tools/dsymutil/CompileUnit.cpp

   1 //===- tools/dsymutil/CompileUnit.h - Dwarf compile unit ------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "CompileUnit.h"
  10 #include "DeclContext.h"
  11
  12 namespace llvm {
  13 namespace dsymutil {
  14
  15 /// Check if the DIE at \p Idx is in the scope of a function.
  16 static bool inFunctionScope(CompileUnit &U, unsigned Idx) {
  17   while (Idx) {
  18     if (U.getOrigUnit().getDIEAtIndex(Idx).getTag() == dwarf::DW_TAG_subprogram)
  19       return true;
  20     Idx = U.getInfo(Idx).ParentIdx;
  21   }
  22   return false;
  23 }
  24
  25 void CompileUnit::markEverythingAsKept() {
  26   unsigned Idx = 0;
  27
  28   setHasInterestingContent();
  29
  30   for (auto &I : Info) {
  31     // Mark everything that wasn't explicit marked for pruning.
  32     I.Keep = !I.Prune;
  33     auto DIE = OrigUnit.getDIEAtIndex(Idx++);
  34
  35     // Try to guess which DIEs must go to the accelerator tables. We do that
  36     // just for variables, because functions will be handled depending on
  37     // whether they carry a DW_AT_low_pc attribute or not.
  38     if (DIE.getTag() != dwarf::DW_TAG_variable &&
  39         DIE.getTag() != dwarf::DW_TAG_constant)
  40       continue;
  41
  42     Optional<DWARFFormValue> Value;
  43     if (!(Value = DIE.find(dwarf::DW_AT_location))) {
  44       if ((Value = DIE.find(dwarf::DW_AT_const_value)) &&
  45           !inFunctionScope(*this, I.ParentIdx))
  46         I.InDebugMap = true;
  47       continue;
  48     }
  49     if (auto Block = Value->getAsBlock()) {
  50       if (Block->size() > OrigUnit.getAddressByteSize() &&
  51           (*Block)[0] == dwarf::DW_OP_addr)
  52         I.InDebugMap = true;
  53     }
  54   }
  55 }
  56
  57 uint64_t CompileUnit::computeNextUnitOffset() {
  58   NextUnitOffset = StartOffset;
  59   if (NewUnit) {
  60     NextUnitOffset += 11 /* Header size */;
  61     NextUnitOffset += NewUnit->getUnitDie().getSize();
  62   }
  63   return NextUnitOffset;
  64 }
  65
  66 /// Keep track of a forward cross-cu reference from this unit
  67 /// to \p Die that lives in \p RefUnit.
  68 void CompileUnit::noteForwardReference(DIE *Die, const CompileUnit *RefUnit,
  69                                        DeclContext *Ctxt, PatchLocation Attr) {
  70   ForwardDIEReferences.emplace_back(Die, RefUnit, Ctxt, Attr);
  71 }
  72
  73 void CompileUnit::fixupForwardReferences() {
  74   for (const auto &Ref : ForwardDIEReferences) {
  75     DIE *RefDie;
  76     const CompileUnit *RefUnit;
  77     PatchLocation Attr;
  78     DeclContext *Ctxt;
  79     std::tie(RefDie, RefUnit, Ctxt, Attr) = Ref;
  80     if (Ctxt && Ctxt->getCanonicalDIEOffset())
  81       Attr.set(Ctxt->getCanonicalDIEOffset());
  82     else
  83       Attr.set(RefDie->getOffset() + RefUnit->getStartOffset());
  84   }
  85 }
  86
  87 void CompileUnit::addLabelLowPc(uint64_t LabelLowPc, int64_t PcOffset) {
  88   Labels.insert({LabelLowPc, PcOffset});
  89 }
  90
  91 void CompileUnit::addFunctionRange(uint64_t FuncLowPc, uint64_t FuncHighPc,
  92                                    int64_t PcOffset) {
  93   //  Don't add empty ranges to the interval map.  They are a problem because
  94   //  the interval map expects half open intervals. This is safe because they
  95   //  are empty anyway.
  96   if (FuncHighPc != FuncLowPc)
  97     Ranges.insert(FuncLowPc, FuncHighPc, PcOffset);
  98   this->LowPc = std::min(LowPc, FuncLowPc + PcOffset);
  99   this->HighPc = std::max(HighPc, FuncHighPc + PcOffset);
 100 }
 101
 102 void CompileUnit::noteRangeAttribute(const DIE &Die, PatchLocation Attr) {
 103   if (Die.getTag() != dwarf::DW_TAG_compile_unit)
 104     RangeAttributes.push_back(Attr);
 105   else
 106     UnitRangeAttribute = Attr;
 107 }
 108
 109 void CompileUnit::noteLocationAttribute(PatchLocation Attr, int64_t PcOffset) {
 110   LocationAttributes.emplace_back(Attr, PcOffset);
 111 }
 112
 113 void CompileUnit::addNamespaceAccelerator(const DIE *Die,
 114                                           DwarfStringPoolEntryRef Name) {
 115   Namespaces.emplace_back(Name, Die);
 116 }
 117
 118 void CompileUnit::addObjCAccelerator(const DIE *Die,
 119                                      DwarfStringPoolEntryRef Name,
 120                                      bool SkipPubSection) {
 121   ObjC.emplace_back(Name, Die, SkipPubSection);
 122 }
 123
 124 void CompileUnit::addNameAccelerator(const DIE *Die,
 125                                      DwarfStringPoolEntryRef Name,
 126                                      bool SkipPubSection) {
 127   Pubnames.emplace_back(Name, Die, SkipPubSection);
 128 }
 129
 130 void CompileUnit::addTypeAccelerator(const DIE *Die,
 131                                      DwarfStringPoolEntryRef Name,
 132                                      bool ObjcClassImplementation,
 133                                      uint32_t QualifiedNameHash) {
 134   Pubtypes.emplace_back(Name, Die, QualifiedNameHash, ObjcClassImplementation);
 135 }
 136
 137 } // namespace dsymutil
 138 } // namespace llvm