Index: runtime/vm/elfgen.h |
diff --git a/runtime/vm/elfgen.h b/runtime/vm/elfgen.h |
deleted file mode 100644 |
index f3fcd70cdc20c4cac15714089dff8bc256de7600..0000000000000000000000000000000000000000 |
--- a/runtime/vm/elfgen.h |
+++ /dev/null |
@@ -1,509 +0,0 @@ |
-// Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file |
-// for details. All rights reserved. Use of this source code is governed by a |
-// BSD-style license that can be found in the LICENSE file. |
- |
-#ifndef VM_ELFGEN_H_ |
-#define VM_ELFGEN_H_ |
- |
-#include "vm/lockers.h" |
-#include "vm/os_thread.h" |
- |
-namespace dart { |
- |
-// ----------------------------------------------------------------------------- |
-// Implementation of ElfGen |
-// |
-// Specification documents: |
-// http://refspecs.freestandards.org |
-// |
-// ELF generic ABI: |
-// http://refspecs.freestandards.org/elf/gabi4+/contents.html |
-// ELF processor-specific supplement for X86_64: |
-// http://refspecs.freestandards.org/elf/x86_64-SysV-psABI.pdf |
-// DWARF 2.0: |
-// http://refspecs.freestandards.org/dwarf/dwarf-2.0.0.pdf |
- |
-// Forward declarations. |
-class File; |
- |
-// ElfGen is used to generate minimal ELF information containing code, symbols, |
-// and line numbers for generated code in the dart VM. This information is |
-// used in two ways: |
-// - it is used to generate in-memory ELF information which is then |
-// registered with gdb using the JIT interface. |
-// - it is also used to generate a file with the ELF information. This file |
-// is not executed, but read by pprof to analyze Dart programs. |
- |
-class ElfGen { |
- public: |
- ElfGen(); |
- ~ElfGen(); |
- |
- // Add the code starting at pc. |
- void AddCode(uword pc, intptr_t size); |
- |
- // Add symbol information for a region (includes the start and end symbol), |
- // does not add the actual code. |
- void AddCodeRegion(const char* name, uword pc, intptr_t size); |
- |
- // Add specified symbol information, does not add the actual code. |
- int AddFunction(const char* name, uword pc, intptr_t size); |
- |
- // Write out all the Elf information using the specified handle. |
- bool WriteToFile(File* handle); |
- bool WriteToMemory(DebugInfo::ByteBuffer* region); |
- |
- // Register this generated section with GDB using the JIT interface. |
- static void RegisterSectionWithGDB(const char* name, |
- uword entry_point, |
- intptr_t size); |
- |
- // Unregister all generated section from GDB. |
- static void UnregisterAllSectionsWithGDB(); |
- |
- private: |
- // ELF helpers |
- typedef int (*OutputWriter)(void* handle, |
- const DebugInfo::ByteBuffer& section); |
- typedef void (*OutputPadder)(void* handle, int padding_size); |
- |
- int AddString(DebugInfo::ByteBuffer* buf, const char* str); |
- int AddSectionName(const char* str); |
- int AddName(const char* str); |
- void AddELFHeader(int shoff); |
- void AddSectionHeader(int section, int offset); |
- int PadSection(DebugInfo::ByteBuffer* section, int offset, int alignment); |
- bool WriteOutput(void* handle, OutputWriter writer, OutputPadder padder); |
- |
- uword text_vma_; // text section vma |
- intptr_t text_size_; // text section size |
- int text_padding_; // padding preceding text section |
- |
- static const int kNumSections = 5; // we generate 5 sections |
- int section_name_[kNumSections]; // array of section name indices |
- DebugInfo::ByteBuffer section_buf_[kNumSections]; // array of section buffers |
- DebugInfo::ByteBuffer header_; // ELF header buffer |
- DebugInfo::ByteBuffer sheaders_; // section header table buffer |
- DebugInfo::ByteBuffer lineprog_; // line statement program, part of |
- // '.debug_line' section |
- |
- // current state of the DWARF line info generator |
- uintptr_t cur_addr_; // current pc |
- int map_offset_; |
- uword map_begin_; |
- uword map_end_; |
- |
- Mutex lock_; |
-}; |
- |
- |
-enum { |
- // Various constant sizes for ELF files. |
- kAddrSize = sizeof(uword), |
- kPageSize = 4*1024, // Memory mapping page size. |
- kTextAlign = 16, |
- kELFHeaderSize = 40 + 3*kAddrSize, |
- kProgramHeaderEntrySize = 8 + 6*kAddrSize, |
- kSectionHeaderEntrySize = 16 + 6*kAddrSize, |
- kSymbolSize = 8 + 2*kAddrSize, |
- |
- // Our own layout of sections. |
- kUndef = 0, // Undefined section. |
- kText, // Text section. |
- kShStrtab, // Section header string table. |
- kStrtab, // String table. |
- kSymtab, // Symbol table. |
- kNumSections, // Num of section header entries in section header table. |
- |
- // Various ELF constants. |
- kELFCLASS32 = 1, |
- kELFCLASS64 = 2, |
- kELFDATA2LSB = 1, |
- kELFDATA2MSB = 2, |
- kEM_386 = 3, |
- kEM_MIPS = 8, |
- kEM_ARM = 40, |
- kEM_X86_64 = 62, |
- kEV_CURRENT = 1, |
- kET_EXEC = 2, // not used |
- kET_DYN = 3, |
- kSHT_PROGBITS = 1, |
- kSHT_SYMTAB = 2, |
- kSHT_STRTAB = 3, |
- kSHF_WRITE = 1, // not used |
- kSHF_ALLOC = 2, |
- kSHF_EXECINSTR = 4, |
- kSTB_LOCAL = 0, |
- kSTB_EXPORTED = 1, |
- kSTT_FUNC = 2, |
-}; |
- |
- |
-// ELF and DWARF constants. |
-static const char* kEI_MAG0_MAG3 = "\177ELF"; |
-static const uint8_t kSpecialOpcodeLengths[] = { 0, 1, 1, 1, 1, 0, 0, 0, 1 }; |
- |
- |
-// Section attributes. |
-// The field names correspond to the field names of Elf32_Shdr and Elf64_Shdr. |
-static const struct { |
- // Section header index (only used to check correct section order). |
- int shndx; |
- const char* name; // sh_name will be the index of name inserted in shstrtab. |
- int sh_type; |
- int sh_flags; |
- int sh_link; |
- int sh_addralign; |
- int sh_entsize; |
-} section_attr[kNumSections + 1] = { |
- { kUndef, "", 0, 0, |
- 0, 0, 0 }, |
- { kText, ".text", kSHT_PROGBITS, kSHF_ALLOC|kSHF_EXECINSTR, |
- 0, kTextAlign, 0 }, |
- { kShStrtab, ".shstrtab", kSHT_STRTAB, 0, |
- 0, 1, 0 }, |
- { kStrtab, ".strtab", kSHT_STRTAB, 0, |
- 0, 1, 0 }, |
- { kSymtab, ".symtab", kSHT_SYMTAB, 0, |
- kStrtab, kAddrSize, kSymbolSize }, |
- // Sentinel to pad the last section |
- // for proper alignment of section header table. |
- { 0, "", 0, 0, |
- 0, kAddrSize, 0 } |
-}; |
- |
- |
-// Convenience function aligning an integer. |
-static inline uintptr_t Align(uintptr_t x, intptr_t size) { |
- // size is a power of 2 |
- ASSERT((size & (size-1)) == 0); |
- return (x + (size-1)) & ~(size-1); |
-} |
- |
- |
-// Convenience function writing a single byte to a ByteBuffer. |
-static inline void WriteByte(DebugInfo::ByteBuffer* buf, uint8_t byte) { |
- buf->Add(byte); |
-} |
- |
- |
-// Convenience function writing an unsigned native word to a ByteBuffer. |
-// The word is 32-bit wide in 32-bit mode and 64-bit wide in 64-bit mode. |
-static inline void WriteWord(DebugInfo::ByteBuffer* buf, uword word) { |
- uint8_t* p = reinterpret_cast<uint8_t*>(&word); |
- for (size_t i = 0; i < sizeof(word); i++) { |
- buf->Add(p[i]); |
- } |
-} |
- |
-static inline void WriteInt(DebugInfo::ByteBuffer* buf, int word) { |
- uint8_t* p = reinterpret_cast<uint8_t*>(&word); |
- for (size_t i = 0; i < sizeof(word); i++) { |
- buf->Add(p[i]); |
- } |
-} |
- |
-static inline void WriteShort(DebugInfo::ByteBuffer* buf, uint16_t word) { |
- uint8_t* p = reinterpret_cast<uint8_t*>(&word); |
- for (size_t i = 0; i < sizeof(word); i++) { |
- buf->Add(p[i]); |
- } |
-} |
- |
-static inline void WriteString(DebugInfo::ByteBuffer* buf, const char* str) { |
- for (size_t i = 0; i < strlen(str); i++) { |
- buf->Add(static_cast<uint8_t>(str[i])); |
- } |
-} |
- |
-static inline void Write(DebugInfo::ByteBuffer* buf, |
- const void* mem, |
- int length) { |
- const uint8_t* p = reinterpret_cast<const uint8_t*>(mem); |
- for (int i = 0; i < length; i++) { |
- buf->Add(p[i]); |
- } |
-} |
- |
- |
-// Write given section to file and return written size. |
-static int WriteSectionToFile(void* handle, |
- const DebugInfo::ByteBuffer& section) { |
-#if 0 |
- File* fp = reinterpret_cast<File*>(handle); |
- int size = section.size(); |
- fp->WriteFully(section.data(), size); |
- return size; |
-#else |
- return 0; |
-#endif |
-} |
- |
- |
-// Pad output file to specified padding size. |
-static void PadFile(void* handle, int padding_size) { |
-#if 0 |
- File* fp = reinterpret_cast<File*>(handle); |
- for (int i = 0; i < padding_size; i++) { |
- fp->WriteFully("", 1); |
- } |
-#endif |
-} |
- |
- |
-// Write given section to specified memory region and return written size. |
-static int WriteSectionToMemory(void* handle, |
- const DebugInfo::ByteBuffer& section) { |
- DebugInfo::ByteBuffer* buffer = |
- reinterpret_cast<DebugInfo::ByteBuffer*>(handle); |
- int size = section.size(); |
- for (int i = 0; i < size; i++) { |
- buffer->Add(static_cast<uint8_t>(section.data()[i])); |
- } |
- return size; |
-} |
- |
- |
-// Pad memory to specified padding size. |
-static void PadMemory(void* handle, int padding_size) { |
- DebugInfo::ByteBuffer* buffer = |
- reinterpret_cast<DebugInfo::ByteBuffer*>(handle); |
- for (int i = 0; i < padding_size; i++) { |
- buffer->Add(static_cast<uint8_t>(0)); |
- } |
-} |
- |
- |
-// Constructor |
-ElfGen::ElfGen() |
- : text_vma_(0), text_size_(0), text_padding_(0), map_offset_(0), lock_() { |
- for (int i = 0; i < kNumSections; i++) { |
- ASSERT(section_attr[i].shndx == i); // Verify layout of sections. |
- section_name_[i] = AddSectionName(section_attr[i].name); |
- } |
- // Section header string table always starts with an empty string, which is |
- // the name of the kUndef section. |
- ASSERT((section_attr[0].name[0] == '\0') && (section_name_[0] == 0)); |
- |
- // String table always starts with an empty string. |
- AddName(""); |
- ASSERT(section_buf_[kStrtab].size() == 1); |
- |
- // Symbol at index 0 in symtab is always STN_UNDEF (all zero): |
- DebugInfo::ByteBuffer* symtab = §ion_buf_[kSymtab]; |
- while (symtab->size() < kSymbolSize) { |
- WriteInt(symtab, 0); |
- } |
- ASSERT(symtab->size() == kSymbolSize); |
-} |
- |
- |
-// Destructor |
-ElfGen::~ElfGen() { |
-} |
- |
- |
-void ElfGen::AddCode(uword pc, intptr_t size) { |
- MutexLocker ml(&lock_); |
- text_vma_ = pc; |
- text_size_ = size; |
- // We pad the text section in the file to align absolute code addresses with |
- // corresponding file offsets as if the code had been loaded by memory |
- // mapping. |
- if (text_vma_ % kPageSize < kELFHeaderSize) { |
- text_padding_ = text_vma_ % kPageSize + kPageSize - kELFHeaderSize; |
- } else { |
- text_padding_ = text_vma_ % kPageSize - kELFHeaderSize; |
- } |
- |
- Write(§ion_buf_[kText], reinterpret_cast<void*>(pc), size); |
- // map_offset is the file offset of the first mapped page. |
- map_offset_ = (kELFHeaderSize + text_padding_)/kPageSize*kPageSize; |
- map_begin_ = Align(text_vma_ - kPageSize + 1, kPageSize); |
- map_end_ = Align(text_vma_ + size, kPageSize); |
-} |
- |
- |
-void ElfGen::AddCodeRegion(const char* name, uword pc, intptr_t size) { |
- MutexLocker ml(&lock_); |
- AddFunction(name, pc, size); |
- char end_name[256]; |
- OS::SNPrint(end_name, sizeof(end_name), "%s_end", name); |
- AddFunction(end_name, pc + size, 0); |
-} |
- |
- |
-int ElfGen::AddFunction(const char* name, uword pc, intptr_t size) { |
- ASSERT(text_vma_ != 0); // code must have been added |
- DebugInfo::ByteBuffer* symtab = §ion_buf_[kSymtab]; |
- const int beg = symtab->size(); |
- WriteInt(symtab, AddName(name)); // st_name |
-#if defined(ARCH_IS_64_BIT) |
- WriteShort(symtab, (kSTB_LOCAL << 4) + kSTT_FUNC); // st_info + (st_other<<8) |
- WriteShort(symtab, kText); // st_shndx |
-#endif |
- WriteWord(symtab, pc); // st_value |
- WriteWord(symtab, size); // st_size |
-#if defined(ARCH_IS_32_BIT) |
- // st_info + (st_other<<8) |
- WriteShort(symtab, (kSTB_EXPORTED << 4) + kSTT_FUNC); |
- WriteShort(symtab, kText); // st_shndx |
-#endif |
- ASSERT(symtab->size() - beg == kSymbolSize); |
- return beg / kSymbolSize; // symbol index in symtab |
-} |
- |
- |
-bool ElfGen::WriteToFile(File* handle) { |
- return WriteOutput(handle, WriteSectionToFile, PadFile); |
-} |
- |
- |
-bool ElfGen::WriteToMemory(DebugInfo::ByteBuffer* region) { |
- return WriteOutput(region, WriteSectionToMemory, PadMemory); |
-} |
- |
- |
-int ElfGen::AddString(DebugInfo::ByteBuffer* buf, const char* str) { |
- const int str_index = buf->size(); |
- WriteString(buf, str); |
- WriteByte(buf, 0); // terminating '\0' |
- return str_index; |
-} |
- |
- |
-int ElfGen::AddSectionName(const char* str) { |
- return AddString(§ion_buf_[kShStrtab], str); |
-} |
- |
- |
-int ElfGen::AddName(const char* str) { |
- return AddString(§ion_buf_[kStrtab], str); |
-} |
- |
- |
-void ElfGen::AddELFHeader(int shoff) { |
- ASSERT(text_vma_ != 0); // Code must have been added. |
- Write(&header_, kEI_MAG0_MAG3, 4); // EI_MAG0..EI_MAG3 |
-#if defined(ARCH_IS_32_BIT) |
- WriteByte(&header_, kELFCLASS32); // EI_CLASS |
-#elif defined(ARCH_IS_64_BIT) |
- WriteByte(&header_, kELFCLASS64); // EI_CLASS |
-#else |
-#error Unknown architecture. |
-#endif |
- WriteByte(&header_, kELFDATA2LSB); // EI_DATA |
- WriteByte(&header_, kEV_CURRENT); // EI_VERSION |
- WriteByte(&header_, 0); // EI_PAD |
- WriteInt(&header_, 0); // EI_PAD |
- WriteInt(&header_, 0); // EI_PAD |
- WriteShort(&header_, kET_DYN); // e_type, fake a shared object. |
-#if defined(TARGET_ARCH_IA32) |
- WriteShort(&header_, kEM_386); // e_machine |
-#elif defined(TARGET_ARCH_X64) |
- WriteShort(&header_, kEM_X86_64); // e_machine |
-#elif defined(TARGET_ARCH_ARM) |
- WriteShort(&header_, kEM_ARM); // e_machine |
-#elif defined(TARGET_ARCH_ARM64) |
- // TODO(zra): Find the right ARM64 constant. |
- WriteShort(&header_, kEM_ARM); // e_machine |
-#elif defined(TARGET_ARCH_MIPS) |
- WriteShort(&header_, kEM_MIPS); // e_machine |
-#else |
-#error Unknown architecture. |
-#endif |
- WriteInt(&header_, kEV_CURRENT); // e_version |
- WriteWord(&header_, 0); // e_entry: none |
- WriteWord(&header_, 0); // e_phoff: no program header table. |
- WriteWord(&header_, shoff); // e_shoff: section header table offset. |
- WriteInt(&header_, 0); // e_flags: no flags. |
- WriteShort(&header_, kELFHeaderSize); // e_ehsize: header size. |
- WriteShort(&header_, kProgramHeaderEntrySize); // e_phentsize |
- WriteShort(&header_, 0); // e_phnum: no entries program header table. |
- WriteShort(&header_, kSectionHeaderEntrySize); // e_shentsize |
- // e_shnum: number of section header entries. |
- WriteShort(&header_, kNumSections); |
- WriteShort(&header_, kShStrtab); // e_shstrndx: index of shstrtab. |
- ASSERT(header_.size() == kELFHeaderSize); |
-} |
- |
- |
-void ElfGen::AddSectionHeader(int section, int offset) { |
- WriteInt(&sheaders_, section_name_[section]); |
- WriteInt(&sheaders_, section_attr[section].sh_type); |
- WriteWord(&sheaders_, section_attr[section].sh_flags); |
- // sh_addr: abs addr |
- WriteWord(&sheaders_, (section == kText) ? text_vma_ : 0); |
- WriteWord(&sheaders_, offset); // sh_offset: section file offset. |
- WriteWord(&sheaders_, section_buf_[section].size()); |
- WriteInt(&sheaders_, section_attr[section].sh_link); |
- WriteInt(&sheaders_, 0); |
- WriteWord(&sheaders_, section_attr[section].sh_addralign); |
- WriteWord(&sheaders_, section_attr[section].sh_entsize); |
- ASSERT(sheaders_.size() == kSectionHeaderEntrySize * (section + 1)); |
-} |
- |
- |
-// Pads the given section with zero bytes for the given aligment, assuming the |
-// section starts at given file offset; returns file offset after padded |
-// section. |
-int ElfGen::PadSection(DebugInfo::ByteBuffer* section, |
- int offset, |
- int alignment) { |
- offset += section->size(); |
- int aligned_offset = Align(offset, alignment); |
- while (offset++ < aligned_offset) { |
- WriteByte(section, 0); // one byte padding. |
- } |
- return aligned_offset; |
-} |
- |
- |
-bool ElfGen::WriteOutput(void* handle, |
- OutputWriter writer, |
- OutputPadder padder) { |
- if (handle == NULL || writer == NULL || padder == NULL) { |
- return false; |
- } |
- |
- // Align all sections before writing the ELF header in order to calculate the |
- // file offset of the section header table, which is needed in the ELF header. |
- // Pad each section as required by the aligment constraint of the immediately |
- // following section, except the ELF header section, which requires special |
- // padding (text_padding_) to align the text_ section. |
- int offset = kELFHeaderSize + text_padding_; |
- for (int i = kText; i < kNumSections; i++) { |
- offset = PadSection(§ion_buf_[i], |
- offset, |
- section_attr[i+1].sh_addralign); |
- } |
- |
- const int shoff = offset; // Section header table offset. |
- |
- // Write elf header. |
- AddELFHeader(shoff); |
- offset = (*writer)(handle, header_); |
- |
- // Pad file before writing text section in order to align vma with file |
- // offset. |
- (*padder)(handle, text_padding_); |
- |
- offset += text_padding_; |
- ASSERT((text_vma_ - offset) % kPageSize == 0); |
- |
- // Section header at index 0 in section header table is always SHN_UNDEF: |
- for (int i = 0; i < kNumSections; i++) { |
- AddSectionHeader(i, offset); |
- offset += (*writer)(handle, section_buf_[i]); |
- } |
- // Write section header table. |
- ASSERT(offset == shoff); |
- offset += (*writer)(handle, sheaders_); |
- ASSERT(offset == shoff + kNumSections * kSectionHeaderEntrySize); |
- |
- return true; |
-} |
- |
-} // namespace dart |
- |
-#endif // VM_ELFGEN_H_ |