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CodeViewDebug.h
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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/ArrayRef.h"
17 #include "llvm/ADT/DenseMap.h"
18 #include "llvm/ADT/DenseSet.h"
19 #include "llvm/ADT/MapVector.h"
20 #include "llvm/ADT/SetVector.h"
21 #include "llvm/ADT/SmallVector.h"
27 #include "llvm/IR/DebugLoc.h"
28 #include "llvm/Support/Allocator.h"
29 #include "llvm/Support/Compiler.h"
30 #include <cstdint>
31 #include <map>
32 #include <string>
33 #include <tuple>
34 #include <unordered_map>
35 #include <utility>
36 #include <vector>
37 
38 namespace llvm {
39 
40 struct ClassInfo;
41 class StringRef;
42 class AsmPrinter;
43 class Function;
44 class GlobalVariable;
45 class MCSectionCOFF;
46 class MCStreamer;
47 class MCSymbol;
48 class MachineFunction;
49 
50 /// Collects and handles line tables information in a CodeView format.
52  MCStreamer &OS;
55 
56  /// Whether to emit type record hashes into .debug$H.
57  bool EmitDebugGlobalHashes = false;
58 
59  /// The codeview CPU type used by the translation unit.
60  codeview::CPUType TheCPU;
61 
62  /// Represents the most general definition range.
63  struct LocalVarDefRange {
64  /// Indicates that variable data is stored in memory relative to the
65  /// specified register.
66  int InMemory : 1;
67 
68  /// Offset of variable data in memory.
69  int DataOffset : 31;
70 
71  /// Non-zero if this is a piece of an aggregate.
72  uint16_t IsSubfield : 1;
73 
74  /// Offset into aggregate.
75  uint16_t StructOffset : 15;
76 
77  /// Register containing the data or the register base of the memory
78  /// location containing the data.
79  uint16_t CVRegister;
80 
81  /// Compares all location fields. This includes all fields except the label
82  /// ranges.
83  bool isDifferentLocation(LocalVarDefRange &O) {
84  return InMemory != O.InMemory || DataOffset != O.DataOffset ||
85  IsSubfield != O.IsSubfield || StructOffset != O.StructOffset ||
86  CVRegister != O.CVRegister;
87  }
88 
90  };
91 
92  static LocalVarDefRange createDefRangeMem(uint16_t CVRegister, int Offset);
93 
94  /// Similar to DbgVariable in DwarfDebug, but not dwarf-specific.
95  struct LocalVariable {
96  const DILocalVariable *DIVar = nullptr;
98  bool UseReferenceType = false;
99  };
100 
101  struct CVGlobalVariable {
102  const DIGlobalVariable *DIGV;
103  const GlobalVariable *GV;
104  };
105 
106  struct InlineSite {
107  SmallVector<LocalVariable, 1> InlinedLocals;
109  const DISubprogram *Inlinee = nullptr;
110 
111  /// The ID of the inline site or function used with .cv_loc. Not a type
112  /// index.
113  unsigned SiteFuncId = 0;
114  };
115 
116  // Combines information from DILexicalBlock and LexicalScope.
117  struct LexicalBlock {
121  const MCSymbol *Begin;
122  const MCSymbol *End;
123  StringRef Name;
124  };
125 
126  // For each function, store a vector of labels to its instructions, as well as
127  // to the end of the function.
128  struct FunctionInfo {
129  FunctionInfo() = default;
130 
131  // Uncopyable.
132  FunctionInfo(const FunctionInfo &FI) = delete;
133 
134  /// Map from inlined call site to inlined instructions and child inlined
135  /// call sites. Listed in program order.
136  std::unordered_map<const DILocation *, InlineSite> InlineSites;
137 
138  /// Ordered list of top-level inlined call sites.
140 
143 
144  std::unordered_map<const DILexicalBlockBase*, LexicalBlock> LexicalBlocks;
145 
146  // Lexical blocks containing local variables.
147  SmallVector<LexicalBlock *, 1> ChildBlocks;
148 
149  std::vector<std::pair<MCSymbol *, MDNode *>> Annotations;
150  std::vector<std::tuple<MCSymbol *, MCSymbol *, DIType *>> HeapAllocSites;
151 
152  const MCSymbol *Begin = nullptr;
153  const MCSymbol *End = nullptr;
154  unsigned FuncId = 0;
155  unsigned LastFileId = 0;
156 
157  /// Number of bytes allocated in the prologue for all local stack objects.
158  unsigned FrameSize = 0;
159 
160  /// Number of bytes of parameters on the stack.
161  unsigned ParamSize = 0;
162 
163  /// Number of bytes pushed to save CSRs.
164  unsigned CSRSize = 0;
165 
166  /// Adjustment to apply on x86 when using the VFRAME frame pointer.
167  int OffsetAdjustment = 0;
168 
169  /// Two-bit value indicating which register is the designated frame pointer
170  /// register for local variables. Included in S_FRAMEPROC.
171  codeview::EncodedFramePtrReg EncodedLocalFramePtrReg =
173 
174  /// Two-bit value indicating which register is the designated frame pointer
175  /// register for stack parameters. Included in S_FRAMEPROC.
176  codeview::EncodedFramePtrReg EncodedParamFramePtrReg =
178 
179  codeview::FrameProcedureOptions FrameProcOpts;
180 
181  bool HasStackRealignment = false;
182 
183  bool HaveLineInfo = false;
184  };
185  FunctionInfo *CurFn = nullptr;
186 
187  // Map used to seperate variables according to the lexical scope they belong
188  // in. This is populated by recordLocalVariable() before
189  // collectLexicalBlocks() separates the variables between the FunctionInfo
190  // and LexicalBlocks.
192 
193  // Map to separate global variables according to the lexical scope they
194  // belong in. A null local scope represents the global scope.
197 
198  // Array of global variables which need to be emitted into a COMDAT section.
199  SmallVector<CVGlobalVariable, 1> ComdatVariables;
200 
201  // Array of non-COMDAT global variables.
202  SmallVector<CVGlobalVariable, 1> GlobalVariables;
203 
204  /// The set of comdat .debug$S sections that we've seen so far. Each section
205  /// must start with a magic version number that must only be emitted once.
206  /// This set tracks which sections we've already opened.
207  DenseSet<MCSectionCOFF *> ComdatDebugSections;
208 
209  /// Switch to the appropriate .debug$S section for GVSym. If GVSym, the symbol
210  /// of an emitted global value, is in a comdat COFF section, this will switch
211  /// to a new .debug$S section in that comdat. This method ensures that the
212  /// section starts with the magic version number on first use. If GVSym is
213  /// null, uses the main .debug$S section.
214  void switchToDebugSectionForSymbol(const MCSymbol *GVSym);
215 
216  /// The next available function index for use with our .cv_* directives. Not
217  /// to be confused with type indices for LF_FUNC_ID records.
218  unsigned NextFuncId = 0;
219 
220  InlineSite &getInlineSite(const DILocation *InlinedAt,
221  const DISubprogram *Inlinee);
222 
223  codeview::TypeIndex getFuncIdForSubprogram(const DISubprogram *SP);
224 
225  void calculateRanges(LocalVariable &Var,
226  const DbgValueHistoryMap::Entries &Entries);
227 
228  static void collectInlineSiteChildren(SmallVectorImpl<unsigned> &Children,
229  const FunctionInfo &FI,
230  const InlineSite &Site);
231 
232  /// Remember some debug info about each function. Keep it in a stable order to
233  /// emit at the end of the TU.
235 
236  /// Map from full file path to .cv_file id. Full paths are built from DIFiles
237  /// and are stored in FileToFilepathMap;
239 
240  /// All inlined subprograms in the order they should be emitted.
241  SmallSetVector<const DISubprogram *, 4> InlinedSubprograms;
242 
243  /// Map from a pair of DI metadata nodes and its DI type (or scope) that can
244  /// be nullptr, to CodeView type indices. Primarily indexed by
245  /// {DIType*, DIType*} and {DISubprogram*, DIType*}.
246  ///
247  /// The second entry in the key is needed for methods as DISubroutineType
248  /// representing static method type are shared with non-method function type.
250  TypeIndices;
251 
252  /// Map from DICompositeType* to complete type index. Non-record types are
253  /// always looked up in the normal TypeIndices map.
255 
256  /// Complete record types to emit after all active type lowerings are
257  /// finished.
258  SmallVector<const DICompositeType *, 4> DeferredCompleteTypes;
259 
260  /// Number of type lowering frames active on the stack.
261  unsigned TypeEmissionLevel = 0;
262 
263  codeview::TypeIndex VBPType;
264 
265  const DISubprogram *CurrentSubprogram = nullptr;
266 
267  // The UDTs we have seen while processing types; each entry is a pair of type
268  // index and type name.
269  std::vector<std::pair<std::string, const DIType *>> LocalUDTs;
270  std::vector<std::pair<std::string, const DIType *>> GlobalUDTs;
271 
272  using FileToFilepathMapTy = std::map<const DIFile *, std::string>;
273  FileToFilepathMapTy FileToFilepathMap;
274 
275  StringRef getFullFilepath(const DIFile *File);
276 
277  unsigned maybeRecordFile(const DIFile *F);
278 
279  void maybeRecordLocation(const DebugLoc &DL, const MachineFunction *MF);
280 
281  void clear();
282 
283  void setCurrentSubprogram(const DISubprogram *SP) {
284  CurrentSubprogram = SP;
285  LocalUDTs.clear();
286  }
287 
288  /// Emit the magic version number at the start of a CodeView type or symbol
289  /// section. Appears at the front of every .debug$S or .debug$T or .debug$P
290  /// section.
291  void emitCodeViewMagicVersion();
292 
293  void emitTypeInformation();
294 
295  void emitTypeGlobalHashes();
296 
297  void emitCompilerInformation();
298 
299  void emitBuildInfo();
300 
301  void emitInlineeLinesSubsection();
302 
303  void emitDebugInfoForThunk(const Function *GV,
304  FunctionInfo &FI,
305  const MCSymbol *Fn);
306 
307  void emitDebugInfoForFunction(const Function *GV, FunctionInfo &FI);
308 
309  void emitDebugInfoForRetainedTypes();
310 
311  void
312  emitDebugInfoForUDTs(ArrayRef<std::pair<std::string, const DIType *>> UDTs);
313 
314  void emitDebugInfoForGlobals();
315  void emitGlobalVariableList(ArrayRef<CVGlobalVariable> Globals);
316  void emitDebugInfoForGlobal(const DIGlobalVariable *DIGV,
317  const GlobalVariable *GV, MCSymbol *GVSym);
318 
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
321  /// finished.
322  MCSymbol *beginCVSubsection(codeview::DebugSubsectionKind Kind);
323  void endCVSubsection(MCSymbol *EndLabel);
324 
325  /// Opens a symbol record of the given kind. Returns an end label for use with
326  /// endSymbolRecord.
327  MCSymbol *beginSymbolRecord(codeview::SymbolKind Kind);
328  void endSymbolRecord(MCSymbol *SymEnd);
329 
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
332  /// involve labels.
333  void emitEndSymbolRecord(codeview::SymbolKind EndKind);
334 
335  void emitInlinedCallSite(const FunctionInfo &FI, const DILocation *InlinedAt,
336  const InlineSite &Site);
337 
338  using InlinedEntity = DbgValueHistoryMap::InlinedEntity;
339 
340  void collectGlobalVariableInfo();
341  void collectVariableInfo(const DISubprogram *SP);
342 
343  void collectVariableInfoFromMFTable(DenseSet<InlinedEntity> &Processed);
344 
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,
351  void collectLexicalBlockInfo(LexicalScope &Scope,
352  SmallVectorImpl<LexicalBlock *> &ParentBlocks,
353  SmallVectorImpl<LocalVariable> &ParentLocals,
354  SmallVectorImpl<CVGlobalVariable> &ParentGlobals);
355 
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);
359 
360  /// Emits local variables in the appropriate order.
361  void emitLocalVariableList(const FunctionInfo &FI,
362  ArrayRef<LocalVariable> Locals);
363 
364  /// Emits an S_LOCAL record and its associated defined ranges.
365  void emitLocalVariable(const FunctionInfo &FI, const LocalVariable &Var);
366 
367  /// Emits a sequence of lexical block scopes and their children.
368  void emitLexicalBlockList(ArrayRef<LexicalBlock *> Blocks,
369  const FunctionInfo& FI);
370 
371  /// Emit a lexical block scope and its children.
372  void emitLexicalBlock(const LexicalBlock &Block, const FunctionInfo& FI);
373 
374  /// Translates the DIType to codeview if necessary and returns a type index
375  /// for it.
376  codeview::TypeIndex getTypeIndex(DITypeRef TypeRef,
377  DITypeRef ClassTyRef = DITypeRef());
378 
380  getTypeIndexForThisPtr(const DIDerivedType *PtrTy,
381  const DISubroutineType *SubroutineTy);
382 
383  codeview::TypeIndex getTypeIndexForReferenceTo(DITypeRef TypeRef);
384 
385  codeview::TypeIndex getMemberFunctionType(const DISubprogram *SP,
386  const DICompositeType *Class);
387 
388  codeview::TypeIndex getScopeIndex(const DIScope *Scope);
389 
390  codeview::TypeIndex getVBPTypeIndex();
391 
392  void addToUDTs(const DIType *Ty);
393 
394  void addUDTSrcLine(const DIType *Ty, codeview::TypeIndex TI);
395 
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,
403  codeview::TypeIndex lowerTypeMemberPointer(
404  const DIDerivedType *Ty,
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,
411  bool IsStaticMethod,
413  codeview::TypeIndex lowerTypeEnum(const DICompositeType *Ty);
414  codeview::TypeIndex lowerTypeClass(const DICompositeType *Ty);
415  codeview::TypeIndex lowerTypeUnion(const DICompositeType *Ty);
416 
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
421  /// the same index.
422  codeview::TypeIndex getCompleteTypeIndex(DITypeRef TypeRef);
423 
424  codeview::TypeIndex lowerCompleteTypeClass(const DICompositeType *Ty);
425  codeview::TypeIndex lowerCompleteTypeUnion(const DICompositeType *Ty);
426 
427  struct TypeLoweringScope;
428 
429  void emitDeferredCompleteTypes();
430 
431  void collectMemberInfo(ClassInfo &Info, const DIDerivedType *DDTy);
432  ClassInfo collectClassInfo(const DICompositeType *Ty);
433 
434  /// Common record member lowering functionality for record types, which are
435  /// structs, classes, and unions. Returns the field list index and the member
436  /// count.
437  std::tuple<codeview::TypeIndex, codeview::TypeIndex, unsigned, bool>
438  lowerRecordFieldList(const DICompositeType *Ty);
439 
440  /// Inserts {{Node, ClassTy}, TI} into TypeIndices and checks for duplicates.
441  codeview::TypeIndex recordTypeIndexForDINode(const DINode *Node,
443  const DIType *ClassTy = nullptr);
444 
445  unsigned getPointerSizeInBytes();
446 
447 protected:
448  /// Gather pre-function debug information.
449  void beginFunctionImpl(const MachineFunction *MF) override;
450 
451  /// Gather post-function debug information.
452  void endFunctionImpl(const MachineFunction *) override;
453 
454 public:
456 
457  void setSymbolSize(const MCSymbol *, uint64_t) override {}
458 
459  /// Emit the COFF section that holds the line table information.
460  void endModule() override;
461 
462  /// Process beginning of an instruction.
463  void beginInstruction(const MachineInstr *MI) override;
464 };
465 
466 } // end namespace llvm
467 
468 #endif // LLVM_LIB_CODEGEN_ASMPRINTER_CODEVIEWDEBUG_H
Profile::FuncID FuncId
Definition: Profile.cpp:320
This class represents lattice values for constants.
Definition: AllocatorList.h:23
MCSymbol - Instances of this class represent a symbol name in the MC file, and MCSymbols are created ...
Definition: MCSymbol.h:41
amdgpu Simplify well known AMD library false FunctionCallee Value const Twine & Name
Implements a dense probed hash-table based set.
Definition: DenseSet.h:249
This class implements a map that also provides access to all stored values in a deterministic order...
Definition: MapVector.h:37
A debug info location.
Definition: DebugLoc.h:33
F(f)
LexicalScope - This class is used to track scope information.
Definition: LexicalScopes.h:44
This file defines the MallocAllocator and BumpPtrAllocator interfaces.
Tagged DWARF-like metadata node.
void setSymbolSize(const MCSymbol *, uint64_t) override
For symbols that have a size designated (e.g.
Holds a subclass of DINode.
Subprogram description.
ArrayRef - Represent a constant reference to an array (0 or more elements consecutively in memory)...
Definition: APInt.h:32
A 32-bit type reference.
Definition: TypeIndex.h:95
Debug location.
Analysis containing CSE Info
Definition: CSEInfo.cpp:20
Streaming machine code generation interface.
Definition: MCStreamer.h:188
EncodedFramePtrReg
Two-bit value indicating which register is the designated frame pointer register. ...
Definition: CodeView.h:519
Allocate memory in an ever growing pool, as if by bump-pointer.
Definition: Allocator.h:140
Instrumentation for Order File
This class is intended to be used as a driving class for all asm writers.
Definition: AsmPrinter.h:78
#define LLVM_LIBRARY_VISIBILITY
LLVM_LIBRARY_VISIBILITY - If a class marked with this attribute is linked into a shared library...
Definition: Compiler.h:107
std::pair< const DINode *, const DILocation * > InlinedEntity
Base class for scope-like contexts.
PointerOptions
Equivalent to misc lfPointerAttr bitfields.
Definition: CodeView.h:354
Basic Register Allocator
A SetVector that performs no allocations if smaller than a certain size.
Definition: SetVector.h:297
Base class for types.
This is a &#39;vector&#39; (really, a variable-sized array), optimized for the case when the array is small...
Definition: SmallVector.h:841
CPUType
These values correspond to the CV_CPU_TYPE_e enumeration, and are documented here: https://msdn...
Definition: CodeView.h:78
Collects and handles line tables information in a CodeView format.
Definition: CodeViewDebug.h:51
static void clear(coro::Shape &Shape)
Definition: Coroutines.cpp:211
Type array for a subprogram.
Representation of each machine instruction.
Definition: MachineInstr.h:63
Base class for debug information backends.
SymbolKind
Duplicate copy of the above enum, but using the official CV names.
Definition: CodeView.h:47
IRTranslator LLVM IR MI
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:48
TypedDINodeRef< DIType > DITypeRef
Basic type, like &#39;int&#39; or &#39;float&#39;.