Mercurial > hg > truffle
view src/os/bsd/vm/decoder_machO.cpp @ 7512:4c269aec7d62
Remove unused variable.
author | Thomas Wuerthinger <thomas.wuerthinger@oracle.com> |
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date | Tue, 22 Jan 2013 16:54:40 +0100 |
parents | b9a9ed0f8eeb |
children | 78bbf4d43a14 |
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/* * Copyright (c) 2011, 2012, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code 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 * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #include "precompiled.hpp" #ifdef __APPLE__ #include "decoder_machO.hpp" #include <cxxabi.h> #include <mach-o/loader.h> #include <mach-o/nlist.h> bool MachODecoder::demangle(const char* symbol, char *buf, int buflen) { int status; char* result; size_t size = (size_t)buflen; // Don't pass buf to __cxa_demangle. In case of the 'buf' is too small, // __cxa_demangle will call system "realloc" for additional memory, which // may use different malloc/realloc mechanism that allocates 'buf'. if ((result = abi::__cxa_demangle(symbol, NULL, NULL, &status)) != NULL) { jio_snprintf(buf, buflen, "%s", result); // call c library's free ::free(result); return true; } return false; } bool MachODecoder::decode(address addr, char *buf, int buflen, int *offset, const void *mach_base) { struct symtab_command * symt = (struct symtab_command *) mach_find_command((struct mach_header_64 *)mach_base, LC_SYMTAB); if (symt == NULL) { DEBUG_ONLY(tty->print_cr("no symtab in mach file at 0x%lx", mach_base)); return false; } uint32_t off = symt->symoff; /* symbol table offset (within this mach file) */ uint32_t nsyms = symt->nsyms; /* number of symbol table entries */ uint32_t stroff = symt->stroff; /* string table offset */ uint32_t strsize = symt->strsize; /* string table size in bytes */ // iterate through symbol table trying to match our offset uint32_t addr_relative = (uintptr_t) mach_base - (uintptr_t) addr; // offset we seek in the symtab void * symtab_addr = (void*) ((uintptr_t) mach_base + off); struct nlist_64 *cur_nlist = (struct nlist_64 *) symtab_addr; struct nlist_64 *last_nlist = cur_nlist; // no size stored in an entry, so keep previously seen nlist int32_t found_strx = 0; int32_t found_symval = 0; for (uint32_t i=0; i < nsyms; i++) { uint32_t this_value = cur_nlist->n_value; if (addr_relative == this_value) { found_strx = cur_nlist->n_un.n_strx; found_symval = this_value; break; } else if (addr_relative > this_value) { // gone past it, use previously seen nlist: found_strx = last_nlist->n_un.n_strx; found_symval = last_nlist->n_value; break; } last_nlist = cur_nlist; cur_nlist = cur_nlist + sizeof(struct nlist_64); } if (found_strx == 0) { return false; } // write the offset: *offset = addr_relative - found_symval; // lookup found_strx in the string table char * symname = mach_find_in_stringtable((char*) ((uintptr_t)mach_base + stroff), strsize, found_strx); if (symname) { strncpy(buf, symname, buflen); return true; } DEBUG_ONLY(tty->print_cr("no string or null string found.")); return false; } void* MachODecoder::mach_find_command(struct mach_header_64 * mach_base, uint32_t command_wanted) { // possibly verify it is a mach_header, use magic number. // commands begin immediately after the header. struct load_command *pos = (struct load_command *) mach_base + sizeof(struct mach_header_64); for (uint32_t i = 0; i < mach_base->ncmds; i++) { struct load_command *this_cmd = (struct load_command *) pos; if (this_cmd->cmd == command_wanted) { return pos; } int cmdsize = this_cmd->cmdsize; pos += cmdsize; } return NULL; } char* MachODecoder::mach_find_in_stringtable(char *strtab, uint32_t tablesize, int strx_wanted) { if (strx_wanted == 0) { return NULL; } char *strtab_end = strtab + tablesize; // find the first string, skip over the space char // (or the four zero bytes we see e.g. in libclient) if (*strtab == ' ') { strtab++; if (*strtab != 0) { DEBUG_ONLY(tty->print_cr("string table has leading space but no following zero.")); return NULL; } strtab++; } else { if ((uint32_t) *strtab != 0) { DEBUG_ONLY(tty->print_cr("string table without leading space or leading int of zero.")); return NULL; } strtab+=4; } // read the real strings starting at index 1 int cur_strx = 1; while (strtab < strtab_end) { if (cur_strx == strx_wanted) { return strtab; } // find start of next string while (*strtab != 0) { strtab++; } strtab++; // skip the terminating zero cur_strx++; } DEBUG_ONLY(tty->print_cr("string number %d not found.", strx_wanted)); return NULL; } #endif