1 | // Copyright (c) 2006, Google Inc. |
2 | // All rights reserved. |
3 | // |
4 | // Redistribution and use in source and binary forms, with or without |
5 | // modification, are permitted provided that the following conditions are |
6 | // met: |
7 | // |
8 | // * Redistributions of source code must retain the above copyright |
9 | // notice, this list of conditions and the following disclaimer. |
10 | // * Redistributions in binary form must reproduce the above |
11 | // copyright notice, this list of conditions and the following disclaimer |
12 | // in the documentation and/or other materials provided with the |
13 | // distribution. |
14 | // * Neither the name of Google Inc. nor the names of its |
15 | // contributors may be used to endorse or promote products derived from |
16 | // this software without specific prior written permission. |
17 | // |
18 | // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
19 | // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
20 | // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
21 | // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
22 | // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
23 | // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
24 | // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
25 | // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
26 | // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
27 | // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
28 | // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
29 | |
30 | #ifndef GOOGLE_BREAKPAD_PROCESSOR_STACK_FRAME_H__ |
31 | #define GOOGLE_BREAKPAD_PROCESSOR_STACK_FRAME_H__ |
32 | |
33 | #include <string> |
34 | |
35 | #include "common/using_std_string.h" |
36 | #include "google_breakpad/common/breakpad_types.h" |
37 | |
38 | namespace google_breakpad { |
39 | |
40 | class CodeModule; |
41 | |
42 | struct StackFrame { |
43 | // Indicates how well the instruction pointer derived during |
44 | // stack walking is trusted. Since the stack walker can resort to |
45 | // stack scanning, it can wind up with dubious frames. |
46 | // In rough order of "trust metric". |
47 | enum FrameTrust { |
48 | FRAME_TRUST_NONE, // Unknown |
49 | FRAME_TRUST_SCAN, // Scanned the stack, found this |
50 | FRAME_TRUST_CFI_SCAN, // Found while scanning stack using call frame info |
51 | FRAME_TRUST_FP, // Derived from frame pointer |
52 | FRAME_TRUST_CFI, // Derived from call frame info |
53 | FRAME_TRUST_PREWALKED, // Explicitly provided by some external stack walker. |
54 | FRAME_TRUST_CONTEXT, // Given as instruction pointer in a context |
55 | FRAME_TRUST_INLINE // Found by inline records in symbol files. |
56 | }; |
57 | |
58 | StackFrame() |
59 | : instruction(), |
60 | module(NULL), |
61 | function_name(), |
62 | function_base(), |
63 | source_file_name(), |
64 | source_line(0), |
65 | source_line_base(), |
66 | trust(FRAME_TRUST_NONE), |
67 | is_multiple(false) {} |
68 | virtual ~StackFrame() {} |
69 | |
70 | // Return a string describing how this stack frame was found |
71 | // by the stackwalker. |
72 | string trust_description() const { |
73 | switch (trust) { |
74 | case StackFrame::FRAME_TRUST_CONTEXT: |
75 | return "given as instruction pointer in context" ; |
76 | case StackFrame::FRAME_TRUST_PREWALKED: |
77 | return "recovered by external stack walker" ; |
78 | case StackFrame::FRAME_TRUST_CFI: |
79 | return "call frame info" ; |
80 | case StackFrame::FRAME_TRUST_CFI_SCAN: |
81 | return "call frame info with scanning" ; |
82 | case StackFrame::FRAME_TRUST_FP: |
83 | return "previous frame's frame pointer" ; |
84 | case StackFrame::FRAME_TRUST_SCAN: |
85 | return "stack scanning" ; |
86 | case StackFrame::FRAME_TRUST_INLINE: |
87 | return "inline record" ; |
88 | default: |
89 | return "unknown" ; |
90 | } |
91 | } |
92 | |
93 | // Return the actual return address, as saved on the stack or in a |
94 | // register. See the comments for 'instruction', below, for details. |
95 | virtual uint64_t ReturnAddress() const { return instruction; } |
96 | |
97 | // The program counter location as an absolute virtual address. |
98 | // |
99 | // - For the innermost called frame in a stack, this will be an exact |
100 | // program counter or instruction pointer value. |
101 | // |
102 | // - For all other frames, this address is within the instruction that |
103 | // caused execution to branch to this frame's callee (although it may |
104 | // not point to the exact beginning of that instruction). This ensures |
105 | // that, when we look up the source code location for this frame, we |
106 | // get the source location of the call, not of the point at which |
107 | // control will resume when the call returns, which may be on the next |
108 | // line. (If the compiler knows the callee never returns, it may even |
109 | // place the call instruction at the very end of the caller's machine |
110 | // code, such that the "return address" (which will never be used) |
111 | // immediately after the call instruction is in an entirely different |
112 | // function, perhaps even from a different source file.) |
113 | // |
114 | // On some architectures, the return address as saved on the stack or in |
115 | // a register is fine for looking up the point of the call. On others, it |
116 | // requires adjustment. ReturnAddress returns the address as saved by the |
117 | // machine. |
118 | uint64_t instruction; |
119 | |
120 | // The module in which the instruction resides. |
121 | const CodeModule *module; |
122 | |
123 | // The function name, may be omitted if debug symbols are not available. |
124 | string function_name; |
125 | |
126 | // The start address of the function, may be omitted if debug symbols |
127 | // are not available. |
128 | uint64_t function_base; |
129 | |
130 | // The source file name, may be omitted if debug symbols are not available. |
131 | string source_file_name; |
132 | |
133 | // The (1-based) source line number, may be omitted if debug symbols are |
134 | // not available. |
135 | int source_line; |
136 | |
137 | // The start address of the source line, may be omitted if debug symbols |
138 | // are not available. |
139 | uint64_t source_line_base; |
140 | |
141 | // Amount of trust the stack walker has in the instruction pointer |
142 | // of this frame. |
143 | FrameTrust trust; |
144 | |
145 | // True if the frame corresponds to multiple functions, for example as the |
146 | // result of identical code folding by the linker. In that case the function |
147 | // name, filename, etc. information above represents the state of an arbitrary |
148 | // one of these functions. |
149 | bool is_multiple; |
150 | }; |
151 | |
152 | } // namespace google_breakpad |
153 | |
154 | #endif // GOOGLE_BREAKPAD_PROCESSOR_STACK_FRAME_H__ |
155 | |