usr/src/cmd/dis/dis_util.c

   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 2006 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 #pragma ident   "%Z%%M% %I%     %E% SMI"
  28
  29 #include <dlfcn.h>
  30 #include <stdarg.h>
  31 #include <stdio.h>
  32 #include <stdlib.h>
  33 #include <demangle.h>
  34
  35 #include "dis_util.h"
  36
  37 int g_error;    /* global process exit status, set when warn() is called */
  38
  39 /*
  40  * Fatal error.  Print out the error with a leading "dis: ", and then exit the
  41  * program.
  42  */
  43 void
  44 die(const char *fmt, ...)
  45 {
  46         va_list ap;
  47
  48         (void) fprintf(stderr, "dis: fatal: ");
  49
  50         va_start(ap, fmt);
  51         (void) vfprintf(stderr, fmt, ap);
  52         va_end(ap);
  53
  54         (void) fprintf(stderr, "\n");
  55
  56         exit(1);
  57 }
  58
  59 /*
  60  * Non-fatal error.  Print out the error with a leading "dis: ", set the global
  61  * error flag, and return.
  62  */
  63 void
  64 warn(const char *fmt, ...)
  65 {
  66         va_list ap;
  67
  68         (void) fprintf(stderr, "dis: warning: ");
  69
  70         va_start(ap, fmt);
  71         (void) vfprintf(stderr, fmt, ap);
  72         va_end(ap);
  73
  74         (void) fprintf(stderr, "\n");
  75
  76         g_error = 1;
  77 }
  78
  79 /*
  80  * Convenience wrapper around malloc() to cleanly exit if any allocation fails.
  81  */
  82 void *
  83 safe_malloc(size_t size)
  84 {
  85         void *ret;
  86
  87         if ((ret = calloc(1, size)) == NULL)
  88                 die("Out of memory");
  89
  90         return (ret);
  91 }
  92
  93
  94 /*
  95  * Generic interface to demangle C++ names.  Calls cplus_demangle to do the
  96  * necessary translation.  If the translation fails, the argument is returned
  97  * unchanged.  The memory returned is only valid until the next call to
  98  * demangle().
  99  *
 100  * We dlopen() libdemangle.so rather than linking directly against it in case it
 101  * is not installed on the system.
 102  */
 103 const char *
 104 dis_demangle(const char *name)
 105 {
 106         static char *demangled_name;
 107         static int (*demangle_func)() = NULL;
 108         static int size = BUFSIZE;
 109         static int first_flag = 0;
 110         int ret;
 111
 112         /*
 113          * If this is the first call, allocate storage
 114          * for the buffer.
 115          */
 116         if (first_flag == 0) {
 117                 void *demangle_hand;
 118
 119                 demangle_hand = dlopen("libdemangle.so.1", RTLD_LAZY);
 120                 if (demangle_hand != NULL)
 121                         demangle_func = (int (*)(int))dlsym(
 122                                 demangle_hand, "cplus_demangle");
 123
 124                 demangled_name = safe_malloc(size);
 125                 first_flag = 1;
 126         }
 127
 128         /*
 129          * If libdemangle is not present, pass through unchanged.
 130          */
 131         if (demangle_func == NULL)
 132                 return (name);
 133
 134         /*
 135          * The function returns -1 when the buffer size is not sufficient.
 136          */
 137         while ((ret = (*demangle_func)(name, demangled_name, size)) == -1) {
 138                 free(demangled_name);
 139                 size = size + BUFSIZE;
 140                 demangled_name = safe_malloc(size);
 141         }
 142
 143         if (ret != 0)
 144                 return (name);
 145
 146         return (demangled_name);
 147 }