1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 
  22 /*
  23  * Copyright (c) 2006, 2010, Oracle and/or its affiliates. All rights reserved.
  24  * Copyright 2018, Joyent, Inc.
  25  */
  26 
  27 #include        <stdio.h>
  28 #include        <demangle-sys.h>
  29 #include        "_conv.h"
  30 #include        "demangle_msg.h"
  31 
  32 /*
  33  * Demangle C++ symbols.
  34  *
  35  * This routine acts as a generic routine for use by liblddbg (and hence tools
  36  * like elfdump(1) and pvs(1)), ld(1) and ld.so.1(1).
  37  *
  38  * The C++ ABI-2 places no limits on symbol names, thus when demangling a name
  39  * it's possible the buffer won't be big enough (DEMANGLE_ESPACE) so here we
  40  * try to allocate bigger buffers.  However, we place a limit on this buffer
  41  * size for fear of a C++ error sending us into an infinit loop.
  42  *
  43  * NOTE. we create and use a common buffer for use by cplus_demangle(), thus
  44  * each call to this routine will override the contents of any existing call.
  45  * Normally this is sufficient for typical error diagnostics referencing one
  46  * symbol.  For those diagnostics using more than one symbol name, all but the
  47  * last name must be copied to a temporary buffer (regardless of whether
  48  * demangling occurred, as the process of attempting to demangle may damage the
  49  * buffer).  One model is:
  50  *
  51  *      if ((_name1 = demangle(name1)) != name1) {
  52  *              char *  __name1 = strdupa(_name1);
  53  *              name1 = (const char *)__name1;
  54  *      }
  55  *      name2 = demangle(name2);
  56  *      eprintf(format, name1, name2);
  57  */
  58 #define SYM_MAX 1000
  59 
  60 const char *
  61 conv_demangle_name(const char *name)
  62 {
  63         static char     *(*fptr)() = 0;
  64         static volatile int loading = 0;
  65         char *d;
  66 
  67         if (loading)
  68                 return (name);
  69 
  70         /*
  71          * If we haven't located the demangler yet try now (we do this rather
  72          * than maintain a static dependency on libdemangle as it's part of an
  73          * optional package).  Null the str element out to reject any other
  74          * callers until this operation is complete - under ld.so.1 we can get
  75          * into serious recursion without this.
  76          */
  77         if (fptr == 0) {
  78                 void    *hdl;
  79 
  80                 loading = 1;
  81                 if (!(hdl = dlopen(MSG_ORIG(MSG_DEM_LIB), RTLD_LAZY)) ||
  82                     !(fptr = (char *(*)())dlsym(hdl, MSG_ORIG(MSG_DEM_SYM))))
  83                         return (name);
  84                 loading = 0;
  85         }
  86 
  87         if ((d = fptr(name, SYSDEM_LANG_AUTO, NULL)) == NULL)
  88                 return (name);
  89 
  90         return (d);
  91 }