tools/perf/util/demangle-java.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <sys/types.h>
   3 #include <stdio.h>
   4 #include <stdlib.h>
   5 #include <string.h>
   6 #include "symbol.h"
   7
   8 #include "demangle-java.h"
   9
  10 #include <linux/ctype.h>
  11 #include <linux/kernel.h>
  12
  13 enum {
  14         MODE_PREFIX = 0,
  15         MODE_CLASS  = 1,
  16         MODE_FUNC   = 2,
  17         MODE_TYPE   = 3,
  18         MODE_CTYPE  = 4, /* class arg */
  19 };
  20
  21 #define BASE_ENT(c, n)  [c - 'A']=n
  22 static const char *base_types['Z' - 'A' + 1] = {
  23         BASE_ENT('B', "byte" ),
  24         BASE_ENT('C', "char" ),
  25         BASE_ENT('D', "double" ),
  26         BASE_ENT('F', "float" ),
  27         BASE_ENT('I', "int" ),
  28         BASE_ENT('J', "long" ),
  29         BASE_ENT('S', "short" ),
  30         BASE_ENT('Z', "boolean" ),
  31 };
  32
  33 /*
  34  * demangle Java symbol between str and end positions and stores
  35  * up to maxlen characters into buf. The parser starts in mode.
  36  *
  37  * Use MODE_PREFIX to process entire prototype till end position
  38  * Use MODE_TYPE to process return type if str starts on return type char
  39  *
  40  *  Return:
  41  *      success: buf
  42  *      error  : NULL
  43  */
  44 static char *
  45 __demangle_java_sym(const char *str, const char *end, char *buf, int maxlen, int mode)
  46 {
  47         int rlen = 0;
  48         int array = 0;
  49         int narg = 0;
  50         const char *q;
  51
  52         if (!end)
  53                 end = str + strlen(str);
  54
  55         for (q = str; q != end; q++) {
  56
  57                 if (rlen == (maxlen - 1))
  58                         break;
  59
  60                 switch (*q) {
  61                 case 'L':
  62                         if (mode == MODE_PREFIX || mode == MODE_TYPE) {
  63                                 if (mode == MODE_TYPE) {
  64                                         if (narg)
  65                                                 rlen += scnprintf(buf + rlen, maxlen - rlen, ", ");
  66                                         narg++;
  67                                 }
  68                                 if (mode == MODE_PREFIX)
  69                                         mode = MODE_CLASS;
  70                                 else
  71                                         mode = MODE_CTYPE;
  72                         } else
  73                                 buf[rlen++] = *q;
  74                         break;
  75                 case 'B':
  76                 case 'C':
  77                 case 'D':
  78                 case 'F':
  79                 case 'I':
  80                 case 'J':
  81                 case 'S':
  82                 case 'Z':
  83                         if (mode == MODE_TYPE) {
  84                                 if (narg)
  85                                         rlen += scnprintf(buf + rlen, maxlen - rlen, ", ");
  86                                 rlen += scnprintf(buf + rlen, maxlen - rlen, "%s", base_types[*q - 'A']);
  87                                 while (array--)
  88                                         rlen += scnprintf(buf + rlen, maxlen - rlen, "[]");
  89                                 array = 0;
  90                                 narg++;
  91                         } else
  92                                 buf[rlen++] = *q;
  93                         break;
  94                 case 'V':
  95                         if (mode == MODE_TYPE) {
  96                                 rlen += scnprintf(buf + rlen, maxlen - rlen, "void");
  97                                 while (array--)
  98                                         rlen += scnprintf(buf + rlen, maxlen - rlen, "[]");
  99                                 array = 0;
 100                         } else
 101                                 buf[rlen++] = *q;
 102                         break;
 103                 case '[':
 104                         if (mode != MODE_TYPE)
 105                                 goto error;
 106                         array++;
 107                         break;
 108                 case '(':
 109                         if (mode != MODE_FUNC)
 110                                 goto error;
 111                         buf[rlen++] = *q;
 112                         mode = MODE_TYPE;
 113                         break;
 114                 case ')':
 115                         if (mode != MODE_TYPE)
 116                                 goto error;
 117                         buf[rlen++] = *q;
 118                         narg = 0;
 119                         break;
 120                 case ';':
 121                         if (mode != MODE_CLASS && mode != MODE_CTYPE)
 122                                 goto error;
 123                         /* safe because at least one other char to process */
 124                         if (isalpha(*(q + 1)) && mode == MODE_CLASS)
 125                                 rlen += scnprintf(buf + rlen, maxlen - rlen, ".");
 126                         if (mode == MODE_CLASS)
 127                                 mode = MODE_FUNC;
 128                         else if (mode == MODE_CTYPE)
 129                                 mode = MODE_TYPE;
 130                         break;
 131                 case '/':
 132                         if (mode != MODE_CLASS && mode != MODE_CTYPE)
 133                                 goto error;
 134                         rlen += scnprintf(buf + rlen, maxlen - rlen, ".");
 135                         break;
 136                 default :
 137                         buf[rlen++] = *q;
 138                 }
 139         }
 140         buf[rlen] = '\0';
 141         return buf;
 142 error:
 143         return NULL;
 144 }
 145
 146 /*
 147  * Demangle Java function signature (openJDK, not GCJ)
 148  * input:
 149  *      str: string to parse. String is not modified
 150  *    flags: comobination of JAVA_DEMANGLE_* flags to modify demangling
 151  * return:
 152  *      if input can be demangled, then a newly allocated string is returned.
 153  *      if input cannot be demangled, then NULL is returned
 154  *
 155  * Note: caller is responsible for freeing demangled string
 156  */
 157 char *
 158 java_demangle_sym(const char *str, int flags)
 159 {
 160         char *buf, *ptr;
 161         char *p;
 162         size_t len, l1 = 0;
 163
 164         if (!str)
 165                 return NULL;
 166
 167         /* find start of retunr type */
 168         p = strrchr(str, ')');
 169         if (!p)
 170                 return NULL;
 171
 172         /*
 173          * expansion factor estimated to 3x
 174          */
 175         len = strlen(str) * 3 + 1;
 176         buf = malloc(len);
 177         if (!buf)
 178                 return NULL;
 179
 180         buf[0] = '\0';
 181         if (!(flags & JAVA_DEMANGLE_NORET)) {
 182                 /*
 183                  * get return type first
 184                  */
 185                 ptr = __demangle_java_sym(p + 1, NULL, buf, len, MODE_TYPE);
 186                 if (!ptr)
 187                         goto error;
 188
 189                 /* add space between return type and function prototype */
 190                 l1 = strlen(buf);
 191                 buf[l1++] = ' ';
 192         }
 193
 194         /* process function up to return type */
 195         ptr = __demangle_java_sym(str, p + 1, buf + l1, len - l1, MODE_PREFIX);
 196         if (!ptr)
 197                 goto error;
 198
 199         return buf;
 200 error:
 201         free(buf);
 202         return NULL;
 203 }