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- {
- Copyright (c) 1998-2006 by Peter Vreman
- Contains the binary elf writer
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2 of the License, or
- (at your option) any later version.
- This program 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 General Public License for more details.
- You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- ****************************************************************************
- }
- unit ogelf;
- {$i fpcdefs.inc}
- interface
- uses
- { common }
- cclasses,globtype,
- { target }
- systems,
- { assembler }
- cpuinfo,cpubase,aasmbase,aasmtai,aasmdata,assemble,
- { output }
- ogbase,
- owbase;
- type
- TElfObjSection = class(TObjSection)
- public
- shstridx,
- shtype,
- shflags,
- shlink,
- shinfo,
- shentsize : longint;
- constructor create(AList:TFPHashObjectList;const Aname:string;Aalign:shortint;Aoptions:TObjSectionOptions);override;
- constructor create_ext(aobjdata:TObjData;const Aname:string;Ashtype,Ashflags:longint;Aalign:shortint;Aentsize:longint);
- constructor create_reloc(aobjdata:TObjData;const Aname:string;allocflag:boolean);
- procedure writeReloc_internal(aTarget:TObjSection;offset:aword;len:byte;reltype:TObjRelocationType);override;
- end;
- TElfSymtabKind = (esk_obj,esk_exe,esk_dyn);
- TElfSymtab = class(TElfObjSection)
- public
- kind: TElfSymtabKind;
- fstrsec: TObjSection;
- symidx: longint;
- constructor create(aObjData:TObjData;aKind:TElfSymtabKind);reintroduce;
- procedure writeSymbol(objsym:TObjSymbol;nameidx:longword=0);
- procedure writeInternalSymbol(avalue:aword;astridx:longword;ainfo:byte;ashndx:word);
- end;
- TElfObjData = class(TObjData)
- public
- constructor create(const n:string);override;
- function sectionname(atype:TAsmSectiontype;const aname:string;aorder:TAsmSectionOrder):string;override;
- procedure CreateDebugSections;override;
- procedure writereloc(data:aint;len:aword;p:TObjSymbol;reltype:TObjRelocationType);override;
- end;
- TElfObjectOutput = class(tObjOutput)
- private
- symtabsect: TElfSymtab;
- shstrtabsect: TElfObjSection;
- procedure createrelocsection(s:TElfObjSection;data:TObjData);
- procedure createshstrtab(data:TObjData);
- procedure createsymtab(data: TObjData);
- procedure writesectionheader(s:TElfObjSection);
- procedure section_write_symbol(p:TObject;arg:pointer);
- procedure section_count_sections(p:TObject;arg:pointer);
- procedure section_create_relocsec(p:TObject;arg:pointer);
- procedure section_write_sechdr(p:TObject;arg:pointer);
- protected
- function encodereloc(objrel:TObjRelocation):byte;virtual;abstract;
- function writedata(data:TObjData):boolean;override;
- public
- constructor Create(AWriter:TObjectWriter);override;
- end;
- implementation
- uses
- SysUtils,
- verbose,
- cutils,globals,fmodule;
- const
- symbolresize = 200*18;
- const
- { ELFHeader.file_class }
- ELFCLASSNONE = 0;
- ELFCLASS32 = 1;
- ELFCLASS64 = 2;
- { ELFHeader.e_type }
- ET_NONE = 0;
- ET_REL = 1;
- ET_EXEC = 2;
- ET_DYN = 3;
- ET_CORE = 4;
- { ELFHeader.e_machine }
- EM_SPARC = 2;
- EM_386 = 3;
- EM_M68K = 4;
- EM_MIPS = 8;
- EM_PPC = 20;
- EM_ARM = 40;
- EM_X86_64 = 62;
- {$ifdef sparc}
- ELFMACHINE = EM_SPARC;
- {$endif sparc}
- {$ifdef i386}
- ELFMACHINE = EM_386;
- {$endif i386}
- {$ifdef m68k}
- ELFMACHINE = EM_M68K;
- {$endif m68k}
- {$ifdef powerpc}
- ELFMACHINE = EM_PPC;
- {$endif powerpc}
- {$ifdef powerpc64}
- ELFMACHINE = EM_PPC; // TODO
- {$endif}
- {$ifdef mips}
- ELFMACHINE = EM_MIPS;
- {$endif}
- {$ifdef arm}
- ELFMACHINE = EM_ARM;
- {$endif arm}
- {$ifdef x86_64}
- ELFMACHINE = EM_X86_64;
- {$endif x86_64}
- SHN_UNDEF = 0;
- SHN_ABS = $fff1;
- SHN_COMMON = $fff2;
- SHT_NULL = 0;
- SHT_PROGBITS = 1;
- SHT_SYMTAB = 2;
- SHT_STRTAB = 3;
- SHT_RELA = 4;
- SHT_HASH = 5;
- SHT_DYNAMIC = 6;
- SHT_NOTE = 7;
- SHT_NOBITS = 8;
- SHT_REL = 9;
- SHT_SHLIB = 10;
- SHT_DYNSYM = 11;
- SHT_INIT_ARRAY = 14;
- SHT_FINI_ARRAY = 15;
- SHT_PREINIT_ARRAY = 16;
- SHT_GROUP = 17;
- SHT_SYMTAB_SHNDX = 18;
- SHF_WRITE = 1;
- SHF_ALLOC = 2;
- SHF_EXECINSTR = 4;
- SHF_MERGE = 16;
- SHF_STRINGS = 32;
- SHF_INFO_LINK = 64;
- SHF_LINK_ORDER = 128;
- SHF_OS_NONCONFORMING = 256;
- SHF_GROUP = 512;
- SHF_TLS = 1024;
- STB_LOCAL = 0;
- STB_GLOBAL = 1;
- STB_WEAK = 2;
- STT_NOTYPE = 0;
- STT_OBJECT = 1;
- STT_FUNC = 2;
- STT_SECTION = 3;
- STT_FILE = 4;
- STT_COMMON = 5;
- STT_TLS = 6;
- STT_GNU_IFUNC = 10;
- { program header types }
- PT_NULL = 0;
- PT_LOAD = 1;
- PT_DYNAMIC = 2;
- PT_INTERP = 3;
- PT_NOTE = 4;
- PT_SHLIB = 5;
- PT_PHDR = 6;
- PT_TLS = 7;
- PT_LOOS = $60000000;
- PT_HIOS = $6FFFFFFF;
- PT_LOPROC = $70000000;
- PT_HIPROC = $7FFFFFFF;
- PT_GNU_EH_FRAME = PT_LOOS + $474e550; { Frame unwind information }
- PT_GNU_STACK = PT_LOOS + $474e551; { Stack flags }
- PT_GNU_RELRO = PT_LOOS + $474e552; { Read-only after relocation }
- { program header flags }
- PF_X = 1;
- PF_W = 2;
- PF_R = 4;
- PF_MASKOS = $0FF00000; { OS-specific reserved bits }
- PF_MASKPROC = $F0000000; { Processor-specific reserved bits }
- { .dynamic tags }
- DT_NULL = 0;
- DT_NEEDED = 1;
- DT_PLTRELSZ = 2;
- DT_PLTGOT = 3;
- DT_HASH = 4;
- DT_STRTAB = 5;
- DT_SYMTAB = 6;
- DT_RELA = 7;
- DT_RELASZ = 8;
- DT_RELAENT = 9;
- DT_STRSZ = 10;
- DT_SYMENT = 11;
- DT_INIT = 12;
- DT_FINI = 13;
- DT_SONAME = 14;
- DT_RPATH = 15;
- DT_SYMBOLIC = 16;
- DT_REL = 17;
- DT_RELSZ = 18;
- DT_RELENT = 19;
- DT_PLTREL = 20;
- DT_DEBUG = 21;
- DT_TEXTREL = 22;
- DT_JMPREL = 23;
- DT_BIND_NOW = 24;
- DT_INIT_ARRAY = 25;
- DT_FINI_ARRAY = 26;
- DT_INIT_ARRAYSZ = 27;
- DT_FINI_ARRAYSZ = 28;
- DT_RUNPATH = 29;
- DT_FLAGS = 30;
- DT_ENCODING = 32;
- DT_PREINIT_ARRAY = 32;
- DT_PREINIT_ARRAYSZ = 33;
- DT_NUM = 34;
- DT_LOOS = $6000000D;
- DT_HIOS = $6ffff000;
- DT_LOPROC = $70000000;
- DT_HIPROC = $7fffffff;
- DT_RELACOUNT = $6ffffff9;
- DT_RELCOUNT = $6ffffffa;
- DT_FLAGS_1 = $6ffffffb;
- DT_VERDEF = $6ffffffc;
- DT_VERDEFNUM = $6ffffffd;
- DT_VERNEED = $6ffffffe;
- DT_VERNEEDNUM = $6fffffff;
- type
- { Structures which are written directly to the output file }
- TElf32header=packed record
- magic : array[0..3] of byte;
- file_class : byte;
- data_encoding : byte;
- file_version : byte;
- padding : array[$07..$0f] of byte;
- e_type : word;
- e_machine : word;
- e_version : longword;
- e_entry : longword; { entrypoint }
- e_phoff : longword; { program header offset }
- e_shoff : longword; { sections header offset }
- e_flags : longword;
- e_ehsize : word; { elf header size in bytes }
- e_phentsize : word; { size of an entry in the program header array }
- e_phnum : word; { 0..e_phnum-1 of entrys }
- e_shentsize : word; { size of an entry in sections header array }
- e_shnum : word; { 0..e_shnum-1 of entrys }
- e_shstrndx : word; { index of string section header }
- end;
- TElf32sechdr=packed record
- sh_name : longword;
- sh_type : longword;
- sh_flags : longword;
- sh_addr : longword;
- sh_offset : longword;
- sh_size : longword;
- sh_link : longword;
- sh_info : longword;
- sh_addralign : longword;
- sh_entsize : longword;
- end;
- TElf32proghdr=packed record
- p_type : longword;
- p_offset : longword;
- p_vaddr : longword;
- p_paddr : longword;
- p_filesz : longword;
- p_memsz : longword;
- p_flags : longword;
- p_align : longword;
- end;
- TElf32reloc=packed record
- address : longword;
- info : longword; { bit 0-7: type, 8-31: symbol }
- addend : longint;
- end;
- TElf32symbol=packed record
- st_name : longword;
- st_value : longword;
- st_size : longword;
- st_info : byte; { bit 0-3: type, 4-7: bind }
- st_other : byte;
- st_shndx : word;
- end;
- TElf32Dyn=packed record
- d_tag: longword;
- case integer of
- 0: (d_val: longword);
- 1: (d_ptr: longword);
- end;
- telf64header=packed record
- magic : array[0..3] of byte;
- file_class : byte;
- data_encoding : byte;
- file_version : byte;
- padding : array[$07..$0f] of byte;
- e_type : word;
- e_machine : word;
- e_version : longword;
- e_entry : qword; { entrypoint }
- e_phoff : qword; { program header offset }
- e_shoff : qword; { sections header offset }
- e_flags : longword;
- e_ehsize : word; { elf header size in bytes }
- e_phentsize : word; { size of an entry in the program header array }
- e_phnum : word; { 0..e_phnum-1 of entrys }
- e_shentsize : word; { size of an entry in sections header array }
- e_shnum : word; { 0..e_shnum-1 of entrys }
- e_shstrndx : word; { index of string section header }
- end;
- telf64sechdr=packed record
- sh_name : longword;
- sh_type : longword;
- sh_flags : qword;
- sh_addr : qword;
- sh_offset : qword;
- sh_size : qword;
- sh_link : longword;
- sh_info : longword;
- sh_addralign : qword;
- sh_entsize : qword;
- end;
- telf64proghdr=packed record
- p_type : longword;
- p_flags : longword;
- p_offset : qword;
- p_vaddr : qword;
- p_paddr : qword;
- p_filesz : qword;
- p_memsz : qword;
- p_align : qword;
- end;
- telf64reloc=packed record
- address : qword;
- info : qword; { bit 0-31: type, 32-63: symbol }
- addend : int64; { signed! }
- end;
- telf64symbol=packed record
- st_name : longword;
- st_info : byte; { bit 0-3: type, 4-7: bind }
- st_other : byte;
- st_shndx : word;
- st_value : qword;
- st_size : qword;
- end;
- TElf64Dyn=packed record
- d_tag: qword;
- case integer of
- 0: (d_val: qword);
- 1: (d_ptr: qword);
- end;
- TElfVerdef=record { same for 32 and 64 bits }
- vd_version: word; { =1 }
- vd_flags: word;
- vd_ndx: word;
- vd_cnt: word; { number of verdaux records }
- vd_hash: longword; { ELF hash of version name }
- vd_aux: longword; { offset to verdaux records }
- vd_next: longword; { offset to next verdef record }
- end;
- TElfVerdaux=record
- vda_name: longword;
- vda_next: longword;
- end;
- TElfVerneed=record
- vn_version: word; { =VER_NEED_CURRENT }
- vn_cnt: word;
- vn_file: longword;
- vn_aux: longword;
- vn_next: longword;
- end;
- TElfVernaux=record
- vna_hash: longword;
- vna_flags: word;
- vna_other: word;
- vna_name: longword;
- vna_next: longword;
- end;
- {$ifdef cpu64bitaddr}
- const
- ELFCLASS = ELFCLASS64;
- type
- telfheader = telf64header;
- telfreloc = telf64reloc;
- telfsymbol = telf64symbol;
- telfsechdr = telf64sechdr;
- telfproghdr = telf64proghdr;
- telfdyn = telf64dyn;
- function ELF_R_INFO(sym:longword;typ:byte):qword;inline;
- begin
- result:=(qword(sym) shl 32) or typ;
- end;
- {$else cpu64bitaddr}
- const
- ELFCLASS = ELFCLASS32;
- type
- telfheader = telf32header;
- telfreloc = telf32reloc;
- telfsymbol = telf32symbol;
- telfsechdr = telf32sechdr;
- telfproghdr = telf32proghdr;
- telfdyn = telf32dyn;
- function ELF_R_INFO(sym:longword;typ:byte):longword;inline;
- begin
- result:=(sym shl 8) or typ;
- end;
- {$endif cpu64bitaddr}
- {$ifdef x86_64}
- const
- relocs_use_addend:Boolean=True;
- {$else x86_64}
- const
- relocs_use_addend:Boolean=False;
- {$endif x86_64}
- procedure MayBeSwapHeader(var h : telf32header);
- begin
- if source_info.endian<>target_info.endian then
- with h do
- begin
- e_type:=swapendian(e_type);
- e_machine:=swapendian(e_machine);
- e_version:=swapendian(e_version);
- e_entry:=swapendian(e_entry);
- e_phoff:=swapendian(e_phoff);
- e_shoff:=swapendian(e_shoff);
- e_flags:=swapendian(e_flags);
- e_ehsize:=swapendian(e_ehsize);
- e_phentsize:=swapendian(e_phentsize);
- e_phnum:=swapendian(e_phnum);
- e_shentsize:=swapendian(e_shentsize);
- e_shnum:=swapendian(e_shnum);
- e_shstrndx:=swapendian(e_shstrndx);
- end;
- end;
- procedure MayBeSwapHeader(var h : telf64header);
- begin
- if source_info.endian<>target_info.endian then
- with h do
- begin
- e_type:=swapendian(e_type);
- e_machine:=swapendian(e_machine);
- e_version:=swapendian(e_version);
- e_entry:=swapendian(e_entry);
- e_phoff:=swapendian(e_phoff);
- e_shoff:=swapendian(e_shoff);
- e_flags:=swapendian(e_flags);
- e_ehsize:=swapendian(e_ehsize);
- e_phentsize:=swapendian(e_phentsize);
- e_phnum:=swapendian(e_phnum);
- e_shentsize:=swapendian(e_shentsize);
- e_shnum:=swapendian(e_shnum);
- e_shstrndx:=swapendian(e_shstrndx);
- end;
- end;
- procedure MayBeSwapHeader(var h : telf32proghdr);
- begin
- if source_info.endian<>target_info.endian then
- with h do
- begin
- p_align:=swapendian(p_align);
- p_filesz:=swapendian(p_filesz);
- p_flags:=swapendian(p_flags);
- p_memsz:=swapendian(p_memsz);
- p_offset:=swapendian(p_offset);
- p_paddr:=swapendian(p_paddr);
- p_type:=swapendian(p_type);
- p_vaddr:=swapendian(p_vaddr);
- end;
- end;
- procedure MayBeSwapHeader(var h : telf64proghdr);
- begin
- if source_info.endian<>target_info.endian then
- with h do
- begin
- p_align:=swapendian(p_align);
- p_filesz:=swapendian(p_filesz);
- p_flags:=swapendian(p_flags);
- p_memsz:=swapendian(p_memsz);
- p_offset:=swapendian(p_offset);
- p_paddr:=swapendian(p_paddr);
- p_type:=swapendian(p_type);
- p_vaddr:=swapendian(p_vaddr);
- end;
- end;
- procedure MaybeSwapSecHeader(var h : telf32sechdr);
- begin
- if source_info.endian<>target_info.endian then
- with h do
- begin
- sh_name:=swapendian(sh_name);
- sh_type:=swapendian(sh_type);
- sh_flags:=swapendian(sh_flags);
- sh_addr:=swapendian(sh_addr);
- sh_offset:=swapendian(sh_offset);
- sh_size:=swapendian(sh_size);
- sh_link:=swapendian(sh_link);
- sh_info:=swapendian(sh_info);
- sh_addralign:=swapendian(sh_addralign);
- sh_entsize:=swapendian(sh_entsize);
- end;
- end;
- procedure MaybeSwapSecHeader(var h : telf64sechdr);
- begin
- if source_info.endian<>target_info.endian then
- with h do
- begin
- sh_name:=swapendian(sh_name);
- sh_type:=swapendian(sh_type);
- sh_flags:=swapendian(sh_flags);
- sh_addr:=swapendian(sh_addr);
- sh_offset:=swapendian(sh_offset);
- sh_size:=swapendian(sh_size);
- sh_link:=swapendian(sh_link);
- sh_info:=swapendian(sh_info);
- sh_addralign:=swapendian(sh_addralign);
- sh_entsize:=swapendian(sh_entsize);
- end;
- end;
- procedure MaybeSwapElfSymbol(var h : telf32symbol);
- begin
- if source_info.endian<>target_info.endian then
- with h do
- begin
- st_name:=swapendian(st_name);
- st_value:=swapendian(st_value);
- st_size:=swapendian(st_size);
- st_shndx:=swapendian(st_shndx);
- end;
- end;
- procedure MaybeSwapElfSymbol(var h : telf64symbol);
- begin
- if source_info.endian<>target_info.endian then
- with h do
- begin
- st_name:=swapendian(st_name);
- st_value:=swapendian(st_value);
- st_size:=swapendian(st_size);
- st_shndx:=swapendian(st_shndx);
- end;
- end;
- procedure MaybeSwapElfReloc(var h : telf32reloc);
- begin
- if source_info.endian<>target_info.endian then
- with h do
- begin
- address:=swapendian(address);
- info:=swapendian(info);
- addend:=swapendian(addend);
- end;
- end;
- procedure MaybeSwapElfReloc(var h : telf64reloc);
- begin
- if source_info.endian<>target_info.endian then
- with h do
- begin
- address:=swapendian(address);
- info:=swapendian(info);
- addend:=swapendian(addend);
- end;
- end;
- procedure MaybeSwapElfDyn(var h : telf32dyn);
- begin
- if source_info.endian<>target_info.endian then
- with h do
- begin
- d_tag:=swapendian(d_tag);
- d_val:=swapendian(d_val);
- end;
- end;
- procedure MaybeSwapElfDyn(var h : telf64dyn);
- begin
- if source_info.endian<>target_info.endian then
- with h do
- begin
- d_tag:=swapendian(d_tag);
- d_val:=swapendian(d_val);
- end;
- end;
- {****************************************************************************
- Helpers
- ****************************************************************************}
- procedure encodesechdrflags(aoptions:TObjSectionOptions;out AshType:longint;out Ashflags:longint);
- begin
- { Section Type }
- AshType:=SHT_PROGBITS;
- if oso_strings in aoptions then
- AshType:=SHT_STRTAB
- else if not(oso_data in aoptions) then
- AshType:=SHT_NOBITS;
- { Section Flags }
- Ashflags:=0;
- if oso_load in aoptions then
- Ashflags:=Ashflags or SHF_ALLOC;
- if oso_executable in aoptions then
- Ashflags:=Ashflags or SHF_EXECINSTR;
- if oso_write in aoptions then
- Ashflags:=Ashflags or SHF_WRITE;
- end;
- procedure decodesechdrflags(AshType:longint;Ashflags:longint;out aoptions:TObjSectionOptions);
- begin
- aoptions:=[];
- { Section Type }
- if AshType<>SHT_NOBITS then
- include(aoptions,oso_data);
- if AshType=SHT_STRTAB then
- include(aoptions,oso_strings);
- { Section Flags }
- if Ashflags and SHF_ALLOC<>0 then
- include(aoptions,oso_load);
- if Ashflags and SHF_WRITE<>0 then
- include(aoptions,oso_write);
- if Ashflags and SHF_EXECINSTR<>0 then
- include(aoptions,oso_executable);
- end;
- {****************************************************************************
- TElfObjSection
- ****************************************************************************}
- constructor TElfObjSection.create(AList:TFPHashObjectList;const Aname:string;Aalign:shortint;Aoptions:TObjSectionOptions);
- begin
- inherited create(AList,Aname,Aalign,aoptions);
- index:=0;
- shstridx:=0;
- encodesechdrflags(aoptions,shtype,shflags);
- shlink:=0;
- shinfo:=0;
- if name='.stab' then
- shentsize:=sizeof(TObjStabEntry);
- end;
- constructor TElfObjSection.create_ext(aobjdata:TObjData;const Aname:string;Ashtype,Ashflags:longint;Aalign:shortint;Aentsize:longint);
- var
- aoptions : TObjSectionOptions;
- begin
- decodesechdrflags(Ashtype,Ashflags,aoptions);
- inherited create(aobjdata.ObjSectionList,Aname,Aalign,aoptions);
- objdata:=aobjdata;
- index:=0;
- shstridx:=0;
- shtype:=AshType;
- shflags:=AshFlags;
- shentsize:=Aentsize;
- end;
- const
- relsec_prefix:array[boolean] of string[5] = ('.rel','.rela');
- relsec_shtype:array[boolean] of longword = (SHT_REL,SHT_RELA);
- constructor TElfObjSection.create_reloc(aobjdata:TObjData;const Aname:string;allocflag:boolean);
- begin
- create_ext(aobjdata,
- relsec_prefix[relocs_use_addend]+aname,
- relsec_shtype[relocs_use_addend],
- SHF_ALLOC*ord(allocflag),
- sizeof(pint),
- (2+ord(relocs_use_addend))*sizeof(pint));
- end;
- procedure TElfObjSection.writeReloc_internal(aTarget:TObjSection;offset:aword;len:byte;reltype:TObjRelocationType);
- var
- reloc: TObjRelocation;
- begin
- reloc:=TObjRelocation.CreateSection(Size,aTarget,reltype);
- reloc.size:=len;
- ObjRelocations.Add(reloc);
- if reltype=RELOC_RELATIVE then
- dec(offset,len)
- else if reltype<>RELOC_ABSOLUTE then
- InternalError(2012062401);
- if relocs_use_addend then
- begin
- reloc.orgsize:=offset;
- offset:=0;
- end;
- write(offset,len);
- end;
- {****************************************************************************
- TElfObjData
- ****************************************************************************}
- constructor TElfObjData.create(const n:string);
- begin
- inherited create(n);
- CObjSection:=TElfObjSection;
- end;
- function TElfObjData.sectionname(atype:TAsmSectiontype;const aname:string;aorder:TAsmSectionOrder):string;
- const
- secnames : array[TAsmSectiontype] of string[length('__DATA, __datacoal_nt,coalesced')] = ('','',
- {$ifdef userodata}
- '.text','.data','.data','.rodata','.bss','.threadvar',
- {$else userodata}
- '.text','.data','.data','.data','.bss','.threadvar',
- {$endif userodata}
- '.pdata',
- '.text', { darwin stubs }
- '__DATA,__nl_symbol_ptr',
- '__DATA,__la_symbol_ptr',
- '__DATA,__mod_init_func',
- '__DATA,__mod_term_func',
- '.stab','.stabstr',
- '.idata$2','.idata$4','.idata$5','.idata$6','.idata$7','.edata',
- '.eh_frame',
- '.debug_frame','.debug_info','.debug_line','.debug_abbrev',
- '.fpc',
- '.toc',
- '.init',
- '.fini',
- '.objc_class',
- '.objc_meta_class',
- '.objc_cat_cls_meth',
- '.objc_cat_inst_meth',
- '.objc_protocol',
- '.objc_string_object',
- '.objc_cls_meth',
- '.objc_inst_meth',
- '.objc_cls_refs',
- '.objc_message_refs',
- '.objc_symbols',
- '.objc_category',
- '.objc_class_vars',
- '.objc_instance_vars',
- '.objc_module_info',
- '.objc_class_names',
- '.objc_meth_var_types',
- '.objc_meth_var_names',
- '.objc_selector_strs',
- '.objc_protocol_ext',
- '.objc_class_ext',
- '.objc_property',
- '.objc_image_info',
- '.objc_cstring_object',
- '.objc_sel_fixup',
- '__DATA,__objc_data',
- '__DATA,__objc_const',
- '.objc_superrefs',
- '__DATA, __datacoal_nt,coalesced',
- '.objc_classlist',
- '.objc_nlclasslist',
- '.objc_catlist',
- '.obcj_nlcatlist',
- '.objc_protolist'
- );
- secnames_pic : array[TAsmSectiontype] of string[length('__DATA, __datacoal_nt,coalesced')] = ('','',
- '.text',
- '.data.rel',
- '.data.rel',
- '.data.rel',
- '.bss',
- '.threadvar',
- '.pdata',
- '', { stubs }
- '__DATA,__nl_symbol_ptr',
- '__DATA,__la_symbol_ptr',
- '__DATA,__mod_init_func',
- '__DATA,__mod_term_func',
- '.stab',
- '.stabstr',
- '.idata$2','.idata$4','.idata$5','.idata$6','.idata$7','.edata',
- '.eh_frame',
- '.debug_frame','.debug_info','.debug_line','.debug_abbrev',
- '.fpc',
- '.toc',
- '.init',
- '.fini',
- '.objc_class',
- '.objc_meta_class',
- '.objc_cat_cls_meth',
- '.objc_cat_inst_meth',
- '.objc_protocol',
- '.objc_string_object',
- '.objc_cls_meth',
- '.objc_inst_meth',
- '.objc_cls_refs',
- '.objc_message_refs',
- '.objc_symbols',
- '.objc_category',
- '.objc_class_vars',
- '.objc_instance_vars',
- '.objc_module_info',
- '.objc_class_names',
- '.objc_meth_var_types',
- '.objc_meth_var_names',
- '.objc_selector_strs',
- '.objc_protocol_ext',
- '.objc_class_ext',
- '.objc_property',
- '.objc_image_info',
- '.objc_cstring_object',
- '.objc_sel_fixup',
- '__DATA,__objc_data',
- '__DATA,__objc_const',
- '.objc_superrefs',
- '__DATA, __datacoal_nt,coalesced',
- '.objc_classlist',
- '.objc_nlclasslist',
- '.objc_catlist',
- '.obcj_nlcatlist',
- '.objc_protolist'
- );
- var
- sep : string[3];
- secname : string;
- begin
- { section type user gives the user full controll on the section name }
- if atype=sec_user then
- result:=aname
- else
- begin
- if (cs_create_pic in current_settings.moduleswitches) and
- not(target_info.system in systems_darwin) then
- secname:=secnames_pic[atype]
- else
- secname:=secnames[atype];
- if (atype=sec_fpc) and (Copy(aname,1,3)='res') then
- begin
- result:=secname+'.'+aname;
- exit;
- end;
- if create_smartlink_sections and (aname<>'') then
- begin
- case aorder of
- secorder_begin :
- sep:='.b_';
- secorder_end :
- sep:='.z_';
- else
- sep:='.n_';
- end;
- result:=secname+sep+aname
- end
- else
- result:=secname;
- end;
- end;
- procedure TElfObjData.CreateDebugSections;
- begin
- if target_dbg.id=dbg_stabs then
- begin
- stabssec:=createsection(sec_stab);
- stabstrsec:=createsection(sec_stabstr);
- end;
- end;
- procedure TElfObjData.writereloc(data:aint;len:aword;p:TObjSymbol;reltype:TObjRelocationType);
- var
- symaddr : aint;
- objreloc: TObjRelocation;
- begin
- if CurrObjSec=nil then
- internalerror(200403292);
- objreloc:=nil;
- if assigned(p) then
- begin
- { real address of the symbol }
- symaddr:=p.address;
- { Local ObjSymbols can be resolved already or need a section reloc }
- if (p.bind=AB_LOCAL) and
- (reltype in [RELOC_RELATIVE,RELOC_ABSOLUTE{$ifdef x86_64},RELOC_ABSOLUTE32{$endif x86_64}]) then
- begin
- { For a reltype relocation in the same section the
- value can be calculated }
- if (p.objsection=CurrObjSec) and
- (reltype=RELOC_RELATIVE) then
- inc(data,symaddr-len-CurrObjSec.Size)
- else
- begin
- objreloc:=TObjRelocation.CreateSection(CurrObjSec.Size,p.objsection,reltype);
- CurrObjSec.ObjRelocations.Add(objreloc);
- inc(data,symaddr);
- end;
- end
- else
- begin
- objreloc:=TObjRelocation.CreateSymbol(CurrObjSec.Size,p,reltype);
- CurrObjSec.ObjRelocations.Add(objreloc);
- { If target is a local label and it isn't handled above,
- patch its type in order to get it written to symtable.
- This may happen e.g. when taking address of Pascal label in PIC mode. }
- if (p.bind=AB_LOCAL) and (p.typ=AT_LABEL) then
- p.typ:=AT_ADDR;
- end;
- end;
- if assigned(objreloc) then
- begin
- objreloc.size:=len;
- if reltype in [RELOC_RELATIVE{$ifdef x86},RELOC_PLT32{$endif}{$ifdef x86_64},RELOC_GOTPCREL{$endif}] then
- dec(data,len);
- if relocs_use_addend then
- begin
- objreloc.orgsize:=data;
- data:=0;
- end;
- end;
- CurrObjSec.write(data,len);
- end;
- {****************************************************************************
- TElfSymtab
- ****************************************************************************}
- const
- symsecnames: array[boolean] of string[8] = ('.symtab','.dynsym');
- strsecnames: array[boolean] of string[8] = ('.strtab','.dynstr');
- symsectypes: array[boolean] of longint = (SHT_SYMTAB,SHT_DYNSYM);
- symsecattrs: array[boolean] of longint = (0,SHF_ALLOC);
- constructor TElfSymtab.create(aObjData:TObjData;aKind:TElfSymtabKind);
- var
- dyn:boolean;
- begin
- dyn:=(aKind=esk_dyn);
- create_ext(aObjData,symsecnames[dyn],symsectypes[dyn],symsecattrs[dyn],sizeof(pint),sizeof(TElfSymbol));
- fstrsec:=TElfObjSection.create_ext(aObjData,strsecnames[dyn],SHT_STRTAB,symsecattrs[dyn],1,0);
- fstrsec.writezeros(1);
- writezeros(sizeof(TElfSymbol));
- symidx:=1;
- shinfo:=1;
- kind:=aKind;
- end;
- procedure TElfSymtab.writeInternalSymbol(avalue:aword;astridx:longword;ainfo:byte;ashndx:word);
- var
- elfsym:TElfSymbol;
- begin
- fillchar(elfsym,sizeof(elfsym),0);
- elfsym.st_value:=avalue;
- elfsym.st_name:=astridx;
- elfsym.st_info:=ainfo;
- elfsym.st_shndx:=ashndx;
- inc(symidx);
- inc(shinfo);
- MaybeSwapElfSymbol(elfsym);
- write(elfsym,sizeof(elfsym));
- end;
- procedure TElfSymtab.writeSymbol(objsym:TObjSymbol;nameidx:longword);
- var
- elfsym:TElfSymbol;
- begin
- fillchar(elfsym,sizeof(elfsym),0);
- if nameidx=0 then
- elfsym.st_name:=fstrsec.writestr(objsym.name)
- else
- elfsym.st_name:=nameidx;
- elfsym.st_size:=objsym.size;
- case objsym.bind of
- AB_LOCAL :
- begin
- elfsym.st_value:=objsym.address;
- elfsym.st_info:=STB_LOCAL shl 4;
- inc(shinfo);
- end;
- AB_COMMON :
- begin
- elfsym.st_value:=var_align(objsym.size);
- elfsym.st_info:=STB_GLOBAL shl 4;
- elfsym.st_shndx:=SHN_COMMON;
- end;
- AB_EXTERNAL :
- elfsym.st_info:=STB_GLOBAL shl 4;
- AB_WEAK_EXTERNAL :
- begin
- elfsym.st_info:=STB_WEAK shl 4;
- elfsym.st_value:=objsym.address;
- end;
- AB_GLOBAL :
- begin
- elfsym.st_value:=objsym.address;
- elfsym.st_info:=STB_GLOBAL shl 4;
- end;
- end;
- if (objsym.bind<>AB_EXTERNAL) {and
- not(assigned(objsym.objsection) and
- not(oso_data in objsym.objsection.secoptions))} then
- begin
- case objsym.typ of
- AT_FUNCTION :
- elfsym.st_info:=elfsym.st_info or STT_FUNC;
- AT_DATA :
- elfsym.st_info:=elfsym.st_info or STT_OBJECT;
- AT_TLS:
- elfsym.st_info:=elfsym.st_info or STT_TLS;
- AT_GNU_IFUNC:
- elfsym.st_info:=elfsym.st_info or STT_GNU_IFUNC;
- end;
- end;
- if objsym.bind<>AB_COMMON then
- begin
- if kind<>esk_obj then
- begin
- { TODO }
- end
- else
- begin
- if assigned(objsym.objsection) then
- elfsym.st_shndx:=objsym.objsection.index
- else
- elfsym.st_shndx:=SHN_UNDEF;
- objsym.symidx:=symidx;
- end;
- end;
- inc(symidx);
- MaybeSwapElfSymbol(elfsym);
- write(elfsym,sizeof(TElfSymbol));
- end;
- {****************************************************************************
- TElfObjectOutput
- ****************************************************************************}
- constructor TElfObjectOutput.create(AWriter:TObjectWriter);
- begin
- inherited Create(AWriter);
- CObjData:=TElfObjData;
- end;
- procedure TElfObjectOutput.createrelocsection(s:TElfObjSection;data:TObjData);
- var
- i : longint;
- rel : telfreloc;
- objreloc : TObjRelocation;
- relsym : longint;
- relocsect : TElfObjSection;
- begin
- { create the reloc section }
- relocsect:=TElfObjSection.create_reloc(data,s.name,false);
- relocsect.shlink:=symtabsect.index;
- relocsect.shinfo:=s.index;
- { add the relocations }
- for i:=0 to s.Objrelocations.count-1 do
- begin
- objreloc:=TObjRelocation(s.Objrelocations[i]);
- { Symbol }
- if assigned(objreloc.symbol) then
- begin
- if objreloc.symbol.symidx=-1 then
- begin
- writeln(objreloc.symbol.Name);
- internalerror(200603012);
- end;
- relsym:=objreloc.symbol.symidx;
- end
- else
- begin
- if objreloc.objsection<>nil then
- relsym:=objreloc.objsection.secsymidx
- else
- relsym:=SHN_UNDEF;
- end;
- rel.address:=objreloc.dataoffset;
- rel.info:=ELF_R_INFO(relsym,encodereloc(objreloc));
- rel.addend:=objreloc.orgsize;
- { write reloc }
- { ElfXX_Rel is essentially ElfXX_Rela without the addend field. }
- MaybeSwapElfReloc(rel);
- relocsect.write(rel,relocsect.shentsize);
- end;
- end;
- procedure TElfObjectOutput.section_write_symbol(p:TObject;arg:pointer);
- begin
- { Must not write symbols for internal sections like .symtab }
- { TODO: maybe use inclusive list of section types instead }
- if (TElfObjSection(p).shtype in [SHT_SYMTAB,SHT_STRTAB,SHT_REL,SHT_RELA]) then
- exit;
- TObjSection(p).secsymidx:=symtabsect.symidx;
- symtabsect.writeInternalSymbol(0,0,STT_SECTION,TObjSection(p).index);
- end;
- procedure TElfObjectOutput.createsymtab(data: TObjData);
- var
- i : longint;
- objsym : TObjSymbol;
- begin
- with data do
- begin
- { filename entry }
- symtabsect.writeInternalSymbol(0,1,STT_FILE,SHN_ABS);
- { section }
- ObjSectionList.ForEachCall(@section_write_symbol,nil);
- { First the Local Symbols, this is required by ELF. The localsyms
- count stored in shinfo is used to skip the local symbols
- when traversing the symtab }
- for i:=0 to ObjSymbolList.Count-1 do
- begin
- objsym:=TObjSymbol(ObjSymbolList[i]);
- if (objsym.bind=AB_LOCAL) and (objsym.typ<>AT_LABEL) then
- symtabsect.WriteSymbol(objsym);
- end;
- { Global Symbols }
- for i:=0 to ObjSymbolList.Count-1 do
- begin
- objsym:=TObjSymbol(ObjSymbolList[i]);
- if (objsym.bind<>AB_LOCAL) then
- symtabsect.WriteSymbol(objsym);
- end;
- { update the .symtab section header }
- symtabsect.shlink:=symtabsect.fstrsec.index;
- end;
- end;
- procedure TElfObjectOutput.createshstrtab(data: TObjData);
- var
- i,prefixlen:longint;
- objsec,target:TElfObjSection;
- begin
- shstrtabsect.writezeros(1);
- prefixlen:=length('.rel')+ord(relocs_use_addend);
- for i:=0 to data.ObjSectionList.Count-1 do
- begin
- objsec:=TElfObjSection(data.ObjSectionList[i]);
- { Alias section names into names of corresponding reloc sections,
- this is allowed by ELF specs and saves good half of .shstrtab space. }
- if objsec.shtype=relsec_shtype[relocs_use_addend] then
- begin
- target:=TElfObjSection(data.ObjSectionList[objsec.shinfo-1]);
- if (target.ObjRelocations.Count=0) or
- (target.shstridx<prefixlen) then
- InternalError(2012101204);
- objsec.shstridx:=target.shstridx-prefixlen;
- end
- else
- begin
- if objsec.ObjRelocations.Count<>0 then
- shstrtabsect.write(relsec_prefix[true][1],prefixlen);
- objsec.shstridx:=shstrtabsect.writestr(objsec.name);
- end;
- end;
- end;
- procedure TElfObjectOutput.writesectionheader(s:TElfObjSection);
- var
- sechdr : telfsechdr;
- begin
- fillchar(sechdr,sizeof(sechdr),0);
- sechdr.sh_name:=s.shstridx;
- sechdr.sh_type:=s.shtype;
- sechdr.sh_flags:=s.shflags;
- sechdr.sh_offset:=s.datapos;
- sechdr.sh_size:=s.Size;
- sechdr.sh_link:=s.shlink;
- sechdr.sh_info:=s.shinfo;
- sechdr.sh_addralign:=s.secalign;
- sechdr.sh_entsize:=s.shentsize;
- MaybeSwapSecHeader(sechdr);
- writer.write(sechdr,sizeof(sechdr));
- end;
- procedure TElfObjectOutput.section_count_sections(p:TObject;arg:pointer);
- begin
- TElfObjSection(p).index:=pword(arg)^;
- inc(pword(arg)^);
- end;
- procedure TElfObjectOutput.section_create_relocsec(p:TObject;arg:pointer);
- begin
- if (TElfObjSection(p).ObjRelocations.count>0) then
- createrelocsection(TElfObjSection(p),TObjData(arg));
- end;
- procedure TElfObjectOutput.section_write_sechdr(p:TObject;arg:pointer);
- begin
- writesectionheader(TElfObjSection(p));
- end;
- function TElfObjectOutput.writedata(data:TObjData):boolean;
- var
- header : telfheader;
- shoffset,
- datapos : aword;
- nsections : word;
- begin
- result:=false;
- with data do
- begin
- { default sections }
- symtabsect:=TElfSymtab.create(data,esk_obj);
- shstrtabsect:=TElfObjSection.create_ext(data,'.shstrtab',SHT_STRTAB,0,1,0);
- { "no executable stack" marker for Linux }
- if (target_info.system in systems_linux) and
- not(cs_executable_stack in current_settings.moduleswitches) then
- TElfObjSection.create_ext(data,'.note.GNU-stack',SHT_PROGBITS,0,1,0);
- { insert filename as first in strtab }
- symtabsect.fstrsec.writestr(ExtractFileName(current_module.mainsource));
- { calc amount of sections we have }
- nsections:=1;
- { also create the index in the section header table }
- ObjSectionList.ForEachCall(@section_count_sections,@nsections);
- { create .symtab and .strtab }
- createsymtab(data);
- { Create the relocation sections, this needs valid secidx and symidx }
- ObjSectionList.ForEachCall(@section_create_relocsec,data);
- { recalc nsections to incude the reloc sections }
- nsections:=1;
- ObjSectionList.ForEachCall(@section_count_sections,@nsections);
- { create .shstrtab }
- createshstrtab(data);
- { Calculate the filepositions }
- datapos:=$40; { elfheader + alignment }
- { section data }
- layoutsections(datapos);
- { section headers }
- shoffset:=datapos;
- inc(datapos,(nsections+1)*sizeof(telfsechdr));
- { Write ELF Header }
- fillchar(header,sizeof(header),0);
- header.magic[0]:=$7f; { = #127'ELF' }
- header.magic[1]:=$45;
- header.magic[2]:=$4c;
- header.magic[3]:=$46;
- header.file_class:=ELFCLASS;
- if target_info.endian=endian_big then
- header.data_encoding:=2
- else
- header.data_encoding:=1;
- header.file_version:=1;
- header.e_type:=ET_REL;
- header.e_machine:=ELFMACHINE;
- {$ifdef arm}
- if (current_settings.fputype=fpu_soft) then
- header.e_flags:=$600;
- {$endif arm}
- header.e_version:=1;
- header.e_shoff:=shoffset;
- header.e_shstrndx:=shstrtabsect.index;
- header.e_shnum:=nsections;
- header.e_ehsize:=sizeof(telfheader);
- header.e_shentsize:=sizeof(telfsechdr);
- MaybeSwapHeader(header);
- writer.write(header,sizeof(header));
- writer.writezeros($40-sizeof(header)); { align }
- { Sections }
- WriteSectionContent(data);
- { section headers, start with an empty header for sh_undef }
- writer.writezeros(sizeof(telfsechdr));
- ObjSectionList.ForEachCall(@section_write_sechdr,nil);
- end;
- result:=true;
- end;
- end.
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