7);
}
break;
case R_C60HI16:
break;
default:
fprintf(stderr,"FIXME: handle reloc type %x at %x [%p] to %x\n",
type, (unsigned)addr, ptr, (unsigned)val);
break;
#elif defined(TCC_TARGET_X86_64)
case R_X86_64_64:
if (s1->output_type == TCC_OUTPUT_DLL) {
qrel->r_info = ELFW(R_INFO)(0, R_X86_64_RELATIVE);
qrel->r_addend = *(long long *)ptr + val;
qrel++;
}
*(long long *)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);
qrel->r_addend = *(int *)ptr + val;
qrel++;
}
*(int *)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);
qrel->r_addend = *(int *)ptr;
qrel++;
break;
}
}
/* fall through */
case R_X86_64_PLT32: {
long long diff;
diff = (long long)val - addr;
if (diff <= -2147483647 || diff > 2147483647) {
#ifdef TCC_HAS_RUNTIME_PLTGOT
/* XXX: naive support for over 32bit jump */
if (s1->output_type == TCC_OUTPUT_MEMORY) {
val = (add_jmp_table(s1, val - rel->r_addend) +
rel->r_addend);
diff = val - addr;
}
#endif
if (diff <= -2147483647 || diff > 2147483647) {
tcc_error("internal error: relocation failed");
}
}
*(int *)ptr += diff;
}
break;
case R_X86_64_GLOB_DAT:
case R_X86_64_JUMP_SLOT:
/* They don't need addend */
*(int *)ptr = val - rel->r_addend;
break;
case R_X86_64_GOTPCREL:
#ifdef TCC_HAS_RUNTIME_PLTGOT
if (s1->output_type == TCC_OUTPUT_MEMORY) {
val = add_got_table(s1, val - rel->r_addend) + rel->r_addend;
*(int *)ptr += val - addr;
break;
}
#endif
*(int *)ptr += (s1->got->sh_addr - addr +
s1->sym_attrs[sym_index].got_offset - 4);
break;
case R_X86_64_GOTTPOFF:
*(int *)ptr += val - s1->got->sh_addr;
break;
case R_X86_64_GOT32:
/* we load the got offset */
*(int *)ptr += s1->sym_attrs[sym_index].got_offset;
break;
#else
#error unsupported processor
#endif
}
}
/* if the relocation is allocated, we change its symbol table */
if (sr->sh_flags & SHF_ALLOC)
sr->link = s1->dynsym;
}
/* relocate relocation table in 'sr' */
static void relocate_rel(TCCState *s1, Section *sr)
{
Section *s;
ElfW_Rel *rel, *rel_end;
s = s1->sections[sr->sh_info];
rel_end = (ElfW_Rel *)(sr->data + sr->data_offset);
for(rel = (ElfW_Rel *)sr->data;
rel < rel_end;
rel++) {
rel->r_offset += s->sh_addr;
}
}
/* count the number of dynamic relocations so that we can reserve
their space */
static int prepare_dynamic_rel(TCCState *s1, Section *sr)
{
ElfW_Rel *rel, *rel_end;
int sym_index, esym_index, type, count;
count = 0;
rel_end = (ElfW_Rel *)(sr->data + sr->data_offset);
for(rel = (ElfW_Rel *)sr->data; rel < rel_end; rel++) {
sym_index = ELFW(R_SYM)(rel->r_info);
type = ELFW(R_TYPE)(rel->r_info);
switch(type) {
#if defined(TCC_TARGET_I386)
case R_386_32:
#elif defined(TCC_TARGET_X86_64)
case R_X86_64_32:
case R_X86_64_32S:
case R_X86_64_64:
#endif
src/tccelf.c view on Meta::CPAN
s1->got->sh_entsize = 4;
add_elf_sym(symtab_section, 0, 4, ELFW(ST_INFO)(STB_GLOBAL, STT_OBJECT),
0, s1->got->sh_num, "_GLOBAL_OFFSET_TABLE_");
ptr = section_ptr_add(s1->got, 3 * PTR_SIZE);
#if PTR_SIZE == 4
/* keep space for _DYNAMIC pointer, if present */
put32(ptr, 0);
/* two dummy got entries */
put32(ptr + 4, 0);
put32(ptr + 8, 0);
#else
/* keep space for _DYNAMIC pointer, if present */
put32(ptr, 0);
put32(ptr + 4, 0);
/* two dummy got entries */
put32(ptr + 8, 0);
put32(ptr + 12, 0);
put32(ptr + 16, 0);
put32(ptr + 20, 0);
#endif
}
/* put a got entry corresponding to a symbol in symtab_section. 'size'
and 'info' can be modifed if more precise info comes from the DLL */
static void put_got_entry(TCCState *s1,
int reloc_type, unsigned long size, int info,
int sym_index)
{
int index;
const char *name;
ElfW(Sym) *sym;
unsigned long offset;
int *ptr;
if (!s1->got)
build_got(s1);
/* if a got entry already exists for that symbol, no need to add one */
if (sym_index < s1->nb_sym_attrs &&
s1->sym_attrs[sym_index].got_offset)
return;
alloc_sym_attr(s1, sym_index)->got_offset = s1->got->data_offset;
if (s1->dynsym) {
sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
name = symtab_section->link->data + sym->st_name;
offset = sym->st_value;
#if defined(TCC_TARGET_I386) || defined(TCC_TARGET_X86_64)
if (reloc_type ==
#ifdef TCC_TARGET_X86_64
R_X86_64_JUMP_SLOT
#else
R_386_JMP_SLOT
#endif
) {
Section *plt;
uint8_t *p;
int modrm;
#if defined(TCC_OUTPUT_DLL_WITH_PLT)
modrm = 0x25;
#else
/* if we build a DLL, we add a %ebx offset */
if (s1->output_type == TCC_OUTPUT_DLL)
modrm = 0xa3;
else
modrm = 0x25;
#endif
/* add a PLT entry */
plt = s1->plt;
if (plt->data_offset == 0) {
/* first plt entry */
p = section_ptr_add(plt, 16);
p[0] = 0xff; /* pushl got + PTR_SIZE */
p[1] = modrm + 0x10;
put32(p + 2, PTR_SIZE);
p[6] = 0xff; /* jmp *(got + PTR_SIZE * 2) */
p[7] = modrm;
put32(p + 8, PTR_SIZE * 2);
}
p = section_ptr_add(plt, 16);
p[0] = 0xff; /* jmp *(got + x) */
p[1] = modrm;
put32(p + 2, s1->got->data_offset);
p[6] = 0x68; /* push $xxx */
put32(p + 7, (plt->data_offset - 32) >> 1);
p[11] = 0xe9; /* jmp plt_start */
put32(p + 12, -(plt->data_offset));
/* the symbol is modified so that it will be relocated to
the PLT */
#if !defined(TCC_OUTPUT_DLL_WITH_PLT)
if (s1->output_type == TCC_OUTPUT_EXE)
#endif
offset = plt->data_offset - 16;
}
#elif defined(TCC_TARGET_ARM)
if (reloc_type == R_ARM_JUMP_SLOT) {
Section *plt;
uint8_t *p;
/* if we build a DLL, we add a %ebx offset */
if (s1->output_type == TCC_OUTPUT_DLL)
tcc_error("DLLs unimplemented!");
/* add a PLT entry */
plt = s1->plt;
if (plt->data_offset == 0) {
/* first plt entry */
p = section_ptr_add(plt, 16);
put32(p , 0xe52de004);
put32(p + 4, 0xe59fe010);
put32(p + 8, 0xe08fe00e);
put32(p + 12, 0xe5bef008);
}
if (s1->sym_attrs[sym_index].plt_thumb_stub) {
p = section_ptr_add(plt, 20);
put32(p , 0x4778); // bx pc
put32(p+2, 0x46c0); // nop
p += 4;
} else
p = section_ptr_add(plt, 16);
put32(p , 0xe59fc004); // ldr ip, [pc, #4] // offset in GOT
put32(p+4, 0xe08fc00c); // add ip, pc, ip // absolute address or offset
put32(p+8, 0xe59cf000); // ldr pc, [ip] // load absolute address or load offset
put32(p+12, s1->got->data_offset);
/* the symbol is modified so that it will be relocated to
the PLT */
if (s1->output_type == TCC_OUTPUT_EXE)
offset = plt->data_offset - 16;
}
#elif defined(TCC_TARGET_C67)
tcc_error("C67 got not implemented");
#else
#error unsupported CPU
#endif
index = put_elf_sym(s1->dynsym, offset,
size, info, 0, sym->st_shndx, name);
/* put a got entry */
put_elf_reloc(s1->dynsym, s1->got,
s1->got->data_offset,
reloc_type, index);
}
ptr = section_ptr_add(s1->got, PTR_SIZE);
*ptr = 0;
}
/* build GOT and PLT entries */
ST_FUNC void build_got_entries(TCCState *s1)
{
Section *s;
ElfW_Rel *rel, *rel_end;
ElfW(Sym) *sym;
int i, type, reloc_type, sym_index;
for(i = 1; i < s1->nb_sections; i++) {
s = s1->sections[i];
if (s->sh_type != SHT_RELX)
continue;
/* no need to handle got relocations */
if (s->link != symtab_section)
continue;
rel_end = (ElfW_Rel *)(s->data + s->data_offset);
for(rel = (ElfW_Rel *)s->data;
rel < rel_end;
rel++) {
type = ELFW(R_TYPE)(rel->r_info);
switch(type) {
#if defined(TCC_TARGET_I386)
case R_386_GOT32:
case R_386_GOTOFF:
case R_386_GOTPC:
case R_386_PLT32:
if (!s1->got)
build_got(s1);
if (type == R_386_GOT32 || type == R_386_PLT32) {
sym_index = ELFW(R_SYM)(rel->r_info);
sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
/* look at the symbol got offset. If none, then add one */
if (type == R_386_GOT32)
reloc_type = R_386_GLOB_DAT;
else
reloc_type = R_386_JMP_SLOT;
put_got_entry(s1, reloc_type, sym->st_size, sym->st_info,
sym_index);
}
break;
#elif defined(TCC_TARGET_ARM)
case R_ARM_GOT_BREL:
src/tccelf.c view on Meta::CPAN
ptr[1] = 1;
memset(ptr + 2, 0, (nb_buckets + 1) * sizeof(int));
return symtab;
}
/* put dynamic tag */
static void put_dt(Section *dynamic, int dt, addr_t val)
{
ElfW(Dyn) *dyn;
dyn = section_ptr_add(dynamic, sizeof(ElfW(Dyn)));
dyn->d_tag = dt;
dyn->d_un.d_val = val;
}
static void add_init_array_defines(TCCState *s1, const char *section_name)
{
Section *s;
long end_offset;
char sym_start[1024];
char sym_end[1024];
snprintf(sym_start, sizeof(sym_start), "__%s_start", section_name + 1);
snprintf(sym_end, sizeof(sym_end), "__%s_end", section_name + 1);
s = find_section(s1, section_name);
if (!s) {
end_offset = 0;
s = data_section;
} else {
end_offset = s->data_offset;
}
add_elf_sym(symtab_section,
0, 0,
ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
s->sh_num, sym_start);
add_elf_sym(symtab_section,
end_offset, 0,
ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
s->sh_num, sym_end);
}
ST_FUNC void tcc_add_bcheck(TCCState *s1)
{
#ifdef CONFIG_TCC_BCHECK
unsigned long *ptr;
Section *init_section;
unsigned char *pinit;
int sym_index;
if (0 == s1->do_bounds_check)
return;
/* XXX: add an object file to do that */
ptr = section_ptr_add(bounds_section, sizeof(unsigned long));
*ptr = 0;
add_elf_sym(symtab_section, 0, 0,
ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
bounds_section->sh_num, "__bounds_start");
#ifdef TCC_TARGET_I386
if (s1->output_type != TCC_OUTPUT_MEMORY) {
/* add 'call __bound_init()' in .init section */
init_section = find_section(s1, ".init");
pinit = section_ptr_add(init_section, 5);
pinit[0] = 0xe8;
put32(pinit + 1, -4);
sym_index = find_elf_sym(symtab_section, "__bound_init");
put_elf_reloc(symtab_section, init_section,
init_section->data_offset - 4, R_386_PC32, sym_index);
}
#endif
#endif
}
static inline int tcc_add_support(TCCState *s1, const char *filename)
{
char buf[1024];
snprintf(buf, sizeof(buf), "%s/%s", s1->tcc_lib_path, filename);
return tcc_add_file(s1, buf);
}
/* add tcc runtime libraries */
ST_FUNC void tcc_add_runtime(TCCState *s1)
{
tcc_add_bcheck(s1);
/* add libc */
if (!s1->nostdlib) {
tcc_add_library(s1, "c");
#ifdef CONFIG_USE_LIBGCC
tcc_add_file(s1, TCC_LIBGCC);
#elif !defined WITHOUT_LIBTCC
tcc_add_support(s1, "libtcc1.a");
#endif
/* add crt end if not memory output */
if (s1->output_type != TCC_OUTPUT_MEMORY)
tcc_add_crt(s1, "crtn.o");
}
}
/* add various standard linker symbols (must be done after the
sections are filled (for example after allocating common
symbols)) */
ST_FUNC void tcc_add_linker_symbols(TCCState *s1)
{
char buf[1024];
int i;
Section *s;
add_elf_sym(symtab_section,
text_section->data_offset, 0,
ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
text_section->sh_num, "_etext");
add_elf_sym(symtab_section,
data_section->data_offset, 0,
ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
data_section->sh_num, "_edata");
add_elf_sym(symtab_section,
bss_section->data_offset, 0,
ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
bss_section->sh_num, "_end");
/* horrible new standard ldscript defines */
add_init_array_defines(s1, ".preinit_array");
add_init_array_defines(s1, ".init_array");
add_init_array_defines(s1, ".fini_array");
/* add start and stop symbols for sections whose name can be
expressed in C */
for(i = 1; i < s1->nb_sections; i++) {
s = s1->sections[i];
if (s->sh_type == SHT_PROGBITS &&
(s->sh_flags & SHF_ALLOC)) {
const char *p;
int ch;
/* check if section name can be expressed in C */
p = s->name;
for(;;) {
ch = *p;
if (!ch)
break;
if (!isid(ch) && !isnum(ch))
goto next_sec;
p++;
}
snprintf(buf, sizeof(buf), "__start_%s", s->name);
add_elf_sym(symtab_section,
0, 0,
ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
s->sh_num, buf);
snprintf(buf, sizeof(buf), "__stop_%s", s->name);
add_elf_sym(symtab_section,
s->data_offset, 0,
ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0,
s->sh_num, buf);
}
src/tccelf.c view on Meta::CPAN
#ifdef TCC_TARGET_X86_64
/* only works for x86-64 */
put32(s1->got->data + offset + 4, sym->st_value >> 32);
#endif
put32(s1->got->data + offset, sym->st_value & 0xffffffff);
}
ST_FUNC void fill_got(TCCState *s1)
{
Section *s;
ElfW_Rel *rel, *rel_end;
int i;
for(i = 1; i < s1->nb_sections; i++) {
s = s1->sections[i];
if (s->sh_type != SHT_RELX)
continue;
/* no need to handle got relocations */
if (s->link != symtab_section)
continue;
rel_end = (ElfW_Rel *) (s->data + s->data_offset);
for(rel = (ElfW_Rel *) s->data; rel < rel_end; rel++) {
switch (ELFW(R_TYPE) (rel->r_info)) {
case R_X86_64_GOT32:
case R_X86_64_GOTPCREL:
case R_X86_64_PLT32:
fill_got_entry(s1, rel);
break;
}
}
}
}
/* output an ELF file */
/* XXX: suppress unneeded sections */
static int elf_output_file(TCCState *s1, const char *filename)
{
ElfW(Ehdr) ehdr;
FILE *f;
int fd, mode, ret;
int *section_order;
int shnum, i, phnum, file_offset, offset, size, j, sh_order_index, k;
long long tmp;
addr_t addr;
Section *strsec, *s;
ElfW(Shdr) shdr, *sh;
ElfW(Phdr) *phdr, *ph;
Section *interp, *dynamic, *dynstr;
unsigned long saved_dynamic_data_offset;
ElfW(Sym) *sym;
int type, file_type;
addr_t rel_addr, rel_size;
#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
addr_t bss_addr, bss_size;
#endif
file_type = s1->output_type;
s1->nb_errors = 0;
if (file_type != TCC_OUTPUT_OBJ) {
tcc_add_runtime(s1);
}
phdr = NULL;
section_order = NULL;
interp = NULL;
dynamic = NULL;
dynstr = NULL; /* avoid warning */
saved_dynamic_data_offset = 0; /* avoid warning */
if (file_type != TCC_OUTPUT_OBJ) {
relocate_common_syms();
tcc_add_linker_symbols(s1);
if (!s1->static_link) {
const char *name;
int sym_index, index;
ElfW(Sym) *esym, *sym_end;
if (file_type == TCC_OUTPUT_EXE) {
char *ptr;
/* allow override the dynamic loader */
const char *elfint = getenv("LD_SO");
if (elfint == NULL)
elfint = CONFIG_TCC_ELFINTERP;
/* add interpreter section only if executable */
interp = new_section(s1, ".interp", SHT_PROGBITS, SHF_ALLOC);
interp->sh_addralign = 1;
ptr = section_ptr_add(interp, 1+strlen(elfint));
strcpy(ptr, elfint);
}
/* add dynamic symbol table */
s1->dynsym = new_symtab(s1, ".dynsym", SHT_DYNSYM, SHF_ALLOC,
".dynstr",
".hash", SHF_ALLOC);
dynstr = s1->dynsym->link;
/* add dynamic section */
dynamic = new_section(s1, ".dynamic", SHT_DYNAMIC,
SHF_ALLOC | SHF_WRITE);
dynamic->link = dynstr;
dynamic->sh_entsize = sizeof(ElfW(Dyn));
/* add PLT */
s1->plt = new_section(s1, ".plt", SHT_PROGBITS,
SHF_ALLOC | SHF_EXECINSTR);
s1->plt->sh_entsize = 4;
build_got(s1);
/* scan for undefined symbols and see if they are in the
dynamic symbols. If a symbol STT_FUNC or STT_GNU_IFUNC
is found, then we add it in the PLT. If a symbol
STT_OBJECT is found, we add it in the .bss section with
a suitable relocation */
sym_end = (ElfW(Sym) *)(symtab_section->data +
symtab_section->data_offset);
if (file_type == TCC_OUTPUT_EXE) {
for(sym = (ElfW(Sym) *)symtab_section->data + 1;
sym < sym_end;
sym++) {
if (sym->st_shndx == SHN_UNDEF) {
name = symtab_section->link->data + sym->st_name;
sym_index = find_elf_sym(s1->dynsymtab_section, name);
if (sym_index) {
esym = &((ElfW(Sym) *)s1->dynsymtab_section->data)[sym_index];
type = ELFW(ST_TYPE)(esym->st_info);
if ((type == STT_FUNC) || (type == STT_GNU_IFUNC)) {
/* Indirect functions shall have STT_FUNC type
* in executable dynsym section. Indeed, a dlsym
* call following a lazy resolution would pick
* the symbol value from the executable dynsym
* entry which would contain the address of the
* function wanted by the caller of dlsym
* instead of the address of the function that
* would return that address */
put_got_entry(s1, R_JMP_SLOT, esym->st_size,
ELFW(ST_INFO)(STB_GLOBAL,STT_FUNC),
sym - (ElfW(Sym) *)symtab_section->data);
} else if (type == STT_OBJECT) {
unsigned long offset;
ElfW(Sym) *dynsym, *dynsym_end;
offset = bss_section->data_offset;
/* XXX: which alignment ? */
offset = (offset + 16 - 1) & -16;
index = put_elf_sym(s1->dynsym, offset, esym->st_size,
esym->st_info, 0,
bss_section->sh_num, name);
// Ensure R_COPY works for weak symbol aliases
if (ELFW(ST_BIND)(esym->st_info) == STB_WEAK) {
dynsym_end = (ElfW(Sym) *)
(s1->dynsymtab_section->data +
s1->dynsymtab_section->data_offset);
for(dynsym = (ElfW(Sym) *)s1->dynsymtab_section->data + 1;
dynsym < dynsym_end; dynsym++) {
if ((dynsym->st_value == esym->st_value)
&& (ELFW(ST_BIND)(dynsym->st_info) == STB_GLOBAL)) {
char *dynname;
dynname = s1->dynsymtab_section->link->data
+ dynsym->st_name;
put_elf_sym(s1->dynsym, offset,
dynsym->st_size,
dynsym->st_info, 0,
bss_section->sh_num,
dynname);
break;
}
}
}
put_elf_reloc(s1->dynsym, bss_section,
offset, R_COPY, index);
offset += esym->st_size;
bss_section->data_offset = offset;
}
} else {
/* STB_WEAK undefined symbols are accepted */
/* XXX: _fp_hw seems to be part of the ABI, so we ignore
it */
if (ELFW(ST_BIND)(sym->st_info) == STB_WEAK ||
!strcmp(name, "_fp_hw")) {
} else {
tcc_error_noabort("undefined symbol '%s'", name);
}
}
} else if (s1->rdynamic &&
ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
/* if -rdynamic option, then export all non
local symbols */
name = symtab_section->link->data + sym->st_name;
put_elf_sym(s1->dynsym, sym->st_value, sym->st_size,
sym->st_info, 0,
sym->st_shndx, name);
}
}
if (s1->nb_errors)
goto fail;
/* now look at unresolved dynamic symbols and export
corresponding symbol */
sym_end = (ElfW(Sym) *)(s1->dynsymtab_section->data +
s1->dynsymtab_section->data_offset);
for(esym = (ElfW(Sym) *)s1->dynsymtab_section->data + 1;
esym < sym_end;
esym++) {
if (esym->st_shndx == SHN_UNDEF) {
name = s1->dynsymtab_section->link->data + esym->st_name;
sym_index = find_elf_sym(symtab_section, name);
if (sym_index) {
/* XXX: avoid adding a symbol if already
present because of -rdynamic ? */
sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
put_elf_sym(s1->dynsym, sym->st_value, sym->st_size,
sym->st_info, 0,
sym->st_shndx, name);
} else {
if (ELFW(ST_BIND)(esym->st_info) == STB_WEAK) {
/* weak symbols can stay undefined */
} else {
tcc_warning("undefined dynamic symbol '%s'", name);
}
}
}
}
} else {
int nb_syms;
/* shared library case : we simply export all the global symbols */
nb_syms = symtab_section->data_offset / sizeof(ElfW(Sym));
s1->symtab_to_dynsym = tcc_mallocz(sizeof(int) * nb_syms);
for(sym = (ElfW(Sym) *)symtab_section->data + 1;
sym < sym_end;
sym++) {
if (ELFW(ST_BIND)(sym->st_info) != STB_LOCAL) {
#if defined(TCC_OUTPUT_DLL_WITH_PLT)
if ((ELFW(ST_TYPE)(sym->st_info) == STT_FUNC ||
ELFW(ST_TYPE)(sym->st_info) == STT_GNU_IFUNC)
&& sym->st_shndx == SHN_UNDEF) {
int visibility = ELFW(ST_BIND)(sym->st_info);
put_got_entry(s1, R_JMP_SLOT, sym->st_size,
ELFW(ST_INFO)(visibility,STT_FUNC),
sym - (ElfW(Sym) *)symtab_section->data);
}
else if (ELFW(ST_TYPE)(sym->st_info) == STT_OBJECT) {
put_got_entry(s1, R_X86_64_GLOB_DAT, sym->st_size,
sym->st_info,
sym - (ElfW(Sym) *)symtab_section->data);
}
else
#endif
{
name = symtab_section->link->data + sym->st_name;
index = put_elf_sym(s1->dynsym, sym->st_value, sym->st_size,
sym->st_info, 0,
sym->st_shndx, name);
s1->symtab_to_dynsym[sym -
(ElfW(Sym) *)symtab_section->data] =
index;
}
}
}
}
build_got_entries(s1);
/* add a list of needed dlls */
for(i = 0; i < s1->nb_loaded_dlls; i++) {
DLLReference *dllref = s1->loaded_dlls[i];
if (dllref->level == 0)
put_dt(dynamic, DT_NEEDED, put_elf_str(dynstr, dllref->name));
}
if (s1->rpath)
put_dt(dynamic, DT_RPATH, put_elf_str(dynstr, s1->rpath));
/* XXX: currently, since we do not handle PIC code, we
must relocate the readonly segments */
if (file_type == TCC_OUTPUT_DLL) {
if (s1->soname)
put_dt(dynamic, DT_SONAME, put_elf_str(dynstr, s1->soname));
put_dt(dynamic, DT_TEXTREL, 0);
}
if (s1->symbolic)
put_dt(dynamic, DT_SYMBOLIC, 0);
/* add necessary space for other entries */
saved_dynamic_data_offset = dynamic->data_offset;
dynamic->data_offset += sizeof(ElfW(Dyn)) * EXTRA_RELITEMS;
} else {
/* still need to build got entries in case of static link */
build_got_entries(s1);
}
}
memset(&ehdr, 0, sizeof(ehdr));
/* we add a section for symbols */
strsec = new_section(s1, ".shstrtab", SHT_STRTAB, 0);
put_elf_str(strsec, "");
/* compute number of sections */
shnum = s1->nb_sections;
/* this array is used to reorder sections in the output file */
section_order = tcc_malloc(sizeof(int) * shnum);
section_order[0] = 0;
sh_order_index = 1;
/* compute number of program headers */
switch(file_type) {
default:
case TCC_OUTPUT_OBJ:
phnum = 0;
break;
case TCC_OUTPUT_EXE:
if (!s1->static_link)
phnum = 4 + HAVE_PHDR;
else
phnum = 2;
break;
case TCC_OUTPUT_DLL:
phnum = 3;
break;
}
/* allocate strings for section names and decide if an unallocated
section should be output */
/* NOTE: the strsec section comes last, so its size is also
correct ! */
for(i = 1; i < s1->nb_sections; i++) {
s = s1->sections[i];
s->sh_name = put_elf_str(strsec, s->name);
#if 0 /* gr */
printf("section: f=%08x t=%08x i=%08x %s %s\n",
s->sh_flags,
s->sh_type,
s->sh_info,
s->name,
s->reloc ? s->reloc->name : "n"
);
#endif
/* when generating a DLL, we include relocations but we may
patch them */
if (file_type == TCC_OUTPUT_DLL &&
s->sh_type == SHT_RELX &&
!(s->sh_flags & SHF_ALLOC)) {
/* //gr: avoid bogus relocs for empty (debug) sections */
if (s1->sections[s->sh_info]->sh_flags & SHF_ALLOC)
prepare_dynamic_rel(s1, s);
else if (s1->do_debug)
s->sh_size = s->data_offset;
} else if (s1->do_debug ||
file_type == TCC_OUTPUT_OBJ ||
(s->sh_flags & SHF_ALLOC) ||
i == (s1->nb_sections - 1)) {
/* we output all sections if debug or object file */
s->sh_size = s->data_offset;
}
}
/* allocate program segment headers */
phdr = tcc_mallocz(phnum * sizeof(ElfW(Phdr)));
if (s1->output_format == TCC_OUTPUT_FORMAT_ELF) {
file_offset = sizeof(ElfW(Ehdr)) + phnum * sizeof(ElfW(Phdr));
} else {
file_offset = 0;
}
if (phnum > 0) {
/* compute section to program header mapping */
if (s1->has_text_addr) {
int a_offset, p_offset;
addr = s1->text_addr;
/* we ensure that (addr % ELF_PAGE_SIZE) == file_offset %
ELF_PAGE_SIZE */
a_offset = (int) (addr & (s1->section_align - 1));
p_offset = file_offset & (s1->section_align - 1);
if (a_offset < p_offset)
a_offset += s1->section_align;
file_offset += (a_offset - p_offset);
} else {
if (file_type == TCC_OUTPUT_DLL)
addr = 0;
else
addr = ELF_START_ADDR;
/* compute address after headers */
addr += (file_offset & (s1->section_align - 1));
}
/* dynamic relocation table information, for .dynamic section */
rel_size = 0;
rel_addr = 0;
#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
bss_addr = bss_size = 0;
#endif
/* leave one program header for the program interpreter */
ph = &phdr[0];
if (interp)
ph += 1 + HAVE_PHDR;
for(j = 0; j < 2; j++) {
ph->p_type = PT_LOAD;
if (j == 0)
ph->p_flags = PF_R | PF_X;
else
ph->p_flags = PF_R | PF_W;
ph->p_align = s1->section_align;
/* we do the following ordering: interp, symbol tables,
relocations, progbits, nobits */
/* XXX: do faster and simpler sorting */
for(k = 0; k < 5; k++) {
for(i = 1; i < s1->nb_sections; i++) {
s = s1->sections[i];
/* compute if section should be included */
if (j == 0) {
if ((s->sh_flags & (SHF_ALLOC | SHF_WRITE)) !=
SHF_ALLOC)
continue;
} else {
if ((s->sh_flags & (SHF_ALLOC | SHF_WRITE)) !=
(SHF_ALLOC | SHF_WRITE))
continue;
}
if (s == interp) {
if (k != 0)
continue;
} else if (s->sh_type == SHT_DYNSYM ||
s->sh_type == SHT_STRTAB ||
s->sh_type == SHT_HASH) {
if (k != 1)
continue;
} else if (s->sh_type == SHT_RELX) {
if (k != 2)
continue;
} else if (s->sh_type == SHT_NOBITS) {
if (k != 4)
continue;
} else {
if (k != 3)
continue;
}
section_order[sh_order_index++] = i;
/* section matches: we align it and add its size */
tmp = addr;
addr = (addr + s->sh_addralign - 1) &
~(s->sh_addralign - 1);
file_offset += (int) ( addr - tmp );
s->sh_offset = file_offset;
s->sh_addr = addr;
/* update program header infos */
if (ph->p_offset == 0) {
ph->p_offset = file_offset;
ph->p_vaddr = addr;
ph->p_paddr = ph->p_vaddr;
}
/* update dynamic relocation infos */
if (s->sh_type == SHT_RELX) {
#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
if (!strcmp(strsec->data + s->sh_name, ".rel.got")) { // rel_size == 0) {
rel_addr = addr;
rel_size += s->sh_size; // XXX only first rel.
}
if (!strcmp(strsec->data + s->sh_name, ".rel.bss")) { // rel_size == 0) {
bss_addr = addr;
bss_size = s->sh_size; // XXX only first rel.
}
#else
if (rel_size == 0)
rel_addr = addr;
rel_size += s->sh_size;
#endif
}
addr += s->sh_size;
if (s->sh_type != SHT_NOBITS)
file_offset += s->sh_size;
}
}
ph->p_filesz = file_offset - ph->p_offset;
ph->p_memsz = addr - ph->p_vaddr;
ph++;
if (j == 0) {
if (s1->output_format == TCC_OUTPUT_FORMAT_ELF) {
/* if in the middle of a page, we duplicate the page in
memory so that one copy is RX and the other is RW */
if ((addr & (s1->section_align - 1)) != 0)
addr += s1->section_align;
} else {
addr = (addr + s1->section_align - 1) & ~(s1->section_align - 1);
file_offset = (file_offset + s1->section_align - 1) &
~(s1->section_align - 1);
}
}
}
/* if interpreter, then add corresponing program header */
if (interp) {
ph = &phdr[0];
#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
{
int len = phnum * sizeof(ElfW(Phdr));
ph->p_type = PT_PHDR;
ph->p_offset = sizeof(ElfW(Ehdr));
ph->p_vaddr = interp->sh_addr - len;
ph->p_paddr = ph->p_vaddr;
ph->p_filesz = ph->p_memsz = len;
ph->p_flags = PF_R | PF_X;
ph->p_align = 4; // interp->sh_addralign;
ph++;
}
#endif
ph->p_type = PT_INTERP;
ph->p_offset = interp->sh_offset;
ph->p_vaddr = interp->sh_addr;
ph->p_paddr = ph->p_vaddr;
ph->p_filesz = interp->sh_size;
ph->p_memsz = interp->sh_size;
ph->p_flags = PF_R;
ph->p_align = interp->sh_addralign;
}
/* if dynamic section, then add corresponing program header */
if (dynamic) {
ElfW(Sym) *sym_end;
ph = &phdr[phnum - 1];
ph->p_type = PT_DYNAMIC;
ph->p_offset = dynamic->sh_offset;
ph->p_vaddr = dynamic->sh_addr;
ph->p_paddr = ph->p_vaddr;
ph->p_filesz = dynamic->sh_size;
ph->p_memsz = dynamic->sh_size;
ph->p_flags = PF_R | PF_W;
ph->p_align = dynamic->sh_addralign;
/* put GOT dynamic section address */
put32(s1->got->data, dynamic->sh_addr);
/* relocate the PLT */
if (file_type == TCC_OUTPUT_EXE
#if defined(TCC_OUTPUT_DLL_WITH_PLT)
|| file_type == TCC_OUTPUT_DLL
#endif
) {
uint8_t *p, *p_end;
p = s1->plt->data;
p_end = p + s1->plt->data_offset;
if (p < p_end) {
#if defined(TCC_TARGET_I386)
put32(p + 2, get32(p + 2) + s1->got->sh_addr);
put32(p + 8, get32(p + 8) + s1->got->sh_addr);
p += 16;
while (p < p_end) {
put32(p + 2, get32(p + 2) + s1->got->sh_addr);
p += 16;
}
#elif defined(TCC_TARGET_X86_64)
int x = s1->got->sh_addr - s1->plt->sh_addr - 6;
put32(p + 2, get32(p + 2) + x);
put32(p + 8, get32(p + 8) + x - 6);
p += 16;
while (p < p_end) {
put32(p + 2, get32(p + 2) + x + s1->plt->data - p);
p += 16;
}
#elif defined(TCC_TARGET_ARM)
int x;
x=s1->got->sh_addr - s1->plt->sh_addr - 12;
p += 16;
while (p < p_end) {
if (get32(p) == 0x46c04778) /* PLT Thumb stub present */
p += 4;
put32(p + 12, x + get32(p + 12) + s1->plt->data - p);
p += 16;
}
#elif defined(TCC_TARGET_C67)
/* XXX: TODO */
#else
#error unsupported CPU
#endif
}
}
/* relocate symbols in .dynsym */
sym_end = (ElfW(Sym) *)(s1->dynsym->data + s1->dynsym->data_offset);
for(sym = (ElfW(Sym) *)s1->dynsym->data + 1;
sym < sym_end;
sym++) {
if (sym->st_shndx == SHN_UNDEF) {
/* relocate to the PLT if the symbol corresponds
to a PLT entry */
if (sym->st_value)
sym->st_value += s1->plt->sh_addr;
} else if (sym->st_shndx < SHN_LORESERVE) {
/* do symbol relocation */
sym->st_value += s1->sections[sym->st_shndx]->sh_addr;
}
}
/* put dynamic section entries */
dynamic->data_offset = saved_dynamic_data_offset;
put_dt(dynamic, DT_HASH, s1->dynsym->hash->sh_addr);
put_dt(dynamic, DT_STRTAB, dynstr->sh_addr);
put_dt(dynamic, DT_SYMTAB, s1->dynsym->sh_addr);
put_dt(dynamic, DT_STRSZ, dynstr->data_offset);
put_dt(dynamic, DT_SYMENT, sizeof(ElfW(Sym)));
#ifdef TCC_TARGET_X86_64
put_dt(dynamic, DT_RELA, rel_addr);
put_dt(dynamic, DT_RELASZ, rel_size);
put_dt(dynamic, DT_RELAENT, sizeof(ElfW_Rel));
#else
#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
put_dt(dynamic, DT_PLTGOT, s1->got->sh_addr);
put_dt(dynamic, DT_PLTRELSZ, rel_size);
put_dt(dynamic, DT_JMPREL, rel_addr);
put_dt(dynamic, DT_PLTREL, DT_REL);
put_dt(dynamic, DT_REL, bss_addr);
put_dt(dynamic, DT_RELSZ, bss_size);
#else
put_dt(dynamic, DT_REL, rel_addr);
put_dt(dynamic, DT_RELSZ, rel_size);
put_dt(dynamic, DT_RELENT, sizeof(ElfW_Rel));
#endif
#endif
if (s1->do_debug)
put_dt(dynamic, DT_DEBUG, 0);
put_dt(dynamic, DT_NULL, 0);
}
ehdr.e_phentsize = sizeof(ElfW(Phdr));
ehdr.e_phnum = phnum;
ehdr.e_phoff = sizeof(ElfW(Ehdr));
}
/* all other sections come after */
for(i = 1; i < s1->nb_sections; i++) {
s = s1->sections[i];
if (phnum > 0 && (s->sh_flags & SHF_ALLOC))
continue;
section_order[sh_order_index++] = i;
file_offset = (file_offset + s->sh_addralign - 1) &
~(s->sh_addralign - 1);
s->sh_offset = file_offset;
if (s->sh_type != SHT_NOBITS)
file_offset += s->sh_size;
}
/* if building executable or DLL, then relocate each section
except the GOT which is already relocated */
if (file_type != TCC_OUTPUT_OBJ) {
relocate_syms(s1, 0);
if (s1->nb_errors != 0) {
fail:
ret = -1;
goto the_end;
}
/* relocate sections */
/* XXX: ignore sections with allocated relocations ? */
for(i = 1; i < s1->nb_sections; i++) {
s = s1->sections[i];
if (s->reloc && s != s1->got)
relocate_section(s1, s);
}
/* relocate relocation entries if the relocation tables are
allocated in the executable */
for(i = 1; i < s1->nb_sections; i++) {
s = s1->sections[i];
if ((s->sh_flags & SHF_ALLOC) &&
s->sh_type == SHT_RELX) {
relocate_rel(s1, s);
}
}
/* get entry point address */
if (file_type == TCC_OUTPUT_EXE)
ehdr.e_entry = get_elf_sym_addr(s1, "_start", 1);
else
ehdr.e_entry = text_section->sh_addr; /* XXX: is it correct ? */
}
if (file_type == TCC_OUTPUT_EXE && s1->static_link)
fill_got(s1);
/* write elf file */
if (file_type == TCC_OUTPUT_OBJ)
mode = 0666;
else
mode = 0777;
unlink(filename);
fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, mode);
if (fd < 0) {
tcc_error_noabort("could not write '%s'", filename);
goto fail;
}
f = fdopen(fd, "wb");
if (s1->verbose)
printf("<- %s\n", filename);
#ifdef TCC_TARGET_COFF
if (s1->output_format == TCC_OUTPUT_FORMAT_COFF) {
tcc_output_coff(s1, f);
} else
#endif
if (s1->output_format == TCC_OUTPUT_FORMAT_ELF) {
sort_syms(s1, symtab_section);
/* align to 4 */
file_offset = (file_offset + 3) & -4;
/* fill header */
ehdr.e_ident[0] = ELFMAG0;
ehdr.e_ident[1] = ELFMAG1;
ehdr.e_ident[2] = ELFMAG2;
ehdr.e_ident[3] = ELFMAG3;
ehdr.e_ident[4] = ELFCLASSW;
ehdr.e_ident[5] = ELFDATA2LSB;
ehdr.e_ident[6] = EV_CURRENT;
#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
ehdr.e_ident[EI_OSABI] = ELFOSABI_FREEBSD;
#endif
#ifdef TCC_TARGET_ARM
#ifdef TCC_ARM_EABI
ehdr.e_ident[EI_OSABI] = 0;
ehdr.e_flags = 4 << 24;
#else
ehdr.e_ident[EI_OSABI] = ELFOSABI_ARM;
#endif
#endif
switch(file_type) {
default:
case TCC_OUTPUT_EXE:
ehdr.e_type = ET_EXEC;
break;
case TCC_OUTPUT_DLL:
ehdr.e_type = ET_DYN;
break;
case TCC_OUTPUT_OBJ:
ehdr.e_type = ET_REL;
break;
}
ehdr.e_machine = EM_TCC_TARGET;
ehdr.e_version = EV_CURRENT;
ehdr.e_shoff = file_offset;
ehdr.e_ehsize = sizeof(ElfW(Ehdr));
ehdr.e_shentsize = sizeof(ElfW(Shdr));
ehdr.e_shnum = shnum;
ehdr.e_shstrndx = shnum - 1;
fwrite(&ehdr, 1, sizeof(ElfW(Ehdr)), f);
fwrite(phdr, 1, phnum * sizeof(ElfW(Phdr)), f);
offset = sizeof(ElfW(Ehdr)) + phnum * sizeof(ElfW(Phdr));
for(i=1;i<s1->nb_sections;i++) {
s = s1->sections[section_order[i]];
if (s->sh_type != SHT_NOBITS) {
if (s->sh_type == SHT_DYNSYM)
patch_dynsym_undef(s1, s);
while (offset < s->sh_offset) {
fputc(0, f);
offset++;
}
size = s->sh_size;
fwrite(s->data, 1, size, f);
offset += size;
}
}
/* output section headers */
while (offset < ehdr.e_shoff) {
fputc(0, f);
offset++;
}
for(i=0;i<s1->nb_sections;i++) {
sh = &shdr;
memset(sh, 0, sizeof(ElfW(Shdr)));
s = s1->sections[i];
if (s) {
sh->sh_name = s->sh_name;
sh->sh_type = s->sh_type;
sh->sh_flags = s->sh_flags;
sh->sh_entsize = s->sh_entsize;
sh->sh_info = s->sh_info;
if (s->link)
sh->sh_link = s->link->sh_num;
sh->sh_addralign = s->sh_addralign;
sh->sh_addr = s->sh_addr;
sh->sh_offset = s->sh_offset;
sh->sh_size = s->sh_size;
}
fwrite(sh, 1, sizeof(ElfW(Shdr)), f);
}
} else {
tcc_output_binary(s1, f, section_order);
}
fclose(f);
ret = 0;
the_end:
tcc_free(s1->symtab_to_dynsym);
tcc_free(section_order);
tcc_free(phdr);
tcc_free(s1->sym_attrs);
return ret;
}
LIBTCCAPI int tcc_output_file(TCCState *s, const char *filename)
{
int ret;
#ifdef TCC_TARGET_PE
if (s->output_type != TCC_OUTPUT_OBJ) {
ret = pe_output_file(s, filename);
} else
#endif
{
ret = elf_output_file(s, filename);
}
return ret;
}
static void *load_data(int fd, unsigned long file_offset, unsigned long size)
{
void *data;
data = tcc_malloc(size);
lseek(fd, file_offset, SEEK_SET);
read(fd, data, size);
return data;
}
typedef struct SectionMergeInfo {
Section *s; /* corresponding existing section */
unsigned long offset; /* offset of the new section in the existing section */
uint8_t new_section; /* true if section 's' was added */
uint8_t link_once; /* true if link once section */
} SectionMergeInfo;
/* load an object file and merge it with current files */
/* XXX: handle correctly stab (debug) info */
ST_FUNC int tcc_load_object_file(TCCState *s1,
int fd, unsigned long file_offset)
{
ElfW(Ehdr) ehdr;
ElfW(Shdr) *shdr, *sh;
int size, i, j, offset, offseti, nb_syms, sym_index, ret;
unsigned char *strsec, *strtab;
int *old_to_new_syms;
char *sh_name, *name;
SectionMergeInfo *sm_table, *sm;
ElfW(Sym) *sym, *symtab;
ElfW_Rel *rel, *rel_end;
Section *s;
int stab_index;
int stabstr_index;
stab_index = stabstr_index = 0;
if (read(fd, &ehdr, sizeof(ehdr)) != sizeof(ehdr))
goto fail1;
if (ehdr.e_ident[0] != ELFMAG0 ||
ehdr.e_ident[1] != ELFMAG1 ||
ehdr.e_ident[2] != ELFMAG2 ||
ehdr.e_ident[3] != ELFMAG3)
goto fail1;
/* test if object file */
if (ehdr.e_type != ET_REL)
goto fail1;
/* test CPU specific stuff */
if (ehdr.e_ident[5] != ELFDATA2LSB ||
ehdr.e_machine != EM_TCC_TARGET) {
src/tccelf.c view on Meta::CPAN
} else {
snprintf(filename, sizeof filename, "lib%s.so", libname);
}
} else if (t != LD_TOK_NAME) {
tcc_error_noabort("filename expected");
ret = -1;
goto lib_parse_error;
}
if (!strcmp(filename, "AS_NEEDED")) {
ret = ld_add_file_list(s1, cmd, 1);
if (ret)
goto lib_parse_error;
} else {
/* TODO: Implement AS_NEEDED support. Ignore it for now */
if (!as_needed) {
ret = ld_add_file(s1, filename);
if (ret)
goto lib_parse_error;
if (group) {
/* Add the filename *and* the libname to avoid future conversions */
dynarray_add((void ***) &libs, &nblibs, tcc_strdup(filename));
if (libname[0] != '\0')
dynarray_add((void ***) &libs, &nblibs, tcc_strdup(libname));
}
}
}
t = ld_next(s1, filename, sizeof(filename));
if (t == ',') {
t = ld_next(s1, filename, sizeof(filename));
}
}
if (group && !as_needed) {
while (new_undef_syms()) {
int i;
for (i = 0; i < nblibs; i ++)
ld_add_file(s1, libs[i]);
}
}
lib_parse_error:
dynarray_reset(&libs, &nblibs);
return ret;
}
/* interpret a subset of GNU ldscripts to handle the dummy libc.so
files */
ST_FUNC int tcc_load_ldscript(TCCState *s1)
{
char cmd[64];
char filename[1024];
int t, ret;
ch = file->buf_ptr[0];
ch = handle_eob();
for(;;) {
t = ld_next(s1, cmd, sizeof(cmd));
if (t == LD_TOK_EOF)
return 0;
else if (t != LD_TOK_NAME)
return -1;
if (!strcmp(cmd, "INPUT") ||
!strcmp(cmd, "GROUP")) {
ret = ld_add_file_list(s1, cmd, 0);
if (ret)
return ret;
} else if (!strcmp(cmd, "OUTPUT_FORMAT") ||
!strcmp(cmd, "TARGET")) {
/* ignore some commands */
t = ld_next(s1, cmd, sizeof(cmd));
if (t != '(')
expect("(");
for(;;) {
t = ld_next(s1, filename, sizeof(filename));
if (t == LD_TOK_EOF) {
tcc_error_noabort("unexpected end of file");
return -1;
} else if (t == ')') {
break;
}
}
} else {
return -1;
}
}
return 0;
}
#endif /* ndef TCC_TARGET_PE */
( run in 0.713 second using v1.01-cache-2.11-cpan-62a16548d74 )