jdk8-mips64-public/hotspot: src/os/bsd/vm/decoder_machO.cpp@fd44df5e3bc3 (annotated)

src/os/bsd/vm/decoder_machO.cpp@fd44df5e3bc3 (annotated)

src/os/bsd/vm/decoder_machO.cpp

Wed, 14 Oct 2020 17:44:48 +0800

author: aoqi
date: Wed, 14 Oct 2020 17:44:48 +0800
changeset 9931: fd44df5e3bc3
parent 6876: 710a3c8b516e
parent 9920: 3a3803a0c789
permissions: -rw-r--r--

Merge

 /*
  * Copyright (c) 2011, 2014, 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", p2i(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);
       buf[buflen - 1] = '\0';
       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

Mercurial > jdk8-mips64-public > hotspot / annotate

src/os/bsd/vm/decoder_machO.cpp@fd44df5e3bc3 (annotated)

src/os/bsd/vm/decoder_machO.cpp