LLVM 20.0.0git
DWARFLinkerCompileUnit.cpp
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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
15
16namespace llvm {
17
18using namespace dwarf_linker;
19using namespace dwarf_linker::classic;
20
21#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
23 llvm::errs() << "{\n";
24 llvm::errs() << " AddrAdjust: " << AddrAdjust << '\n';
25 llvm::errs() << " Ctxt: " << formatv("{0:x}", Ctxt) << '\n';
26 llvm::errs() << " Clone: " << formatv("{0:x}", Clone) << '\n';
27 llvm::errs() << " ParentIdx: " << ParentIdx << '\n';
28 llvm::errs() << " Keep: " << Keep << '\n';
29 llvm::errs() << " InDebugMap: " << InDebugMap << '\n';
30 llvm::errs() << " Prune: " << Prune << '\n';
31 llvm::errs() << " Incomplete: " << Incomplete << '\n';
32 llvm::errs() << " InModuleScope: " << InModuleScope << '\n';
33 llvm::errs() << " ODRMarkingDone: " << ODRMarkingDone << '\n';
34 llvm::errs() << " UnclonedReference: " << UnclonedReference << '\n';
35 llvm::errs() << "}\n";
36}
37#endif // if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
38
39/// Check if the DIE at \p Idx is in the scope of a function.
40static bool inFunctionScope(CompileUnit &U, unsigned Idx) {
41 while (Idx) {
42 if (U.getOrigUnit().getDIEAtIndex(Idx).getTag() == dwarf::DW_TAG_subprogram)
43 return true;
44 Idx = U.getInfo(Idx).ParentIdx;
45 }
46 return false;
47}
48
50 if (!Language) {
52 Language = dwarf::toUnsigned(CU.find(dwarf::DW_AT_language), 0);
53 }
54 return Language;
55}
56
58 if (SysRoot.empty()) {
60 SysRoot = dwarf::toStringRef(CU.find(dwarf::DW_AT_LLVM_sysroot)).str();
61 }
62 return SysRoot;
63}
64
66 unsigned Idx = 0;
67
68 for (auto &I : Info) {
69 // Mark everything that wasn't explicit marked for pruning.
70 I.Keep = !I.Prune;
71 auto DIE = OrigUnit.getDIEAtIndex(Idx++);
72 DWARFUnit *U = DIE.getDwarfUnit();
73
74 // Try to guess which DIEs must go to the accelerator tables. We do that
75 // just for variables, because functions will be handled depending on
76 // whether they carry a DW_AT_low_pc attribute or not.
77 if (DIE.getTag() != dwarf::DW_TAG_variable &&
78 DIE.getTag() != dwarf::DW_TAG_constant)
79 continue;
80
81 std::optional<DWARFFormValue> Value;
82 if (!(Value = DIE.find(dwarf::DW_AT_location))) {
83 if ((Value = DIE.find(dwarf::DW_AT_const_value)) &&
84 !inFunctionScope(*this, I.ParentIdx))
85 I.InDebugMap = true;
86 continue;
87 }
88
89 if (auto ExprLockBlock = Value->getAsBlock()) {
90 // Parse 'exprloc' expression.
91 DataExtractor Data(toStringRef(*ExprLockBlock),
92 U->getContext().isLittleEndian(),
93 U->getAddressByteSize());
94 DWARFExpression Expression(Data, U->getAddressByteSize(),
95 U->getFormParams().Format);
96
97 for (DWARFExpression::iterator It = Expression.begin();
98 (It != Expression.end()) && !I.InDebugMap; ++It) {
99 DWARFExpression::iterator NextIt = It;
100 ++NextIt;
101
102 switch (It->getCode()) {
103 case dwarf::DW_OP_const2u:
104 case dwarf::DW_OP_const4u:
105 case dwarf::DW_OP_const8u:
106 case dwarf::DW_OP_const2s:
107 case dwarf::DW_OP_const4s:
108 case dwarf::DW_OP_const8s:
109 if (NextIt == Expression.end() ||
110 NextIt->getCode() != dwarf::DW_OP_form_tls_address)
111 break;
112 [[fallthrough]];
113 case dwarf::DW_OP_constx:
114 case dwarf::DW_OP_addr:
115 case dwarf::DW_OP_addrx:
116 I.InDebugMap = true;
117 break;
118 default:
119 // Nothing to do.
120 break;
121 }
122 }
123 }
124 }
125}
126
128 NextUnitOffset = StartOffset;
129 if (NewUnit) {
130 NextUnitOffset += (DwarfVersion >= 5) ? 12 : 11; // Header size
131 NextUnitOffset += NewUnit->getUnitDie().getSize();
132 }
133 return NextUnitOffset;
134}
135
136/// Keep track of a forward cross-cu reference from this unit
137/// to \p Die that lives in \p RefUnit.
139 DeclContext *Ctxt, PatchLocation Attr) {
140 ForwardDIEReferences.emplace_back(Die, RefUnit, Ctxt, Attr);
141}
142
144 for (const auto &Ref : ForwardDIEReferences) {
145 DIE *RefDie;
146 const CompileUnit *RefUnit;
147 PatchLocation Attr;
148 DeclContext *Ctxt;
149 std::tie(RefDie, RefUnit, Ctxt, Attr) = Ref;
150 if (Ctxt && Ctxt->hasCanonicalDIE()) {
152 "Canonical die offset is not set");
153 Attr.set(Ctxt->getCanonicalDIEOffset());
154 } else {
155 assert(RefDie->getOffset() && "Referenced die offset is not set");
156 Attr.set(RefDie->getOffset() + RefUnit->getStartOffset());
157 }
158 }
159}
160
161void CompileUnit::addLabelLowPc(uint64_t LabelLowPc, int64_t PcOffset) {
162 Labels.insert({LabelLowPc, PcOffset});
163}
164
166 int64_t PcOffset) {
167 Ranges.insert({FuncLowPc, FuncHighPc}, PcOffset);
168 if (LowPc)
169 LowPc = std::min(*LowPc, FuncLowPc + PcOffset);
170 else
171 LowPc = FuncLowPc + PcOffset;
172 this->HighPc = std::max(HighPc, FuncHighPc + PcOffset);
173}
174
176 if (Die.getTag() == dwarf::DW_TAG_compile_unit) {
177 UnitRangeAttribute = Attr;
178 return;
179 }
180
181 RangeAttributes.emplace_back(Attr);
182}
183
185 LocationAttributes.emplace_back(Attr);
186}
187
190 Namespaces.emplace_back(Name, Die);
191}
192
195 bool SkipPubSection) {
196 ObjC.emplace_back(Name, Die, SkipPubSection);
197}
198
201 bool SkipPubSection) {
202 Pubnames.emplace_back(Name, Die, SkipPubSection);
203}
204
207 bool ObjcClassImplementation,
208 uint32_t QualifiedNameHash) {
209 Pubtypes.emplace_back(Name, Die, QualifiedNameHash, ObjcClassImplementation);
210}
211
212} // namespace llvm
#define LLVM_DUMP_METHOD
Mark debug helper function definitions like dump() that should not be stripped from debug builds.
Definition: Compiler.h:537
Returns the sub type a function will return at a given Idx Should correspond to the result type of an ExtractValue instruction executed with just that one unsigned Idx
std::string Name
#define I(x, y, z)
Definition: MD5.cpp:58
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
This file contains some functions that are useful when dealing with strings.
void insert(AddressRange Range, int64_t Value)
A structured debug information entry.
Definition: DIE.h:819
unsigned getOffset() const
Get the compile/type unit relative offset of this DIE.
Definition: DIE.h:857
dwarf::Tag getTag() const
Definition: DIE.h:855
Utility class that carries the DWARF compile/type unit and the debug info entry in an object.
Definition: DWARFDie.h:42
An iterator to go through the expression operations.
DWARFDie getUnitDIE(bool ExtractUnitDIEOnly=true)
Definition: DWARFUnit.h:443
DWARFDie getDIEAtIndex(unsigned Index)
Return the DIE object at the given index Index.
Definition: DWARFUnit.h:521
std::pair< iterator, bool > insert(const std::pair< KeyT, ValueT > &KV)
Definition: DenseMap.h:211
DwarfStringPoolEntryRef: Dwarf string pool entry reference.
Class representing an expression and its matching format.
reference emplace_back(ArgTypes &&... Args)
Definition: SmallVector.h:951
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:50
std::string str() const
str - Get the contents as an std::string.
Definition: StringRef.h:215
LLVM Value Representation.
Definition: Value.h:74
Stores all information relating to a compile unit, be it in its original instance in the object file ...
void addFunctionRange(uint64_t LowPC, uint64_t HighPC, int64_t PCOffset)
Add a function range [LowPC, HighPC) that is relocated by applying offset PCOffset.
void fixupForwardReferences()
Apply all fixups recorded by noteForwardReference().
void noteForwardReference(DIE *Die, const CompileUnit *RefUnit, DeclContext *Ctxt, PatchLocation Attr)
Keep track of a forward reference to DIE Die in RefUnit by Attr.
void noteLocationAttribute(PatchLocation Attr)
Keep track of a location attribute pointing to a location list in the debug_loc section.
void addNameAccelerator(const DIE *Die, DwarfStringPoolEntryRef Name, bool SkipPubnamesSection=false)
Add a name accelerator entry for Die with Name.
void addNamespaceAccelerator(const DIE *Die, DwarfStringPoolEntryRef Name)
Add a name accelerator entry for Die with Name.
StringRef getSysRoot()
Return the DW_AT_LLVM_sysroot of the compile unit or an empty StringRef.
void noteRangeAttribute(const DIE &Die, PatchLocation Attr)
Keep track of a DW_AT_range attribute that we will need to patch up later.
void addObjCAccelerator(const DIE *Die, DwarfStringPoolEntryRef Name, bool SkipPubnamesSection=false)
Add various accelerator entries for Die with Name which is stored in the string table at Offset.
void addTypeAccelerator(const DIE *Die, DwarfStringPoolEntryRef Name, bool ObjcClassImplementation, uint32_t QualifiedNameHash)
Add a type accelerator entry for Die with Name which is stored in the string table at Offset.
uint64_t computeNextUnitOffset(uint16_t DwarfVersion)
Compute the end offset for this unit.
void addLabelLowPc(uint64_t LabelLowPc, int64_t PcOffset)
Add the low_pc of a label that is relocated by applying offset PCOffset.
void markEverythingAsKept()
Mark every DIE in this unit as kept.
A DeclContext is a named program scope that is used for ODR uniquing of types.
StringRef toStringRef(const std::optional< DWARFFormValue > &V, StringRef Default={})
Take an optional DWARFFormValue and try to extract a string value from it.
std::optional< uint64_t > toUnsigned(const std::optional< DWARFFormValue > &V)
Take an optional DWARFFormValue and try to extract an unsigned constant.
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
auto formatv(const char *Fmt, Ts &&...Vals) -> formatv_object< decltype(std::make_tuple(support::detail::build_format_adapter(std::forward< Ts >(Vals))...))>
static bool inFunctionScope(CompileUnit &U, unsigned Idx)
Check if the DIE at Idx is in the scope of a function.
raw_fd_ostream & errs()
This returns a reference to a raw_ostream for standard error.
@ Ref
The access may reference the value stored in memory.
@ Keep
No function return thunk.