LLVM  4.0.0
CodeViewDebug.h
Go to the documentation of this file.
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 
17 #include "DebugHandlerBase.h"
18 #include "llvm/ADT/DenseMap.h"
19 #include "llvm/ADT/StringMap.h"
25 #include "llvm/IR/DebugInfo.h"
26 #include "llvm/IR/DebugLoc.h"
27 #include "llvm/MC/MCStreamer.h"
29 
30 namespace llvm {
31 
32 class StringRef;
33 class LexicalScope;
34 struct ClassInfo;
35 
36 /// \brief Collects and handles line tables information in a CodeView format.
38  MCStreamer &OS;
41 
42  /// Represents the most general definition range.
43  struct LocalVarDefRange {
44  /// Indicates that variable data is stored in memory relative to the
45  /// specified register.
46  int InMemory : 1;
47 
48  /// Offset of variable data in memory.
49  int DataOffset : 31;
50 
51  /// Non-zero if this is a piece of an aggregate.
52  uint16_t IsSubfield : 1;
53 
54  /// Offset into aggregate.
55  uint16_t StructOffset : 15;
56 
57  /// Register containing the data or the register base of the memory
58  /// location containing the data.
59  uint16_t CVRegister;
60 
61  /// Compares all location fields. This includes all fields except the label
62  /// ranges.
63  bool isDifferentLocation(LocalVarDefRange &O) {
64  return InMemory != O.InMemory || DataOffset != O.DataOffset ||
65  IsSubfield != O.IsSubfield || StructOffset != O.StructOffset ||
66  CVRegister != O.CVRegister;
67  }
68 
70  };
71 
72  static LocalVarDefRange createDefRangeMem(uint16_t CVRegister, int Offset);
73  static LocalVarDefRange createDefRangeGeneral(uint16_t CVRegister,
74  bool InMemory, int Offset,
75  bool IsSubfield,
76  uint16_t StructOffset);
77 
78  /// Similar to DbgVariable in DwarfDebug, but not dwarf-specific.
79  struct LocalVariable {
80  const DILocalVariable *DIVar = nullptr;
82  };
83 
84  struct InlineSite {
85  SmallVector<LocalVariable, 1> InlinedLocals;
87  const DISubprogram *Inlinee = nullptr;
88 
89  /// The ID of the inline site or function used with .cv_loc. Not a type
90  /// index.
91  unsigned SiteFuncId = 0;
92  };
93 
94  // For each function, store a vector of labels to its instructions, as well as
95  // to the end of the function.
96  struct FunctionInfo {
97  /// Map from inlined call site to inlined instructions and child inlined
98  /// call sites. Listed in program order.
99  std::unordered_map<const DILocation *, InlineSite> InlineSites;
100 
101  /// Ordered list of top-level inlined call sites.
103 
105 
106  DebugLoc LastLoc;
107  const MCSymbol *Begin = nullptr;
108  const MCSymbol *End = nullptr;
109  unsigned FuncId = 0;
110  unsigned LastFileId = 0;
111  bool HaveLineInfo = false;
112  };
113  FunctionInfo *CurFn;
114 
115  /// The set of comdat .debug$S sections that we've seen so far. Each section
116  /// must start with a magic version number that must only be emitted once.
117  /// This set tracks which sections we've already opened.
118  DenseSet<MCSectionCOFF *> ComdatDebugSections;
119 
120  /// Switch to the appropriate .debug$S section for GVSym. If GVSym, the symbol
121  /// of an emitted global value, is in a comdat COFF section, this will switch
122  /// to a new .debug$S section in that comdat. This method ensures that the
123  /// section starts with the magic version number on first use. If GVSym is
124  /// null, uses the main .debug$S section.
125  void switchToDebugSectionForSymbol(const MCSymbol *GVSym);
126 
127  /// The next available function index for use with our .cv_* directives. Not
128  /// to be confused with type indices for LF_FUNC_ID records.
129  unsigned NextFuncId = 0;
130 
131  InlineSite &getInlineSite(const DILocation *InlinedAt,
132  const DISubprogram *Inlinee);
133 
134  codeview::TypeIndex getFuncIdForSubprogram(const DISubprogram *SP);
135 
136  static void collectInlineSiteChildren(SmallVectorImpl<unsigned> &Children,
137  const FunctionInfo &FI,
138  const InlineSite &Site);
139 
140  /// Remember some debug info about each function. Keep it in a stable order to
141  /// emit at the end of the TU.
143 
144  /// Map from DIFile to .cv_file id.
146 
147  /// All inlined subprograms in the order they should be emitted.
148  SmallSetVector<const DISubprogram *, 4> InlinedSubprograms;
149 
150  /// Map from a pair of DI metadata nodes and its DI type (or scope) that can
151  /// be nullptr, to CodeView type indices. Primarily indexed by
152  /// {DIType*, DIType*} and {DISubprogram*, DIType*}.
153  ///
154  /// The second entry in the key is needed for methods as DISubroutineType
155  /// representing static method type are shared with non-method function type.
157  TypeIndices;
158 
159  /// Map from DICompositeType* to complete type index. Non-record types are
160  /// always looked up in the normal TypeIndices map.
162 
163  /// Complete record types to emit after all active type lowerings are
164  /// finished.
165  SmallVector<const DICompositeType *, 4> DeferredCompleteTypes;
166 
167  /// Number of type lowering frames active on the stack.
168  unsigned TypeEmissionLevel = 0;
169 
170  codeview::TypeIndex VBPType;
171 
172  const DISubprogram *CurrentSubprogram = nullptr;
173 
174  // The UDTs we have seen while processing types; each entry is a pair of type
175  // index and type name.
176  std::vector<std::pair<std::string, codeview::TypeIndex>> LocalUDTs,
177  GlobalUDTs;
178 
179  typedef std::map<const DIFile *, std::string> FileToFilepathMapTy;
180  FileToFilepathMapTy FileToFilepathMap;
181  StringRef getFullFilepath(const DIFile *S);
182 
183  unsigned maybeRecordFile(const DIFile *F);
184 
185  void maybeRecordLocation(const DebugLoc &DL, const MachineFunction *MF);
186 
187  void clear();
188 
189  void setCurrentSubprogram(const DISubprogram *SP) {
190  CurrentSubprogram = SP;
191  LocalUDTs.clear();
192  }
193 
194  /// Emit the magic version number at the start of a CodeView type or symbol
195  /// section. Appears at the front of every .debug$S or .debug$T section.
196  void emitCodeViewMagicVersion();
197 
198  void emitTypeInformation();
199 
200  void emitCompilerInformation();
201 
202  void emitInlineeLinesSubsection();
203 
204  void emitDebugInfoForFunction(const Function *GV, FunctionInfo &FI);
205 
206  void emitDebugInfoForGlobals();
207 
208  void emitDebugInfoForRetainedTypes();
209 
210  void emitDebugInfoForUDTs(
211  ArrayRef<std::pair<std::string, codeview::TypeIndex>> UDTs);
212 
213  void emitDebugInfoForGlobal(const DIGlobalVariable *DIGV,
214  const GlobalVariable *GV, MCSymbol *GVSym);
215 
216  /// Opens a subsection of the given kind in a .debug$S codeview section.
217  /// Returns an end label for use with endCVSubsection when the subsection is
218  /// finished.
219  MCSymbol *beginCVSubsection(codeview::ModuleSubstreamKind Kind);
220 
221  void endCVSubsection(MCSymbol *EndLabel);
222 
223  void emitInlinedCallSite(const FunctionInfo &FI, const DILocation *InlinedAt,
224  const InlineSite &Site);
225 
226  typedef DbgValueHistoryMap::InlinedVariable InlinedVariable;
227 
228  void collectVariableInfo(const DISubprogram *SP);
229 
230  void collectVariableInfoFromMFTable(DenseSet<InlinedVariable> &Processed);
231 
232  /// Records information about a local variable in the appropriate scope. In
233  /// particular, locals from inlined code live inside the inlining site.
234  void recordLocalVariable(LocalVariable &&Var, const DILocation *Loc);
235 
236  /// Emits local variables in the appropriate order.
237  void emitLocalVariableList(ArrayRef<LocalVariable> Locals);
238 
239  /// Emits an S_LOCAL record and its associated defined ranges.
240  void emitLocalVariable(const LocalVariable &Var);
241 
242  /// Translates the DIType to codeview if necessary and returns a type index
243  /// for it.
244  codeview::TypeIndex getTypeIndex(DITypeRef TypeRef,
245  DITypeRef ClassTyRef = DITypeRef());
246 
247  codeview::TypeIndex getMemberFunctionType(const DISubprogram *SP,
248  const DICompositeType *Class);
249 
250  codeview::TypeIndex getScopeIndex(const DIScope *Scope);
251 
252  codeview::TypeIndex getVBPTypeIndex();
253 
254  void addToUDTs(const DIType *Ty, codeview::TypeIndex TI);
255 
256  codeview::TypeIndex lowerType(const DIType *Ty, const DIType *ClassTy);
257  codeview::TypeIndex lowerTypeAlias(const DIDerivedType *Ty);
258  codeview::TypeIndex lowerTypeArray(const DICompositeType *Ty);
259  codeview::TypeIndex lowerTypeBasic(const DIBasicType *Ty);
260  codeview::TypeIndex lowerTypePointer(const DIDerivedType *Ty);
261  codeview::TypeIndex lowerTypeMemberPointer(const DIDerivedType *Ty);
262  codeview::TypeIndex lowerTypeModifier(const DIDerivedType *Ty);
263  codeview::TypeIndex lowerTypeFunction(const DISubroutineType *Ty);
264  codeview::TypeIndex lowerTypeVFTableShape(const DIDerivedType *Ty);
265  codeview::TypeIndex lowerTypeMemberFunction(const DISubroutineType *Ty,
266  const DIType *ClassTy,
267  int ThisAdjustment);
268  codeview::TypeIndex lowerTypeEnum(const DICompositeType *Ty);
269  codeview::TypeIndex lowerTypeClass(const DICompositeType *Ty);
270  codeview::TypeIndex lowerTypeUnion(const DICompositeType *Ty);
271 
272  /// Symbol records should point to complete types, but type records should
273  /// always point to incomplete types to avoid cycles in the type graph. Only
274  /// use this entry point when generating symbol records. The complete and
275  /// incomplete type indices only differ for record types. All other types use
276  /// the same index.
277  codeview::TypeIndex getCompleteTypeIndex(DITypeRef TypeRef);
278 
279  codeview::TypeIndex lowerCompleteTypeClass(const DICompositeType *Ty);
280  codeview::TypeIndex lowerCompleteTypeUnion(const DICompositeType *Ty);
281 
282  struct TypeLoweringScope;
283 
284  void emitDeferredCompleteTypes();
285 
286  void collectMemberInfo(ClassInfo &Info, const DIDerivedType *DDTy);
287  ClassInfo collectClassInfo(const DICompositeType *Ty);
288 
289  /// Common record member lowering functionality for record types, which are
290  /// structs, classes, and unions. Returns the field list index and the member
291  /// count.
292  std::tuple<codeview::TypeIndex, codeview::TypeIndex, unsigned, bool>
293  lowerRecordFieldList(const DICompositeType *Ty);
294 
295  /// Inserts {{Node, ClassTy}, TI} into TypeIndices and checks for duplicates.
296  codeview::TypeIndex recordTypeIndexForDINode(const DINode *Node,
298  const DIType *ClassTy = nullptr);
299 
300  unsigned getPointerSizeInBytes();
301 
302 public:
304 
305  void setSymbolSize(const llvm::MCSymbol *, uint64_t) override {}
306 
307  /// \brief Emit the COFF section that holds the line table information.
308  void endModule() override;
309 
310  /// \brief Gather pre-function debug information.
311  void beginFunction(const MachineFunction *MF) override;
312 
313  /// \brief Gather post-function debug information.
314  void endFunction(const MachineFunction *) override;
315 
316  /// \brief Process beginning of an instruction.
317  void beginInstruction(const MachineInstr *MI) override;
318 };
319 } // End of namespace llvm
320 
321 #endif
MCSymbol - Instances of this class represent a symbol name in the MC file, and MCSymbols are created ...
Definition: MCSymbol.h:39
Implements a dense probed hash-table based set.
Definition: DenseSet.h:202
This class implements a map that also provides access to all stored values in a deterministic order...
Definition: MapVector.h:32
A debug info location.
Definition: DebugLoc.h:34
Tagged DWARF-like metadata node.
Holds a subclass of DINode.
Subprogram description.
#define F(x, y, z)
Definition: MD5.cpp:51
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:89
Debug location.
void setSymbolSize(const llvm::MCSymbol *, uint64_t) override
For symbols that have a size designated (e.g.
Streaming machine code generation interface.
Definition: MCStreamer.h:161
Allocate memory in an ever growing pool, as if by bump-pointer.
Definition: Allocator.h:138
This class is intended to be used as a driving class for all asm writers.
Definition: AsmPrinter.h:67
Greedy Register Allocator
uint32_t Offset
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.
A SetVector that performs no allocations if smaller than a certain size.
Definition: SetVector.h:292
Base class for types.
This is a 'vector' (really, a variable-sized array), optimized for the case when the array is small...
Definition: SmallVector.h:843
Collects and handles line tables information in a CodeView format.
Definition: CodeViewDebug.h:37
static void clear(coro::Shape &Shape)
Definition: Coroutines.cpp:191
Type array for a subprogram.
Representation of each machine instruction.
Definition: MachineInstr.h:52
Base class for debug information backends.
const unsigned Kind
std::pair< const DILocalVariable *, const DILocation * > InlinedVariable
IRTranslator LLVM IR MI
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:47
TypedDINodeRef< DIType > DITypeRef
Basic type, like 'int' or 'float'.