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 "llvm/DebugInfo/DWARFFormValue.h"
  15 #include "llvm/Support/Debug.h"
  16 #include "llvm/Support/Dwarf.h"
  17 #include "llvm/Support/Format.h"
  18 #include "llvm/Support/raw_ostream.h"
  19 using namespace llvm;
  20 using namespace dwarf;
  21
  22 void DWARFDebugInfoEntryMinimal::dump(raw_ostream &OS,
  23                                       const DWARFCompileUnit *cu,
  24                                       unsigned recurseDepth,
  25                                       unsigned indent) const {
  26   DataExtractor debug_info_data = cu->getDebugInfoExtractor();
  27   uint32_t offset = Offset;
  28
  29   if (debug_info_data.isValidOffset(offset)) {
  30     uint32_t abbrCode = debug_info_data.getULEB128(&offset);
  31
  32     OS << format("\n0x%8.8x: ", Offset);
  33     if (abbrCode) {
  34       if (AbbrevDecl) {
  35         const char *tagString = TagString(getTag());
  36         if (tagString)
  37           OS.indent(indent) << tagString;
  38         else
  39           OS.indent(indent) << format("DW_TAG_Unknown_%x", getTag());
  40         OS << format(" [%u] %c\n", abbrCode,
  41                      AbbrevDecl->hasChildren() ? '*' : ' ');
  42
  43         // Dump all data in the DIE for the attributes.
  44         const uint32_t numAttributes = AbbrevDecl->getNumAttributes();
  45         for (uint32_t i = 0; i != numAttributes; ++i) {
  46           uint16_t attr = AbbrevDecl->getAttrByIndex(i);
  47           uint16_t form = AbbrevDecl->getFormByIndex(i);
  48           dumpAttribute(OS, cu, &offset, attr, form, indent);
  49         }
  50
  51         const DWARFDebugInfoEntryMinimal *child = getFirstChild();
  52         if (recurseDepth > 0 && child) {
  53           while (child) {
  54             child->dump(OS, cu, recurseDepth-1, indent+2);
  55             child = child->getSibling();
  56           }
  57         }
  58       } else {
  59         OS << "Abbreviation code not found in 'debug_abbrev' class for code: "
  60            << abbrCode << '\n';
  61       }
  62     } else {
  63       OS.indent(indent) << "NULL\n";
  64     }
  65   }
  66 }
  67
  68 void DWARFDebugInfoEntryMinimal::dumpAttribute(raw_ostream &OS,
  69                                                const DWARFCompileUnit *cu,
  70                                                uint32_t* offset_ptr,
  71                                                uint16_t attr,
  72                                                uint16_t form,
  73                                                unsigned indent) const {
  74   OS << "            ";
  75   OS.indent(indent+2);
  76   const char *attrString = AttributeString(attr);
  77   if (attrString)
  78     OS << attrString;
  79   else
  80     OS << format("DW_AT_Unknown_%x", attr);
  81   const char *formString = FormEncodingString(form);
  82   if (formString)
  83     OS << " [" << formString << ']';
  84   else
  85     OS << format(" [DW_FORM_Unknown_%x]", form);
  86
  87   DWARFFormValue formValue(form);
  88
  89   if (!formValue.extractValue(cu->getDebugInfoExtractor(), offset_ptr, cu))
  90     return;
  91
  92   OS << "\t(";
  93   formValue.dump(OS, cu);
  94   OS << ")\n";
  95 }
  96
  97 bool DWARFDebugInfoEntryMinimal::extractFast(const DWARFCompileUnit *CU,
  98                                              const uint8_t *FixedFormSizes,
  99                                              uint32_t *OffsetPtr) {
 100   Offset = *OffsetPtr;
 101   DataExtractor DebugInfoData = CU->getDebugInfoExtractor();
 102   uint64_t AbbrCode = DebugInfoData.getULEB128(OffsetPtr);
 103   if (0 == AbbrCode) {
 104     // NULL debug tag entry.
 105     AbbrevDecl = NULL;
 106     return true;
 107   }
 108   AbbrevDecl = CU->getAbbreviations()->getAbbreviationDeclaration(AbbrCode);
 109   assert(AbbrevDecl);
 110   assert(FixedFormSizes); // For best performance this should be specified!
 111
 112   // Skip all data in the .debug_info for the attributes
 113   for (uint32_t i = 0, n = AbbrevDecl->getNumAttributes(); i < n; ++i) {
 114     uint16_t Form = AbbrevDecl->getFormByIndex(i);
 115
 116     // FIXME: Currently we're checking if this is less than the last
 117     // entry in the fixed_form_sizes table, but this should be changed
 118     // to use dynamic dispatch.
 119     uint8_t FixedFormSize =
 120         (Form < DW_FORM_ref_sig8) ? FixedFormSizes[Form] : 0;
 121     if (FixedFormSize)
 122       *OffsetPtr += FixedFormSize;
 123     else if (!DWARFFormValue::skipValue(Form, DebugInfoData, OffsetPtr,
 124                                         CU)) {
 125       // Restore the original offset.
 126       *OffsetPtr = Offset;
 127       return false;
 128     }
 129   }
 130   return true;
 131 }
 132
 133 bool
 134 DWARFDebugInfoEntryMinimal::extract(const DWARFCompileUnit *CU,
 135                                     uint32_t *OffsetPtr) {
 136   DataExtractor DebugInfoData = CU->getDebugInfoExtractor();
 137   const uint32_t CUEndOffset = CU->getNextCompileUnitOffset();
 138   Offset = *OffsetPtr;
 139   if ((Offset >= CUEndOffset) || !DebugInfoData.isValidOffset(Offset))
 140     return false;
 141   uint64_t AbbrCode = DebugInfoData.getULEB128(OffsetPtr);
 142   if (0 == AbbrCode) {
 143     // NULL debug tag entry.
 144     AbbrevDecl = NULL;
 145     return true;
 146   }
 147   AbbrevDecl = CU->getAbbreviations()->getAbbreviationDeclaration(AbbrCode);
 148   if (0 == AbbrevDecl) {
 149     // Restore the original offset.
 150     *OffsetPtr = Offset;
 151     return false;
 152   }
 153   bool IsCompileUnitTag = (AbbrevDecl->getTag() == DW_TAG_compile_unit);
 154   if (IsCompileUnitTag)
 155     const_cast<DWARFCompileUnit*>(CU)->setBaseAddress(0);
 156
 157   // Skip all data in the .debug_info for the attributes
 158   for (uint32_t i = 0, n = AbbrevDecl->getNumAttributes(); i < n; ++i) {
 159     uint16_t Attr = AbbrevDecl->getAttrByIndex(i);
 160     uint16_t Form = AbbrevDecl->getFormByIndex(i);
 161
 162     if (IsCompileUnitTag &&
 163         ((Attr == DW_AT_entry_pc) || (Attr == DW_AT_low_pc))) {
 164       DWARFFormValue FormValue(Form);
 165       if (FormValue.extractValue(DebugInfoData, OffsetPtr, CU)) {
 166         if (Attr == DW_AT_low_pc || Attr == DW_AT_entry_pc)
 167           const_cast<DWARFCompileUnit*>(CU)
 168             ->setBaseAddress(FormValue.getUnsigned());
 169       }
 170     } else if (!DWARFFormValue::skipValue(Form, DebugInfoData, OffsetPtr,
 171                                           CU)) {
 172       // Restore the original offset.
 173       *OffsetPtr = Offset;
 174       return false;
 175     }
 176   }
 177   return true;
 178 }
 179
 180 bool DWARFDebugInfoEntryMinimal::isSubprogramDIE() const {
 181   return getTag() == DW_TAG_subprogram;
 182 }
 183
 184 bool DWARFDebugInfoEntryMinimal::isSubroutineDIE() const {
 185   uint32_t Tag = getTag();
 186   return Tag == DW_TAG_subprogram ||
 187          Tag == DW_TAG_inlined_subroutine;
 188 }
 189
 190 uint32_t
 191 DWARFDebugInfoEntryMinimal::getAttributeValue(const DWARFCompileUnit *cu,
 192                                               const uint16_t attr,
 193                                               DWARFFormValue &form_value,
 194                                               uint32_t *end_attr_offset_ptr)
 195                                               const {
 196   if (AbbrevDecl) {
 197     uint32_t attr_idx = AbbrevDecl->findAttributeIndex(attr);
 198
 199     if (attr_idx != -1U) {
 200       uint32_t offset = getOffset();
 201
 202       DataExtractor debug_info_data = cu->getDebugInfoExtractor();
 203
 204       // Skip the abbreviation code so we are at the data for the attributes
 205       debug_info_data.getULEB128(&offset);
 206
 207       uint32_t idx = 0;
 208       while (idx < attr_idx)
 209         DWARFFormValue::skipValue(AbbrevDecl->getFormByIndex(idx++),
 210                                   debug_info_data, &offset, cu);
 211
 212       const uint32_t attr_offset = offset;
 213       form_value = DWARFFormValue(AbbrevDecl->getFormByIndex(idx));
 214       if (form_value.extractValue(debug_info_data, &offset, cu)) {
 215         if (end_attr_offset_ptr)
 216           *end_attr_offset_ptr = offset;
 217         return attr_offset;
 218       }
 219     }
 220   }
 221
 222   return 0;
 223 }
 224
 225 const char *DWARFDebugInfoEntryMinimal::getAttributeValueAsString(
 226     const DWARFCompileUnit *CU, const uint16_t Attr,
 227     const char *FailValue) const {
 228   DWARFFormValue FormValue;
 229   if (getAttributeValue(CU, Attr, FormValue))
 230     return FormValue.getAsCString(CU);
 231   return FailValue;
 232 }
 233
 234 uint64_t DWARFDebugInfoEntryMinimal::getAttributeValueAsAddress(
 235     const DWARFCompileUnit *CU, const uint16_t Attr, uint64_t FailValue) const {
 236   DWARFFormValue FormValue;
 237   if (getAttributeValue(CU, Attr, FormValue))
 238     return FormValue.getAsAddress(CU);
 239   return FailValue;
 240 }
 241
 242 uint64_t DWARFDebugInfoEntryMinimal::getAttributeValueAsUnsigned(
 243     const DWARFCompileUnit *CU, const uint16_t Attr, uint64_t FailValue) const {
 244   DWARFFormValue FormValue;
 245   if (getAttributeValue(CU, Attr, FormValue)) {
 246     return FormValue.getUnsigned();
 247   }
 248   return FailValue;
 249 }
 250
 251 int64_t
 252 DWARFDebugInfoEntryMinimal::getAttributeValueAsSigned(
 253                                                      const DWARFCompileUnit* cu,
 254                                                      const uint16_t attr,
 255                                                      int64_t fail_value) const {
 256   DWARFFormValue form_value;
 257   if (getAttributeValue(cu, attr, form_value))
 258       return form_value.getSigned();
 259   return fail_value;
 260 }
 261
 262 uint64_t
 263 DWARFDebugInfoEntryMinimal::getAttributeValueAsReference(
 264                                                      const DWARFCompileUnit* cu,
 265                                                      const uint16_t attr,
 266                                                      uint64_t fail_value)
 267                                                      const {
 268   DWARFFormValue form_value;
 269   if (getAttributeValue(cu, attr, form_value))
 270       return form_value.getReference(cu);
 271   return fail_value;
 272 }
 273
 274 bool DWARFDebugInfoEntryMinimal::getLowAndHighPC(const DWARFCompileUnit *CU,
 275                                                  uint64_t &LowPC,
 276                                                  uint64_t &HighPC) const {
 277   HighPC = -1ULL;
 278   LowPC = getAttributeValueAsAddress(CU, DW_AT_low_pc, -1ULL);
 279   if (LowPC != -1ULL)
 280     HighPC = getAttributeValueAsAddress(CU, DW_AT_high_pc, -1ULL);
 281   return (HighPC != -1ULL);
 282 }
 283
 284 void
 285 DWARFDebugInfoEntryMinimal::buildAddressRangeTable(const DWARFCompileUnit *CU,
 286                                                DWARFDebugAranges *DebugAranges,
 287                                                uint32_t CUOffsetInAranges)
 288                                                    const {
 289   if (AbbrevDecl) {
 290     if (isSubprogramDIE()) {
 291       uint64_t LowPC, HighPC;
 292       if (getLowAndHighPC(CU, LowPC, HighPC))
 293         DebugAranges->appendRange(CUOffsetInAranges, LowPC, HighPC);
 294       // FIXME: try to append ranges from .debug_ranges section.
 295     }
 296
 297     const DWARFDebugInfoEntryMinimal *Child = getFirstChild();
 298     while (Child) {
 299       Child->buildAddressRangeTable(CU, DebugAranges, CUOffsetInAranges);
 300       Child = Child->getSibling();
 301     }
 302   }
 303 }
 304
 305 bool
 306 DWARFDebugInfoEntryMinimal::addressRangeContainsAddress(
 307                                                      const DWARFCompileUnit *CU,
 308                                                      const uint64_t Address)
 309                                                      const {
 310   if (isNULL())
 311     return false;
 312   uint64_t LowPC, HighPC;
 313   if (getLowAndHighPC(CU, LowPC, HighPC))
 314     return (LowPC <= Address && Address <= HighPC);
 315   // Try to get address ranges from .debug_ranges section.
 316   uint32_t RangesOffset = getAttributeValueAsReference(CU, DW_AT_ranges, -1U);
 317   if (RangesOffset != -1U) {
 318     DWARFDebugRangeList RangeList;
 319     if (CU->extractRangeList(RangesOffset, RangeList))
 320       return RangeList.containsAddress(CU->getBaseAddress(), Address);
 321   }
 322   return false;
 323 }
 324
 325 const char*
 326 DWARFDebugInfoEntryMinimal::getSubroutineName(const DWARFCompileUnit *CU)
 327                                                                          const {
 328   if (!isSubroutineDIE())
 329     return 0;
 330   // Try to get mangled name if possible.
 331   if (const char *name =
 332       getAttributeValueAsString(CU, DW_AT_MIPS_linkage_name, 0))
 333     return name;
 334   if (const char *name = getAttributeValueAsString(CU, DW_AT_linkage_name, 0))
 335     return name;
 336   if (const char *name = getAttributeValueAsString(CU, DW_AT_name, 0))
 337     return name;
 338   // Try to get name from specification DIE.
 339   uint32_t spec_ref =
 340       getAttributeValueAsReference(CU, DW_AT_specification, -1U);
 341   if (spec_ref != -1U) {
 342     DWARFDebugInfoEntryMinimal spec_die;
 343     if (spec_die.extract(CU, &spec_ref)) {
 344       if (const char *name = spec_die.getSubroutineName(CU))
 345         return name;
 346     }
 347   }
 348   // Try to get name from abstract origin DIE.
 349   uint32_t abs_origin_ref =
 350       getAttributeValueAsReference(CU, DW_AT_abstract_origin, -1U);
 351   if (abs_origin_ref != -1U) {
 352     DWARFDebugInfoEntryMinimal abs_origin_die;
 353     if (abs_origin_die.extract(CU, &abs_origin_ref)) {
 354       if (const char *name = abs_origin_die.getSubroutineName(CU))
 355         return name;
 356     }
 357   }
 358   return 0;
 359 }
 360
 361 void DWARFDebugInfoEntryMinimal::getCallerFrame(const DWARFCompileUnit *CU,
 362                                                 uint32_t &CallFile,
 363                                                 uint32_t &CallLine,
 364                                                 uint32_t &CallColumn) const {
 365   CallFile = getAttributeValueAsUnsigned(CU, DW_AT_call_file, 0);
 366   CallLine = getAttributeValueAsUnsigned(CU, DW_AT_call_line, 0);
 367   CallColumn = getAttributeValueAsUnsigned(CU, DW_AT_call_column, 0);
 368 }
 369
 370 DWARFDebugInfoEntryInlinedChain
 371 DWARFDebugInfoEntryMinimal::getInlinedChainForAddress(
 372     const DWARFCompileUnit *CU, const uint64_t Address) const {
 373   DWARFDebugInfoEntryInlinedChain InlinedChain;
 374   InlinedChain.CU = CU;
 375   if (isNULL())
 376     return InlinedChain;
 377   for (const DWARFDebugInfoEntryMinimal *DIE = this; DIE; ) {
 378     // Append current DIE to inlined chain only if it has correct tag
 379     // (e.g. it is not a lexical block).
 380     if (DIE->isSubroutineDIE()) {
 381       InlinedChain.DIEs.push_back(*DIE);
 382     }
 383     // Try to get child which also contains provided address.
 384     const DWARFDebugInfoEntryMinimal *Child = DIE->getFirstChild();
 385     while (Child) {
 386       if (Child->addressRangeContainsAddress(CU, Address)) {
 387         // Assume there is only one such child.
 388         break;
 389       }
 390       Child = Child->getSibling();
 391     }
 392     DIE = Child;
 393   }
 394   // Reverse the obtained chain to make the root of inlined chain last.
 395   std::reverse(InlinedChain.DIEs.begin(), InlinedChain.DIEs.end());
 396   return InlinedChain;
 397 }