internal/symbolize.h
Go to the documentation of this file.
1 // Copyright 2018 The Abseil Authors.
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 // https://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14 
15 // This file contains internal parts of the Abseil symbolizer.
16 // Do not depend on the anything in this file, it may change at anytime.
17 
18 #ifndef ABSL_DEBUGGING_INTERNAL_SYMBOLIZE_H_
19 #define ABSL_DEBUGGING_INTERNAL_SYMBOLIZE_H_
20 
21 #include <cstddef>
22 #include <cstdint>
23 
24 #ifdef ABSL_INTERNAL_HAVE_ELF_SYMBOLIZE
25 #error ABSL_INTERNAL_HAVE_ELF_SYMBOLIZE cannot be directly set
26 #elif defined(__ELF__) && defined(__GLIBC__) && !defined(__native_client__) && \
27  !defined(__asmjs__) && !defined(__wasm__)
28 #define ABSL_INTERNAL_HAVE_ELF_SYMBOLIZE 1
29 
30 #include <elf.h>
31 #include <link.h> // For ElfW() macro.
32 #include <functional>
33 #include <string>
34 
35 namespace absl {
36 namespace debugging_internal {
37 
38 // Iterates over all sections, invoking callback on each with the section name
39 // and the section header.
40 //
41 // Returns true on success; otherwise returns false in case of errors.
42 //
43 // This is not async-signal-safe.
44 bool ForEachSection(int fd,
45  const std::function<bool(const std::string& name,
46  const ElfW(Shdr) &)>& callback);
47 
48 // Gets the section header for the given name, if it exists. Returns true on
49 // success. Otherwise, returns false.
50 bool GetSectionHeaderByName(int fd, const char *name, size_t name_len,
51  ElfW(Shdr) *out);
52 
53 } // namespace debugging_internal
54 } // namespace absl
55 
56 #endif // ABSL_INTERNAL_HAVE_ELF_SYMBOLIZE
57 
58 namespace absl {
59 namespace debugging_internal {
60 
62  // The program counter we are getting symbolic name for.
63  const void *pc;
64  // 0 for main executable, load address for shared libraries.
65  ptrdiff_t relocation;
66  // Read-only file descriptor for ELF image covering "pc",
67  // or -1 if no such ELF image exists in /proc/self/maps.
68  int fd;
69  // Output buffer, size.
70  // Note: the buffer may not be empty -- default symbolizer may have already
71  // produced some output, and earlier decorators may have adorned it in
72  // some way. You are free to replace or augment the contents (within the
73  // symbol_buf_size limit).
74  char *const symbol_buf;
76  // Temporary scratch space, size.
77  // Use that space in preference to allocating your own stack buffer to
78  // conserve stack.
79  char *const tmp_buf;
80  size_t tmp_buf_size;
81  // User-provided argument
82  void* arg;
83 };
84 using SymbolDecorator = void (*)(const SymbolDecoratorArgs *);
85 
86 // Installs a function-pointer as a decorator. Returns a value less than zero
87 // if the system cannot install the decorator. Otherwise, returns a unique
88 // identifier corresponding to the decorator. This identifier can be used to
89 // uninstall the decorator - See RemoveSymbolDecorator() below.
90 int InstallSymbolDecorator(SymbolDecorator decorator, void* arg);
91 
92 // Removes a previously installed function-pointer decorator. Parameter "ticket"
93 // is the return-value from calling InstallSymbolDecorator().
94 bool RemoveSymbolDecorator(int ticket);
95 
96 // Remove all installed decorators. Returns true if successful, false if
97 // symbolization is currently in progress.
98 bool RemoveAllSymbolDecorators(void);
99 
100 // Registers an address range to a file mapping.
101 //
102 // Preconditions:
103 // start <= end
104 // filename != nullptr
105 //
106 // Returns true if the file was successfully registered.
108  const void* start, const void* end, uint64_t offset, const char* filename);
109 
110 // Looks up the file mapping registered by RegisterFileMappingHint for an
111 // address range. If there is one, the file name is stored in *filename and
112 // *start and *end are modified to reflect the registered mapping. Returns
113 // whether any hint was found.
114 bool GetFileMappingHint(const void** start,
115  const void** end,
116  uint64_t * offset,
117  const char** filename);
118 
119 } // namespace debugging_internal
120 } // namespace absl
121 
122 #endif // ABSL_DEBUGGING_INTERNAL_SYMBOLIZE_H_
int InstallSymbolDecorator(SymbolDecorator decorator, void *arg)
char * end
Definition: algorithm.h:29
bool RegisterFileMappingHint(const void *start, const void *end, uint64_t offset, const char *filename)
bool RemoveAllSymbolDecorators(void)
char name[1]
Definition: mutex.cc:296
void * arg
Definition: mutex.cc:292
void(*)(const SymbolDecoratorArgs *) SymbolDecorator
char * out
Definition: mutex.h:1013
bool GetFileMappingHint(const void **start, const void **end, uint64_t *offset, const char **filename)
bool RemoveSymbolDecorator(int ticket)


abseil_cpp
Author(s):
autogenerated on Wed Jun 19 2019 19:19:58