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, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*
  23  * Copyright 2001-2002 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  *
  26  * Copyright 2017 Jason King
  27  */
  28 
  29 #include <mdb/mdb_modapi.h>
  30 #include <mdb/mdb_demangle.h>
  31 #include <mdb/mdb_err.h>
  32 #include <mdb/mdb.h>
  33 
  34 #include <demangle.h>
  35 #include <strings.h>
  36 #include <unistd.h>
  37 #include <dlfcn.h>
  38 #include <link.h>
  39 #include <sysdemangle.h>
  40 
  41 static void *
  42 mdb_dem_alloc(size_t len)
  43 {
  44         return (mdb_alloc(len, UM_SLEEP));
  45 }
  46 
  47 static void
  48 mdb_dem_free(void *p, size_t len)
  49 {
  50         mdb_free(p, len);
  51 }
  52 
  53 static sysdem_ops_t mdb_dem_demops = {
  54         .alloc = mdb_dem_alloc,
  55         .free = mdb_dem_free
  56 };
  57 
  58 mdb_demangler_t *
  59 mdb_dem_load(void)
  60 {
  61         mdb_demangler_t *dmp;
  62 
  63         dmp = mdb_alloc(sizeof (mdb_demangler_t), UM_SLEEP);
  64         dmp->dm_len = 0;
  65         dmp->dm_buf = NULL;
  66         dmp->dm_flags = MDB_DM_SCOPE;
  67         /* stick with C++ for now to match old behavior */
  68         dmp->dm_lang = SYSDEM_LANG_CPP;
  69 
  70         return (dmp);
  71 }
  72 
  73 void
  74 mdb_dem_unload(mdb_demangler_t *dmp)
  75 {
  76         mdb_free(dmp->dm_buf, dmp->dm_len);
  77         mdb_free(dmp, sizeof (mdb_demangler_t));
  78 }
  79 
  80 static const char *
  81 mdb_dem_filter(mdb_demangler_t *dmp, const char *name)
  82 {
  83         static const char s_pref[] = "static ";
  84         static const char c_suff[] = " const";
  85         static const char v_suff[] = " volatile";
  86 
  87         /*
  88          * We process dm_dem, which skips the prefix in dm_buf (if any)
  89          */
  90         size_t len = strlen(dmp->dm_dem);
  91         char *end = dmp->dm_dem + len;
  92         size_t resid;
  93 
  94         /*
  95          * If static, const, and volatile qualifiers should not be displayed,
  96          * rip all of them out of dmp->dm_dem.
  97          */
  98         if (!(dmp->dm_flags & MDB_DM_QUAL)) {
  99                 if (strncmp(dmp->dm_dem, s_pref, sizeof (s_pref) - 1) == 0) {
 100                         bcopy(dmp->dm_dem + sizeof (s_pref) - 1, dmp->dm_dem,
 101                             len - (sizeof (s_pref) - 1) + 1);
 102                         end -= sizeof (s_pref) - 1;
 103                         len -= sizeof (s_pref) - 1;
 104                 }
 105 
 106                 for (;;) {
 107                         if (len > sizeof (c_suff) - 1 &&
 108                             strcmp(end - (sizeof (c_suff) - 1), c_suff) == 0) {
 109                                 end -= sizeof (c_suff) - 1;
 110                                 len -= sizeof (c_suff) - 1;
 111                                 *end = '\0';
 112                                 continue;
 113                         }
 114                         if (len > sizeof (v_suff) - 1 &&
 115                             strcmp(end - (sizeof (v_suff) - 1), v_suff) == 0) {
 116                                 end -= sizeof (v_suff) - 1;
 117                                 len -= sizeof (v_suff) - 1;
 118                                 *end = '\0';
 119                                 continue;
 120                         }
 121                         break;
 122                 }
 123         }
 124 
 125         /*
 126          * If function arguments should not be displayed, remove everything
 127          * between the outermost set of parentheses in dmp->dm_dem.
 128          */
 129         if (!(dmp->dm_flags & MDB_DM_FUNCARG)) {
 130                 char *lp = strchr(dmp->dm_dem, '(');
 131                 char *rp = strrchr(dmp->dm_dem, ')');
 132 
 133                 if (lp != NULL && rp != NULL)
 134                         bcopy(rp + 1, lp, strlen(rp) + 1);
 135         }
 136 
 137         /*
 138          * If function scope specifiers should not be displayed, remove text
 139          * from the leftmost space to the rightmost colon prior to any paren.
 140          */
 141         if (!(dmp->dm_flags & MDB_DM_SCOPE)) {
 142                 char *c, *s, *lp = strchr(dmp->dm_dem, '(');
 143 
 144                 if (lp != NULL)
 145                         *lp = '\0';
 146 
 147                 c = strrchr(dmp->dm_dem, ':');
 148                 s = strchr(dmp->dm_dem, ' ');
 149 
 150                 if (lp != NULL)
 151                         *lp = '(';
 152 
 153                 if (c != NULL) {
 154                         if (s == NULL || s > c)
 155                                 bcopy(c + 1, dmp->dm_dem, strlen(c + 1) + 1);
 156                         else
 157                                 bcopy(c + 1, s + 1, strlen(c + 1) + 1);
 158                 }
 159         }
 160 
 161         len = strlen(dmp->dm_dem); /* recompute length of buffer */
 162 
 163         /*
 164          * Compute bytes remaining
 165          */
 166         resid = (dmp->dm_buf + dmp->dm_len) - (dmp->dm_dem + len);
 167 
 168         /*
 169          * If we want to append the mangled name as well and there is enough
 170          * space for "[]\0" and at least one character, append "["+name+"]".
 171          */
 172         if ((dmp->dm_flags & MDB_DM_MANGLED) && resid > 3) {
 173                 char *p = dmp->dm_dem + len;
 174 
 175                 *p++ = '[';
 176                 (void) strncpy(p, name, resid - 3);
 177                 p[resid - 3] = '\0';
 178                 p += strlen(p);
 179                 (void) strcpy(p, "]");
 180         }
 181 
 182         /*
 183          * We return the whole string
 184          */
 185         return (dmp->dm_buf);
 186 }
 187 
 188 /*
 189  * Take a name: (the foo`bar` is optional)
 190  *      foo`bar`__mangled_
 191  * and put:
 192  *      foo`bar`demangled
 193  * into dmp->dm_buf.  Point dmp->dm_dem to the beginning of the
 194  * demangled section of the result.
 195  */
 196 static int
 197 mdb_dem_process(mdb_demangler_t *dmp, const char *name)
 198 {
 199         char *res = NULL;
 200         size_t reslen = 0;
 201 
 202         char *prefix = strrchr(name, '`');
 203         size_t prefixlen = 0;
 204 
 205         if (prefix) {
 206                 prefix++;               /* the ` is part of the prefix */
 207                 prefixlen = prefix - name;
 208         }
 209 
 210         res = sysdemangle(name + prefixlen, dmp->dm_lang, &mdb_dem_demops);
 211         if (res == NULL && errno != EINVAL)
 212                 mdb_warn("Error while demangling");
 213 
 214         mdb_free(dmp->dm_buf, dmp->dm_len);
 215         dmp->dm_dem = NULL;
 216         dmp->dm_len = 0;
 217 
 218         reslen = (res != NULL) ? strlen(res) : 0;
 219         reslen += prefixlen;
 220         reslen += 1;
 221 
 222         dmp->dm_buf = mdb_zalloc(reslen, UM_SLEEP);
 223         if (dmp->dm_buf == NULL) {
 224                 mdb_warn("Unable to allocate memory for demangling");
 225                 return (-1);
 226         }
 227 
 228         dmp->dm_len = reslen;
 229 
 230         if (prefixlen > 0)
 231                 (void) strlcpy(dmp->dm_buf, name, prefixlen);
 232         if (res != NULL)
 233                 (void) strlcat(dmp->dm_buf, res, dmp->dm_len);
 234 
 235         /*
 236          * Save the position of the demangled string for mdb_dem_filter()
 237          */
 238         dmp->dm_dem = dmp->dm_buf + prefixlen;
 239 
 240         return (0);
 241 }
 242 
 243 /* used by mdb_io.c:iob_addr2str */
 244 const char *
 245 mdb_dem_convert(mdb_demangler_t *dmp, const char *name)
 246 {
 247         if (mdb_dem_process(dmp, name) != 0 ||
 248             strcmp(dmp->dm_buf, name) == 0)
 249                 return (name);
 250 
 251         return (mdb_dem_filter(dmp, name));
 252 }
 253 
 254 /*ARGSUSED*/
 255 int
 256 cmd_demangle(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
 257 {
 258         mdb_demangler_t *dmp = mdb.m_demangler;
 259 
 260         if (argc > 0)
 261                 return (DCMD_USAGE);
 262 
 263         if (dmp != NULL && !(mdb.m_flags & MDB_FL_DEMANGLE)) {
 264                 mdb_printf("C++ symbol demangling enabled\n");
 265                 mdb.m_flags |= MDB_FL_DEMANGLE;
 266 
 267         } else if (dmp == NULL) {
 268                 if ((mdb.m_demangler = mdb_dem_load()) != NULL) {
 269                         mdb_printf("C++ symbol demangling enabled\n");
 270                         mdb.m_flags |= MDB_FL_DEMANGLE;
 271                 } else {
 272                         mdb_warn("no memory to load C++ demangler");
 273                         mdb.m_flags &= ~MDB_FL_DEMANGLE;
 274                 }
 275 
 276         } else {
 277                 mdb_dem_unload(mdb.m_demangler);
 278                 mdb.m_flags &= ~MDB_FL_DEMANGLE;
 279                 mdb.m_demangler = NULL;
 280                 mdb_printf("C++ symbol demangling disabled\n");
 281         }
 282 
 283         return (DCMD_OK);
 284 }
 285 
 286 /*ARGSUSED*/
 287 int
 288 cmd_demflags(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
 289 {
 290         static const char *const dm_desc[] = {
 291                 "static/const/volatile member func qualifiers displayed",
 292                 "scope resolution specifiers displayed",
 293                 "function arguments displayed",
 294                 "mangled name displayed"
 295         };
 296 
 297         mdb_demangler_t *dmp = mdb.m_demangler;
 298         int i;
 299 
 300         if (argc > 0)
 301                 return (DCMD_USAGE);
 302 
 303         if (dmp == NULL || !(mdb.m_flags & MDB_FL_DEMANGLE)) {
 304                 mdb_warn("C++ demangling facility is currently disabled\n");
 305                 return (DCMD_ERR);
 306         }
 307 
 308         if (flags & DCMD_ADDRSPEC)
 309                 dmp->dm_flags = ((uint_t)addr & MDB_DM_ALL);
 310 
 311         for (i = 0; i < sizeof (dm_desc) / sizeof (dm_desc[0]); i++) {
 312                 mdb_printf("0x%x\t%s\t%s\n", 1 << i,
 313                     (dmp->dm_flags & (1 << i)) ? "on" : "off", dm_desc[i]);
 314         }
 315 
 316         return (DCMD_OK);
 317 }
 318 
 319 /*ARGSUSED*/
 320 int
 321 cmd_demstr(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
 322 {
 323         if ((flags & DCMD_ADDRSPEC) || argc == 0)
 324                 return (DCMD_USAGE);
 325 
 326         for (; argc != 0; argc--, argv++) {
 327                 mdb_printf("%s == %s\n", argv->a_un.a_str,
 328                     mdb_dem_convert(mdb.m_demangler, argv->a_un.a_str));
 329         }
 330 
 331         return (DCMD_OK);
 332 }