lib/DebugInfo/DWARFDebugInfoEntry.cpp

   1 //===-- DWARFDebugInfoEntry.cpp --------------------------------------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 #include "DWARFDebugInfoEntry.h"
  11 #include "DWARFCompileUnit.h"
  12 #include "DWARFContext.h"
  13 #include "DWARFDebugAbbrev.h"
  14 #include "DWARFFormValue.h"
  15 #include "llvm/Support/Dwarf.h"
  16 #include "llvm/Support/Format.h"
  17 #include "llvm/Support/raw_ostream.h"
  18 using namespace llvm;
  19 using namespace dwarf;
  20
  21 void DWARFDebugInfoEntryMinimal::dump(raw_ostream &OS,
  22                                       const DWARFCompileUnit *cu,
  23                                       unsigned recurseDepth,
  24                                       unsigned indent) const {
  25   DataExtractor debug_info_data = cu->getDebugInfoExtractor();
  26   uint32_t offset = Offset;
  27
  28   if (debug_info_data.isValidOffset(offset)) {
  29     uint64_t abbrCode = debug_info_data.getULEB128(&offset);
  30
  31     OS.indent(indent) << format("\n0x%8.8x: ", Offset);
  32     if (abbrCode) {
  33       if (AbbrevDecl) {
  34         OS << TagString(AbbrevDecl->getTag())
  35            << format(" [%u] %c\n", abbrCode,
  36                                    AbbrevDecl->hasChildren() ? '*': ' ');
  37
  38         // Dump all data in the .debug_info for the attributes
  39         const uint32_t numAttributes = AbbrevDecl->getNumAttributes();
  40         for (uint32_t i = 0; i != numAttributes; ++i) {
  41           uint16_t attr = AbbrevDecl->getAttrByIndex(i);
  42           uint16_t form = AbbrevDecl->getFormByIndex(i);
  43           dumpAttribute(OS, cu, &offset, attr, form, indent);
  44         }
  45
  46         const DWARFDebugInfoEntryMinimal *child = getFirstChild();
  47         if (recurseDepth > 0 && child) {
  48           while (child) {
  49             child->dump(OS, cu, recurseDepth-1, indent+2);
  50             child = child->getSibling();
  51           }
  52         }
  53       } else {
  54         OS << "Abbreviation code not found in 'debug_abbrev' class for code: "
  55            << abbrCode << '\n';
  56       }
  57     } else {
  58       OS << "NULL\n";
  59     }
  60   }
  61 }
  62
  63 void DWARFDebugInfoEntryMinimal::dumpAttribute(raw_ostream &OS,
  64                                                const DWARFCompileUnit *cu,
  65                                                uint32_t* offset_ptr,
  66                                                uint16_t attr,
  67                                                uint16_t form,
  68                                                unsigned indent) const {
  69   OS.indent(indent) << format("0x%8.8x: ", *offset_ptr)
  70                     << AttributeString(attr)
  71                     << " [" << FormEncodingString(form) << ']';
  72
  73   DWARFFormValue formValue(form);
  74
  75   if (!formValue.extractValue(cu->getDebugInfoExtractor(), offset_ptr, cu))
  76     return;
  77
  78   OS << "\t(";
  79   formValue.dump(OS, 0, cu);
  80   OS << ")\n";
  81 }
  82
  83 bool DWARFDebugInfoEntryMinimal::extractFast(const DWARFCompileUnit *cu,
  84                                              const uint8_t *fixed_form_sizes,
  85                                              uint32_t *offset_ptr) {
  86   Offset = *offset_ptr;
  87
  88   DataExtractor debug_info_data = cu->getDebugInfoExtractor();
  89   uint64_t abbrCode = debug_info_data.getULEB128(offset_ptr);
  90
  91   assert (fixed_form_sizes); // For best performance this should be specified!
  92
  93   if (abbrCode) {
  94     uint32_t offset = *offset_ptr;
  95
  96     AbbrevDecl = cu->getAbbreviations()->getAbbreviationDeclaration(abbrCode);
  97
  98     // Skip all data in the .debug_info for the attributes
  99     const uint32_t numAttributes = AbbrevDecl->getNumAttributes();
 100     uint32_t i;
 101     uint16_t form;
 102     for (i=0; i<numAttributes; ++i) {
 103       form = AbbrevDecl->getFormByIndex(i);
 104
 105       const uint8_t fixed_skip_size = fixed_form_sizes[form];
 106       if (fixed_skip_size)
 107         offset += fixed_skip_size;
 108       else {
 109         bool form_is_indirect = false;
 110         do {
 111           form_is_indirect = false;
 112           uint32_t form_size = 0;
 113           switch (form) {
 114           // Blocks if inlined data that have a length field and the data bytes
 115           // inlined in the .debug_info.
 116           case DW_FORM_block:
 117             form_size = debug_info_data.getULEB128(&offset);
 118             break;
 119           case DW_FORM_block1:
 120             form_size = debug_info_data.getU8(&offset);
 121             break;
 122           case DW_FORM_block2:
 123             form_size = debug_info_data.getU16(&offset);
 124             break;
 125           case DW_FORM_block4:
 126             form_size = debug_info_data.getU32(&offset);
 127             break;
 128
 129           // Inlined NULL terminated C-strings
 130           case DW_FORM_string:
 131             debug_info_data.getCStr(&offset);
 132             break;
 133
 134           // Compile unit address sized values
 135           case DW_FORM_addr:
 136           case DW_FORM_ref_addr:
 137             form_size = cu->getAddressByteSize();
 138             break;
 139
 140           // 1 byte values
 141           case DW_FORM_data1:
 142           case DW_FORM_flag:
 143           case DW_FORM_ref1:
 144             form_size = 1;
 145             break;
 146
 147           // 2 byte values
 148           case DW_FORM_data2:
 149           case DW_FORM_ref2:
 150             form_size = 2;
 151             break;
 152
 153           // 4 byte values
 154           case DW_FORM_strp:
 155           case DW_FORM_data4:
 156           case DW_FORM_ref4:
 157             form_size = 4;
 158             break;
 159
 160           // 8 byte values
 161           case DW_FORM_data8:
 162           case DW_FORM_ref8:
 163             form_size = 8;
 164             break;
 165
 166           // signed or unsigned LEB 128 values
 167           case DW_FORM_sdata:
 168           case DW_FORM_udata:
 169           case DW_FORM_ref_udata:
 170             debug_info_data.getULEB128(&offset);
 171             break;
 172
 173           case DW_FORM_indirect:
 174             form_is_indirect = true;
 175             form = debug_info_data.getULEB128(&offset);
 176             break;
 177
 178           default:
 179             *offset_ptr = Offset;
 180             return false;
 181           }
 182           offset += form_size;
 183
 184         } while (form_is_indirect);
 185       }
 186     }
 187     *offset_ptr = offset;
 188     return true;
 189   } else {
 190     AbbrevDecl = NULL;
 191     return true; // NULL debug tag entry
 192   }
 193
 194   return false;
 195 }
 196
 197 bool
 198 DWARFDebugInfoEntryMinimal::extract(const DWARFCompileUnit *cu,
 199                                     uint32_t *offset_ptr) {
 200   DataExtractor debug_info_data = cu->getDebugInfoExtractor();
 201   const uint32_t cu_end_offset = cu->getNextCompileUnitOffset();
 202   const uint8_t cu_addr_size = cu->getAddressByteSize();
 203   uint32_t offset = *offset_ptr;
 204   if ((offset < cu_end_offset) && debug_info_data.isValidOffset(offset)) {
 205     Offset = offset;
 206
 207     uint64_t abbrCode = debug_info_data.getULEB128(&offset);
 208
 209     if (abbrCode) {
 210       AbbrevDecl = cu->getAbbreviations()->getAbbreviationDeclaration(abbrCode);
 211
 212       if (AbbrevDecl) {
 213         uint16_t tag = AbbrevDecl->getTag();
 214
 215         bool isCompileUnitTag = tag == DW_TAG_compile_unit;
 216         if(cu && isCompileUnitTag)
 217           const_cast<DWARFCompileUnit*>(cu)->setBaseAddress(0);
 218
 219         // Skip all data in the .debug_info for the attributes
 220         const uint32_t numAttributes = AbbrevDecl->getNumAttributes();
 221         for (uint32_t i = 0; i != numAttributes; ++i) {
 222           uint16_t attr = AbbrevDecl->getAttrByIndex(i);
 223           uint16_t form = AbbrevDecl->getFormByIndex(i);
 224
 225           if (isCompileUnitTag &&
 226               ((attr == DW_AT_entry_pc) || (attr == DW_AT_low_pc))) {
 227             DWARFFormValue form_value(form);
 228             if (form_value.extractValue(debug_info_data, &offset, cu)) {
 229               if (attr == DW_AT_low_pc || attr == DW_AT_entry_pc)
 230                 const_cast<DWARFCompileUnit*>(cu)
 231                   ->setBaseAddress(form_value.getUnsigned());
 232             }
 233           } else {
 234             bool form_is_indirect = false;
 235             do {
 236               form_is_indirect = false;
 237               register uint32_t form_size = 0;
 238               switch (form) {
 239               // Blocks if inlined data that have a length field and the data
 240               // bytes // inlined in the .debug_info
 241               case DW_FORM_block:
 242                 form_size = debug_info_data.getULEB128(&offset);
 243                 break;
 244               case DW_FORM_block1:
 245                 form_size = debug_info_data.getU8(&offset);
 246                 break;
 247               case DW_FORM_block2:
 248                 form_size = debug_info_data.getU16(&offset);
 249                 break;
 250               case DW_FORM_block4:
 251                 form_size = debug_info_data.getU32(&offset);
 252                 break;
 253
 254               // Inlined NULL terminated C-strings
 255               case DW_FORM_string:
 256                 debug_info_data.getCStr(&offset);
 257                 break;
 258
 259               // Compile unit address sized values
 260               case DW_FORM_addr:
 261               case DW_FORM_ref_addr:
 262                 form_size = cu_addr_size;
 263                 break;
 264
 265               // 1 byte values
 266               case DW_FORM_data1:
 267               case DW_FORM_flag:
 268               case DW_FORM_ref1:
 269                 form_size = 1;
 270                 break;
 271
 272               // 2 byte values
 273               case DW_FORM_data2:
 274               case DW_FORM_ref2:
 275                 form_size = 2;
 276                 break;
 277
 278                 // 4 byte values
 279               case DW_FORM_strp:
 280                 form_size = 4;
 281                 break;
 282
 283               case DW_FORM_data4:
 284               case DW_FORM_ref4:
 285                 form_size = 4;
 286                 break;
 287
 288               // 8 byte values
 289               case DW_FORM_data8:
 290               case DW_FORM_ref8:
 291                 form_size = 8;
 292                 break;
 293
 294               // signed or unsigned LEB 128 values
 295               case DW_FORM_sdata:
 296               case DW_FORM_udata:
 297               case DW_FORM_ref_udata:
 298                 debug_info_data.getULEB128(&offset);
 299                 break;
 300
 301               case DW_FORM_indirect:
 302                 form = debug_info_data.getULEB128(&offset);
 303                 form_is_indirect = true;
 304                 break;
 305
 306               default:
 307                 *offset_ptr = offset;
 308                 return false;
 309               }
 310
 311               offset += form_size;
 312             } while (form_is_indirect);
 313           }
 314         }
 315         *offset_ptr = offset;
 316         return true;
 317       }
 318     } else {
 319       AbbrevDecl = NULL;
 320       *offset_ptr = offset;
 321       return true;    // NULL debug tag entry
 322     }
 323   }
 324
 325   return false;
 326 }
 327
 328 uint32_t
 329 DWARFDebugInfoEntryMinimal::getAttributeValue(const DWARFCompileUnit *cu,
 330                                               const uint16_t attr,
 331                                               DWARFFormValue &form_value,
 332                                               uint32_t *end_attr_offset_ptr)
 333                                               const {
 334   if (AbbrevDecl) {
 335     uint32_t attr_idx = AbbrevDecl->findAttributeIndex(attr);
 336
 337     if (attr_idx != -1U) {
 338       uint32_t offset = getOffset();
 339
 340       DataExtractor debug_info_data = cu->getDebugInfoExtractor();
 341
 342       // Skip the abbreviation code so we are at the data for the attributes
 343       debug_info_data.getULEB128(&offset);
 344
 345       uint32_t idx = 0;
 346       while (idx < attr_idx)
 347         DWARFFormValue::skipValue(AbbrevDecl->getFormByIndex(idx++),
 348                                   debug_info_data, &offset, cu);
 349
 350       const uint32_t attr_offset = offset;
 351       form_value = DWARFFormValue(AbbrevDecl->getFormByIndex(idx));
 352       if (form_value.extractValue(debug_info_data, &offset, cu)) {
 353         if (end_attr_offset_ptr)
 354           *end_attr_offset_ptr = offset;
 355         return attr_offset;
 356       }
 357     }
 358   }
 359
 360   return 0;
 361 }
 362
 363 const char*
 364 DWARFDebugInfoEntryMinimal::getAttributeValueAsString(
 365     const DWARFCompileUnit* cu,
 366     const uint16_t attr,
 367     const char* fail_value) const {
 368   DWARFFormValue form_value;
 369   if (getAttributeValue(cu, attr, form_value)) {
 370     DataExtractor stringExtractor(cu->getContext().getStringSection(),
 371         false, 0);
 372     return form_value.getAsCString(&stringExtractor);
 373   }
 374   return fail_value;
 375 }
 376
 377 uint64_t
 378 DWARFDebugInfoEntryMinimal::getAttributeValueAsUnsigned(
 379     const DWARFCompileUnit* cu,
 380     const uint16_t attr,
 381     uint64_t fail_value) const {
 382   DWARFFormValue form_value;
 383   if (getAttributeValue(cu, attr, form_value))
 384       return form_value.getUnsigned();
 385   return fail_value;
 386 }
 387
 388 int64_t
 389 DWARFDebugInfoEntryMinimal::getAttributeValueAsSigned(
 390     const DWARFCompileUnit* cu,
 391     const uint16_t attr,
 392     int64_t fail_value) const {
 393   DWARFFormValue form_value;
 394   if (getAttributeValue(cu, attr, form_value))
 395       return form_value.getSigned();
 396   return fail_value;
 397 }
 398
 399 uint64_t
 400 DWARFDebugInfoEntryMinimal::getAttributeValueAsReference(const DWARFCompileUnit* cu,
 401                                                   const uint16_t attr,
 402                                                   uint64_t fail_value) const {
 403   DWARFFormValue form_value;
 404   if (getAttributeValue(cu, attr, form_value))
 405       return form_value.getReference(cu);
 406   return fail_value;
 407 }