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| 1 // Copyright (c) 2010 Google Inc. All Rights Reserved. | |
| 2 // | |
| 3 // Redistribution and use in source and binary forms, with or without | |
| 4 // modification, are permitted provided that the following conditions are | |
| 5 // met: | |
| 6 // | |
| 7 // * Redistributions of source code must retain the above copyright | |
| 8 // notice, this list of conditions and the following disclaimer. | |
| 9 // * Redistributions in binary form must reproduce the above | |
| 10 // copyright notice, this list of conditions and the following disclaimer | |
| 11 // in the documentation and/or other materials provided with the | |
| 12 // distribution. | |
| 13 // * Neither the name of Google Inc. nor the names of its | |
| 14 // contributors may be used to endorse or promote products derived from | |
| 15 // this software without specific prior written permission. | |
| 16 // | |
| 17 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | |
| 18 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | |
| 19 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR | |
| 20 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT | |
| 21 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, | |
| 22 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT | |
| 23 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
| 24 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
| 25 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
| 26 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE | |
| 27 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
| 28 | |
| 29 // Original author: Jim Blandy <jimb@mozilla.com> <jimb@red-bean.com> | |
| 30 | |
| 31 // This file implements the google_breakpad::StabsReader class. | |
| 32 // See stabs_reader.h. | |
| 33 | |
| 34 #include <a.out.h> | |
| 35 #include <stab.h> | |
| 36 #include <cstring> | |
| 37 #include <cassert> | |
| 38 | |
| 39 #include "common/stabs_reader.h" | |
| 40 | |
| 41 namespace google_breakpad { | |
| 42 | |
| 43 StabsReader::StabsReader(const uint8_t *stab, size_t stab_size, | |
| 44 const uint8_t *stabstr, size_t stabstr_size, | |
| 45 StabsHandler *handler) : | |
| 46 stabstr_(stabstr), | |
| 47 stabstr_size_(stabstr_size), | |
| 48 handler_(handler), | |
| 49 string_offset_(0), | |
| 50 next_cu_string_offset_(0), | |
| 51 symbol_(NULL), | |
| 52 current_source_file_(NULL) { | |
| 53 symbols_ = reinterpret_cast<const struct nlist *>(stab); | |
| 54 symbols_end_ = symbols_ + (stab_size / sizeof (*symbols_)); | |
| 55 } | |
| 56 | |
| 57 const char *StabsReader::SymbolString() { | |
| 58 ptrdiff_t offset = string_offset_ + symbol_->n_un.n_strx; | |
| 59 if (offset < 0 || (size_t) offset >= stabstr_size_) { | |
| 60 handler_->Warning("symbol %d: name offset outside the string section\n", | |
| 61 symbol_ - symbols_); | |
| 62 // Return our null string, to keep our promise about all names being | |
| 63 // taken from the string section. | |
| 64 offset = 0; | |
| 65 } | |
| 66 return reinterpret_cast<const char *>(stabstr_ + offset); | |
| 67 } | |
| 68 | |
| 69 bool StabsReader::Process() { | |
| 70 symbol_ = symbols_; | |
| 71 while (symbol_ < symbols_end_) { | |
| 72 if (symbol_->n_type == N_SO) { | |
| 73 if (! ProcessCompilationUnit()) | |
| 74 return false; | |
| 75 } else if (symbol_->n_type == N_UNDF) { | |
| 76 // At the head of each compilation unit's entries there is an | |
| 77 // N_UNDF stab giving the number of symbols in the compilation | |
| 78 // unit, and the number of bytes that compilation unit's strings | |
| 79 // take up in the .stabstr section. Each CU's strings are | |
| 80 // separate; the n_strx values are offsets within the current | |
| 81 // CU's portion of the .stabstr section. | |
| 82 // | |
| 83 // As an optimization, the GNU linker combines all the | |
| 84 // compilation units into one, with a single N_UNDF at the | |
| 85 // beginning. However, other linkers, like Gold, do not perform | |
| 86 // this optimization. | |
| 87 string_offset_ = next_cu_string_offset_; | |
| 88 next_cu_string_offset_ = SymbolValue(); | |
| 89 symbol_++; | |
| 90 } else | |
| 91 symbol_++; | |
| 92 } | |
| 93 return true; | |
| 94 } | |
| 95 | |
| 96 bool StabsReader::ProcessCompilationUnit() { | |
| 97 assert(symbol_ < symbols_end_ && symbol_->n_type == N_SO); | |
| 98 | |
| 99 // There may be an N_SO entry whose name ends with a slash, | |
| 100 // indicating the directory in which the compilation occurred. | |
| 101 // The build directory defaults to NULL. | |
| 102 const char *build_directory = NULL; | |
| 103 { | |
| 104 const char *name = SymbolString(); | |
| 105 if (name[0] && name[strlen(name) - 1] == '/') { | |
| 106 build_directory = name; | |
| 107 symbol_++; | |
| 108 } | |
| 109 } | |
| 110 | |
| 111 // We expect to see an N_SO entry with a filename next, indicating | |
| 112 // the start of the compilation unit. | |
| 113 { | |
| 114 if (symbol_ >= symbols_end_ || symbol_->n_type != N_SO) | |
| 115 return true; | |
| 116 const char *name = SymbolString(); | |
| 117 if (name[0] == '\0') { | |
| 118 // This seems to be a stray end-of-compilation-unit marker; | |
| 119 // consume it, but don't report the end, since we didn't see a | |
| 120 // beginning. | |
| 121 symbol_++; | |
| 122 return true; | |
| 123 } | |
| 124 current_source_file_ = name; | |
| 125 } | |
| 126 | |
| 127 if (! handler_->StartCompilationUnit(current_source_file_, | |
| 128 SymbolValue(), | |
| 129 build_directory)) | |
| 130 return false; | |
| 131 | |
| 132 symbol_++; | |
| 133 | |
| 134 // The STABS documentation says that some compilers may emit | |
| 135 // additional N_SO entries with names immediately following the | |
| 136 // first, and that they should be ignored. However, the original | |
| 137 // Breakpad STABS reader doesn't ignore them, so we won't either. | |
| 138 | |
| 139 // Process the body of the compilation unit, up to the next N_SO. | |
| 140 while (symbol_ < symbols_end_ && symbol_->n_type != N_SO) { | |
| 141 if (symbol_->n_type == N_FUN) { | |
| 142 if (! ProcessFunction()) | |
| 143 return false; | |
| 144 } else | |
| 145 // Ignore anything else. | |
| 146 symbol_++; | |
| 147 } | |
| 148 | |
| 149 // An N_SO with an empty name indicates the end of the compilation | |
| 150 // unit. Default to zero. | |
| 151 uint64_t ending_address = 0; | |
| 152 if (symbol_ < symbols_end_) { | |
| 153 assert(symbol_->n_type == N_SO); | |
| 154 const char *name = SymbolString(); | |
| 155 if (name[0] == '\0') { | |
| 156 ending_address = SymbolValue(); | |
| 157 symbol_++; | |
| 158 } | |
| 159 } | |
| 160 | |
| 161 if (! handler_->EndCompilationUnit(ending_address)) | |
| 162 return false; | |
| 163 | |
| 164 return true; | |
| 165 } | |
| 166 | |
| 167 bool StabsReader::ProcessFunction() { | |
| 168 assert(symbol_ < symbols_end_ && symbol_->n_type == N_FUN); | |
| 169 | |
| 170 uint64_t function_address = SymbolValue(); | |
| 171 // The STABS string for an N_FUN entry is the name of the function, | |
| 172 // followed by a colon, followed by type information for the | |
| 173 // function. We want to pass the name alone to StartFunction. | |
| 174 const char *stab_string = SymbolString(); | |
| 175 const char *name_end = strchr(stab_string, ':'); | |
| 176 if (! name_end) | |
| 177 name_end = stab_string + strlen(stab_string); | |
| 178 std::string name(stab_string, name_end - stab_string); | |
| 179 if (! handler_->StartFunction(name, function_address)) | |
| 180 return false; | |
| 181 symbol_++; | |
| 182 | |
| 183 while (symbol_ < symbols_end_) { | |
| 184 if (symbol_->n_type == N_SO || symbol_->n_type == N_FUN) | |
| 185 break; | |
| 186 else if (symbol_->n_type == N_SLINE) { | |
| 187 // The value of an N_SLINE entry is the offset of the line from | |
| 188 // the function's start address. | |
| 189 uint64_t line_address = function_address + SymbolValue(); | |
| 190 // The n_desc of a N_SLINE entry is the line number. It's a | |
| 191 // signed 16-bit field; line numbers from 32768 to 65535 are | |
| 192 // stored as n-65536. | |
| 193 uint16_t line_number = symbol_->n_desc; | |
| 194 if (! handler_->Line(line_address, current_source_file_, line_number)) | |
| 195 return false; | |
| 196 symbol_++; | |
| 197 } else if (symbol_->n_type == N_SOL) { | |
| 198 current_source_file_ = SymbolString(); | |
| 199 symbol_++; | |
| 200 } else | |
| 201 // Ignore anything else. | |
| 202 symbol_++; | |
| 203 } | |
| 204 | |
| 205 // If there is a subsequent N_SO or N_FUN entry, its address is our | |
| 206 // end address. | |
| 207 uint64_t ending_address = 0; | |
| 208 if (symbol_ < symbols_end_) { | |
| 209 assert(symbol_->n_type == N_SO || symbol_->n_type == N_FUN); | |
| 210 ending_address = SymbolValue(); | |
| 211 // Note: we do not increment symbol_ here, since we haven't consumed it. | |
| 212 } | |
| 213 | |
| 214 if (! handler_->EndFunction(ending_address)) | |
| 215 return false; | |
| 216 | |
| 217 return true; | |
| 218 } | |
| 219 | |
| 220 } // namespace google_breakpad | |
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Chromium Code Reviews
Issue 10928195:
First round of dead file removal (Closed)
Base URL: https://github.com/samclegg/nativeclient-sdk.git@master