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: combination 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 return 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 }
204
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