michael@0: /* -*- Mode: C++ -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #ifndef elf_symbol_table_h__
michael@0: #define elf_symbol_table_h__
michael@0: 
michael@0: /*
michael@0: 
michael@0:   Utility class for reading ELF symbol tables.
michael@0: 
michael@0:  */
michael@0: 
michael@0: #include <elf.h>
michael@0: #include <sys/mman.h>
michael@0: 
michael@0: #include "interval_map.h"
michael@0: 
michael@0: class elf_symbol_table {
michael@0: protected:
michael@0:     int              m_fd;
michael@0:     void            *m_mapping;
michael@0:     size_t           m_size;
michael@0:     const char      *m_strtab;
michael@0:     const Elf32_Sym *m_symbols;
michael@0:     int              m_nsymbols;
michael@0:     int              m_text_shndx;
michael@0: 
michael@0:     typedef interval_map<unsigned int, const Elf32_Sym *> rsymtab_t;
michael@0:     rsymtab_t        m_rsymtab;
michael@0: 
michael@0:     int verify_elf_header(const Elf32_Ehdr *hdr);
michael@0:     int finish();
michael@0: 
michael@0: public:
michael@0:     elf_symbol_table()
michael@0:         : m_fd(-1),
michael@0:           m_mapping(MAP_FAILED),
michael@0:           m_size(0),
michael@0:           m_strtab(0),
michael@0:           m_symbols(0),
michael@0:           m_nsymbols(0),
michael@0:           m_text_shndx(0) {}
michael@0: 
michael@0:     ~elf_symbol_table() { finish(); }
michael@0: 
michael@0:     /**
michael@0:      * Read the symbol table information from the specified file. (This will
michael@0:      * memory-map the file.)
michael@0:      *
michael@0:      * Currently, only symbols from the `.text' section are loaded.
michael@0:      */
michael@0:     int init(const char *file);
michael@0: 
michael@0:     /**
michael@0:      * Determine what symbol the specified image address corresponds
michael@0:      * to. Addresses need not refer to a symbol's start address:
michael@0:      * symbol size information is used to reverse-map the address.
michael@0:      */
michael@0:     const Elf32_Sym *lookup(unsigned int addr) const;
michael@0: 
michael@0:     /**
michael@0:      * Determine the symbol name for the specified symbol.
michael@0:      */
michael@0:     const char *get_symbol_name(const Elf32_Sym *sym) const;
michael@0: 
michael@0:     /**
michael@0:      * Return `true' if the specified symbol is a function.
michael@0:      */
michael@0:     bool is_function(const Elf32_Sym *sym) const {
michael@0:         return (sym->st_size > 0) &&
michael@0:             (ELF32_ST_TYPE(sym->st_info) == STT_FUNC) &&
michael@0:             (sym->st_shndx == m_text_shndx); }
michael@0: 
michael@0:     typedef const Elf32_Sym *const_iterator;
michael@0: 
michael@0:     const_iterator begin() const { return const_iterator(m_symbols); }
michael@0:     const_iterator end() const { return const_iterator(m_symbols + m_nsymbols); }
michael@0: };
michael@0: 
michael@0: #endif // elf_symbol_table_h__