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machobj.d
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machobj.d
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/**
* Generate Mach-O object files
*
* Compiler implementation of the
* $(LINK2 https://www.dlang.org, D programming language).
*
* Copyright: Copyright (C) 2009-2024 by The D Language Foundation, All Rights Reserved
* Authors: $(LINK2 https://www.digitalmars.com, Walter Bright)
* License: $(LINK2 https://www.boost.org/LICENSE_1_0.txt, Boost License 1.0)
* Source: $(LINK2 https://github.com/dlang/dmd/blob/master/src/dmd/backend/machobj.d, backend/machobj.d)
*/
module dmd.backend.machobj;
import core.stdc.ctype;
import core.stdc.stdint;
import core.stdc.stdio;
import core.stdc.stdlib;
import core.stdc.string;
import dmd.backend.barray;
import dmd.backend.cc;
import dmd.backend.cdef;
import dmd.backend.code;
import dmd.backend.x86.code_x86;
import dmd.backend.mem;
import dmd.backend.aarray;
import dmd.backend.dlist;
import dmd.backend.el;
import dmd.backend.global;
import dmd.backend.obj;
import dmd.backend.oper;
import dmd.backend.ty;
import dmd.backend.type;
import dmd.common.outbuffer;
nothrow:
@safe:
private enum log = false;
alias _compare_fp_t = extern(C) nothrow int function(const void*, const void*);
extern(C) void qsort(void* base, size_t nmemb, size_t size, _compare_fp_t compar);
import dmd.backend.dwarf;
import dmd.backend.mach;
alias nlist = dmd.backend.mach.nlist; // avoid conflict with dmd.backend.dlist.nlist
/****************************************
* Sort the relocation entry buffer.
* put before nothrow because qsort was not marked nothrow until version 2.086
*/
extern (C) {
@trusted
private int mach_rel_fp(scope const(void*) e1, scope const(void*) e2)
{ Relocation *r1 = cast(Relocation *)e1;
Relocation *r2 = cast(Relocation *)e2;
return cast(int)(r1.offset - r2.offset);
}
}
@trusted
void mach_relsort(OutBuffer *buf)
{
qsort(buf.buf, buf.length() / Relocation.sizeof, Relocation.sizeof, &mach_rel_fp);
}
private extern (D) __gshared OutBuffer *fobjbuf;
enum DEST_LEN = (IDMAX + IDOHD + 1);
public import dmd.backend.dwarfdbginf : except_table_seg, eh_frame_seg;
/******************************************
*/
/// Returns: a reference to the global offset table
@trusted
Symbol* MachObj_getGOTsym()
{
__gshared Symbol *GOTsym;
if (!GOTsym)
{
GOTsym = symbol_name("_GLOBAL_OFFSET_TABLE_",SC.global,tspvoid);
}
return GOTsym;
}
void MachObj_refGOTsym()
{
assert(0);
}
// The object file is built is several separate pieces
// String Table - String table for all other names
private extern (D) __gshared OutBuffer *symtab_strings;
// Section Headers
__gshared OutBuffer *SECbuf; // Buffer to build section table in
@trusted
section* SecHdrTab() { return cast(section *)SECbuf.buf; }
@trusted
section_64* SecHdrTab64() { return cast(section_64 *)SECbuf.buf; }
__gshared
{
// The relocation for text and data seems to get lost.
// Try matching the order gcc output them
// This means defining the sections and then removing them if they are
// not used.
private int section_cnt; // Number of sections in table
enum SEC_TAB_INIT = 16; // Initial number of sections in buffer
enum SEC_TAB_INC = 4; // Number of sections to increment buffer by
enum SYM_TAB_INIT = 100; // Initial number of symbol entries in buffer
enum SYM_TAB_INC = 50; // Number of symbols to increment buffer by
/* Three symbol tables, because the different types of symbols
* are grouped into 3 different types (and a 4th for comdef's).
*/
private OutBuffer *local_symbuf;
private OutBuffer *public_symbuf;
private OutBuffer *extern_symbuf;
}
@trusted
private void reset_symbols(OutBuffer *buf)
{
Symbol **p = cast(Symbol **)buf.buf;
const size_t n = buf.length() / (Symbol *).sizeof;
for (size_t i = 0; i < n; ++i)
symbol_reset(*p[i]);
}
__gshared
{
struct Comdef { Symbol *sym; targ_size_t size; int count; }
private OutBuffer *comdef_symbuf; // Comdef's are stored here
private OutBuffer *indirectsymbuf1; // indirect symbol table of Symbol*'s
private int jumpTableSeg; // segment index for __jump_table
private OutBuffer *indirectsymbuf2; // indirect symbol table of Symbol*'s
private int pointersSeg; // segment index for __pointers
/* If an MachObj_external_def() happens, set this to the string index,
* to be added last to the symbol table.
* Obviously, there can be only one.
*/
private IDXSTR extdef;
}
// Each compiler segment is a section
// Predefined compiler segments CODE,DATA,CDATA,UDATA map to indexes
// into SegData[]
// New compiler segments are added to end.
/******************************
* Returns !=0 if this segment is a code segment.
*/
@trusted
int mach_seg_data_isCode(const ref seg_data sd)
{
// The codegen assumes that code.data references are indirect,
// but when CDATA is treated as code reftoident will emit a direct
// relocation.
if (&sd == SegData[CDATA])
return false;
if (I64)
{
//printf("SDshtidx = %d, x%x\n", SDshtidx, SecHdrTab64[sd.SDshtidx].flags);
return strcmp(SecHdrTab64[sd.SDshtidx].segname.ptr, "__TEXT") == 0;
}
else
{
//printf("SDshtidx = %d, x%x\n", SDshtidx, SecHdrTab[sd.SDshtidx].flags);
return strcmp(SecHdrTab[sd.SDshtidx].segname.ptr, "__TEXT") == 0;
}
}
import dmd.backend.code: SegData;
__gshared
{
/**
* Section index for the __thread_vars/__tls_data section.
*
* This section is used for the variable symbol for TLS variables.
*/
private extern (D) int seg_tlsseg = UNKNOWN;
/**
* Section index for the __thread_bss section.
*
* This section is used for the data symbol ($tlv$init) for TLS variables
* without an initializer.
*/
private extern (D) int seg_tlsseg_bss = UNKNOWN;
/**
* Section index for the __thread_data section.
*
* This section is used for the data symbol ($tlv$init) for TLS variables
* with an initializer.
*/
int seg_tlsseg_data = UNKNOWN;
int seg_cstring = UNKNOWN; // __cstring section
int seg_mod_init_func = UNKNOWN; // __mod_init_func section
int seg_mod_term_func = UNKNOWN; // __mod_term_func section
int seg_deh_eh = UNKNOWN; // __deh_eh section
int seg_textcoal_nt = UNKNOWN;
int seg_tlscoal_nt = UNKNOWN;
int seg_datacoal_nt = UNKNOWN;
}
/*******************************************************
* Because the Mach-O relocations cannot be computed until after
* all the segments are written out, and we need more information
* than the Mach-O relocations provide, make our own relocation
* type. Later, translate to Mach-O relocation structure.
*/
enum
{
RELaddr = 0, // straight address
RELrel = 1, // relative to location to be fixed up
}
struct Relocation
{ // Relocations are attached to the struct seg_data they refer to
targ_size_t offset; // location in segment to be fixed up
Symbol *funcsym; // function in which offset lies, if any
Symbol *targsym; // if !=null, then location is to be fixed up
// to address of this symbol
uint targseg; // if !=0, then location is to be fixed up
// to address of start of this segment
ubyte rtype; // RELaddr or RELrel
ubyte flag; // 1: emit SUBTRACTOR/UNSIGNED pair
short val; // 0, -1, -2, -4
}
/*******************************
* Output a string into a string table
* Input:
* strtab = string table for entry
* str = string to add
*
* Returns index into the specified string table.
*/
@trusted
IDXSTR MachObj_addstr(OutBuffer *strtab, const(char)* str)
{
//printf("MachObj_addstr(strtab = %p str = '%s')\n",strtab,str);
IDXSTR idx = cast(IDXSTR)strtab.length(); // remember starting offset
strtab.writeStringz(str);
//printf("\tidx %d, new size %d\n",idx,strtab.length());
return idx;
}
/*******************************
* Output a mangled string into the symbol string table
* Input:
* str = string to add
*
* Returns index into the table.
*/
@trusted
private IDXSTR mach_addmangled(Symbol *s)
{
//printf("mach_addmangled(%s)\n", s.Sident);
char[DEST_LEN] dest = void;
char *destr;
const(char)* name;
IDXSTR namidx;
namidx = cast(IDXSTR)symtab_strings.length();
destr = obj_mangle2(s, dest.ptr);
name = destr;
if (CPP && name[0] == '_' && name[1] == '_')
{
if (strncmp(name,"__ct__",6) == 0)
name += 4;
}
else if (tyfunc(s.ty()) && s.Sfunc && s.Sfunc.Fredirect)
name = s.Sfunc.Fredirect;
symtab_strings.writeStringz(name);
if (destr != dest.ptr) // if we resized result
mem_free(destr);
//dbg_printf("\telf_addmagled symtab_strings %s namidx %d len %d size %d\n",name, namidx,len,symtab_strings.length());
return namidx;
}
/**************************
* Ouput read only data and generate a symbol for it.
*
*/
Symbol * MachObj_sym_cdata(tym_t ty,char *p,int len)
{
Symbol *s;
//printf("MachObj_sym_cdata(ty = %x, p = %x, len = %d, Offset(CDATA) = %x)\n", ty, p, len, Offset(CDATA));
alignOffset(CDATA, tysize(ty));
s = symboldata(Offset(CDATA), ty);
s.Sseg = CDATA;
//MachObj_pubdef(CDATA, s, Offset(CDATA));
MachObj_bytes(CDATA, Offset(CDATA), len, p);
s.Sfl = /*(config.flags3 & CFG3pic) ? FLgotoff :*/ FLextern;
return s;
}
/**************************
* Ouput read only data for data
*
*/
@trusted
int MachObj_data_readonly(char *p, int len, int *pseg)
{
int oldoff = cast(int)Offset(CDATA);
SegData[CDATA].SDbuf.reserve(len);
SegData[CDATA].SDbuf.writen(p,len);
Offset(CDATA) += len;
*pseg = CDATA;
return oldoff;
}
@trusted
int MachObj_data_readonly(char *p, int len)
{
int pseg;
return MachObj_data_readonly(p, len, &pseg);
}
/*****************************
* Get segment for readonly string literals.
* The linker will pool strings in this section.
* Params:
* sz = number of bytes per character (1, 2, or 4)
* Returns:
* segment index
*/
@trusted
int MachObj_string_literal_segment(uint sz)
{
if (sz == 1)
return getsegment2(seg_cstring, "__cstring", "__TEXT", 0, S_CSTRING_LITERALS);
return CDATA; // no special handling for other wstring, dstring; use __const
}
/******************************
* Perform initialization that applies to all .o output files.
* Called before any other obj_xxx routines
*/
@system
Obj MachObj_init(OutBuffer *objbuf, const(char)* filename, const(char)* csegname)
{
//printf("MachObj_init()\n");
Obj obj = cast(Obj)mem_calloc(__traits(classInstanceSize, Obj));
cseg = CODE;
fobjbuf = objbuf;
seg_tlsseg = UNKNOWN;
seg_tlsseg_bss = UNKNOWN;
seg_tlsseg_data = UNKNOWN;
seg_cstring = UNKNOWN;
seg_mod_init_func = UNKNOWN;
seg_mod_term_func = UNKNOWN;
seg_deh_eh = UNKNOWN;
seg_textcoal_nt = UNKNOWN;
seg_tlscoal_nt = UNKNOWN;
seg_datacoal_nt = UNKNOWN;
// Initialize buffers
if (symtab_strings)
symtab_strings.setsize(1);
else
{
symtab_strings = cast(OutBuffer*) calloc(1, OutBuffer.sizeof);
if (!symtab_strings)
err_nomem();
symtab_strings.reserve(2048);
symtab_strings.writeByte(0);
}
if (!local_symbuf)
{
local_symbuf = cast(OutBuffer*) calloc(1, OutBuffer.sizeof);
if (!local_symbuf)
err_nomem();
local_symbuf.reserve((Symbol *).sizeof * SYM_TAB_INIT);
}
local_symbuf.reset();
if (public_symbuf)
{
reset_symbols(public_symbuf);
public_symbuf.reset();
}
else
{
public_symbuf = cast(OutBuffer*) calloc(1, OutBuffer.sizeof);
if (!public_symbuf)
err_nomem();
public_symbuf.reserve((Symbol *).sizeof * SYM_TAB_INIT);
}
if (extern_symbuf)
{
reset_symbols(extern_symbuf);
extern_symbuf.reset();
}
else
{
extern_symbuf = cast(OutBuffer*) calloc(1, OutBuffer.sizeof);
if (!extern_symbuf)
err_nomem();
extern_symbuf.reserve((Symbol *).sizeof * SYM_TAB_INIT);
}
if (!comdef_symbuf)
{
comdef_symbuf = cast(OutBuffer*) calloc(1, OutBuffer.sizeof);
if (!comdef_symbuf)
err_nomem();
comdef_symbuf.reserve((Symbol *).sizeof * SYM_TAB_INIT);
}
comdef_symbuf.reset();
extdef = 0;
if (indirectsymbuf1)
indirectsymbuf1.reset();
jumpTableSeg = 0;
if (indirectsymbuf2)
indirectsymbuf2.reset();
pointersSeg = 0;
// Initialize segments for CODE, DATA, UDATA and CDATA
size_t struct_section_size = I64 ? section_64.sizeof : section.sizeof;
if (SECbuf)
{
SECbuf.setsize(cast(uint)struct_section_size);
}
else
{
SECbuf = cast(OutBuffer*) calloc(1, OutBuffer.sizeof);
if (!SECbuf)
err_nomem();
SECbuf.reserve(cast(uint)(SEC_TAB_INIT * struct_section_size));
// Ignore the first section - section numbers start at 1
SECbuf.writezeros(cast(uint)struct_section_size);
}
section_cnt = 1;
SegData.reset(); // recycle memory
SegData.push(); // element 0 is reserved
int align_ = I64 ? 4 : 2; // align to 16 bytes for floating point
MachObj_getsegment("__text", "__TEXT", 2, S_REGULAR | S_ATTR_PURE_INSTRUCTIONS | S_ATTR_SOME_INSTRUCTIONS);
MachObj_getsegment("__data", "__DATA", align_, S_REGULAR); // DATA
MachObj_getsegment("__const", "__TEXT", 2, S_REGULAR); // CDATA
MachObj_getsegment("__bss", "__DATA", 4, S_ZEROFILL); // UDATA
MachObj_getsegment("__const", "__DATA", align_, S_REGULAR); // CDATAREL
dwarf_initfile(filename);
return obj;
}
/**************************
* Initialize the start of object output for this particular .o file.
*
* Input:
* filename: Name of source file
* csegname: User specified default code segment name
*/
@trusted
void MachObj_initfile(const(char)* filename, const(char)* csegname, const(char)* modname)
{
//dbg_printf("MachObj_initfile(filename = %s, modname = %s)\n",filename,modname);
if (config.fulltypes)
dwarf_initmodule(filename, modname);
}
/************************************
* Patch pseg/offset by adding in the vmaddr difference from
* pseg/offset to start of seg.
*/
@trusted
int32_t *patchAddr(int seg, targ_size_t offset)
{
return cast(int32_t *)(fobjbuf.buf + SecHdrTab[SegData[seg].SDshtidx].offset + offset);
}
@trusted
int32_t *patchAddr64(int seg, targ_size_t offset)
{
return cast(int32_t *)(fobjbuf.buf + SecHdrTab64[SegData[seg].SDshtidx].offset + offset);
}
@trusted
void patch(seg_data *pseg, targ_size_t offset, int seg, targ_size_t value)
{
//printf("patch(offset = x%04x, seg = %d, value = x%llx)\n", cast(uint)offset, seg, value);
if (I64)
{
int32_t *p = cast(int32_t *)(fobjbuf.buf + SecHdrTab64[pseg.SDshtidx].offset + offset);
if (log)
debug printf("\taddr1 = x%llx\n\taddr2 = x%llx\n\t*p = x%x\n\tdelta = x%llx\n",
SecHdrTab64[pseg.SDshtidx].addr,
SecHdrTab64[SegData[seg].SDshtidx].addr,
*p,
SecHdrTab64[SegData[seg].SDshtidx].addr -
(SecHdrTab64[pseg.SDshtidx].addr + offset));
*p += SecHdrTab64[SegData[seg].SDshtidx].addr -
(SecHdrTab64[pseg.SDshtidx].addr - value);
}
else
{
int32_t *p = cast(int32_t *)(fobjbuf.buf + SecHdrTab[pseg.SDshtidx].offset + offset);
if (log)
debug printf("\taddr1 = x%x\n\taddr2 = x%x\n\t*p = x%x\n\tdelta = x%llx\n",
SecHdrTab[pseg.SDshtidx].addr,
SecHdrTab[SegData[seg].SDshtidx].addr,
*p,
SecHdrTab[SegData[seg].SDshtidx].addr -
(SecHdrTab[pseg.SDshtidx].addr + offset));
*p += SecHdrTab[SegData[seg].SDshtidx].addr -
(SecHdrTab[pseg.SDshtidx].addr - value);
}
}
/***************************
* Number symbols so they are
* ordered as locals, public and then extern/comdef
*/
@trusted
void mach_numbersyms()
{
//printf("mach_numbersyms()\n");
int n = 0;
int dim;
dim = cast(int)(local_symbuf.length() / (Symbol *).sizeof);
for (int i = 0; i < dim; i++)
{ Symbol *s = (cast(Symbol **)local_symbuf.buf)[i];
s.Sxtrnnum = n;
n++;
}
dim = cast(int)(public_symbuf.length() / (Symbol *).sizeof);
for (int i = 0; i < dim; i++)
{ Symbol *s = (cast(Symbol **)public_symbuf.buf)[i];
s.Sxtrnnum = n;
n++;
}
dim = cast(int)(extern_symbuf.length() / (Symbol *).sizeof);
for (int i = 0; i < dim; i++)
{ Symbol *s = (cast(Symbol **)extern_symbuf.buf)[i];
s.Sxtrnnum = n;
n++;
}
dim = cast(int)(comdef_symbuf.length() / Comdef.sizeof);
for (int i = 0; i < dim; i++)
{ Comdef *c = (cast(Comdef *)comdef_symbuf.buf) + i;
c.sym.Sxtrnnum = n;
n++;
}
}
/***************************
* Fixup and terminate object file.
*/
@trusted
void MachObj_termfile()
{
//dbg_printf("MachObj_termfile\n");
if (configv.addlinenumbers)
{
dwarf_termmodule();
}
}
/*********************************
* Terminate package.
*/
@trusted
void MachObj_term(const(char)[] objfilename)
{
//printf("MachObj_term()\n");
outfixlist(); // backpatches
if (configv.addlinenumbers)
{
dwarf_termfile();
}
/* Write out the object file in the following order:
* header
* commands
* segment_command
* { sections }
* symtab_command
* dysymtab_command
* build_version_command/version_min_command
* { segment contents }
* { relocations }
* symbol table
* string table
* indirect symbol table
*/
auto version_command = VersionCommand(operatingSystemVersion);
uint foffset;
uint headersize;
uint sizeofcmds;
// Write out the bytes for the header
if (I64)
{
mach_header_64 header = void;
header.magic = MH_MAGIC_64;
header.cputype = CPU_TYPE_X86_64;
header.cpusubtype = CPU_SUBTYPE_I386_ALL;
header.filetype = MH_OBJECT;
header.ncmds = 4;
header.sizeofcmds = cast(uint)(segment_command_64.sizeof +
(section_cnt - 1) * section_64.sizeof +
version_command.size +
symtab_command.sizeof +
dysymtab_command.sizeof);
header.flags = MH_SUBSECTIONS_VIA_SYMBOLS;
header.reserved = 0;
fobjbuf.write(&header, header.sizeof);
foffset = header.sizeof; // start after header
headersize = header.sizeof;
sizeofcmds = header.sizeofcmds;
// Write the actual data later
fobjbuf.writezeros(header.sizeofcmds);
foffset += header.sizeofcmds;
}
else
{
mach_header header = void;
header.magic = MH_MAGIC;
header.cputype = CPU_TYPE_I386;
header.cpusubtype = CPU_SUBTYPE_I386_ALL;
header.filetype = MH_OBJECT;
header.ncmds = 4;
header.sizeofcmds = cast(uint)(segment_command.sizeof +
(section_cnt - 1) * section.sizeof +
version_command.size +
symtab_command.sizeof +
dysymtab_command.sizeof);
header.flags = MH_SUBSECTIONS_VIA_SYMBOLS;
fobjbuf.write(&header, header.sizeof);
foffset = header.sizeof; // start after header
headersize = header.sizeof;
sizeofcmds = header.sizeofcmds;
// Write the actual data later
fobjbuf.writezeros(header.sizeofcmds);
foffset += header.sizeofcmds;
}
segment_command segment_cmd = void;
segment_command_64 segment_cmd64 = void;
symtab_command symtab_cmd = void;
dysymtab_command dysymtab_cmd = void;
memset(&segment_cmd, 0, segment_cmd.sizeof);
memset(&segment_cmd64, 0, segment_cmd64.sizeof);
memset(&symtab_cmd, 0, symtab_cmd.sizeof);
memset(&dysymtab_cmd, 0, dysymtab_cmd.sizeof);
if (I64)
{
segment_cmd64.cmd = LC_SEGMENT_64;
segment_cmd64.cmdsize = cast(uint)(segment_cmd64.sizeof +
(section_cnt - 1) * section_64.sizeof);
segment_cmd64.nsects = section_cnt - 1;
segment_cmd64.maxprot = 7;
segment_cmd64.initprot = 7;
}
else
{
segment_cmd.cmd = LC_SEGMENT;
segment_cmd.cmdsize = cast(uint)(segment_cmd.sizeof +
(section_cnt - 1) * section.sizeof);
segment_cmd.nsects = section_cnt - 1;
segment_cmd.maxprot = 7;
segment_cmd.initprot = 7;
}
symtab_cmd.cmd = LC_SYMTAB;
symtab_cmd.cmdsize = symtab_cmd.sizeof;
dysymtab_cmd.cmd = LC_DYSYMTAB;
dysymtab_cmd.cmdsize = dysymtab_cmd.sizeof;
/* If a __pointers section was emitted, need to set the .reserved1
* field to the symbol index in the indirect symbol table of the
* start of the __pointers symbols.
*/
if (pointersSeg)
{
seg_data *pseg = SegData[pointersSeg];
if (I64)
{
section_64 *psechdr = &SecHdrTab64[pseg.SDshtidx]; // corresponding section
psechdr.reserved1 = cast(uint)(indirectsymbuf1
? indirectsymbuf1.length() / (Symbol *).sizeof
: 0);
}
else
{
section *psechdr = &SecHdrTab[pseg.SDshtidx]; // corresponding section
psechdr.reserved1 = cast(uint)(indirectsymbuf1
? indirectsymbuf1.length() / (Symbol *).sizeof
: 0);
}
}
// Walk through sections determining size and file offsets
//
// First output individual section data associate with program
// code and data
//
foffset = elf_align(I64 ? 8 : 4, foffset);
if (I64)
segment_cmd64.fileoff = foffset;
else
segment_cmd.fileoff = foffset;
uint vmaddr = 0;
//printf("Setup offsets and sizes foffset %d\n\tsection_cnt %d, SegData.length %d\n",foffset,section_cnt,SegData.length);
// Zero filled segments go at the end, so go through segments twice
for (int i = 0; i < 2; i++)
{
for (int seg = 1; seg < SegData.length; seg++)
{
seg_data *pseg = SegData[seg];
if (I64)
{
section_64 *psechdr = &SecHdrTab64[pseg.SDshtidx]; // corresponding section
// Do zero-fill the second time through this loop
if (i ^ (psechdr.flags == S_ZEROFILL || psechdr.flags == S_THREAD_LOCAL_ZEROFILL))
continue;
int align_ = 1 << psechdr._align;
while (psechdr._align > 0 && align_ < pseg.SDalignment)
{
psechdr._align += 1;
align_ <<= 1;
}
foffset = elf_align(align_, foffset);
vmaddr = (vmaddr + align_ - 1) & ~(align_ - 1);
if (psechdr.flags == S_ZEROFILL || psechdr.flags == S_THREAD_LOCAL_ZEROFILL)
{
psechdr.offset = 0;
psechdr.size = pseg.SDoffset; // accumulated size
}
else
{
psechdr.offset = foffset;
psechdr.size = 0;
//printf("\tsection name %s,", psechdr.sectname);
if (pseg.SDbuf && pseg.SDbuf.length())
{
//printf("\tsize %d\n", pseg.SDbuf.length());
psechdr.size = pseg.SDbuf.length();
fobjbuf.write(pseg.SDbuf.buf, cast(uint)psechdr.size);
foffset += psechdr.size;
}
}
psechdr.addr = vmaddr;
vmaddr += psechdr.size;
//printf(" assigned offset %d, size %d\n", foffset, psechdr.sh_size);
}
else
{
section *psechdr = &SecHdrTab[pseg.SDshtidx]; // corresponding section
// Do zero-fill the second time through this loop
if (i ^ (psechdr.flags == S_ZEROFILL || psechdr.flags == S_THREAD_LOCAL_ZEROFILL))
continue;
int align_ = 1 << psechdr._align;
while (psechdr._align > 0 && align_ < pseg.SDalignment)
{
psechdr._align += 1;
align_ <<= 1;
}
foffset = elf_align(align_, foffset);
vmaddr = (vmaddr + align_ - 1) & ~(align_ - 1);
if (psechdr.flags == S_ZEROFILL || psechdr.flags == S_THREAD_LOCAL_ZEROFILL)
{
psechdr.offset = 0;
psechdr.size = cast(uint)pseg.SDoffset; // accumulated size
}
else
{
psechdr.offset = foffset;
psechdr.size = 0;
//printf("\tsection name %s,", psechdr.sectname);
if (pseg.SDbuf && pseg.SDbuf.length())
{
//printf("\tsize %d\n", pseg.SDbuf.length());
psechdr.size = cast(uint)pseg.SDbuf.length();
fobjbuf.write(pseg.SDbuf.buf, psechdr.size);
foffset += psechdr.size;
}
}
psechdr.addr = vmaddr;
vmaddr += psechdr.size;
//printf(" assigned offset %d, size %d\n", foffset, psechdr.sh_size);
}
}
}
if (I64)
{
segment_cmd64.vmsize = vmaddr;
segment_cmd64.filesize = foffset - segment_cmd64.fileoff;
/* Bugzilla 5331: Apparently having the filesize field greater than the vmsize field is an
* error, and is happening sometimes.
*/
if (segment_cmd64.filesize > vmaddr)
segment_cmd64.vmsize = segment_cmd64.filesize;
}
else
{
segment_cmd.vmsize = vmaddr;
segment_cmd.filesize = foffset - segment_cmd.fileoff;
/* Bugzilla 5331: Apparently having the filesize field greater than the vmsize field is an
* error, and is happening sometimes.
*/
if (segment_cmd.filesize > vmaddr)
segment_cmd.vmsize = segment_cmd.filesize;
}
// Put out relocation data
// See mach-o/reloc.h for some examples of what should be generated and when:
// https://github.com/apple-oss-distributions/xnu/blob/rel/xnu-10002/EXTERNAL_HEADERS/mach-o/x86_64/reloc.h
mach_numbersyms();
for (int seg = 1; seg < SegData.length; seg++)
{
seg_data *pseg = SegData[seg];
section *psechdr = null;
section_64 *psechdr64 = null;
if (I64)
{
psechdr64 = &SecHdrTab64[pseg.SDshtidx]; // corresponding section
//printf("psechdr.addr = x%llx\n", psechdr64.addr);
}
else
{
psechdr = &SecHdrTab[pseg.SDshtidx]; // corresponding section
//printf("psechdr.addr = x%x\n", psechdr.addr);
}
foffset = elf_align(I64 ? 8 : 4, foffset);
uint reloff = foffset;
uint nreloc = 0;
if (pseg.SDrel)
{ Relocation *r = cast(Relocation *)pseg.SDrel.buf;
Relocation *rend = cast(Relocation *)(pseg.SDrel.buf + pseg.SDrel.length());
for (; r != rend; r++)
{ Symbol *s = r.targsym;
const(char)* rs = r.rtype == RELaddr ? "addr" : "rel";
//printf("%d:x%04llx : tseg %d tsym %s REL%s\n", seg, r.offset, r.targseg, s ? s.Sident.ptr : "0", rs);
relocation_info rel;
scattered_relocation_info srel;
if (s)
{
//printf("Relocation\n");
//symbol_print(s);
if (r.flag == 1) // emit SUBTRACTOR/UNSIGNED pair
{
if (I64)
{
rel.r_type = X86_64_RELOC_SUBTRACTOR;
rel.r_address = cast(int)r.offset;
rel.r_symbolnum = r.funcsym.Sxtrnnum;
rel.r_pcrel = 0;
rel.r_length = 3;
rel.r_extern = 1;
fobjbuf.write(&rel, rel.sizeof);
foffset += (rel).sizeof;
++nreloc;
rel.r_type = X86_64_RELOC_UNSIGNED;
rel.r_symbolnum = s.Sxtrnnum;
fobjbuf.write(&rel, rel.sizeof);
foffset += rel.sizeof;
++nreloc;
// patch with fdesym.Soffset - offset
long *p = cast(long *)patchAddr64(seg, r.offset);
*p += r.funcsym.Soffset - r.offset;
continue;
}
else
{
// address = segment + offset
int targ_address = cast(int)(SecHdrTab[SegData[s.Sseg].SDshtidx].addr + s.Soffset);
int fixup_address = cast(int)(psechdr.addr + r.offset);
srel.r_scattered = 1;
srel.r_type = GENERIC_RELOC_LOCAL_SECTDIFF;
srel.r_address = cast(uint)r.offset;
srel.r_pcrel = 0;
srel.r_length = 2;
srel.r_value = targ_address;
fobjbuf.write((&srel)[0 .. 1]);
foffset += srel.sizeof;
++nreloc;
srel.r_type = GENERIC_RELOC_PAIR;
srel.r_address = 0;
srel.r_value = fixup_address;
fobjbuf.write(&srel, srel.sizeof);
foffset += srel.sizeof;
++nreloc;
int32_t *p = patchAddr(seg, r.offset);
*p += targ_address - fixup_address;
continue;
}
}
else if (pseg.isCode())
{
if (I64)
{
rel.r_type = (r.rtype == RELrel)
? X86_64_RELOC_BRANCH
: X86_64_RELOC_SIGNED;
if (r.val == -1)
rel.r_type = X86_64_RELOC_SIGNED_1;
else if (r.val == -2)
rel.r_type = X86_64_RELOC_SIGNED_2;
if (r.val == -4)
rel.r_type = X86_64_RELOC_SIGNED_4;
if (s.Sclass == SC.extern_ ||
s.Sclass == SC.comdef ||
s.Sclass == SC.comdat ||
s.Sclass == SC.static_ ||
s.Sclass == SC.global)
{
if ((s.ty() & mTYLINK) == mTYthread && r.rtype == RELaddr)
rel.r_type = X86_64_RELOC_TLV;
else if (s.Sfl == FLfunc && s.Sclass == SC.static_ && r.rtype == RELaddr)
rel.r_type = X86_64_RELOC_SIGNED;
else if ((s.Sfl == FLfunc || s.Sfl == FLextern || s.Sclass == SC.global ||
s.Sclass == SC.comdat || s.Sclass == SC.comdef) && r.rtype == RELaddr)
rel.r_type = X86_64_RELOC_GOT;
rel.r_address = cast(int)r.offset;
rel.r_symbolnum = s.Sxtrnnum;
rel.r_pcrel = 1;
rel.r_length = 2;
rel.r_extern = 1;
fobjbuf.write(&rel, rel.sizeof);
foffset += rel.sizeof;
nreloc++;
continue;
}
else
{
rel.r_address = cast(int)r.offset;
rel.r_symbolnum = s.Sseg;
rel.r_pcrel = 1;