Stephen Hines | 7cd4c49 | 2012-03-13 19:57:37 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2012, The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | #include "bcinfo/Wrap/bitcode_wrapperer.h" |
| 18 | |
| 19 | #define LOG_TAG "bcinfo" |
| 20 | #include <cutils/log.h> |
| 21 | |
| 22 | #include <stdio.h> |
| 23 | #include <sys/stat.h> |
| 24 | |
| 25 | using std::vector; |
| 26 | |
| 27 | // The number of bytes in a 32 bit integer. |
| 28 | static const uint32_t kWordSize = 4; |
| 29 | |
| 30 | // Number of LLVM-defined fixed fields in the header. |
| 31 | static const uint32_t kLLVMFields = 4; |
| 32 | |
| 33 | // Total number of fixed fields in the header. |
| 34 | static const uint32_t kFixedFields = 7; |
| 35 | |
| 36 | // The magic number that must exist for bitcode wrappers. |
| 37 | static const uint32_t kWrapperMagicNumber = 0x0B17C0DE; |
| 38 | |
| 39 | // The version number associated with a wrapper file. |
| 40 | // Note: llvm currently only allows the value 0. When this changes, |
| 41 | // we should consider making this a command line option. |
| 42 | static const uint32_t kLLVMVersionNumber = 0; |
| 43 | |
| 44 | // Fields defined by Android bitcode header. |
| 45 | static const uint32_t kAndroidHeaderVersion = 0; |
| 46 | static const uint32_t kAndroidTargetAPI = 0; |
| 47 | static const uint32_t kAndroidDefaultCompilerVersion = 0; |
| 48 | static const uint32_t kAndroidDefaultOptimizationLevel = 3; |
| 49 | |
| 50 | // PNaCl bitcode version number. |
| 51 | static const uint32_t kPnaclBitcodeVersion = 0; |
| 52 | |
| 53 | // Max size for variable fields. Currently only used for writing them |
| 54 | // out to files (the parsing works for arbitrary sizes). |
| 55 | static const size_t kMaxVariableFieldSize = 256; |
| 56 | |
| 57 | BitcodeWrapperer::BitcodeWrapperer(WrapperInput* infile, WrapperOutput* outfile) |
| 58 | : infile_(infile), |
| 59 | outfile_(outfile), |
| 60 | buffer_size_(0), |
| 61 | cursor_(0), |
| 62 | infile_at_eof_(false), |
| 63 | infile_bc_offset_(0), |
| 64 | wrapper_bc_offset_(0), |
| 65 | wrapper_bc_size_(0), |
| 66 | android_header_version_(kAndroidHeaderVersion), |
| 67 | android_target_api_(kAndroidTargetAPI), |
| 68 | android_compiler_version_(kAndroidDefaultCompilerVersion), |
| 69 | android_optimization_level_(kAndroidDefaultOptimizationLevel), |
| 70 | pnacl_bc_version_(0), |
| 71 | error_(false) { |
| 72 | buffer_.resize(kBitcodeWrappererBufferSize); |
| 73 | if (IsInputBitcodeWrapper()) { |
| 74 | ParseWrapperHeader(); |
| 75 | } else if (IsInputBitcodeFile()) { |
| 76 | wrapper_bc_offset_ = kWordSize * kFixedFields; |
| 77 | wrapper_bc_size_ = GetInFileSize(); |
| 78 | } else { |
| 79 | ALOGE("Error: input file is not a bitcode file.\n"); |
| 80 | error_ = true; |
| 81 | } |
| 82 | } |
| 83 | |
| 84 | BitcodeWrapperer::~BitcodeWrapperer() { |
| 85 | for(size_t i = 0; i < variable_field_data_.size(); i++) { |
| 86 | delete [] variable_field_data_[i]; |
| 87 | } |
| 88 | } |
| 89 | |
| 90 | |
| 91 | void BitcodeWrapperer::ClearBuffer() { |
| 92 | buffer_size_ = 0; |
| 93 | cursor_ = 0; |
| 94 | infile_at_eof_ = false; |
| 95 | } |
| 96 | |
| 97 | bool BitcodeWrapperer::Seek(uint32_t pos) { |
Chris Wailes | 900c6c1 | 2014-08-13 15:40:00 -0700 | [diff] [blame] | 98 | if (infile_ != nullptr && infile_->Seek(pos)) { |
Stephen Hines | 7cd4c49 | 2012-03-13 19:57:37 -0700 | [diff] [blame] | 99 | ClearBuffer(); |
| 100 | return true; |
| 101 | } |
| 102 | return false; |
| 103 | } |
| 104 | |
| 105 | bool BitcodeWrapperer::CanReadWord() { |
| 106 | if (GetBufferUnreadBytes() < kWordSize) { |
| 107 | FillBuffer(); |
| 108 | return GetBufferUnreadBytes() >= kWordSize; |
| 109 | } else { |
| 110 | return true; |
| 111 | } |
| 112 | } |
| 113 | |
| 114 | void BitcodeWrapperer::FillBuffer() { |
| 115 | if (cursor_ > 0) { |
| 116 | // Before filling, move any remaining bytes to the |
| 117 | // front of the buffer. This allows us to assume |
| 118 | // that after the call to FillBuffer, readable |
| 119 | // text is contiguous. |
| 120 | if (cursor_ < buffer_size_) { |
| 121 | size_t i = 0; |
| 122 | while (cursor_ < buffer_size_) { |
| 123 | buffer_[i++] = buffer_[cursor_++]; |
| 124 | } |
| 125 | cursor_ = 0; |
| 126 | buffer_size_ = i; |
| 127 | } |
| 128 | } else { |
| 129 | // Assume the buffer contents have been used, |
| 130 | // and we want to completely refill it. |
| 131 | buffer_size_ = 0; |
| 132 | } |
| 133 | |
Stephen Hines | 1ad35fb | 2012-03-26 10:20:46 -0700 | [diff] [blame] | 134 | // If we don't have an input, we can't refill the buffer at all. |
Chris Wailes | 900c6c1 | 2014-08-13 15:40:00 -0700 | [diff] [blame] | 135 | if (infile_ == nullptr) { |
Stephen Hines | 1ad35fb | 2012-03-26 10:20:46 -0700 | [diff] [blame] | 136 | return; |
| 137 | } |
| 138 | |
Stephen Hines | 7cd4c49 | 2012-03-13 19:57:37 -0700 | [diff] [blame] | 139 | // Now fill in remaining space. |
| 140 | size_t needed = buffer_.size() - buffer_size_; |
| 141 | |
| 142 | while (buffer_.size() > buffer_size_) { |
| 143 | int actually_read = infile_->Read(&buffer_[buffer_size_], needed); |
| 144 | if (infile_->AtEof()) { |
| 145 | infile_at_eof_ = true; |
| 146 | } |
| 147 | if (actually_read) { |
| 148 | buffer_size_ += actually_read; |
| 149 | needed -= actually_read; |
| 150 | } else if (infile_at_eof_) { |
| 151 | break; |
| 152 | } |
| 153 | } |
| 154 | } |
| 155 | |
| 156 | bool BitcodeWrapperer::ReadWord(uint32_t& word) { |
| 157 | if (!CanReadWord()) return false; |
| 158 | word = (((uint32_t) BufferLookahead(0)) << 0) |
| 159 | | (((uint32_t) BufferLookahead(1)) << 8) |
| 160 | | (((uint32_t) BufferLookahead(2)) << 16) |
| 161 | | (((uint32_t) BufferLookahead(3)) << 24); |
| 162 | cursor_ += kWordSize; |
| 163 | return true; |
| 164 | } |
| 165 | |
| 166 | bool BitcodeWrapperer::WriteWord(uint32_t value) { |
| 167 | uint8_t buffer[kWordSize]; |
| 168 | buffer[3] = (value >> 24) & 0xFF; |
| 169 | buffer[2] = (value >> 16) & 0xFF; |
| 170 | buffer[1] = (value >> 8) & 0xFF; |
| 171 | buffer[0] = (value >> 0) & 0xFF; |
| 172 | return outfile_->Write(buffer, kWordSize); |
| 173 | } |
| 174 | |
| 175 | bool BitcodeWrapperer::WriteVariableFields() { |
| 176 | // This buffer may have to be bigger if we start using the fields |
| 177 | // for larger things. |
| 178 | uint8_t buffer[kMaxVariableFieldSize]; |
| 179 | for (vector<BCHeaderField>::iterator it = header_fields_.begin(); |
| 180 | it != header_fields_.end(); ++it) { |
| 181 | if (!it->Write(buffer, kMaxVariableFieldSize) || |
| 182 | !outfile_->Write(buffer, it->GetTotalSize())) { |
| 183 | return false; |
| 184 | } |
| 185 | } |
| 186 | return true; |
| 187 | } |
| 188 | |
| 189 | bool BitcodeWrapperer::ParseWrapperHeader() { |
| 190 | // Make sure LLVM-defined fields have been parsed |
| 191 | if (!IsInputBitcodeWrapper()) return false; |
| 192 | // Check the android/pnacl fields |
| 193 | if (!ReadWord(android_header_version_) || |
| 194 | !ReadWord(android_target_api_) || !ReadWord(pnacl_bc_version_)) { |
| 195 | ALOGW("Error: file not long enough to contain header\n"); |
| 196 | return false; |
| 197 | } |
| 198 | if (pnacl_bc_version_ != kPnaclBitcodeVersion) { |
| 199 | ALOGW("Error: bad PNaCl Bitcode version\n"); |
| 200 | return false; |
| 201 | } |
| 202 | int field_data_total = wrapper_bc_offset_ - kWordSize * kFixedFields; |
| 203 | if (field_data_total > 0) { |
| 204 | // Read in the variable fields. We need to allocate space for the data. |
| 205 | int field_data_read = 0; |
| 206 | |
| 207 | while (field_data_read < field_data_total) { |
| 208 | FillBuffer(); |
| 209 | size_t buffer_needed = BCHeaderField::GetDataSizeFromSerialized( |
| 210 | &buffer_[cursor_]); |
| 211 | if (buffer_needed > buffer_.size()) { |
| 212 | buffer_.resize(buffer_needed + |
| 213 | sizeof(BCHeaderField::FixedSubfield) * 2); |
| 214 | FillBuffer(); |
| 215 | } |
| 216 | variable_field_data_.push_back(new uint8_t[buffer_needed]); |
| 217 | |
| 218 | BCHeaderField field(BCHeaderField::kInvalid, 0, |
| 219 | variable_field_data_.back()); |
| 220 | field.Read(&buffer_[cursor_], buffer_size_); |
| 221 | header_fields_.push_back(field); |
| 222 | size_t field_size = field.GetTotalSize(); |
| 223 | cursor_ += field_size; |
| 224 | field_data_read += field_size; |
| 225 | if (field_data_read > field_data_total) { |
| 226 | // We read too much data, the header is corrupted |
| 227 | ALOGE("Error: raw bitcode offset inconsistent with " |
| 228 | "variable field data\n"); |
| 229 | return false; |
| 230 | } |
| 231 | |
| 232 | struct IntFieldHelper { |
| 233 | BCHeaderField::FixedSubfield tag; |
| 234 | uint16_t len; |
| 235 | uint32_t val; |
| 236 | }; |
| 237 | IntFieldHelper tempIntField; |
| 238 | |
| 239 | switch (field.getID()) { |
| 240 | case BCHeaderField::kAndroidCompilerVersion: |
| 241 | if (field.Write((uint8_t*)&tempIntField, |
| 242 | sizeof(tempIntField))) { |
| 243 | android_compiler_version_ = tempIntField.val; |
| 244 | } |
| 245 | break; |
| 246 | case BCHeaderField::kAndroidOptimizationLevel: |
| 247 | if (field.Write((uint8_t*)&tempIntField, |
| 248 | sizeof(tempIntField))) { |
| 249 | android_optimization_level_ = tempIntField.val; |
| 250 | } |
| 251 | break; |
| 252 | default: |
| 253 | // Ignore other field types for now |
| 254 | break; |
| 255 | } |
| 256 | } |
| 257 | Seek(0); |
| 258 | } |
| 259 | return true; |
| 260 | } |
| 261 | |
| 262 | bool BitcodeWrapperer::IsInputBitcodeWrapper() { |
| 263 | ResetCursor(); |
| 264 | // First make sure that there are enough words (LLVM header) |
| 265 | // to peek at. |
| 266 | if (GetBufferUnreadBytes() < kLLVMFields * kWordSize) { |
| 267 | FillBuffer(); |
| 268 | if (GetBufferUnreadBytes() < kLLVMFields * kWordSize) return false; |
| 269 | } |
| 270 | |
| 271 | // Now make sure the magic number is right. |
| 272 | uint32_t first_word; |
| 273 | if ((!ReadWord(first_word)) || |
| 274 | (kWrapperMagicNumber != first_word)) return false; |
| 275 | |
| 276 | // Make sure the version is right. |
| 277 | uint32_t second_word; |
| 278 | if ((!ReadWord(second_word)) || |
| 279 | (kLLVMVersionNumber != second_word)) return false; |
| 280 | |
| 281 | // Make sure that the offset and size (for llvm) is defined. |
| 282 | uint32_t bc_offset; |
| 283 | uint32_t bc_size; |
| 284 | if (ReadWord(bc_offset) && |
| 285 | ReadWord(bc_size)) { |
| 286 | // Before returning, save the extracted values. |
| 287 | wrapper_bc_offset_ = bc_offset; |
| 288 | infile_bc_offset_ = bc_offset; |
| 289 | wrapper_bc_size_ = bc_size; |
| 290 | return true; |
| 291 | } |
| 292 | // If reached, unable to read wrapped header. |
| 293 | return false; |
| 294 | } |
| 295 | |
| 296 | bool BitcodeWrapperer::IsInputBitcodeFile() { |
| 297 | ResetCursor(); |
| 298 | // First make sure that there are four bytes to peek at. |
| 299 | if (GetBufferUnreadBytes() < kWordSize) { |
| 300 | FillBuffer(); |
| 301 | if (GetBufferUnreadBytes() < kWordSize) return false; |
| 302 | } |
| 303 | // If reached, Check if first 4 bytes match bitcode |
| 304 | // file magic number. |
| 305 | return (BufferLookahead(0) == 'B') && |
| 306 | (BufferLookahead(1) == 'C') && |
| 307 | (BufferLookahead(2) == 0xc0) && |
| 308 | (BufferLookahead(3) == 0xde); |
| 309 | } |
| 310 | |
| 311 | bool BitcodeWrapperer::BufferCopyInToOut(uint32_t size) { |
| 312 | while (size > 0) { |
| 313 | // Be sure buffer is non-empty before writing. |
| 314 | if (0 == buffer_size_) { |
| 315 | FillBuffer(); |
| 316 | if (0 == buffer_size_) { |
| 317 | return false; |
| 318 | } |
| 319 | } |
| 320 | // copy the buffer to the output file. |
| 321 | size_t block = (buffer_size_ < size) ? buffer_size_ : size; |
| 322 | if (!outfile_->Write(&buffer_[cursor_], block)) return false; |
| 323 | size -= block; |
| 324 | buffer_size_ = 0; |
| 325 | } |
| 326 | // Be sure that there isn't more bytes on the input stream. |
| 327 | FillBuffer(); |
| 328 | return buffer_size_ == 0; |
| 329 | } |
| 330 | |
| 331 | void BitcodeWrapperer::AddHeaderField(BCHeaderField* field) { |
| 332 | header_fields_.push_back(*field); |
| 333 | wrapper_bc_offset_ += field->GetTotalSize(); |
| 334 | } |
| 335 | |
| 336 | bool BitcodeWrapperer::WriteBitcodeWrapperHeader() { |
| 337 | return |
| 338 | // Note: This writes out the 4 word header required by llvm wrapped |
| 339 | // bitcode. |
| 340 | WriteWord(kWrapperMagicNumber) && |
| 341 | WriteWord(kLLVMVersionNumber) && |
| 342 | WriteWord(wrapper_bc_offset_) && |
| 343 | WriteWord(wrapper_bc_size_) && |
| 344 | // 2 fixed fields defined by Android |
| 345 | WriteWord(android_header_version_) && |
| 346 | WriteWord(android_target_api_) && |
| 347 | // PNaClBitcode version |
| 348 | WriteWord(kPnaclBitcodeVersion) && |
| 349 | // Common variable-length fields |
| 350 | WriteVariableFields(); |
| 351 | } |
| 352 | |
| 353 | void BitcodeWrapperer::PrintWrapperHeader() { |
| 354 | if (error_) { |
| 355 | fprintf(stderr, "Error condition exists: the following" |
| 356 | "data may not be reliable\n"); |
| 357 | } |
| 358 | fprintf(stderr, "Wrapper magic:\t\t%x\n", kWrapperMagicNumber); |
| 359 | fprintf(stderr, "LLVM Bitcode version:\t%d\n", kLLVMVersionNumber); |
| 360 | fprintf(stderr, "Raw bitcode offset:\t%d\n", wrapper_bc_offset_); |
| 361 | fprintf(stderr, "Raw bitcode size:\t%d\n", wrapper_bc_size_); |
| 362 | fprintf(stderr, "Android header version:\t%d\n", android_header_version_); |
| 363 | fprintf(stderr, "Android target API:\t%d\n", android_target_api_); |
| 364 | fprintf(stderr, "PNaCl bitcode version:\t%d\n", kPnaclBitcodeVersion); |
| 365 | for (size_t i = 0; i < header_fields_.size(); i++) header_fields_[i].Print(); |
| 366 | } |
| 367 | |
| 368 | bool BitcodeWrapperer::GenerateWrappedBitcodeFile() { |
| 369 | if (!error_ && |
| 370 | WriteBitcodeWrapperHeader() && |
| 371 | Seek(infile_bc_offset_) && |
| 372 | BufferCopyInToOut(wrapper_bc_size_)) { |
| 373 | off_t dangling = wrapper_bc_size_ & 3; |
| 374 | if (dangling) { |
| 375 | return outfile_->Write((const uint8_t*) "\0\0\0\0", 4 - dangling); |
| 376 | } |
| 377 | return true; |
| 378 | } |
| 379 | return false; |
| 380 | } |
| 381 | |
| 382 | bool BitcodeWrapperer::GenerateRawBitcodeFile() { |
| 383 | return !error_ && Seek(infile_bc_offset_) && |
| 384 | BufferCopyInToOut(wrapper_bc_size_); |
| 385 | } |