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51f15d9971
tinycc/tccmacho.c
Michael Matz 51f15d9971 macos: Deal with leading underscore on Mach-O 
all C/C++/ObjC symbols in symbols tables have a leading underscore
in Mach-O.  Within TCC there's some confusion with tcc_add_symbol
(not adding it) and tcc_get_elf_symbol (not expecting it), and
resolve_syms (using dlsym, which doesn't expect it) and -run support.
But this sort of works.
2020-06-20 22:12:02 +02:00

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/*
* Mach-O file handling for TCC
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "tcc.h"
struct mach_header {
uint32_t magic; /* mach magic number identifier */
int cputype; /* cpu specifier */
int cpusubtype; /* machine specifier */
uint32_t filetype; /* type of file */
uint32_t ncmds; /* number of load commands */
uint32_t sizeofcmds; /* the size of all the load commands */
uint32_t flags; /* flags */
};
struct mach_header_64 {
struct mach_header mh;
uint32_t reserved; /* reserved, pad to 64bit */
};
/* Constant for the magic field of the mach_header (32-bit architectures) */
#define MH_MAGIC 0xfeedface /* the mach magic number */
#define MH_CIGAM 0xcefaedfe /* NXSwapInt(MH_MAGIC) */
#define MH_MAGIC_64 0xfeedfacf /* the 64-bit mach magic number */
#define MH_CIGAM_64 0xcffaedfe /* NXSwapInt(MH_MAGIC_64) */
struct load_command {
uint32_t cmd; /* type of load command */
uint32_t cmdsize; /* total size of command in bytes */
};
typedef int vm_prot_t;
struct segment_command { /* for 32-bit architectures */
uint32_t cmd; /* LC_SEGMENT */
uint32_t cmdsize; /* includes sizeof section structs */
char segname[16]; /* segment name */
uint32_t vmaddr; /* memory address of this segment */
uint32_t vmsize; /* memory size of this segment */
uint32_t fileoff; /* file offset of this segment */
uint32_t filesize; /* amount to map from the file */
vm_prot_t maxprot; /* maximum VM protection */
vm_prot_t initprot; /* initial VM protection */
uint32_t nsects; /* number of sections in segment */
uint32_t flags; /* flags */
};
struct segment_command_64 { /* for 64-bit architectures */
uint32_t cmd; /* LC_SEGMENT_64 */
uint32_t cmdsize; /* includes sizeof section_64 structs */
char segname[16]; /* segment name */
uint64_t vmaddr; /* memory address of this segment */
uint64_t vmsize; /* memory size of this segment */
uint64_t fileoff; /* file offset of this segment */
uint64_t filesize; /* amount to map from the file */
vm_prot_t maxprot; /* maximum VM protection */
vm_prot_t initprot; /* initial VM protection */
uint32_t nsects; /* number of sections in segment */
uint32_t flags; /* flags */
};
struct section { /* for 32-bit architectures */
char sectname[16]; /* name of this section */
char segname[16]; /* segment this section goes in */
uint32_t addr; /* memory address of this section */
uint32_t size; /* size in bytes of this section */
uint32_t offset; /* file offset of this section */
uint32_t align; /* section alignment (power of 2) */
uint32_t reloff; /* file offset of relocation entries */
uint32_t nreloc; /* number of relocation entries */
uint32_t flags; /* flags (section type and attributes)*/
uint32_t reserved1; /* reserved (for offset or index) */
uint32_t reserved2; /* reserved (for count or sizeof) */
};
struct section_64 { /* for 64-bit architectures */
char sectname[16]; /* name of this section */
char segname[16]; /* segment this section goes in */
uint64_t addr; /* memory address of this section */
uint64_t size; /* size in bytes of this section */
uint32_t offset; /* file offset of this section */
uint32_t align; /* section alignment (power of 2) */
uint32_t reloff; /* file offset of relocation entries */
uint32_t nreloc; /* number of relocation entries */
uint32_t flags; /* flags (section type and attributes)*/
uint32_t reserved1; /* reserved (for offset or index) */
uint32_t reserved2; /* reserved (for count or sizeof) */
uint32_t reserved3; /* reserved */
};
typedef uint32_t lc_str;
struct dylib_command {
uint32_t cmd; /* LC_ID_DYLIB, LC_LOAD_{,WEAK_}DYLIB,
LC_REEXPORT_DYLIB */
uint32_t cmdsize; /* includes pathname string */
lc_str name; /* library's path name */
uint32_t timestamp; /* library's build time stamp */
uint32_t current_version; /* library's current version number */
uint32_t compatibility_version; /* library's compatibility vers number*/
};
struct dylinker_command {
uint32_t cmd; /* LC_ID_DYLINKER, LC_LOAD_DYLINKER or
LC_DYLD_ENVIRONMENT */
uint32_t cmdsize; /* includes pathname string */
lc_str name; /* dynamic linker's path name */
};
struct symtab_command {
uint32_t cmd; /* LC_SYMTAB */
uint32_t cmdsize; /* sizeof(struct symtab_command) */
uint32_t symoff; /* symbol table offset */
uint32_t nsyms; /* number of symbol table entries */
uint32_t stroff; /* string table offset */
uint32_t strsize; /* string table size in bytes */
};
struct dysymtab_command {
uint32_t cmd; /* LC_DYSYMTAB */
uint32_t cmdsize; /* sizeof(struct dysymtab_command) */
uint32_t ilocalsym; /* index to local symbols */
uint32_t nlocalsym; /* number of local symbols */
uint32_t iextdefsym;/* index to externally defined symbols */
uint32_t nextdefsym;/* number of externally defined symbols */
uint32_t iundefsym; /* index to undefined symbols */
uint32_t nundefsym; /* number of undefined symbols */
uint32_t tocoff; /* file offset to table of contents */
uint32_t ntoc; /* number of entries in table of contents */
uint32_t modtaboff; /* file offset to module table */
uint32_t nmodtab; /* number of module table entries */
uint32_t extrefsymoff; /* offset to referenced symbol table */
uint32_t nextrefsyms; /* number of referenced symbol table entries */
uint32_t indirectsymoff; /* file offset to the indirect symbol table */
uint32_t nindirectsyms; /* number of indirect symbol table entries */
uint32_t extreloff; /* offset to external relocation entries */
uint32_t nextrel; /* number of external relocation entries */
uint32_t locreloff; /* offset to local relocation entries */
uint32_t nlocrel; /* number of local relocation entries */
};
struct linkedit_data_command {
uint32_t cmd; /* LC_CODE_SIGNATURE, LC_SEGMENT_SPLIT_INFO,
LC_FUNCTION_STARTS, LC_DATA_IN_CODE,
LC_DYLIB_CODE_SIGN_DRS or
LC_LINKER_OPTIMIZATION_HINT. */
uint32_t cmdsize; /* sizeof(struct linkedit_data_command) */
uint32_t dataoff; /* file offset of data in __LINKEDIT segment */
uint32_t datasize; /* file size of data in __LINKEDIT segment */
};
struct entry_point_command {
uint32_t cmd; /* LC_MAIN only used in MH_EXECUTE filetypes */
uint32_t cmdsize; /* 24 */
uint64_t entryoff; /* file (__TEXT) offset of main() */
uint64_t stacksize;/* if not zero, initial stack size */
};
enum skind {
sk_unknown = 0,
sk_discard,
sk_text,
sk_stubs,
sk_ro_data,
sk_uw_info,
sk_nl_ptr, // non-lazy pointers, aka GOT
sk_la_ptr, // lazy pointers
sk_rw_data,
sk_bss,
sk_linkedit,
sk_last
};
struct nlist_64 {
uint32_t n_strx; /* index into the string table */
uint8_t n_type; /* type flag, see below */
uint8_t n_sect; /* section number or NO_SECT */
uint16_t n_desc; /* see <mach-o/stab.h> */
uint64_t n_value; /* value of this symbol (or stab offset) */
};
struct macho {
struct mach_header_64 mh;
struct segment_command_64 *seg[4];
int nseg;
struct load_command **lc;
int nlc;
struct entry_point_command ep;
struct {
Section *s;
int machosect;
} sk_to_sect[sk_last];
int *elfsectomacho;
int *e2msym;
Section *linkedit, *symtab, *strtab, *wdata, *indirsyms, *stubs;
int stubsym;
uint32_t ilocal, iextdef, iundef;
};
#define SHT_LINKEDIT (SHT_LOOS + 42)
#define SHN_FROMDLL (SHN_LOOS + 2) /* Symbol is undefined, comes from a DLL */
#define LC_REQ_DYLD 0x80000000
#define LC_SYMTAB 0x2
#define LC_DYSYMTAB 0xb
#define LC_LOAD_DYLIB 0xc
#define LC_LOAD_DYLINKER 0xe
#define LC_MAIN (0x28|LC_REQ_DYLD)
/* Hack for now, 46_grep.c needs fopen, but due to aliasing games
in darwin headers it's searching for _fopen also via dlsym. */
FILE *_fopen(const char*, const char*);
FILE *_fopen(const char * filename, const char *mode)
{
return fopen(filename, mode);
}
static struct segment_command_64 * add_segment(struct macho *mo, char *name)
{
struct segment_command_64 *sc = tcc_mallocz(sizeof *sc);
strncpy(sc->segname, name, 16);
sc->cmd = 0x19; // LC_SEGMENT_64
sc->cmdsize = sizeof(*sc);
mo->seg[mo->nseg++] = sc;
return sc;
}
static int add_section(struct macho *mo, struct segment_command_64 **_seg, char *name)
{
struct segment_command_64 *seg = *_seg;
int ret = seg->nsects;
struct section_64 *sec;
seg->nsects++;
seg->cmdsize += sizeof(*sec);
seg = tcc_realloc(seg, sizeof(*seg) + seg->nsects * sizeof(*sec));
sec = (struct section_64*)((char*)seg + sizeof(*seg)) + ret;
memset(sec, 0, sizeof(*sec));
strncpy(sec->sectname, name, 16);
strncpy(sec->segname, seg->segname, 16);
*_seg = seg;
return ret;
}
static struct section_64 *get_section(struct segment_command_64 *seg, int i)
{
struct section_64 *sec;
sec = (struct section_64*)((char*)seg + sizeof(*seg)) + i;
return sec;
}
static void * add_lc(struct macho *mo, void *lc)
{
mo->lc = tcc_realloc(mo->lc, sizeof(mo->lc[0]) * (mo->nlc + 1));
mo->lc[mo->nlc++] = lc;
return lc;
}
static void * add_dylib(struct macho *mo, char *name)
{
struct dylib_command *lc;
int sz = (sizeof(*lc) + strlen(name) + 1 + 7) & -8;
lc = tcc_mallocz(sz);
lc->cmd = LC_LOAD_DYLIB;
lc->cmdsize = sz;
lc->name = sizeof(*lc);
strcpy((char*)lc + lc->name, name);
lc->timestamp = 2;
lc->current_version = 1 << 16;
lc->compatibility_version = 1 << 16;
return add_lc(mo, lc);
}
static void check_relocs(TCCState *s1, struct macho *mo)
{
Section *s;
ElfW_Rel *rel;
ElfW(Sym) *sym;
int i, type, gotplt_entry, sym_index, for_code;
struct sym_attr *attr;
s1->got = new_section(s1, ".got", SHT_PROGBITS, SHF_ALLOC | SHF_WRITE);
mo->indirsyms = new_section(s1, "LEINDIR", SHT_LINKEDIT, SHF_ALLOC | SHF_WRITE);
for (i = 1; i < s1->nb_sections; i++) {
s = s1->sections[i];
if (s->sh_type != SHT_RELX)
continue;
for_each_elem(s, 0, rel, ElfW_Rel) {
type = ELFW(R_TYPE)(rel->r_info);
gotplt_entry = gotplt_entry_type(type);
for_code = code_reloc(type);
/* We generate a non-lazy pointer for used undefined symbols
and for defined symbols that must have a place for their
address due to codegen (i.e. a reloc requiring a got slot). */
sym_index = ELFW(R_SYM)(rel->r_info);
sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
if (sym->st_shndx == SHN_UNDEF
|| gotplt_entry == ALWAYS_GOTPLT_ENTRY) {
attr = get_sym_attr(s1, sym_index, 1);
if (!attr->dyn_index) {
uint32_t *pi = section_ptr_add(mo->indirsyms, sizeof(*pi));
attr->got_offset = s1->got->data_offset;
attr->plt_offset = -1;
attr->dyn_index = 1; /* used as flag */
section_ptr_add(s1->got, PTR_SIZE);
if (ELFW(ST_BIND)(sym->st_info) == STB_LOCAL) {
if (sym->st_shndx == SHN_UNDEF)
tcc_error("undefined local symbol???");
*pi = 0x80000000; /* INDIRECT_SYMBOL_LOCAL */
/* The pointer slot we generated must point to the
symbol, whose address is only known after layout,
so register a simply relocation for that. */
put_elf_reloc(s1->symtab, s1->got, attr->got_offset,
R_DATA_PTR, sym_index);
} else
*pi = mo->e2msym[sym_index];
}
if (for_code) {
if (attr->plt_offset == -1) {
uint8_t *jmp;
attr->plt_offset = mo->stubs->data_offset;
jmp = section_ptr_add(mo->stubs, 6);
jmp[0] = 0xff; /* jmpq *ofs(%rip) */
jmp[1] = 0x25;
put_elf_reloc(s1->symtab, mo->stubs,
attr->plt_offset + 2,
R_X86_64_GOTPCREL, sym_index);
}
rel->r_info = ELFW(R_INFO)(mo->stubsym, type);
rel->r_addend += attr->plt_offset;
}
}
}
}
}
static int check_symbols(TCCState *s1, struct macho *mo)
{
int sym_index, sym_end;
int ret = 0;
mo->ilocal = mo->iextdef = mo->iundef = -1;
sym_end = symtab_section->data_offset / sizeof(ElfW(Sym));
for (sym_index = 1; sym_index < sym_end; ++sym_index) {
int elf_index = ((struct nlist_64 *)mo->symtab->data + sym_index - 1)->n_value;
ElfW(Sym) *sym = (ElfW(Sym) *)symtab_section->data + elf_index;
const char *name = (char*)symtab_section->link->data + sym->st_name;
unsigned type = ELFW(ST_TYPE)(sym->st_info);
unsigned bind = ELFW(ST_BIND)(sym->st_info);
unsigned vis = ELFW(ST_VISIBILITY)(sym->st_other);
printf("%4d (%4d): %09llx %4d %4d %4d %3d %s\n",
sym_index, elf_index, sym->st_value,
type, bind, vis, sym->st_shndx, name);
if (bind == STB_LOCAL) {
if (mo->ilocal == -1)
mo->ilocal = sym_index - 1;
if (mo->iextdef != -1 || mo->iundef != -1)
tcc_error("local syms after global ones");
} else if (sym->st_shndx != SHN_UNDEF) {
if (mo->iextdef == -1)
mo->iextdef = sym_index - 1;
if (mo->iundef != -1)
tcc_error("external defined symbol after undefined");
} else if (sym->st_shndx == SHN_UNDEF) {
if (mo->iundef == -1)
mo->iundef = sym_index - 1;
if (ELFW(ST_BIND)(sym->st_info) == STB_WEAK)
continue;
if (get_sym_attr(s1, elf_index, 0)) {
/* Mark the symbol as coming from a dylib so that
relocate_syms doesn't complain. Normally we would have
checked that any dylib in fact exports this one, and listed
those in s1->dynsymtab, which would cause us to enter this
symbol into s1->dynsym, which is checked by relocate_syms.
But for now we fake this and regard all undefined as
coming from a dylib, and we don't use the dynsymtab/dynsym
scheme. */
sym->st_shndx = SHN_FROMDLL;
continue;
}
tcc_error_noabort("undefined symbol '%s'", name);
ret = -1;
}
}
return ret;
}
static void convert_symbol(TCCState *s1, struct macho *mo, struct nlist_64 *pn)
{
struct nlist_64 n = *pn;
ElfSym *sym = (ElfW(Sym) *)symtab_section->data + pn->n_value;
const char *name = (char*)symtab_section->link->data + sym->st_name;
switch(ELFW(ST_TYPE)(sym->st_info)) {
case STT_NOTYPE:
case STT_OBJECT:
case STT_FUNC:
n.n_type = 0xe; /* default type is N_SECT */
break;
case STT_FILE:
n.n_type = 2; /* N_ABS */
break;
default:
tcc_error("unhandled ELF symbol type %d %s",
ELFW(ST_TYPE)(sym->st_info), name);
}
if (sym->st_shndx == SHN_UNDEF)
tcc_error("should have been rewritten to SHN_FROMDLL");
else if (sym->st_shndx == SHN_FROMDLL)
n.n_type = 0 /* N_UNDF */, n.n_sect = 0;
else if (sym->st_shndx == SHN_ABS)
n.n_type = 2 /* N_ABS */, n.n_sect = 0;
else if (sym->st_shndx >= SHN_LORESERVE)
tcc_error("unhandled ELF symbol section %d %s", sym->st_shndx, name);
else if (!mo->elfsectomacho[sym->st_shndx])
tcc_error("ELF section %d not mapped into Mach-O for symbol %s",
sym->st_shndx, name);
else
n.n_sect = mo->elfsectomacho[sym->st_shndx];
if (ELFW(ST_BIND)(sym->st_info) == STB_GLOBAL)
n.n_type |= 1; /* N_EXT */
else if (ELFW(ST_BIND)(sym->st_info) == STB_WEAK)
tcc_error("weak symbol %s unhandled", name);
n.n_strx = pn->n_strx;
n.n_value = sym->st_value;
*pn = n;
}
static void convert_symbols(TCCState *s1, struct macho *mo)
{
int sym_index, sym_end;
struct nlist_64 *pn = (struct nlist_64 *)mo->symtab->data;
sym_end = symtab_section->data_offset / sizeof(ElfW(Sym));
for (sym_index = 1; sym_index < sym_end; ++sym_index) {
convert_symbol(s1, mo, pn + sym_index - 1);
}
}
static int machosymcmp(const void *_a, const void *_b)
{
TCCState *s1 = tcc_state;
int ea = ((struct nlist_64 *)_a)->n_value;
int eb = ((struct nlist_64 *)_b)->n_value;
ElfSym *sa = (ElfSym *)symtab_section->data + ea;
ElfSym *sb = (ElfSym *)symtab_section->data + eb;
int r;
r = (ELFW(ST_BIND)(sb->st_info) == STB_LOCAL)
- (ELFW(ST_BIND)(sa->st_info) == STB_LOCAL);
if (r)
return r;
r = (sa->st_shndx == SHN_UNDEF) - (sb->st_shndx == SHN_UNDEF);
if (r)
return r;
if (ELFW(ST_BIND)(sa->st_info) != STB_LOCAL) {
const char * na = (char*)symtab_section->link->data + sa->st_name;
const char * nb = (char*)symtab_section->link->data + sb->st_name;
r = strcmp(na, nb);
if (r)
return r;
}
return ea - eb;
}
static void create_symtab(TCCState *s1, struct macho *mo)
{
int sym_index, sym_end;
struct nlist_64 *pn;
/* Stub creation belongs to check_relocs, but we need to create
the symbol now, so its included in the sorting. */
mo->stubs = new_section(s1, "__stubs", SHT_PROGBITS, SHF_ALLOC | SHF_EXECINSTR);
mo->stubsym = put_elf_sym(s1->symtab, 0, 0,
ELFW(ST_INFO)(STB_LOCAL, STT_NOTYPE), 0,
mo->stubs->sh_num, ".__stubs");
mo->symtab = new_section(s1, "LESYMTAB", SHT_LINKEDIT, SHF_ALLOC | SHF_WRITE);
mo->strtab = new_section(s1, "LESTRTAB", SHT_LINKEDIT, SHF_ALLOC | SHF_WRITE);
put_elf_str(mo->strtab, " "); /* Mach-O starts strtab with a space */
sym_end = symtab_section->data_offset / sizeof(ElfW(Sym));
pn = section_ptr_add(mo->symtab, sizeof(*pn) * (sym_end - 1));
for (sym_index = 1; sym_index < sym_end; ++sym_index) {
ElfW(Sym) *sym = (ElfW(Sym) *)symtab_section->data + sym_index;
const char *name = (char*)symtab_section->link->data + sym->st_name;
pn[sym_index - 1].n_strx = put_elf_str(mo->strtab, name);
pn[sym_index - 1].n_value = sym_index;
}
tcc_enter_state(s1); /* qsort needs global state */
qsort(pn, sym_end - 1, sizeof(*pn), machosymcmp);
tcc_exit_state();
mo->e2msym = tcc_malloc(sym_end * sizeof(*mo->e2msym));
mo->e2msym[0] = -1;
for (sym_index = 1; sym_index < sym_end; ++sym_index) {
mo->e2msym[pn[sym_index - 1].n_value] = sym_index - 1;
}
}
struct {
int seg;
uint32_t flags;
char *name;
} skinfo[sk_last] = {
[sk_text] = { 1, 0x80000400, "__text" },
[sk_ro_data] = { 1, 0, "__rodata" },
[sk_nl_ptr] = { 2, 6, "__got" }, /* S_NON_LAZY_SYMBOL_POINTERS */
[sk_rw_data] = { 2, 0, "__data" },
[sk_bss] = { 2, 1, "__bss" },
[sk_linkedit] = { 3, 0, NULL },
};
static void collect_sections(TCCState *s1, struct macho *mo)
{
int i, sk, numsec;
uint64_t curaddr, fileofs;
Section *s;
struct segment_command_64 *seg = NULL;
struct dylinker_command *dyldlc;
struct symtab_command *symlc;
struct dysymtab_command *dysymlc;
char *str;
//struct segment_command_64 *zc, *tc, *sc, *lc;
add_segment(mo, "__PAGEZERO");
add_segment(mo, "__TEXT");
add_segment(mo, "__DATA");
add_segment(mo, "__LINKEDIT");
mo->seg[0]->vmsize = (uint64_t)1 << 32;
mo->seg[1]->vmaddr = (uint64_t)1 << 32;
mo->seg[1]->maxprot = 7; // rwx
mo->seg[1]->initprot = 5; // r-x
mo->seg[2]->vmaddr = -1;
mo->seg[2]->maxprot = 7; // rwx
mo->seg[2]->initprot = 3; // rw-
mo->seg[3]->vmaddr = -1;
mo->seg[3]->maxprot = 7; // rwx
mo->seg[3]->initprot = 1; // r--
mo->ep.cmd = LC_MAIN;
mo->ep.cmdsize = sizeof(mo->ep);
mo->ep.entryoff = 4096;
mo->ep.stacksize = 0;
add_lc(mo, &mo->ep);
i = (sizeof(*dyldlc) + strlen("/usr/lib/dyld") + 1 + 7) &-8;
dyldlc = tcc_mallocz(i);
dyldlc->cmd = LC_LOAD_DYLINKER;
dyldlc->cmdsize = i;
dyldlc->name = sizeof(*dyldlc);
str = (char*)dyldlc + dyldlc->name;
strcpy(str, "/usr/lib/dyld");
add_lc(mo, dyldlc);
symlc = tcc_mallocz(sizeof(*symlc));
symlc->cmd = LC_SYMTAB;
symlc->cmdsize = sizeof(*symlc);
add_lc(mo, symlc);
dysymlc = tcc_mallocz(sizeof(*dysymlc));
dysymlc->cmd = LC_DYSYMTAB;
dysymlc->cmdsize = sizeof(*dysymlc);
add_lc(mo, dysymlc);
add_dylib(mo, "/usr/lib/libSystem.B.dylib");
mo->linkedit = new_section(s1, "LINKEDIT", SHT_LINKEDIT, SHF_ALLOC | SHF_WRITE);
/* LINKEDIT can't be empty (XXX remove once we have symbol table) */
section_ptr_add(mo->linkedit, 256);
/* dyld requires a writable segment, but ignores zero-sized segments
for this, so force to have some data. */
mo->wdata = new_section(s1, " wdata", SHT_PROGBITS, SHF_ALLOC | SHF_WRITE);
section_ptr_add(mo->wdata, 64);
memset (mo->sk_to_sect, 0, sizeof(mo->sk_to_sect));
for (i = s1->nb_sections; i-- > 1;) {
int type, flags;
s = s1->sections[i];
type = s->sh_type;
flags = s->sh_flags;
sk = sk_unknown;
if (flags & SHF_ALLOC) {
switch (type) {
default: sk = sk_unknown; break;
case SHT_NOBITS: sk = sk_bss; break;
case SHT_SYMTAB: sk = sk_discard; break;
case SHT_STRTAB: sk = sk_discard; break;
case SHT_RELX: sk = sk_discard; break;
case SHT_LINKEDIT: sk = sk_linkedit; break;
case SHT_PROGBITS:
if (s == s1->got)
sk = sk_nl_ptr;
else if (flags & SHF_EXECINSTR)
sk = sk_text;
else if (flags & SHF_WRITE)
sk = sk_rw_data;
else
sk = sk_ro_data;
break;
}
} else
sk = sk_discard;
s->prev = mo->sk_to_sect[sk].s;
mo->sk_to_sect[sk].s = s;
}
fileofs = 4096; /* leave space for mach-o headers */
curaddr = mo->seg[1]->vmaddr;
curaddr += 4096;
seg = NULL;
numsec = 0;
mo->elfsectomacho = tcc_mallocz(sizeof(*mo->elfsectomacho) * s1->nb_sections);
for (sk = sk_unknown; sk < sk_last; sk++) {
struct section_64 *sec = NULL;
if (seg) {
seg->vmsize = curaddr - seg->vmaddr;
seg->filesize = fileofs - seg->fileoff;
}
if (skinfo[sk].seg && mo->sk_to_sect[sk].s) {
uint64_t al = 0;
int si;
seg = mo->seg[skinfo[sk].seg];
if (skinfo[sk].name) {
si = add_section(mo, &seg, skinfo[sk].name);
numsec++;
mo->seg[skinfo[sk].seg] = seg;
mo->sk_to_sect[sk].machosect = si;
sec = get_section(seg, si);
sec->flags = skinfo[sk].flags;
}
if (seg->vmaddr == -1) {
curaddr = (curaddr + 4095) & -4096;
seg->vmaddr = curaddr;
fileofs = (fileofs + 4095) & -4096;
seg->fileoff = fileofs;
}
for (s = mo->sk_to_sect[sk].s; s; s = s->prev) {
int a = exact_log2p1(s->sh_addralign);
if (a && al < (a - 1))
al = a - 1;
s->sh_size = s->data_offset;
}
if (sec)
sec->align = al;
al = 1U << al;
if (al > 4096)
tcc_warning("alignment > 4096"), sec->align = 12, al = 4096;
curaddr = (curaddr + al - 1) & -al;
fileofs = (fileofs + al - 1) & -al;
if (sec) {
sec->addr = curaddr;
sec->offset = fileofs;
}
for (s = mo->sk_to_sect[sk].s; s; s = s->prev) {
al = s->sh_addralign;
curaddr = (curaddr + al - 1) & -al;
tcc_warning("curaddr now 0x%llx", curaddr);
s->sh_addr = curaddr;
curaddr += s->sh_size;
if (s->sh_type != SHT_NOBITS) {
fileofs = (fileofs + al - 1) & -al;
s->sh_offset = fileofs;
fileofs += s->sh_size;
tcc_warning("fileofs now %lld", fileofs);
}
if (sec)
mo->elfsectomacho[s->sh_num] = numsec;
}
if (sec)
sec->size = curaddr - sec->addr;
}
for (s = mo->sk_to_sect[sk].s; s; s = s->prev) {
int type = s->sh_type;
int flags = s->sh_flags;
printf("%d section %-16s %-10s %09llx %04x %02d %s,%s,%s\n",
sk,
s->name,
type == SHT_PROGBITS ? "progbits" :
type == SHT_NOBITS ? "nobits" :
type == SHT_SYMTAB ? "symtab" :
type == SHT_STRTAB ? "strtab" :
type == SHT_RELX ? "rel" : "???",
s->sh_addr,
(unsigned)s->data_offset,
s->sh_addralign,
flags & SHF_ALLOC ? "alloc" : "",
flags & SHF_WRITE ? "write" : "",
flags & SHF_EXECINSTR ? "exec" : ""
);
}
}
if (seg) {
seg->vmsize = curaddr - seg->vmaddr;
seg->filesize = fileofs - seg->fileoff;
}
/* Fill symtab info */
symlc->symoff = mo->symtab->sh_offset;
symlc->nsyms = mo->symtab->data_offset / sizeof(struct nlist_64);
symlc->stroff = mo->strtab->sh_offset;
symlc->strsize = mo->strtab->data_offset;
dysymlc->iundefsym = mo->iundef == -1 ? symlc->nsyms : mo->iundef;
dysymlc->iextdefsym = mo->iextdef == -1 ? dysymlc->iundefsym : mo->iextdef;
dysymlc->ilocalsym = mo->ilocal == -1 ? dysymlc->iextdefsym : mo->ilocal;
dysymlc->nlocalsym = dysymlc->iextdefsym - dysymlc->ilocalsym;
dysymlc->nextdefsym = dysymlc->iundefsym - dysymlc->iextdefsym;
dysymlc->nundefsym = symlc->nsyms - dysymlc->iundefsym;
dysymlc->indirectsymoff = mo->indirsyms->sh_offset;
dysymlc->nindirectsyms = mo->indirsyms->data_offset / sizeof(uint32_t);
}
static void macho_write(TCCState *s1, struct macho *mo, FILE *fp)
{
int i, sk;
uint64_t fileofs = 0;
Section *s;
mo->mh.mh.magic = MH_MAGIC_64;
mo->mh.mh.cputype = 0x1000007; // x86_64
mo->mh.mh.cpusubtype = 0x80000003;// all | CPU_SUBTYPE_LIB64
mo->mh.mh.filetype = 2; // MH_EXECUTE
mo->mh.mh.flags = 4; // DYLDLINK
mo->mh.mh.ncmds = mo->nseg + mo->nlc;
mo->mh.mh.sizeofcmds = 0;
for (i = 0; i < mo->nseg; i++)
mo->mh.mh.sizeofcmds += mo->seg[i]->cmdsize;
for (i = 0; i < mo->nlc; i++)
mo->mh.mh.sizeofcmds += mo->lc[i]->cmdsize;
fwrite(&mo->mh, 1, sizeof(mo->mh), fp);
fileofs += sizeof(mo->mh);
for (i = 0; i < mo->nseg; i++) {
fwrite(mo->seg[i], 1, mo->seg[i]->cmdsize, fp);
fileofs += mo->seg[i]->cmdsize;
}
for (i = 0; i < mo->nlc; i++) {
fwrite(mo->lc[i], 1, mo->lc[i]->cmdsize, fp);
fileofs += mo->lc[i]->cmdsize;
}
for (sk = sk_unknown; sk < sk_last; sk++) {
struct segment_command_64 *seg;
//struct section_64 *sec;
if (!skinfo[sk].seg || !mo->sk_to_sect[sk].s)
continue;
seg = mo->seg[skinfo[sk].seg];
/*sec = get_section(seg, mo->sk_to_sect[sk].machosect);
while (fileofs < sec->offset)
fputc(0, fp), fileofs++;*/
for (s = mo->sk_to_sect[sk].s; s; s = s->prev) {
if (s->sh_type != SHT_NOBITS) {
while (fileofs < s->sh_offset)
fputc(0, fp), fileofs++;
if (s->sh_size) {
fwrite(s->data, 1, s->sh_size, fp);
fileofs += s->sh_size;
}
}
}
}
}
ST_FUNC int macho_output_file(TCCState *s1, const char *filename)
{
int fd, mode, file_type;
FILE *fp;
int ret = -1;
struct macho mo = {0,};
file_type = s1->output_type;
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: %s'", filename, strerror(errno));
return -1;
}
fp = fdopen(fd, "wb");
if (s1->verbose)
printf("<- %s\n", filename);
resolve_common_syms(s1);
create_symtab(s1, &mo);
check_relocs(s1, &mo);
ret = check_symbols(s1, &mo);
if (!ret) {
int i;
Section *s;
collect_sections(s1, &mo);
relocate_syms(s1, s1->symtab, 0);
mo.ep.entryoff = get_elf_sym_addr(s1, "_main", 1) - mo.seg[1]->vmaddr;
if (s1->nb_errors)
goto do_ret;
for(i = 1; i < s1->nb_sections; i++) {
s = s1->sections[i];
if (s->reloc)
relocate_section(s1, s);
}
convert_symbols(s1, &mo);
macho_write(s1, &mo, fp);
}
ret = 0;
do_ret:
fclose(fp);
return ret;
}
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