1 /*
2 * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25
26 #ifndef SHARE_VM_UTILITIES_DECODER_HPP
27 #define SHARE_VM_UTILITIES_DECODER_HPP
28
29 #include "memory/allocation.hpp"
30 #include "runtime/mutex.hpp"
31 #include "runtime/mutexLocker.hpp"
32 #include "utilities/ostream.hpp"
33
34 class AbstractDecoder : public CHeapObj<mtInternal> {
35 public:
36 // status code for decoding native C frame
37 enum decoder_status {
38 not_available = -10, // real decoder is not available
39 no_error = 0, // no error encountered
40 no_debug_symbols, // no debug symbol ELF section
41 out_of_memory, // out of memory
42 file_invalid, // invalid elf file
43 file_not_found, // could not found symbol file (on windows), such as jvm.pdb or jvm.map
44 helper_func_error, // decoding functions not found (Windows only)
45 helper_init_error // SymInitialize failed (Windows only)
46 };
47
48 protected:
49 decoder_status _decoder_status;
50
51 public:
52 virtual ~AbstractDecoder() {}
53
54 // decode an pc address to corresponding function name and an offset from the beginning of
55 // the function
56 //
57 // Note: the 'base' variant does not demangle names. The
58 // demangling that was done systematically in the 'modulepath' variant
59 // is now optional.
60 virtual bool decode(address pc, char* buf, int buflen, int* offset,
61 const char* modulepath = NULL, bool demangle = true) = 0;
62 virtual bool decode(address pc, char* buf, int buflen, int* offset, const void* base) = 0;
63
64 // demangle a C++ symbol
65 virtual bool demangle(const char* symbol, char* buf, int buflen) = 0;
66
67 virtual decoder_status status() const {
68 return _decoder_status;
69 }
70
71 virtual bool has_error() const {
72 return is_error(_decoder_status);
73 }
74
75 static bool is_error(decoder_status status) {
76 return (status > no_error);
77 }
78 };
79
80 // Do nothing decoder
81 class NullDecoder : public AbstractDecoder {
82 public:
83 NullDecoder() {
84 _decoder_status = not_available;
85 }
86
87 virtual ~NullDecoder() {};
88
89 virtual bool decode(address pc, char* buf, int buflen, int* offset,
90 const char* modulepath, bool demangle) {
91 return false;
92 }
93
94 virtual bool decode(address pc, char* buf, int buflen, int* offset, const void* base) {
95 return false;
96 }
97
98 virtual bool demangle(const char* symbol, char* buf, int buflen) {
99 return false;
100 }
101 };
102
103 class Decoder : AllStatic {
104 public:
105 static bool decode(address pc, char* buf, int buflen, int* offset, const char* modulepath = NULL, bool demangle = true);
106 static bool decode(address pc, char* buf, int buflen, int* offset, bool demangle) {
107 return decode(pc, buf, buflen, offset, (const char*) NULL, demangle);
108 }
109 static bool decode(address pc, char* buf, int buflen, int* offset, const void* base);
110 static bool demangle(const char* symbol, char* buf, int buflen);
111
112 // Attempts to retrieve source file name and line number associated with a pc.
113 // If buf != NULL, points to a buffer of size buflen which will receive the
114 // file name. File name will be silently truncated if output buffer is too small.
115 static bool get_source_info(address pc, char* buf, size_t buflen, int* line);
116
117 static void print_state_on(outputStream* st);
118
119 protected:
120 // shared decoder instance, _shared_instance_lock is needed
121 static AbstractDecoder* get_shared_instance();
122 // a private instance for error handler. Error handler can be
123 // triggered almost everywhere, including signal handler, where
124 // no lock can be taken. So the shared decoder can not be used
125 // in this scenario.
126 static AbstractDecoder* get_error_handler_instance();
127
128 static AbstractDecoder* create_decoder();
129 private:
130 static AbstractDecoder* _shared_decoder;
131 static AbstractDecoder* _error_handler_decoder;
132 static NullDecoder _do_nothing_decoder;
133
134 protected:
135 static Mutex* _shared_decoder_lock;
136 static Mutex* shared_decoder_lock();
137
138 friend class DecoderLocker;
139 };
140
141 class DecoderLocker : public MutexLockerEx {
142 AbstractDecoder* _decoder;
143 inline bool is_first_error_thread();
144 public:
145 DecoderLocker();
146 AbstractDecoder* decoder() {
147 return _decoder;
148 }
149 };
150
151 #endif // SHARE_VM_UTILITIES_DECODER_HPP