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Diffstat (limited to '3rdParty/Breakpad/src/common/dwarf/elf_reader.h')
-rw-r--r-- | 3rdParty/Breakpad/src/common/dwarf/elf_reader.h | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/3rdParty/Breakpad/src/common/dwarf/elf_reader.h b/3rdParty/Breakpad/src/common/dwarf/elf_reader.h new file mode 100644 index 0000000..b1bb67a --- /dev/null +++ b/3rdParty/Breakpad/src/common/dwarf/elf_reader.h @@ -0,0 +1,166 @@ +// Copyright 2005 Google Inc. All Rights Reserved. +// Author: chatham@google.com (Andrew Chatham) +// Author: satorux@google.com (Satoru Takabayashi) +// +// ElfReader handles reading in ELF. It can extract symbols from the +// current process, which may be used to symbolize stack traces +// without having to make a potentially dangerous call to fork(). +// +// ElfReader dynamically allocates memory, so it is not appropriate to +// use once the address space might be corrupted, such as during +// process death. +// +// ElfReader supports both 32-bit and 64-bit ELF binaries. + +#ifndef COMMON_DWARF_ELF_READER_H__ +#define COMMON_DWARF_ELF_READER_H__ + +#include <string> +#include <vector> + +#include "common/dwarf/types.h" +#include "common/using_std_string.h" + +using std::vector; +using std::pair; + +namespace dwarf2reader { + +class SymbolMap; +class Elf32; +class Elf64; +template<typename ElfArch> +class ElfReaderImpl; + +class ElfReader { + public: + explicit ElfReader(const string &path); + ~ElfReader(); + + // Parse the ELF prologue of this file and return whether it was + // successfully parsed and matches the word size and byte order of + // the current process. + bool IsNativeElfFile() const; + + // Similar to IsNativeElfFile but checks if it's a 32-bit ELF file. + bool IsElf32File() const; + + // Similar to IsNativeElfFile but checks if it's a 64-bit ELF file. + bool IsElf64File() const; + + // Checks if it's an ELF file of type ET_DYN (shared object file). + bool IsDynamicSharedObject(); + + // Add symbols in the given ELF file into the provided SymbolMap, + // assuming that the file has been loaded into the specified + // offset. + // + // The remaining arguments are typically taken from a + // ProcMapsIterator (base/sysinfo.h) and describe which portions of + // the ELF file are mapped into which parts of memory: + // + // mem_offset - position at which the segment is mapped into memory + // file_offset - offset in the file where the mapping begins + // length - length of the mapped segment + void AddSymbols(SymbolMap *symbols, + uint64 mem_offset, uint64 file_offset, + uint64 length); + + class SymbolSink { + public: + virtual ~SymbolSink() {} + virtual void AddSymbol(const char *name, uint64 address, uint64 size) = 0; + }; + + // Like AddSymbols above, but with no address correction. + // Processes any SHT_SYMTAB section, followed by any SHT_DYNSYM section. + void VisitSymbols(SymbolSink *sink); + + // Like VisitSymbols above, but for a specific symbol binding/type. + // A negative value for the binding and type parameters means any + // binding or type. + void VisitSymbols(SymbolSink *sink, int symbol_binding, int symbol_type); + + // Like VisitSymbols above but can optionally export raw symbol values instead + // of adjusted ones. + void VisitSymbols(SymbolSink *sink, int symbol_binding, int symbol_type, + bool get_raw_symbol_values); + + // p_vaddr of the first PT_LOAD segment (if any), or 0 if no PT_LOAD + // segments are present. This is the address an ELF image was linked + // (by static linker) to be loaded at. Usually (but not always) 0 for + // shared libraries and position-independent executables. + uint64 VaddrOfFirstLoadSegment(); + + // Return the name of section "shndx". Returns NULL if the section + // is not found. + const char *GetSectionName(int shndx); + + // Return the number of sections in the given ELF file. + uint64 GetNumSections(); + + // Get section "shndx" from the given ELF file. On success, return + // the pointer to the section and store the size in "size". + // On error, return NULL. The returned section data is only valid + // until the ElfReader gets destroyed. + const char *GetSectionByIndex(int shndx, size_t *size); + + // Get section with "section_name" (ex. ".text", ".symtab") in the + // given ELF file. On success, return the pointer to the section + // and store the size in "size". On error, return NULL. The + // returned section data is only valid until the ElfReader gets + // destroyed. + const char *GetSectionByName(const string §ion_name, size_t *size); + + // This is like GetSectionByName() but it returns a lot of extra information + // about the section. The SectionInfo structure is almost identical to + // the typedef struct Elf64_Shdr defined in <elf.h>, but is redefined + // here so that the many short macro names in <elf.h> don't have to be + // added to our already cluttered namespace. + struct SectionInfo { + uint32 type; // Section type (SHT_xxx constant from elf.h). + uint64 flags; // Section flags (SHF_xxx constants from elf.h). + uint64 addr; // Section virtual address at execution. + uint64 offset; // Section file offset. + uint64 size; // Section size in bytes. + uint32 link; // Link to another section. + uint32 info; // Additional section information. + uint64 addralign; // Section alignment. + uint64 entsize; // Entry size if section holds a table. + }; + const char *GetSectionInfoByName(const string §ion_name, + SectionInfo *info); + + // Check if "path" is an ELF binary that has not been stripped of symbol + // tables. This function supports both 32-bit and 64-bit ELF binaries. + static bool IsNonStrippedELFBinary(const string &path); + + // Check if "path" is an ELF binary that has not been stripped of debug + // info. Unlike IsNonStrippedELFBinary, this function will return + // false for binaries passed through "strip -S". + static bool IsNonDebugStrippedELFBinary(const string &path); + + // Match a requested section name with the section name as it + // appears in the elf-file, adjusting for compressed debug section + // names. For example, returns true if name == ".debug_abbrev" and + // sh_name == ".zdebug_abbrev" + static bool SectionNamesMatch(const string &name, const string &sh_name); + + private: + // Lazily initialize impl32_ and return it. + ElfReaderImpl<Elf32> *GetImpl32(); + // Ditto for impl64_. + ElfReaderImpl<Elf64> *GetImpl64(); + + // Path of the file we're reading. + const string path_; + // Read-only file descriptor for the file. May be -1 if there was an + // error during open. + int fd_; + ElfReaderImpl<Elf32> *impl32_; + ElfReaderImpl<Elf64> *impl64_; +}; + +} // namespace dwarf2reader + +#endif // COMMON_DWARF_ELF_READER_H__ |