1 //===- DWARFLinkerCompileUnit.cpp -----------------------------------------===//
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 "llvm/DWARFLinker/DWARFLinkerCompileUnit.h"
10 #include "llvm/DWARFLinker/DWARFLinkerDeclContext.h"
11 #include "llvm/Support/FormatVariadic.h"
12
13 namespace llvm {
14
15 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
dump()16 LLVM_DUMP_METHOD void CompileUnit::DIEInfo::dump() {
17 llvm::errs() << "{\n";
18 llvm::errs() << " AddrAdjust: " << AddrAdjust << '\n';
19 llvm::errs() << " Ctxt: " << formatv("{0:x}", Ctxt) << '\n';
20 llvm::errs() << " Clone: " << formatv("{0:x}", Clone) << '\n';
21 llvm::errs() << " ParentIdx: " << ParentIdx << '\n';
22 llvm::errs() << " Keep: " << Keep << '\n';
23 llvm::errs() << " InDebugMap: " << InDebugMap << '\n';
24 llvm::errs() << " Prune: " << Prune << '\n';
25 llvm::errs() << " Incomplete: " << Incomplete << '\n';
26 llvm::errs() << " InModuleScope: " << InModuleScope << '\n';
27 llvm::errs() << " ODRMarkingDone: " << ODRMarkingDone << '\n';
28 llvm::errs() << " UnclonedReference: " << UnclonedReference << '\n';
29 llvm::errs() << "}\n";
30 }
31 #endif // if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
32
33 /// Check if the DIE at \p Idx is in the scope of a function.
inFunctionScope(CompileUnit & U,unsigned Idx)34 static bool inFunctionScope(CompileUnit &U, unsigned Idx) {
35 while (Idx) {
36 if (U.getOrigUnit().getDIEAtIndex(Idx).getTag() == dwarf::DW_TAG_subprogram)
37 return true;
38 Idx = U.getInfo(Idx).ParentIdx;
39 }
40 return false;
41 }
42
getLanguage()43 uint16_t CompileUnit::getLanguage() {
44 if (!Language) {
45 DWARFDie CU = getOrigUnit().getUnitDIE();
46 Language = dwarf::toUnsigned(CU.find(dwarf::DW_AT_language), 0);
47 }
48 return Language;
49 }
50
getSysRoot()51 StringRef CompileUnit::getSysRoot() {
52 if (SysRoot.empty()) {
53 DWARFDie CU = getOrigUnit().getUnitDIE();
54 SysRoot = dwarf::toStringRef(CU.find(dwarf::DW_AT_LLVM_sysroot)).str();
55 }
56 return SysRoot;
57 }
58
markEverythingAsKept()59 void CompileUnit::markEverythingAsKept() {
60 unsigned Idx = 0;
61
62 for (auto &I : Info) {
63 // Mark everything that wasn't explicit marked for pruning.
64 I.Keep = !I.Prune;
65 auto DIE = OrigUnit.getDIEAtIndex(Idx++);
66
67 // Try to guess which DIEs must go to the accelerator tables. We do that
68 // just for variables, because functions will be handled depending on
69 // whether they carry a DW_AT_low_pc attribute or not.
70 if (DIE.getTag() != dwarf::DW_TAG_variable &&
71 DIE.getTag() != dwarf::DW_TAG_constant)
72 continue;
73
74 std::optional<DWARFFormValue> Value;
75 if (!(Value = DIE.find(dwarf::DW_AT_location))) {
76 if ((Value = DIE.find(dwarf::DW_AT_const_value)) &&
77 !inFunctionScope(*this, I.ParentIdx))
78 I.InDebugMap = true;
79 continue;
80 }
81 if (auto Block = Value->getAsBlock()) {
82 if (Block->size() > OrigUnit.getAddressByteSize() &&
83 (*Block)[0] == dwarf::DW_OP_addr)
84 I.InDebugMap = true;
85 }
86 }
87 }
88
computeNextUnitOffset(uint16_t DwarfVersion)89 uint64_t CompileUnit::computeNextUnitOffset(uint16_t DwarfVersion) {
90 NextUnitOffset = StartOffset;
91 if (NewUnit) {
92 NextUnitOffset += (DwarfVersion >= 5) ? 12 : 11; // Header size
93 NextUnitOffset += NewUnit->getUnitDie().getSize();
94 }
95 return NextUnitOffset;
96 }
97
98 /// Keep track of a forward cross-cu reference from this unit
99 /// to \p Die that lives in \p RefUnit.
noteForwardReference(DIE * Die,const CompileUnit * RefUnit,DeclContext * Ctxt,PatchLocation Attr)100 void CompileUnit::noteForwardReference(DIE *Die, const CompileUnit *RefUnit,
101 DeclContext *Ctxt, PatchLocation Attr) {
102 ForwardDIEReferences.emplace_back(Die, RefUnit, Ctxt, Attr);
103 }
104
fixupForwardReferences()105 void CompileUnit::fixupForwardReferences() {
106 for (const auto &Ref : ForwardDIEReferences) {
107 DIE *RefDie;
108 const CompileUnit *RefUnit;
109 PatchLocation Attr;
110 DeclContext *Ctxt;
111 std::tie(RefDie, RefUnit, Ctxt, Attr) = Ref;
112 if (Ctxt && Ctxt->hasCanonicalDIE()) {
113 assert(Ctxt->getCanonicalDIEOffset() &&
114 "Canonical die offset is not set");
115 Attr.set(Ctxt->getCanonicalDIEOffset());
116 } else {
117 assert(RefDie->getOffset() && "Referenced die offset is not set");
118 Attr.set(RefDie->getOffset() + RefUnit->getStartOffset());
119 }
120 }
121 }
122
addLabelLowPc(uint64_t LabelLowPc,int64_t PcOffset)123 void CompileUnit::addLabelLowPc(uint64_t LabelLowPc, int64_t PcOffset) {
124 Labels.insert({LabelLowPc, PcOffset});
125 }
126
addFunctionRange(uint64_t FuncLowPc,uint64_t FuncHighPc,int64_t PcOffset)127 void CompileUnit::addFunctionRange(uint64_t FuncLowPc, uint64_t FuncHighPc,
128 int64_t PcOffset) {
129 Ranges.insert({FuncLowPc, FuncHighPc}, PcOffset);
130 if (LowPc)
131 LowPc = std::min(*LowPc, FuncLowPc + PcOffset);
132 else
133 LowPc = FuncLowPc + PcOffset;
134 this->HighPc = std::max(HighPc, FuncHighPc + PcOffset);
135 }
136
noteRangeAttribute(const DIE & Die,PatchLocation Attr)137 void CompileUnit::noteRangeAttribute(const DIE &Die, PatchLocation Attr) {
138 if (Die.getTag() != dwarf::DW_TAG_compile_unit)
139 RangeAttributes.push_back(Attr);
140 else
141 UnitRangeAttribute = Attr;
142 }
143
noteLocationAttribute(PatchLocation Attr,int64_t PcOffset)144 void CompileUnit::noteLocationAttribute(PatchLocation Attr, int64_t PcOffset) {
145 LocationAttributes.emplace_back(Attr, PcOffset);
146 }
147
addNamespaceAccelerator(const DIE * Die,DwarfStringPoolEntryRef Name)148 void CompileUnit::addNamespaceAccelerator(const DIE *Die,
149 DwarfStringPoolEntryRef Name) {
150 Namespaces.emplace_back(Name, Die);
151 }
152
addObjCAccelerator(const DIE * Die,DwarfStringPoolEntryRef Name,bool SkipPubSection)153 void CompileUnit::addObjCAccelerator(const DIE *Die,
154 DwarfStringPoolEntryRef Name,
155 bool SkipPubSection) {
156 ObjC.emplace_back(Name, Die, SkipPubSection);
157 }
158
addNameAccelerator(const DIE * Die,DwarfStringPoolEntryRef Name,bool SkipPubSection)159 void CompileUnit::addNameAccelerator(const DIE *Die,
160 DwarfStringPoolEntryRef Name,
161 bool SkipPubSection) {
162 Pubnames.emplace_back(Name, Die, SkipPubSection);
163 }
164
addTypeAccelerator(const DIE * Die,DwarfStringPoolEntryRef Name,bool ObjcClassImplementation,uint32_t QualifiedNameHash)165 void CompileUnit::addTypeAccelerator(const DIE *Die,
166 DwarfStringPoolEntryRef Name,
167 bool ObjcClassImplementation,
168 uint32_t QualifiedNameHash) {
169 Pubtypes.emplace_back(Name, Die, QualifiedNameHash, ObjcClassImplementation);
170 }
171
172 } // namespace llvm
173