summaryrefslogtreecommitdiff
path: root/absl/debugging/internal/symbolize.h
blob: 663d774d42fa0932e802007cbd37ef6276b2310a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
// Copyright 2018 The Abseil Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

// This file contains internal parts of the Abseil symbolizer.
// Do not depend on the anything in this file, it may change at anytime.

#ifndef ABSL_DEBUGGING_INTERNAL_SYMBOLIZE_H_
#define ABSL_DEBUGGING_INTERNAL_SYMBOLIZE_H_

#include <cstddef>
#include <cstdint>

#include "absl/base/config.h"
#include "absl/strings/string_view.h"

#ifdef ABSL_INTERNAL_HAVE_ELF_SYMBOLIZE
#error ABSL_INTERNAL_HAVE_ELF_SYMBOLIZE cannot be directly set
#elif defined(__ELF__) && defined(__GLIBC__) && !defined(__native_client__) && \
    !defined(__asmjs__) && !defined(__wasm__)
#define ABSL_INTERNAL_HAVE_ELF_SYMBOLIZE 1

#include <elf.h>
#include <link.h>  // For ElfW() macro.
#include <functional>
#include <string>

namespace absl {
ABSL_NAMESPACE_BEGIN
namespace debugging_internal {

// Iterates over all sections, invoking callback on each with the section name
// and the section header.
//
// Returns true on success; otherwise returns false in case of errors.
//
// This is not async-signal-safe.
bool ForEachSection(int fd,
                    const std::function<bool(absl::string_view name,
                                             const ElfW(Shdr) &)>& callback);

// Gets the section header for the given name, if it exists. Returns true on
// success. Otherwise, returns false.
bool GetSectionHeaderByName(int fd, const char *name, size_t name_len,
                            ElfW(Shdr) *out);

}  // namespace debugging_internal
ABSL_NAMESPACE_END
}  // namespace absl

#endif  // ABSL_INTERNAL_HAVE_ELF_SYMBOLIZE

#ifdef ABSL_INTERNAL_HAVE_DARWIN_SYMBOLIZE
#error ABSL_INTERNAL_HAVE_DARWIN_SYMBOLIZE cannot be directly set
#elif defined(__APPLE__)
#define ABSL_INTERNAL_HAVE_DARWIN_SYMBOLIZE 1
#endif

namespace absl {
ABSL_NAMESPACE_BEGIN
namespace debugging_internal {

struct SymbolDecoratorArgs {
  // The program counter we are getting symbolic name for.
  const void *pc;
  // 0 for main executable, load address for shared libraries.
  ptrdiff_t relocation;
  // Read-only file descriptor for ELF image covering "pc",
  // or -1 if no such ELF image exists in /proc/self/maps.
  int fd;
  // Output buffer, size.
  // Note: the buffer may not be empty -- default symbolizer may have already
  // produced some output, and earlier decorators may have adorned it in
  // some way. You are free to replace or augment the contents (within the
  // symbol_buf_size limit).
  char *const symbol_buf;
  size_t symbol_buf_size;
  // Temporary scratch space, size.
  // Use that space in preference to allocating your own stack buffer to
  // conserve stack.
  char *const tmp_buf;
  size_t tmp_buf_size;
  // User-provided argument
  void* arg;
};
using SymbolDecorator = void (*)(const SymbolDecoratorArgs *);

// Installs a function-pointer as a decorator. Returns a value less than zero
// if the system cannot install the decorator. Otherwise, returns a unique
// identifier corresponding to the decorator. This identifier can be used to
// uninstall the decorator - See RemoveSymbolDecorator() below.
int InstallSymbolDecorator(SymbolDecorator decorator, void* arg);

// Removes a previously installed function-pointer decorator. Parameter "ticket"
// is the return-value from calling InstallSymbolDecorator().
bool RemoveSymbolDecorator(int ticket);

// Remove all installed decorators.  Returns true if successful, false if
// symbolization is currently in progress.
bool RemoveAllSymbolDecorators(void);

// Registers an address range to a file mapping.
//
// Preconditions:
//   start <= end
//   filename != nullptr
//
// Returns true if the file was successfully registered.
bool RegisterFileMappingHint(
    const void* start, const void* end, uint64_t offset, const char* filename);

// Looks up the file mapping registered by RegisterFileMappingHint for an
// address range. If there is one, the file name is stored in *filename and
// *start and *end are modified to reflect the registered mapping. Returns
// whether any hint was found.
bool GetFileMappingHint(const void** start,
                        const void** end,
                        uint64_t    *  offset,
                        const char** filename);

}  // namespace debugging_internal
ABSL_NAMESPACE_END
}  // namespace absl

#endif  // ABSL_DEBUGGING_INTERNAL_SYMBOLIZE_H_