LLVM  7.0.0svn
CodeViewDebug.h
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1 //===- llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.h --------------*- C++ -*-===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file contains support for writing Microsoft CodeView debug info.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_LIB_CODEGEN_ASMPRINTER_CODEVIEWDEBUG_H
15 #define LLVM_LIB_CODEGEN_ASMPRINTER_CODEVIEWDEBUG_H
16 
18 #include "DebugHandlerBase.h"
19 #include "llvm/ADT/ArrayRef.h"
20 #include "llvm/ADT/DenseMap.h"
21 #include "llvm/ADT/DenseSet.h"
22 #include "llvm/ADT/MapVector.h"
23 #include "llvm/ADT/SetVector.h"
24 #include "llvm/ADT/SmallVector.h"
28 #include "llvm/IR/DebugLoc.h"
29 #include "llvm/Support/Allocator.h"
30 #include "llvm/Support/Compiler.h"
31 #include <cstdint>
32 #include <map>
33 #include <string>
34 #include <tuple>
35 #include <unordered_map>
36 #include <utility>
37 #include <vector>
38 
39 namespace llvm {
40 
41 struct ClassInfo;
42 class StringRef;
43 class AsmPrinter;
44 class Function;
45 class GlobalVariable;
46 class MCSectionCOFF;
47 class MCStreamer;
48 class MCSymbol;
49 class MachineFunction;
50 
51 /// Collects and handles line tables information in a CodeView format.
53  MCStreamer &OS;
56 
57  /// Represents the most general definition range.
58  struct LocalVarDefRange {
59  /// Indicates that variable data is stored in memory relative to the
60  /// specified register.
61  int InMemory : 1;
62 
63  /// Offset of variable data in memory.
64  int DataOffset : 31;
65 
66  /// Non-zero if this is a piece of an aggregate.
67  uint16_t IsSubfield : 1;
68 
69  /// Offset into aggregate.
70  uint16_t StructOffset : 15;
71 
72  /// Register containing the data or the register base of the memory
73  /// location containing the data.
74  uint16_t CVRegister;
75 
76  /// Compares all location fields. This includes all fields except the label
77  /// ranges.
78  bool isDifferentLocation(LocalVarDefRange &O) {
79  return InMemory != O.InMemory || DataOffset != O.DataOffset ||
80  IsSubfield != O.IsSubfield || StructOffset != O.StructOffset ||
81  CVRegister != O.CVRegister;
82  }
83 
85  };
86 
87  static LocalVarDefRange createDefRangeMem(uint16_t CVRegister, int Offset);
88  static LocalVarDefRange createDefRangeGeneral(uint16_t CVRegister,
89  bool InMemory, int Offset,
90  bool IsSubfield,
91  uint16_t StructOffset);
92 
93  /// Similar to DbgVariable in DwarfDebug, but not dwarf-specific.
94  struct LocalVariable {
95  const DILocalVariable *DIVar = nullptr;
97  bool UseReferenceType = false;
98  };
99 
100  struct InlineSite {
101  SmallVector<LocalVariable, 1> InlinedLocals;
103  const DISubprogram *Inlinee = nullptr;
104 
105  /// The ID of the inline site or function used with .cv_loc. Not a type
106  /// index.
107  unsigned SiteFuncId = 0;
108  };
109 
110  // Combines information from DILexicalBlock and LexicalScope.
111  struct LexicalBlock {
114  const MCSymbol *Begin;
115  const MCSymbol *End;
116  StringRef Name;
117  };
118 
119  // For each function, store a vector of labels to its instructions, as well as
120  // to the end of the function.
121  struct FunctionInfo {
122  FunctionInfo() = default;
123 
124  // Uncopyable.
125  FunctionInfo(const FunctionInfo &FI) = delete;
126 
127  /// Map from inlined call site to inlined instructions and child inlined
128  /// call sites. Listed in program order.
129  std::unordered_map<const DILocation *, InlineSite> InlineSites;
130 
131  /// Ordered list of top-level inlined call sites.
133 
135 
136  std::unordered_map<const DILexicalBlockBase*, LexicalBlock> LexicalBlocks;
137 
138  // Lexical blocks containing local variables.
139  SmallVector<LexicalBlock *, 1> ChildBlocks;
140 
141  std::vector<std::pair<MCSymbol *, MDNode *>> Annotations;
142 
143  const MCSymbol *Begin = nullptr;
144  const MCSymbol *End = nullptr;
145  unsigned FuncId = 0;
146  unsigned LastFileId = 0;
147  bool HaveLineInfo = false;
148  };
149  FunctionInfo *CurFn = nullptr;
150 
151  // Map used to seperate variables according to the lexical scope they belong
152  // in. This is populated by recordLocalVariable() before
153  // collectLexicalBlocks() separates the variables between the FunctionInfo
154  // and LexicalBlocks.
156 
157  /// The set of comdat .debug$S sections that we've seen so far. Each section
158  /// must start with a magic version number that must only be emitted once.
159  /// This set tracks which sections we've already opened.
160  DenseSet<MCSectionCOFF *> ComdatDebugSections;
161 
162  /// Switch to the appropriate .debug$S section for GVSym. If GVSym, the symbol
163  /// of an emitted global value, is in a comdat COFF section, this will switch
164  /// to a new .debug$S section in that comdat. This method ensures that the
165  /// section starts with the magic version number on first use. If GVSym is
166  /// null, uses the main .debug$S section.
167  void switchToDebugSectionForSymbol(const MCSymbol *GVSym);
168 
169  /// The next available function index for use with our .cv_* directives. Not
170  /// to be confused with type indices for LF_FUNC_ID records.
171  unsigned NextFuncId = 0;
172 
173  InlineSite &getInlineSite(const DILocation *InlinedAt,
174  const DISubprogram *Inlinee);
175 
176  codeview::TypeIndex getFuncIdForSubprogram(const DISubprogram *SP);
177 
178  void calculateRanges(LocalVariable &Var,
179  const DbgValueHistoryMap::InstrRanges &Ranges);
180 
181  static void collectInlineSiteChildren(SmallVectorImpl<unsigned> &Children,
182  const FunctionInfo &FI,
183  const InlineSite &Site);
184 
185  /// Remember some debug info about each function. Keep it in a stable order to
186  /// emit at the end of the TU.
188 
189  /// Map from full file path to .cv_file id. Full paths are built from DIFiles
190  /// and are stored in FileToFilepathMap;
192 
193  /// All inlined subprograms in the order they should be emitted.
194  SmallSetVector<const DISubprogram *, 4> InlinedSubprograms;
195 
196  /// Map from a pair of DI metadata nodes and its DI type (or scope) that can
197  /// be nullptr, to CodeView type indices. Primarily indexed by
198  /// {DIType*, DIType*} and {DISubprogram*, DIType*}.
199  ///
200  /// The second entry in the key is needed for methods as DISubroutineType
201  /// representing static method type are shared with non-method function type.
203  TypeIndices;
204 
205  /// Map from DICompositeType* to complete type index. Non-record types are
206  /// always looked up in the normal TypeIndices map.
208 
209  /// Complete record types to emit after all active type lowerings are
210  /// finished.
211  SmallVector<const DICompositeType *, 4> DeferredCompleteTypes;
212 
213  /// Number of type lowering frames active on the stack.
214  unsigned TypeEmissionLevel = 0;
215 
216  codeview::TypeIndex VBPType;
217 
218  const DISubprogram *CurrentSubprogram = nullptr;
219 
220  // The UDTs we have seen while processing types; each entry is a pair of type
221  // index and type name.
222  std::vector<std::pair<std::string, const DIType *>> LocalUDTs;
223  std::vector<std::pair<std::string, const DIType *>> GlobalUDTs;
224 
225  using FileToFilepathMapTy = std::map<const DIFile *, std::string>;
226  FileToFilepathMapTy FileToFilepathMap;
227 
228  StringRef getFullFilepath(const DIFile *S);
229 
230  unsigned maybeRecordFile(const DIFile *F);
231 
232  void maybeRecordLocation(const DebugLoc &DL, const MachineFunction *MF);
233 
234  void clear();
235 
236  void setCurrentSubprogram(const DISubprogram *SP) {
237  CurrentSubprogram = SP;
238  LocalUDTs.clear();
239  }
240 
241  /// Emit the magic version number at the start of a CodeView type or symbol
242  /// section. Appears at the front of every .debug$S or .debug$T or .debug$P
243  /// section.
244  void emitCodeViewMagicVersion();
245 
246  void emitTypeInformation();
247 
248  void emitTypeGlobalHashes();
249 
250  void emitCompilerInformation();
251 
252  void emitInlineeLinesSubsection();
253 
254  void emitDebugInfoForThunk(const Function *GV,
255  FunctionInfo &FI,
256  const MCSymbol *Fn);
257 
258  void emitDebugInfoForFunction(const Function *GV, FunctionInfo &FI);
259 
260  void emitDebugInfoForGlobals();
261 
262  void emitDebugInfoForRetainedTypes();
263 
264  void
265  emitDebugInfoForUDTs(ArrayRef<std::pair<std::string, const DIType *>> UDTs);
266 
267  void emitDebugInfoForGlobal(const DIGlobalVariable *DIGV,
268  const GlobalVariable *GV, MCSymbol *GVSym);
269 
270  /// Opens a subsection of the given kind in a .debug$S codeview section.
271  /// Returns an end label for use with endCVSubsection when the subsection is
272  /// finished.
273  MCSymbol *beginCVSubsection(codeview::DebugSubsectionKind Kind);
274 
275  void endCVSubsection(MCSymbol *EndLabel);
276 
277  void emitInlinedCallSite(const FunctionInfo &FI, const DILocation *InlinedAt,
278  const InlineSite &Site);
279 
280  using InlinedVariable = DbgValueHistoryMap::InlinedVariable;
281 
282  void collectVariableInfo(const DISubprogram *SP);
283 
284  void collectVariableInfoFromMFTable(DenseSet<InlinedVariable> &Processed);
285 
286  // Construct the lexical block tree for a routine, pruning emptpy lexical
287  // scopes, and populate it with local variables.
288  void collectLexicalBlockInfo(SmallVectorImpl<LexicalScope *> &Scopes,
291  void collectLexicalBlockInfo(LexicalScope &Scope,
292  SmallVectorImpl<LexicalBlock *> &ParentBlocks,
293  SmallVectorImpl<LocalVariable> &ParentLocals);
294 
295  /// Records information about a local variable in the appropriate scope. In
296  /// particular, locals from inlined code live inside the inlining site.
297  void recordLocalVariable(LocalVariable &&Var, const LexicalScope *LS);
298 
299  /// Emits local variables in the appropriate order.
300  void emitLocalVariableList(ArrayRef<LocalVariable> Locals);
301 
302  /// Emits an S_LOCAL record and its associated defined ranges.
303  void emitLocalVariable(const LocalVariable &Var);
304 
305  /// Emits a sequence of lexical block scopes and their children.
306  void emitLexicalBlockList(ArrayRef<LexicalBlock *> Blocks,
307  const FunctionInfo& FI);
308 
309  /// Emit a lexical block scope and its children.
310  void emitLexicalBlock(const LexicalBlock &Block, const FunctionInfo& FI);
311 
312  /// Translates the DIType to codeview if necessary and returns a type index
313  /// for it.
314  codeview::TypeIndex getTypeIndex(DITypeRef TypeRef,
315  DITypeRef ClassTyRef = DITypeRef());
316 
317  codeview::TypeIndex getTypeIndexForReferenceTo(DITypeRef TypeRef);
318 
319  codeview::TypeIndex getMemberFunctionType(const DISubprogram *SP,
320  const DICompositeType *Class);
321 
322  codeview::TypeIndex getScopeIndex(const DIScope *Scope);
323 
324  codeview::TypeIndex getVBPTypeIndex();
325 
326  void addToUDTs(const DIType *Ty);
327 
328  void addUDTSrcLine(const DIType *Ty, codeview::TypeIndex TI);
329 
330  codeview::TypeIndex lowerType(const DIType *Ty, const DIType *ClassTy);
331  codeview::TypeIndex lowerTypeAlias(const DIDerivedType *Ty);
332  codeview::TypeIndex lowerTypeArray(const DICompositeType *Ty);
333  codeview::TypeIndex lowerTypeBasic(const DIBasicType *Ty);
334  codeview::TypeIndex lowerTypePointer(
335  const DIDerivedType *Ty,
337  codeview::TypeIndex lowerTypeMemberPointer(
338  const DIDerivedType *Ty,
340  codeview::TypeIndex lowerTypeModifier(const DIDerivedType *Ty);
341  codeview::TypeIndex lowerTypeFunction(const DISubroutineType *Ty);
342  codeview::TypeIndex lowerTypeVFTableShape(const DIDerivedType *Ty);
343  codeview::TypeIndex lowerTypeMemberFunction(const DISubroutineType *Ty,
344  const DIType *ClassTy,
345  int ThisAdjustment,
346  bool IsStaticMethod);
347  codeview::TypeIndex lowerTypeEnum(const DICompositeType *Ty);
348  codeview::TypeIndex lowerTypeClass(const DICompositeType *Ty);
349  codeview::TypeIndex lowerTypeUnion(const DICompositeType *Ty);
350 
351  /// Symbol records should point to complete types, but type records should
352  /// always point to incomplete types to avoid cycles in the type graph. Only
353  /// use this entry point when generating symbol records. The complete and
354  /// incomplete type indices only differ for record types. All other types use
355  /// the same index.
356  codeview::TypeIndex getCompleteTypeIndex(DITypeRef TypeRef);
357 
358  codeview::TypeIndex lowerCompleteTypeClass(const DICompositeType *Ty);
359  codeview::TypeIndex lowerCompleteTypeUnion(const DICompositeType *Ty);
360 
361  struct TypeLoweringScope;
362 
363  void emitDeferredCompleteTypes();
364 
365  void collectMemberInfo(ClassInfo &Info, const DIDerivedType *DDTy);
366  ClassInfo collectClassInfo(const DICompositeType *Ty);
367 
368  /// Common record member lowering functionality for record types, which are
369  /// structs, classes, and unions. Returns the field list index and the member
370  /// count.
371  std::tuple<codeview::TypeIndex, codeview::TypeIndex, unsigned, bool>
372  lowerRecordFieldList(const DICompositeType *Ty);
373 
374  /// Inserts {{Node, ClassTy}, TI} into TypeIndices and checks for duplicates.
375  codeview::TypeIndex recordTypeIndexForDINode(const DINode *Node,
377  const DIType *ClassTy = nullptr);
378 
379  unsigned getPointerSizeInBytes();
380 
381 protected:
382  /// Gather pre-function debug information.
383  void beginFunctionImpl(const MachineFunction *MF) override;
384 
385  /// Gather post-function debug information.
386  void endFunctionImpl(const MachineFunction *) override;
387 
388 public:
390 
391  void setSymbolSize(const MCSymbol *, uint64_t) override {}
392 
393  /// Emit the COFF section that holds the line table information.
394  void endModule() override;
395 
396  /// Process beginning of an instruction.
397  void beginInstruction(const MachineInstr *MI) override;
398 };
399 
400 } // end namespace llvm
401 
402 #endif // LLVM_LIB_CODEGEN_ASMPRINTER_CODEVIEWDEBUG_H
Compute iterated dominance frontiers using a linear time algorithm.
Definition: AllocatorList.h:24
std::pair< const DILocalVariable *, const DILocation * > InlinedVariable
MCSymbol - Instances of this class represent a symbol name in the MC file, and MCSymbols are created ...
Definition: MCSymbol.h:42
Implements a dense probed hash-table based set.
Definition: DenseSet.h:221
This class implements a map that also provides access to all stored values in a deterministic order...
Definition: MapVector.h:38
A debug info location.
Definition: DebugLoc.h:34
F(f)
LexicalScope - This class is used to track scope information.
Definition: LexicalScopes.h:45
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:33
A 32-bit type reference.
Definition: TypeIndex.h:96
Debug location.
Streaming machine code generation interface.
Definition: MCStreamer.h:183
Allocate memory in an ever growing pool, as if by bump-pointer.
Definition: Allocator.h:140
This class is intended to be used as a driving class for all asm writers.
Definition: AsmPrinter.h:78
static const unsigned End
#define LLVM_LIBRARY_VISIBILITY
LLVM_LIBRARY_VISIBILITY - If a class marked with this attribute is linked into a shared library...
Definition: Compiler.h:105
Base class for scope-like contexts.
PointerOptions
Equivalent to misc lfPointerAttr bitfields.
Definition: CodeView.h:352
Basic Register Allocator
A SetVector that performs no allocations if smaller than a certain size.
Definition: SetVector.h:298
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:861
Collects and handles line tables information in a CodeView format.
Definition: CodeViewDebug.h:52
static void clear(coro::Shape &Shape)
Definition: Coroutines.cpp:211
Type array for a subprogram.
Representation of each machine instruction.
Definition: MachineInstr.h:60
Base class for debug information backends.
const unsigned Kind
IRTranslator LLVM IR MI
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:49
TypedDINodeRef< DIType > DITypeRef
Basic type, like &#39;int&#39; or &#39;float&#39;.