1//===- llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.h --------------*- C++ -*-===//
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// This file contains support for writing Microsoft CodeView debug info.
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_LIB_CODEGEN_ASMPRINTER_CODEVIEWDEBUG_H
14#define LLVM_LIB_CODEGEN_ASMPRINTER_CODEVIEWDEBUG_H
15
16#include "llvm/ADT/APSInt.h"
17#include "llvm/ADT/ArrayRef.h"
18#include "llvm/ADT/DenseMap.h"
19#include "llvm/ADT/DenseSet.h"
20#include "llvm/ADT/MapVector.h"
21#include "llvm/ADT/PointerUnion.h"
22#include "llvm/ADT/SetVector.h"
23#include "llvm/ADT/SmallSet.h"
24#include "llvm/ADT/SmallVector.h"
25#include "llvm/CodeGen/DbgEntityHistoryCalculator.h"
26#include "llvm/CodeGen/DebugHandlerBase.h"
27#include "llvm/CodeGen/MachineJumpTableInfo.h"
28#include "llvm/DebugInfo/CodeView/CodeView.h"
29#include "llvm/DebugInfo/CodeView/GlobalTypeTableBuilder.h"
30#include "llvm/DebugInfo/CodeView/TypeIndex.h"
31#include "llvm/IR/DebugLoc.h"
32#include "llvm/Support/Allocator.h"
33#include "llvm/Support/Compiler.h"
34#include <cstdint>
35#include <map>
36#include <string>
37#include <tuple>
38#include <unordered_map>
39#include <utility>
40#include <vector>
41
42namespace llvm {
43
44struct ClassInfo;
45class StringRef;
46class AsmPrinter;
47class Function;
48class GlobalVariable;
49class MCSectionCOFF;
50class MCStreamer;
51class MCSymbol;
52class MachineFunction;
53
54/// Collects and handles line tables information in a CodeView format.
55class LLVM_LIBRARY_VISIBILITY CodeViewDebug : public DebugHandlerBase {
56public:
57 struct LocalVarDef {
58 /// Indicates that variable data is stored in memory relative to the
59 /// specified register.
60 int InMemory : 1;
61
62 /// Offset of variable data in memory.
63 int DataOffset : 31;
64
65 /// Non-zero if this is a piece of an aggregate.
66 uint16_t IsSubfield : 1;
67
68 /// Offset into aggregate.
69 uint16_t StructOffset : 15;
70
71 /// Register containing the data or the register base of the memory
72 /// location containing the data.
73 uint16_t CVRegister;
74
75 uint64_t static toOpaqueValue(const LocalVarDef DR) {
76 uint64_t Val = 0;
77 std::memcpy(dest: &Val, src: &DR, n: sizeof(Val));
78 return Val;
79 }
80
81 LocalVarDef static createFromOpaqueValue(uint64_t Val) {
82 LocalVarDef DR;
83 std::memcpy(dest: &DR, src: &Val, n: sizeof(Val));
84 return DR;
85 }
86 };
87
88 static_assert(sizeof(uint64_t) == sizeof(LocalVarDef));
89
90private:
91 MCStreamer &OS;
92 BumpPtrAllocator Allocator;
93 codeview::GlobalTypeTableBuilder TypeTable;
94
95 /// Whether to emit type record hashes into .debug$H.
96 bool EmitDebugGlobalHashes = false;
97
98 /// The codeview CPU type used by the translation unit.
99 codeview::CPUType TheCPU;
100
101 static LocalVarDef createDefRangeMem(uint16_t CVRegister, int Offset);
102
103 /// Similar to DbgVariable in DwarfDebug, but not dwarf-specific.
104 struct LocalVariable {
105 const DILocalVariable *DIVar = nullptr;
106 MapVector<LocalVarDef,
107 SmallVector<std::pair<const MCSymbol *, const MCSymbol *>, 1>>
108 DefRanges;
109 bool UseReferenceType = false;
110 std::optional<APSInt> ConstantValue;
111 };
112
113 struct CVGlobalVariable {
114 const DIGlobalVariable *DIGV;
115 PointerUnion<const GlobalVariable *, const DIExpression *> GVInfo;
116 };
117
118 struct InlineSite {
119 SmallVector<LocalVariable, 1> InlinedLocals;
120 SmallVector<const DILocation *, 1> ChildSites;
121 const DISubprogram *Inlinee = nullptr;
122
123 /// The ID of the inline site or function used with .cv_loc. Not a type
124 /// index.
125 unsigned SiteFuncId = 0;
126 };
127
128 // Combines information from DILexicalBlock and LexicalScope.
129 struct LexicalBlock {
130 SmallVector<LocalVariable, 1> Locals;
131 SmallVector<CVGlobalVariable, 1> Globals;
132 SmallVector<LexicalBlock *, 1> Children;
133 const MCSymbol *Begin;
134 const MCSymbol *End;
135 StringRef Name;
136 };
137
138 struct JumpTableInfo {
139 codeview::JumpTableEntrySize EntrySize;
140 const MCSymbol *Base;
141 uint64_t BaseOffset;
142 const MCSymbol *Branch;
143 const MCSymbol *Table;
144 size_t TableSize;
145 };
146
147 // For each function, store a vector of labels to its instructions, as well as
148 // to the end of the function.
149 struct FunctionInfo {
150 FunctionInfo() = default;
151
152 // Uncopyable.
153 FunctionInfo(const FunctionInfo &FI) = delete;
154
155 /// Map from inlined call site to inlined instructions and child inlined
156 /// call sites. Listed in program order.
157 std::unordered_map<const DILocation *, InlineSite> InlineSites;
158
159 /// Ordered list of top-level inlined call sites.
160 SmallVector<const DILocation *, 1> ChildSites;
161
162 /// Set of all functions directly inlined into this one.
163 SmallSet<codeview::TypeIndex, 1> Inlinees;
164
165 SmallVector<LocalVariable, 1> Locals;
166 SmallVector<CVGlobalVariable, 1> Globals;
167
168 std::unordered_map<const DILexicalBlockBase*, LexicalBlock> LexicalBlocks;
169
170 // Lexical blocks containing local variables.
171 SmallVector<LexicalBlock *, 1> ChildBlocks;
172
173 std::vector<std::pair<MCSymbol *, MDNode *>> Annotations;
174 std::vector<std::tuple<const MCSymbol *, const MCSymbol *, const DIType *>>
175 HeapAllocSites;
176
177 std::vector<JumpTableInfo> JumpTables;
178
179 const MCSymbol *Begin = nullptr;
180 const MCSymbol *End = nullptr;
181 unsigned FuncId = 0;
182 unsigned LastFileId = 0;
183
184 /// Number of bytes allocated in the prologue for all local stack objects.
185 unsigned FrameSize = 0;
186
187 /// Number of bytes of parameters on the stack.
188 unsigned ParamSize = 0;
189
190 /// Number of bytes pushed to save CSRs.
191 unsigned CSRSize = 0;
192
193 /// Adjustment to apply on x86 when using the VFRAME frame pointer.
194 int OffsetAdjustment = 0;
195
196 /// Two-bit value indicating which register is the designated frame pointer
197 /// register for local variables. Included in S_FRAMEPROC.
198 codeview::EncodedFramePtrReg EncodedLocalFramePtrReg =
199 codeview::EncodedFramePtrReg::None;
200
201 /// Two-bit value indicating which register is the designated frame pointer
202 /// register for stack parameters. Included in S_FRAMEPROC.
203 codeview::EncodedFramePtrReg EncodedParamFramePtrReg =
204 codeview::EncodedFramePtrReg::None;
205
206 codeview::FrameProcedureOptions FrameProcOpts;
207
208 bool HasStackRealignment = false;
209
210 bool HaveLineInfo = false;
211
212 bool HasFramePointer = false;
213 };
214 FunctionInfo *CurFn = nullptr;
215
216 codeview::SourceLanguage CurrentSourceLanguage =
217 codeview::SourceLanguage::Masm;
218
219 // This map records the constant offset in DIExpression of the
220 // DIGlobalVariableExpression referencing the DIGlobalVariable.
221 DenseMap<const DIGlobalVariable *, uint64_t> CVGlobalVariableOffsets;
222
223 // Map used to separate variables according to the lexical scope they belong
224 // in. This is populated by recordLocalVariable() before
225 // collectLexicalBlocks() separates the variables between the FunctionInfo
226 // and LexicalBlocks.
227 DenseMap<const LexicalScope *, SmallVector<LocalVariable, 1>> ScopeVariables;
228
229 // Map to separate global variables according to the lexical scope they
230 // belong in. A null local scope represents the global scope.
231 typedef SmallVector<CVGlobalVariable, 1> GlobalVariableList;
232 DenseMap<const DIScope*, std::unique_ptr<GlobalVariableList> > ScopeGlobals;
233
234 // Array of global variables which need to be emitted into a COMDAT section.
235 SmallVector<CVGlobalVariable, 1> ComdatVariables;
236
237 // Array of non-COMDAT global variables.
238 SmallVector<CVGlobalVariable, 1> GlobalVariables;
239
240 /// List of static const data members to be emitted as S_CONSTANTs.
241 SmallVector<const DIDerivedType *, 4> StaticConstMembers;
242
243 /// The set of comdat .debug$S sections that we've seen so far. Each section
244 /// must start with a magic version number that must only be emitted once.
245 /// This set tracks which sections we've already opened.
246 DenseSet<MCSectionCOFF *> ComdatDebugSections;
247
248 /// Switch to the appropriate .debug$S section for GVSym. If GVSym, the symbol
249 /// of an emitted global value, is in a comdat COFF section, this will switch
250 /// to a new .debug$S section in that comdat. This method ensures that the
251 /// section starts with the magic version number on first use. If GVSym is
252 /// null, uses the main .debug$S section.
253 void switchToDebugSectionForSymbol(const MCSymbol *GVSym);
254
255 /// The next available function index for use with our .cv_* directives. Not
256 /// to be confused with type indices for LF_FUNC_ID records.
257 unsigned NextFuncId = 0;
258
259 InlineSite &getInlineSite(const DILocation *InlinedAt,
260 const DISubprogram *Inlinee);
261
262 codeview::TypeIndex getFuncIdForSubprogram(const DISubprogram *SP);
263
264 void calculateRanges(LocalVariable &Var,
265 const DbgValueHistoryMap::Entries &Entries);
266
267 /// Remember some debug info about each function. Keep it in a stable order to
268 /// emit at the end of the TU.
269 MapVector<const Function *, std::unique_ptr<FunctionInfo>> FnDebugInfo;
270
271 /// Map from full file path to .cv_file id. Full paths are built from DIFiles
272 /// and are stored in FileToFilepathMap;
273 DenseMap<StringRef, unsigned> FileIdMap;
274
275 /// All inlined subprograms in the order they should be emitted.
276 SmallSetVector<const DISubprogram *, 4> InlinedSubprograms;
277
278 /// Map from a pair of DI metadata nodes and its DI type (or scope) that can
279 /// be nullptr, to CodeView type indices. Primarily indexed by
280 /// {DIType*, DIType*} and {DISubprogram*, DIType*}.
281 ///
282 /// The second entry in the key is needed for methods as DISubroutineType
283 /// representing static method type are shared with non-method function type.
284 DenseMap<std::pair<const DINode *, const DIType *>, codeview::TypeIndex>
285 TypeIndices;
286
287 /// Map from DICompositeType* to complete type index. Non-record types are
288 /// always looked up in the normal TypeIndices map.
289 DenseMap<const DICompositeType *, codeview::TypeIndex> CompleteTypeIndices;
290
291 /// Complete record types to emit after all active type lowerings are
292 /// finished.
293 SmallVector<const DICompositeType *, 4> DeferredCompleteTypes;
294
295 /// Number of type lowering frames active on the stack.
296 unsigned TypeEmissionLevel = 0;
297
298 codeview::TypeIndex VBPType;
299
300 const DISubprogram *CurrentSubprogram = nullptr;
301
302 // The UDTs we have seen while processing types; each entry is a pair of type
303 // index and type name.
304 std::vector<std::pair<std::string, const DIType *>> LocalUDTs;
305 std::vector<std::pair<std::string, const DIType *>> GlobalUDTs;
306
307 using FileToFilepathMapTy = std::map<const DIFile *, std::string>;
308 FileToFilepathMapTy FileToFilepathMap;
309
310 StringRef getFullFilepath(const DIFile *File);
311
312 unsigned maybeRecordFile(const DIFile *F);
313
314 void maybeRecordLocation(const DebugLoc &DL, const MachineFunction *MF);
315
316 void clear();
317
318 void setCurrentSubprogram(const DISubprogram *SP) {
319 CurrentSubprogram = SP;
320 LocalUDTs.clear();
321 }
322
323 /// Emit the magic version number at the start of a CodeView type or symbol
324 /// section. Appears at the front of every .debug$S or .debug$T or .debug$P
325 /// section.
326 void emitCodeViewMagicVersion();
327
328 void emitTypeInformation();
329
330 void emitTypeGlobalHashes();
331
332 void emitObjName();
333
334 void emitCompilerInformation();
335
336 void emitBuildInfo();
337
338 void emitInlineeLinesSubsection();
339
340 void emitDebugInfoForThunk(const Function *GV,
341 FunctionInfo &FI,
342 const MCSymbol *Fn);
343
344 void emitDebugInfoForFunction(const Function *GV, FunctionInfo &FI);
345
346 void emitDebugInfoForRetainedTypes();
347
348 void emitDebugInfoForUDTs(
349 const std::vector<std::pair<std::string, const DIType *>> &UDTs);
350
351 void collectDebugInfoForGlobals();
352 void emitDebugInfoForGlobals();
353 void emitGlobalVariableList(ArrayRef<CVGlobalVariable> Globals);
354 void emitConstantSymbolRecord(const DIType *DTy, APSInt &Value,
355 const std::string &QualifiedName);
356 void emitDebugInfoForGlobal(const CVGlobalVariable &CVGV);
357 void emitStaticConstMemberList();
358
359 /// Opens a subsection of the given kind in a .debug$S codeview section.
360 /// Returns an end label for use with endCVSubsection when the subsection is
361 /// finished.
362 MCSymbol *beginCVSubsection(codeview::DebugSubsectionKind Kind);
363 void endCVSubsection(MCSymbol *EndLabel);
364
365 /// Opens a symbol record of the given kind. Returns an end label for use with
366 /// endSymbolRecord.
367 MCSymbol *beginSymbolRecord(codeview::SymbolKind Kind);
368 void endSymbolRecord(MCSymbol *SymEnd);
369
370 /// Emits an S_END, S_INLINESITE_END, or S_PROC_ID_END record. These records
371 /// are empty, so we emit them with a simpler assembly sequence that doesn't
372 /// involve labels.
373 void emitEndSymbolRecord(codeview::SymbolKind EndKind);
374
375 void emitInlinedCallSite(const FunctionInfo &FI, const DILocation *InlinedAt,
376 const InlineSite &Site);
377
378 void emitInlinees(const SmallSet<codeview::TypeIndex, 1> &Inlinees);
379
380 using InlinedEntity = DbgValueHistoryMap::InlinedEntity;
381
382 void collectGlobalVariableInfo();
383 void collectVariableInfo(const DISubprogram *SP);
384
385 void collectVariableInfoFromMFTable(DenseSet<InlinedEntity> &Processed);
386
387 // Construct the lexical block tree for a routine, pruning emptpy lexical
388 // scopes, and populate it with local variables.
389 void collectLexicalBlockInfo(SmallVectorImpl<LexicalScope *> &Scopes,
390 SmallVectorImpl<LexicalBlock *> &Blocks,
391 SmallVectorImpl<LocalVariable> &Locals,
392 SmallVectorImpl<CVGlobalVariable> &Globals);
393 void collectLexicalBlockInfo(LexicalScope &Scope,
394 SmallVectorImpl<LexicalBlock *> &ParentBlocks,
395 SmallVectorImpl<LocalVariable> &ParentLocals,
396 SmallVectorImpl<CVGlobalVariable> &ParentGlobals);
397
398 /// Records information about a local variable in the appropriate scope. In
399 /// particular, locals from inlined code live inside the inlining site.
400 void recordLocalVariable(LocalVariable &&Var, const LexicalScope *LS);
401
402 /// Emits local variables in the appropriate order.
403 void emitLocalVariableList(const FunctionInfo &FI,
404 ArrayRef<LocalVariable> Locals);
405
406 /// Emits an S_LOCAL record and its associated defined ranges.
407 void emitLocalVariable(const FunctionInfo &FI, const LocalVariable &Var);
408
409 /// Emits a sequence of lexical block scopes and their children.
410 void emitLexicalBlockList(ArrayRef<LexicalBlock *> Blocks,
411 const FunctionInfo& FI);
412
413 /// Emit a lexical block scope and its children.
414 void emitLexicalBlock(const LexicalBlock &Block, const FunctionInfo& FI);
415
416 /// Translates the DIType to codeview if necessary and returns a type index
417 /// for it.
418 codeview::TypeIndex getTypeIndex(const DIType *Ty,
419 const DIType *ClassTy = nullptr);
420
421 codeview::TypeIndex
422 getTypeIndexForThisPtr(const DIDerivedType *PtrTy,
423 const DISubroutineType *SubroutineTy);
424
425 codeview::TypeIndex getTypeIndexForReferenceTo(const DIType *Ty);
426
427 codeview::TypeIndex getMemberFunctionType(const DISubprogram *SP,
428 const DICompositeType *Class);
429
430 codeview::TypeIndex getScopeIndex(const DIScope *Scope);
431
432 codeview::TypeIndex getVBPTypeIndex();
433
434 void addToUDTs(const DIType *Ty);
435
436 void addUDTSrcLine(const DIType *Ty, codeview::TypeIndex TI);
437
438 codeview::TypeIndex lowerType(const DIType *Ty, const DIType *ClassTy);
439 codeview::TypeIndex lowerTypeAlias(const DIDerivedType *Ty);
440 codeview::TypeIndex lowerTypeArray(const DICompositeType *Ty);
441 codeview::TypeIndex lowerTypeString(const DIStringType *Ty);
442 codeview::TypeIndex lowerTypeBasic(const DIBasicType *Ty);
443 codeview::TypeIndex lowerTypePointer(
444 const DIDerivedType *Ty,
445 codeview::PointerOptions PO = codeview::PointerOptions::None);
446 codeview::TypeIndex lowerTypeMemberPointer(
447 const DIDerivedType *Ty,
448 codeview::PointerOptions PO = codeview::PointerOptions::None);
449 codeview::TypeIndex lowerTypeModifier(const DIDerivedType *Ty);
450 codeview::TypeIndex lowerTypeFunction(const DISubroutineType *Ty);
451 codeview::TypeIndex lowerTypeVFTableShape(const DIDerivedType *Ty);
452 codeview::TypeIndex lowerTypeMemberFunction(
453 const DISubroutineType *Ty, const DIType *ClassTy, int ThisAdjustment,
454 bool IsStaticMethod,
455 codeview::FunctionOptions FO = codeview::FunctionOptions::None);
456 codeview::TypeIndex lowerTypeEnum(const DICompositeType *Ty);
457 codeview::TypeIndex lowerTypeClass(const DICompositeType *Ty);
458 codeview::TypeIndex lowerTypeUnion(const DICompositeType *Ty);
459
460 /// Symbol records should point to complete types, but type records should
461 /// always point to incomplete types to avoid cycles in the type graph. Only
462 /// use this entry point when generating symbol records. The complete and
463 /// incomplete type indices only differ for record types. All other types use
464 /// the same index.
465 codeview::TypeIndex getCompleteTypeIndex(const DIType *Ty);
466
467 codeview::TypeIndex lowerCompleteTypeClass(const DICompositeType *Ty);
468 codeview::TypeIndex lowerCompleteTypeUnion(const DICompositeType *Ty);
469
470 struct TypeLoweringScope;
471
472 void emitDeferredCompleteTypes();
473
474 void collectMemberInfo(ClassInfo &Info, const DIDerivedType *DDTy);
475 ClassInfo collectClassInfo(const DICompositeType *Ty);
476
477 /// Common record member lowering functionality for record types, which are
478 /// structs, classes, and unions. Returns the field list index and the member
479 /// count.
480 std::tuple<codeview::TypeIndex, codeview::TypeIndex, unsigned, bool>
481 lowerRecordFieldList(const DICompositeType *Ty);
482
483 /// Inserts {{Node, ClassTy}, TI} into TypeIndices and checks for duplicates.
484 codeview::TypeIndex recordTypeIndexForDINode(const DINode *Node,
485 codeview::TypeIndex TI,
486 const DIType *ClassTy = nullptr);
487
488 /// Collect the names of parent scopes, innermost to outermost. Return the
489 /// innermost subprogram scope if present. Ensure that parent type scopes are
490 /// inserted into the type table.
491 const DISubprogram *
492 collectParentScopeNames(const DIScope *Scope,
493 SmallVectorImpl<StringRef> &ParentScopeNames);
494 std::string getFullyQualifiedName(const DIScope *Scope, StringRef Name);
495 std::string getFullyQualifiedName(const DIScope *Scope);
496
497 unsigned getPointerSizeInBytes();
498
499 void discoverJumpTableBranches(const MachineFunction *MF, bool isThumb);
500 void collectDebugInfoForJumpTables(const MachineFunction *MF, bool isThumb);
501 void emitDebugInfoForJumpTables(const FunctionInfo &FI);
502
503protected:
504 /// Gather pre-function debug information.
505 void beginFunctionImpl(const MachineFunction *MF) override;
506
507 /// Gather post-function debug information.
508 void endFunctionImpl(const MachineFunction *) override;
509
510 /// Check if the current module is in Fortran.
511 bool moduleIsInFortran() {
512 return CurrentSourceLanguage == codeview::SourceLanguage::Fortran;
513 }
514
515public:
516 CodeViewDebug(AsmPrinter *AP);
517
518 void beginModule(Module *M) override;
519
520 /// Emit the COFF section that holds the line table information.
521 void endModule() override;
522
523 /// Process beginning of an instruction.
524 void beginInstruction(const MachineInstr *MI) override;
525};
526
527template <> struct DenseMapInfo<CodeViewDebug::LocalVarDef> {
528
529 static inline CodeViewDebug::LocalVarDef getEmptyKey() {
530 return CodeViewDebug::LocalVarDef::createFromOpaqueValue(Val: ~0ULL);
531 }
532
533 static inline CodeViewDebug::LocalVarDef getTombstoneKey() {
534 return CodeViewDebug::LocalVarDef::createFromOpaqueValue(Val: ~0ULL - 1ULL);
535 }
536
537 static unsigned getHashValue(const CodeViewDebug::LocalVarDef &DR) {
538 return CodeViewDebug::LocalVarDef::toOpaqueValue(DR) * 37ULL;
539 }
540
541 static bool isEqual(const CodeViewDebug::LocalVarDef &LHS,
542 const CodeViewDebug::LocalVarDef &RHS) {
543 return CodeViewDebug::LocalVarDef::toOpaqueValue(DR: LHS) ==
544 CodeViewDebug::LocalVarDef::toOpaqueValue(DR: RHS);
545 }
546};
547
548} // end namespace llvm
549
550#endif // LLVM_LIB_CODEGEN_ASMPRINTER_CODEVIEWDEBUG_H
551