/*
* Copyright (C) 2012 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef ART_COMPILER_ELF_WRITER_QUICK_H_
#define ART_COMPILER_ELF_WRITER_QUICK_H_
#include "elf_utils.h"
#include "elf_writer.h"
#include "instruction_set.h"
namespace art {
class ElfWriterQuick FINAL : public ElfWriter {
public:
// Write an ELF file. Returns true on success, false on failure.
static bool Create(File* file,
OatWriter* oat_writer,
const std::vector<const DexFile*>& dex_files,
const std::string& android_root,
bool is_host,
const CompilerDriver& driver)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
protected:
bool Write(OatWriter* oat_writer,
const std::vector<const DexFile*>& dex_files,
const std::string& android_root,
bool is_host)
OVERRIDE
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
private:
ElfWriterQuick(const CompilerDriver& driver, File* elf_file)
: ElfWriter(driver, elf_file) {}
~ElfWriterQuick() {}
class ElfBuilder;
void AddDebugSymbols(ElfBuilder& builder,
OatWriter* oat_writer,
bool debug);
void ReservePatchSpace(std::vector<uint8_t>* buffer, bool debug);
class ElfSectionBuilder {
public:
ElfSectionBuilder(const std::string& sec_name, Elf32_Word type, Elf32_Word flags,
const ElfSectionBuilder *link, Elf32_Word info, Elf32_Word align,
Elf32_Word entsize)
: name_(sec_name), link_(link) {
memset(§ion_, 0, sizeof(section_));
section_.sh_type = type;
section_.sh_flags = flags;
section_.sh_info = info;
section_.sh_addralign = align;
section_.sh_entsize = entsize;
}
virtual ~ElfSectionBuilder() {}
Elf32_Shdr section_;
Elf32_Word section_index_ = 0;
protected:
const std::string name_;
const ElfSectionBuilder* link_;
Elf32_Word GetLink() {
return (link_) ? link_->section_index_ : 0;
}
private:
friend class ElfBuilder;
};
class ElfDynamicBuilder : public ElfSectionBuilder {
public:
void AddDynamicTag(Elf32_Sword tag, Elf32_Word d_un);
void AddDynamicTag(Elf32_Sword tag, Elf32_Word offset, ElfSectionBuilder* section);
ElfDynamicBuilder(const std::string& sec_name, ElfSectionBuilder *link)
: ElfSectionBuilder(sec_name, SHT_DYNAMIC, SHF_ALLOC | SHF_ALLOC, link,
0, kPageSize, sizeof(Elf32_Dyn)) {}
~ElfDynamicBuilder() {}
protected:
struct ElfDynamicState {
ElfSectionBuilder* section_;
Elf32_Sword tag_;
Elf32_Word off_;
};
std::vector<ElfDynamicState> dynamics_;
Elf32_Word GetSize() {
// Add 1 for the DT_NULL, 1 for DT_STRSZ, and 1 for DT_SONAME. All of
// these must be added when we actually put the file together because
// their values are very dependent on state.
return dynamics_.size() + 3;
}
// Create the actual dynamic vector. strsz should be the size of the .dynstr
// table and soname_off should be the offset of the soname in .dynstr.
// Since niether can be found prior to final layout we will wait until here
// to add them.
std::vector<Elf32_Dyn> GetDynamics(Elf32_Word strsz, Elf32_Word soname_off);
private:
friend class ElfBuilder;
};
class ElfRawSectionBuilder : public ElfSectionBuilder {
public:
ElfRawSectionBuilder(const std::string& sec_name, Elf32_Word type, Elf32_Word flags,
const ElfSectionBuilder* link, Elf32_Word info, Elf32_Word align,
Elf32_Word entsize)
: ElfSectionBuilder(sec_name, type, flags, link, info, align, entsize) {}
~ElfRawSectionBuilder() {}
std::vector<uint8_t>* GetBuffer() { return &buf_; }
void SetBuffer(std::vector<uint8_t> buf) { buf_ = buf; }
protected:
std::vector<uint8_t> buf_;
private:
friend class ElfBuilder;
};
class ElfOatSectionBuilder : public ElfSectionBuilder {
public:
ElfOatSectionBuilder(const std::string& sec_name, Elf32_Word size, Elf32_Word offset,
Elf32_Word type, Elf32_Word flags)
: ElfSectionBuilder(sec_name, type, flags, NULL, 0, kPageSize, 0),
offset_(offset), size_(size) {}
~ElfOatSectionBuilder() {}
protected:
// Offset of the content within the file.
Elf32_Word offset_;
// Size of the content within the file.
Elf32_Word size_;
private:
friend class ElfBuilder;
};
class ElfSymtabBuilder : public ElfSectionBuilder {
public:
// Add a symbol with given name to this symtab. The symbol refers to
// 'relative_addr' within the given section and has the given attributes.
void AddSymbol(const std::string& name,
const ElfSectionBuilder* section,
Elf32_Addr addr,
bool is_relative,
Elf32_Word size,
uint8_t binding,
uint8_t type,
uint8_t other = 0);
ElfSymtabBuilder(const std::string& sec_name, Elf32_Word type,
const std::string& str_name, Elf32_Word str_type, bool alloc)
: ElfSectionBuilder(sec_name, type, ((alloc) ? SHF_ALLOC : 0U), &strtab_, 0,
sizeof(Elf32_Word), sizeof(Elf32_Sym)),
str_name_(str_name), str_type_(str_type),
strtab_(str_name, str_type, ((alloc) ? SHF_ALLOC : 0U), NULL, 0, 1, 1) {}
~ElfSymtabBuilder() {}
protected:
std::vector<Elf32_Word> GenerateHashContents();
std::string GenerateStrtab();
std::vector<Elf32_Sym> GenerateSymtab();
Elf32_Word GetSize() {
// 1 is for the implicit NULL symbol.
return symbols_.size() + 1;
}
struct ElfSymbolState {
const std::string name_;
const ElfSectionBuilder* section_;
Elf32_Addr addr_;
Elf32_Word size_;
bool is_relative_;
uint8_t info_;
uint8_t other_;
// Used during Write() to temporarially hold name index in the strtab.
Elf32_Word name_idx_;
};
// Information for the strsym for dynstr sections.
const std::string str_name_;
Elf32_Word str_type_;
// The symbols in the same order they will be in the symbol table.
std::vector<ElfSymbolState> symbols_;
ElfSectionBuilder strtab_;
private:
friend class ElfBuilder;
};
class ElfBuilder FINAL {
public:
ElfBuilder(OatWriter* oat_writer,
File* elf_file,
InstructionSet isa,
Elf32_Word rodata_relative_offset,
Elf32_Word rodata_size,
Elf32_Word text_relative_offset,
Elf32_Word text_size,
const bool add_symbols,
bool debug = false)
: oat_writer_(oat_writer),
elf_file_(elf_file),
add_symbols_(add_symbols),
debug_logging_(debug),
text_builder_(".text", text_size, text_relative_offset, SHT_PROGBITS,
SHF_ALLOC | SHF_EXECINSTR),
rodata_builder_(".rodata", rodata_size, rodata_relative_offset,
SHT_PROGBITS, SHF_ALLOC),
dynsym_builder_(".dynsym", SHT_DYNSYM, ".dynstr", SHT_STRTAB, true),
symtab_builder_(".symtab", SHT_SYMTAB, ".strtab", SHT_STRTAB, false),
hash_builder_(".hash", SHT_HASH, SHF_ALLOC, &dynsym_builder_, 0,
sizeof(Elf32_Word), sizeof(Elf32_Word)),
dynamic_builder_(".dynamic", &dynsym_builder_),
shstrtab_builder_(".shstrtab", SHT_STRTAB, 0, NULL, 0, 1, 1) {
SetupEhdr();
SetupDynamic();
SetupRequiredSymbols();
SetISA(isa);
}
~ElfBuilder() {}
bool Write();
// Adds the given raw section to the builder. This will copy it. The caller
// is responsible for deallocating their copy.
void RegisterRawSection(ElfRawSectionBuilder bld) {
other_builders_.push_back(bld);
}
private:
OatWriter* oat_writer_;
File* elf_file_;
const bool add_symbols_;
const bool debug_logging_;
bool fatal_error_ = false;
Elf32_Ehdr elf_header_;
public:
ElfOatSectionBuilder text_builder_;
ElfOatSectionBuilder rodata_builder_;
ElfSymtabBuilder dynsym_builder_;
ElfSymtabBuilder symtab_builder_;
ElfSectionBuilder hash_builder_;
ElfDynamicBuilder dynamic_builder_;
ElfSectionBuilder shstrtab_builder_;
std::vector<ElfRawSectionBuilder> other_builders_;
private:
void SetISA(InstructionSet isa);
void SetupEhdr();
// Sets up a bunch of the required Dynamic Section entries.
// Namely it will initialize all the mandatory ones that it can.
// Specifically:
// DT_HASH
// DT_STRTAB
// DT_SYMTAB
// DT_SYMENT
//
// Some such as DT_SONAME, DT_STRSZ and DT_NULL will be put in later.
void SetupDynamic();
// Sets up the basic dynamic symbols that are needed, namely all those we
// can know already.
//
// Specifically adds:
// oatdata
// oatexec
// oatlastword
void SetupRequiredSymbols();
void AssignSectionStr(ElfSectionBuilder *builder, std::string* strtab);
bool IncludingDebugSymbols() { return add_symbols_ && symtab_builder_.GetSize() > 1; }
};
/*
* @brief Generate the DWARF debug_info and debug_abbrev sections
* @param oat_writer The Oat file Writer.
* @param dbg_info Compilation unit information.
* @param dbg_abbrev Abbreviations used to generate dbg_info.
* @param dbg_str Debug strings.
*/
void FillInCFIInformation(OatWriter* oat_writer, std::vector<uint8_t>* dbg_info,
std::vector<uint8_t>* dbg_abbrev, std::vector<uint8_t>* dbg_str);
DISALLOW_IMPLICIT_CONSTRUCTORS(ElfWriterQuick);
};
} // namespace art
#endif // ART_COMPILER_ELF_WRITER_QUICK_H_