1 //===- llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.h --------------*- C++ -*-===//
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
7 //===----------------------------------------------------------------------===//
9 // This file contains support for writing Microsoft CodeView debug info.
11 //===----------------------------------------------------------------------===//
13 #ifndef LLVM_LIB_CODEGEN_ASMPRINTER_CODEVIEWDEBUG_H
14 #define LLVM_LIB_CODEGEN_ASMPRINTER_CODEVIEWDEBUG_H
16 #include "llvm/ADT/ArrayRef.h"
17 #include "llvm/ADT/DenseMap.h"
18 #include "llvm/ADT/DenseSet.h"
19 #include "llvm/ADT/MapVector.h"
20 #include "llvm/ADT/PointerUnion.h"
21 #include "llvm/ADT/SetVector.h"
22 #include "llvm/ADT/SmallVector.h"
23 #include "llvm/CodeGen/DbgEntityHistoryCalculator.h"
24 #include "llvm/CodeGen/DebugHandlerBase.h"
25 #include "llvm/DebugInfo/CodeView/CodeView.h"
26 #include "llvm/DebugInfo/CodeView/GlobalTypeTableBuilder.h"
27 #include "llvm/DebugInfo/CodeView/TypeIndex.h"
28 #include "llvm/IR/DebugLoc.h"
29 #include "llvm/Support/Allocator.h"
30 #include "llvm/Support/Compiler.h"
35 #include <unordered_map>
49 class MachineFunction;
51 /// Collects and handles line tables information in a CodeView format.
52 class LLVM_LIBRARY_VISIBILITY CodeViewDebug : public DebugHandlerBase {
54 BumpPtrAllocator Allocator;
55 codeview::GlobalTypeTableBuilder TypeTable;
57 /// Whether to emit type record hashes into .debug$H.
58 bool EmitDebugGlobalHashes = false;
60 /// The codeview CPU type used by the translation unit.
61 codeview::CPUType TheCPU;
63 /// Represents the most general definition range.
64 struct LocalVarDefRange {
65 /// Indicates that variable data is stored in memory relative to the
66 /// specified register.
69 /// Offset of variable data in memory.
72 /// Non-zero if this is a piece of an aggregate.
73 uint16_t IsSubfield : 1;
75 /// Offset into aggregate.
76 uint16_t StructOffset : 15;
78 /// Register containing the data or the register base of the memory
79 /// location containing the data.
82 /// Compares all location fields. This includes all fields except the label
84 bool isDifferentLocation(LocalVarDefRange &O) {
85 return InMemory != O.InMemory || DataOffset != O.DataOffset ||
86 IsSubfield != O.IsSubfield || StructOffset != O.StructOffset ||
87 CVRegister != O.CVRegister;
90 SmallVector<std::pair<const MCSymbol *, const MCSymbol *>, 1> Ranges;
93 static LocalVarDefRange createDefRangeMem(uint16_t CVRegister, int Offset);
95 /// Similar to DbgVariable in DwarfDebug, but not dwarf-specific.
96 struct LocalVariable {
97 const DILocalVariable *DIVar = nullptr;
98 SmallVector<LocalVarDefRange, 1> DefRanges;
99 bool UseReferenceType = false;
102 struct CVGlobalVariable {
103 const DIGlobalVariable *DIGV;
104 PointerUnion<const GlobalVariable *, const DIExpression *> GVInfo;
108 SmallVector<LocalVariable, 1> InlinedLocals;
109 SmallVector<const DILocation *, 1> ChildSites;
110 const DISubprogram *Inlinee = nullptr;
112 /// The ID of the inline site or function used with .cv_loc. Not a type
114 unsigned SiteFuncId = 0;
117 // Combines information from DILexicalBlock and LexicalScope.
118 struct LexicalBlock {
119 SmallVector<LocalVariable, 1> Locals;
120 SmallVector<CVGlobalVariable, 1> Globals;
121 SmallVector<LexicalBlock *, 1> Children;
122 const MCSymbol *Begin;
127 // For each function, store a vector of labels to its instructions, as well as
128 // to the end of the function.
129 struct FunctionInfo {
130 FunctionInfo() = default;
133 FunctionInfo(const FunctionInfo &FI) = delete;
135 /// Map from inlined call site to inlined instructions and child inlined
136 /// call sites. Listed in program order.
137 std::unordered_map<const DILocation *, InlineSite> InlineSites;
139 /// Ordered list of top-level inlined call sites.
140 SmallVector<const DILocation *, 1> ChildSites;
142 SmallVector<LocalVariable, 1> Locals;
143 SmallVector<CVGlobalVariable, 1> Globals;
145 std::unordered_map<const DILexicalBlockBase*, LexicalBlock> LexicalBlocks;
147 // Lexical blocks containing local variables.
148 SmallVector<LexicalBlock *, 1> ChildBlocks;
150 std::vector<std::pair<MCSymbol *, MDNode *>> Annotations;
151 std::vector<std::tuple<MCSymbol *, MCSymbol *, DIType *>> HeapAllocSites;
153 const MCSymbol *Begin = nullptr;
154 const MCSymbol *End = nullptr;
156 unsigned LastFileId = 0;
158 /// Number of bytes allocated in the prologue for all local stack objects.
159 unsigned FrameSize = 0;
161 /// Number of bytes of parameters on the stack.
162 unsigned ParamSize = 0;
164 /// Number of bytes pushed to save CSRs.
165 unsigned CSRSize = 0;
167 /// Adjustment to apply on x86 when using the VFRAME frame pointer.
168 int OffsetAdjustment = 0;
170 /// Two-bit value indicating which register is the designated frame pointer
171 /// register for local variables. Included in S_FRAMEPROC.
172 codeview::EncodedFramePtrReg EncodedLocalFramePtrReg =
173 codeview::EncodedFramePtrReg::None;
175 /// Two-bit value indicating which register is the designated frame pointer
176 /// register for stack parameters. Included in S_FRAMEPROC.
177 codeview::EncodedFramePtrReg EncodedParamFramePtrReg =
178 codeview::EncodedFramePtrReg::None;
180 codeview::FrameProcedureOptions FrameProcOpts;
182 bool HasStackRealignment = false;
184 bool HaveLineInfo = false;
186 FunctionInfo *CurFn = nullptr;
188 // Map used to seperate variables according to the lexical scope they belong
189 // in. This is populated by recordLocalVariable() before
190 // collectLexicalBlocks() separates the variables between the FunctionInfo
191 // and LexicalBlocks.
192 DenseMap<const LexicalScope *, SmallVector<LocalVariable, 1>> ScopeVariables;
194 // Map to separate global variables according to the lexical scope they
195 // belong in. A null local scope represents the global scope.
196 typedef SmallVector<CVGlobalVariable, 1> GlobalVariableList;
197 DenseMap<const DIScope*, std::unique_ptr<GlobalVariableList> > ScopeGlobals;
199 // Array of global variables which need to be emitted into a COMDAT section.
200 SmallVector<CVGlobalVariable, 1> ComdatVariables;
202 // Array of non-COMDAT global variables.
203 SmallVector<CVGlobalVariable, 1> GlobalVariables;
205 /// The set of comdat .debug$S sections that we've seen so far. Each section
206 /// must start with a magic version number that must only be emitted once.
207 /// This set tracks which sections we've already opened.
208 DenseSet<MCSectionCOFF *> ComdatDebugSections;
210 /// Switch to the appropriate .debug$S section for GVSym. If GVSym, the symbol
211 /// of an emitted global value, is in a comdat COFF section, this will switch
212 /// to a new .debug$S section in that comdat. This method ensures that the
213 /// section starts with the magic version number on first use. If GVSym is
214 /// null, uses the main .debug$S section.
215 void switchToDebugSectionForSymbol(const MCSymbol *GVSym);
217 /// The next available function index for use with our .cv_* directives. Not
218 /// to be confused with type indices for LF_FUNC_ID records.
219 unsigned NextFuncId = 0;
221 InlineSite &getInlineSite(const DILocation *InlinedAt,
222 const DISubprogram *Inlinee);
224 codeview::TypeIndex getFuncIdForSubprogram(const DISubprogram *SP);
226 void calculateRanges(LocalVariable &Var,
227 const DbgValueHistoryMap::Entries &Entries);
229 static void collectInlineSiteChildren(SmallVectorImpl<unsigned> &Children,
230 const FunctionInfo &FI,
231 const InlineSite &Site);
233 /// Remember some debug info about each function. Keep it in a stable order to
234 /// emit at the end of the TU.
235 MapVector<const Function *, std::unique_ptr<FunctionInfo>> FnDebugInfo;
237 /// Map from full file path to .cv_file id. Full paths are built from DIFiles
238 /// and are stored in FileToFilepathMap;
239 DenseMap<StringRef, unsigned> FileIdMap;
241 /// All inlined subprograms in the order they should be emitted.
242 SmallSetVector<const DISubprogram *, 4> InlinedSubprograms;
244 /// Map from a pair of DI metadata nodes and its DI type (or scope) that can
245 /// be nullptr, to CodeView type indices. Primarily indexed by
246 /// {DIType*, DIType*} and {DISubprogram*, DIType*}.
248 /// The second entry in the key is needed for methods as DISubroutineType
249 /// representing static method type are shared with non-method function type.
250 DenseMap<std::pair<const DINode *, const DIType *>, codeview::TypeIndex>
253 /// Map from DICompositeType* to complete type index. Non-record types are
254 /// always looked up in the normal TypeIndices map.
255 DenseMap<const DICompositeType *, codeview::TypeIndex> CompleteTypeIndices;
257 /// Complete record types to emit after all active type lowerings are
259 SmallVector<const DICompositeType *, 4> DeferredCompleteTypes;
261 /// Number of type lowering frames active on the stack.
262 unsigned TypeEmissionLevel = 0;
264 codeview::TypeIndex VBPType;
266 const DISubprogram *CurrentSubprogram = nullptr;
268 // The UDTs we have seen while processing types; each entry is a pair of type
269 // index and type name.
270 std::vector<std::pair<std::string, const DIType *>> LocalUDTs;
271 std::vector<std::pair<std::string, const DIType *>> GlobalUDTs;
273 using FileToFilepathMapTy = std::map<const DIFile *, std::string>;
274 FileToFilepathMapTy FileToFilepathMap;
276 StringRef getFullFilepath(const DIFile *File);
278 unsigned maybeRecordFile(const DIFile *F);
280 void maybeRecordLocation(const DebugLoc &DL, const MachineFunction *MF);
284 void setCurrentSubprogram(const DISubprogram *SP) {
285 CurrentSubprogram = SP;
289 /// Emit the magic version number at the start of a CodeView type or symbol
290 /// section. Appears at the front of every .debug$S or .debug$T or .debug$P
292 void emitCodeViewMagicVersion();
294 void emitTypeInformation();
296 void emitTypeGlobalHashes();
298 void emitCompilerInformation();
300 void emitBuildInfo();
302 void emitInlineeLinesSubsection();
304 void emitDebugInfoForThunk(const Function *GV,
308 void emitDebugInfoForFunction(const Function *GV, FunctionInfo &FI);
310 void emitDebugInfoForRetainedTypes();
313 emitDebugInfoForUDTs(ArrayRef<std::pair<std::string, const DIType *>> UDTs);
315 void emitDebugInfoForGlobals();
316 void emitGlobalVariableList(ArrayRef<CVGlobalVariable> Globals);
317 void emitDebugInfoForGlobal(const CVGlobalVariable &CVGV);
319 /// Opens a subsection of the given kind in a .debug$S codeview section.
320 /// Returns an end label for use with endCVSubsection when the subsection is
322 MCSymbol *beginCVSubsection(codeview::DebugSubsectionKind Kind);
323 void endCVSubsection(MCSymbol *EndLabel);
325 /// Opens a symbol record of the given kind. Returns an end label for use with
327 MCSymbol *beginSymbolRecord(codeview::SymbolKind Kind);
328 void endSymbolRecord(MCSymbol *SymEnd);
330 /// Emits an S_END, S_INLINESITE_END, or S_PROC_ID_END record. These records
331 /// are empty, so we emit them with a simpler assembly sequence that doesn't
333 void emitEndSymbolRecord(codeview::SymbolKind EndKind);
335 void emitInlinedCallSite(const FunctionInfo &FI, const DILocation *InlinedAt,
336 const InlineSite &Site);
338 using InlinedEntity = DbgValueHistoryMap::InlinedEntity;
340 void collectGlobalVariableInfo();
341 void collectVariableInfo(const DISubprogram *SP);
343 void collectVariableInfoFromMFTable(DenseSet<InlinedEntity> &Processed);
345 // Construct the lexical block tree for a routine, pruning emptpy lexical
346 // scopes, and populate it with local variables.
347 void collectLexicalBlockInfo(SmallVectorImpl<LexicalScope *> &Scopes,
348 SmallVectorImpl<LexicalBlock *> &Blocks,
349 SmallVectorImpl<LocalVariable> &Locals,
350 SmallVectorImpl<CVGlobalVariable> &Globals);
351 void collectLexicalBlockInfo(LexicalScope &Scope,
352 SmallVectorImpl<LexicalBlock *> &ParentBlocks,
353 SmallVectorImpl<LocalVariable> &ParentLocals,
354 SmallVectorImpl<CVGlobalVariable> &ParentGlobals);
356 /// Records information about a local variable in the appropriate scope. In
357 /// particular, locals from inlined code live inside the inlining site.
358 void recordLocalVariable(LocalVariable &&Var, const LexicalScope *LS);
360 /// Emits local variables in the appropriate order.
361 void emitLocalVariableList(const FunctionInfo &FI,
362 ArrayRef<LocalVariable> Locals);
364 /// Emits an S_LOCAL record and its associated defined ranges.
365 void emitLocalVariable(const FunctionInfo &FI, const LocalVariable &Var);
367 /// Emits a sequence of lexical block scopes and their children.
368 void emitLexicalBlockList(ArrayRef<LexicalBlock *> Blocks,
369 const FunctionInfo& FI);
371 /// Emit a lexical block scope and its children.
372 void emitLexicalBlock(const LexicalBlock &Block, const FunctionInfo& FI);
374 /// Translates the DIType to codeview if necessary and returns a type index
376 codeview::TypeIndex getTypeIndex(const DIType *Ty,
377 const DIType *ClassTy = nullptr);
380 getTypeIndexForThisPtr(const DIDerivedType *PtrTy,
381 const DISubroutineType *SubroutineTy);
383 codeview::TypeIndex getTypeIndexForReferenceTo(const DIType *Ty);
385 codeview::TypeIndex getMemberFunctionType(const DISubprogram *SP,
386 const DICompositeType *Class);
388 codeview::TypeIndex getScopeIndex(const DIScope *Scope);
390 codeview::TypeIndex getVBPTypeIndex();
392 void addToUDTs(const DIType *Ty);
394 void addUDTSrcLine(const DIType *Ty, codeview::TypeIndex TI);
396 codeview::TypeIndex lowerType(const DIType *Ty, const DIType *ClassTy);
397 codeview::TypeIndex lowerTypeAlias(const DIDerivedType *Ty);
398 codeview::TypeIndex lowerTypeArray(const DICompositeType *Ty);
399 codeview::TypeIndex lowerTypeBasic(const DIBasicType *Ty);
400 codeview::TypeIndex lowerTypePointer(
401 const DIDerivedType *Ty,
402 codeview::PointerOptions PO = codeview::PointerOptions::None);
403 codeview::TypeIndex lowerTypeMemberPointer(
404 const DIDerivedType *Ty,
405 codeview::PointerOptions PO = codeview::PointerOptions::None);
406 codeview::TypeIndex lowerTypeModifier(const DIDerivedType *Ty);
407 codeview::TypeIndex lowerTypeFunction(const DISubroutineType *Ty);
408 codeview::TypeIndex lowerTypeVFTableShape(const DIDerivedType *Ty);
409 codeview::TypeIndex lowerTypeMemberFunction(
410 const DISubroutineType *Ty, const DIType *ClassTy, int ThisAdjustment,
412 codeview::FunctionOptions FO = codeview::FunctionOptions::None);
413 codeview::TypeIndex lowerTypeEnum(const DICompositeType *Ty);
414 codeview::TypeIndex lowerTypeClass(const DICompositeType *Ty);
415 codeview::TypeIndex lowerTypeUnion(const DICompositeType *Ty);
417 /// Symbol records should point to complete types, but type records should
418 /// always point to incomplete types to avoid cycles in the type graph. Only
419 /// use this entry point when generating symbol records. The complete and
420 /// incomplete type indices only differ for record types. All other types use
422 codeview::TypeIndex getCompleteTypeIndex(const DIType *Ty);
424 codeview::TypeIndex lowerCompleteTypeClass(const DICompositeType *Ty);
425 codeview::TypeIndex lowerCompleteTypeUnion(const DICompositeType *Ty);
427 struct TypeLoweringScope;
429 void emitDeferredCompleteTypes();
431 void collectMemberInfo(ClassInfo &Info, const DIDerivedType *DDTy);
432 ClassInfo collectClassInfo(const DICompositeType *Ty);
434 /// Common record member lowering functionality for record types, which are
435 /// structs, classes, and unions. Returns the field list index and the member
437 std::tuple<codeview::TypeIndex, codeview::TypeIndex, unsigned, bool>
438 lowerRecordFieldList(const DICompositeType *Ty);
440 /// Inserts {{Node, ClassTy}, TI} into TypeIndices and checks for duplicates.
441 codeview::TypeIndex recordTypeIndexForDINode(const DINode *Node,
442 codeview::TypeIndex TI,
443 const DIType *ClassTy = nullptr);
445 unsigned getPointerSizeInBytes();
448 /// Gather pre-function debug information.
449 void beginFunctionImpl(const MachineFunction *MF) override;
451 /// Gather post-function debug information.
452 void endFunctionImpl(const MachineFunction *) override;
455 CodeViewDebug(AsmPrinter *AP);
457 void setSymbolSize(const MCSymbol *, uint64_t) override {}
459 /// Emit the COFF section that holds the line table information.
460 void endModule() override;
462 /// Process beginning of an instruction.
463 void beginInstruction(const MachineInstr *MI) override;
466 } // end namespace llvm
468 #endif // LLVM_LIB_CODEGEN_ASMPRINTER_CODEVIEWDEBUG_H