1//===-- llvm/CodeGen/MachineModuleInfo.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// Collect meta information for a module.  This information should be in a
11// neutral form that can be used by different debugging and exception handling
12// schemes.
13//
14// The organization of information is primarily clustered around the source
15// compile units.  The main exception is source line correspondence where
16// inlining may interleave code from various compile units.
17//
18// The following information can be retrieved from the MachineModuleInfo.
19//
20//  -- Source directories - Directories are uniqued based on their canonical
21//     string and assigned a sequential numeric ID (base 1.)
22//  -- Source files - Files are also uniqued based on their name and directory
23//     ID.  A file ID is sequential number (base 1.)
24//  -- Source line correspondence - A vector of file ID, line#, column# triples.
25//     A DEBUG_LOCATION instruction is generated  by the DAG Legalizer
26//     corresponding to each entry in the source line list.  This allows a debug
27//     emitter to generate labels referenced by debug information tables.
28//
29//===----------------------------------------------------------------------===//
30
31#ifndef LLVM_CODEGEN_MACHINEMODULEINFO_H
32#define LLVM_CODEGEN_MACHINEMODULEINFO_H
33
34#include "llvm/ADT/DenseMap.h"
35#include "llvm/ADT/PointerIntPair.h"
36#include "llvm/ADT/SmallPtrSet.h"
37#include "llvm/ADT/SmallVector.h"
38#include "llvm/IR/DebugLoc.h"
39#include "llvm/IR/Metadata.h"
40#include "llvm/IR/ValueHandle.h"
41#include "llvm/MC/MCContext.h"
42#include "llvm/MC/MachineLocation.h"
43#include "llvm/Pass.h"
44#include "llvm/Support/DataTypes.h"
45#include "llvm/Support/Dwarf.h"
46
47namespace llvm {
48
49//===----------------------------------------------------------------------===//
50// Forward declarations.
51class Constant;
52class GlobalVariable;
53class MDNode;
54class MMIAddrLabelMap;
55class MachineBasicBlock;
56class MachineFunction;
57class Module;
58class PointerType;
59class StructType;
60
61//===----------------------------------------------------------------------===//
62/// LandingPadInfo - This structure is used to retain landing pad info for
63/// the current function.
64///
65struct LandingPadInfo {
66  MachineBasicBlock *LandingPadBlock;    // Landing pad block.
67  SmallVector<MCSymbol*, 1> BeginLabels; // Labels prior to invoke.
68  SmallVector<MCSymbol*, 1> EndLabels;   // Labels after invoke.
69  MCSymbol *LandingPadLabel;             // Label at beginning of landing pad.
70  const Function *Personality;           // Personality function.
71  std::vector<int> TypeIds;              // List of type ids (filters negative)
72
73  explicit LandingPadInfo(MachineBasicBlock *MBB)
74    : LandingPadBlock(MBB), LandingPadLabel(nullptr), Personality(nullptr) {}
75};
76
77//===----------------------------------------------------------------------===//
78/// MachineModuleInfoImpl - This class can be derived from and used by targets
79/// to hold private target-specific information for each Module.  Objects of
80/// type are accessed/created with MMI::getInfo and destroyed when the
81/// MachineModuleInfo is destroyed.
82///
83class MachineModuleInfoImpl {
84public:
85  typedef PointerIntPair<MCSymbol*, 1, bool> StubValueTy;
86  virtual ~MachineModuleInfoImpl();
87  typedef std::vector<std::pair<MCSymbol*, StubValueTy> > SymbolListTy;
88protected:
89  static SymbolListTy GetSortedStubs(const DenseMap<MCSymbol*, StubValueTy>&);
90};
91
92//===----------------------------------------------------------------------===//
93/// MachineModuleInfo - This class contains meta information specific to a
94/// module.  Queries can be made by different debugging and exception handling
95/// schemes and reformated for specific use.
96///
97class MachineModuleInfo : public ImmutablePass {
98  /// Context - This is the MCContext used for the entire code generator.
99  MCContext Context;
100
101  /// TheModule - This is the LLVM Module being worked on.
102  const Module *TheModule;
103
104  /// ObjFileMMI - This is the object-file-format-specific implementation of
105  /// MachineModuleInfoImpl, which lets targets accumulate whatever info they
106  /// want.
107  MachineModuleInfoImpl *ObjFileMMI;
108
109  /// List of moves done by a function's prolog.  Used to construct frame maps
110  /// by debug and exception handling consumers.
111  std::vector<MCCFIInstruction> FrameInstructions;
112
113  /// CompactUnwindEncoding - If the target supports it, this is the compact
114  /// unwind encoding. It replaces a function's CIE and FDE.
115  uint32_t CompactUnwindEncoding;
116
117  /// LandingPads - List of LandingPadInfo describing the landing pad
118  /// information in the current function.
119  std::vector<LandingPadInfo> LandingPads;
120
121  /// LPadToCallSiteMap - Map a landing pad's EH symbol to the call site
122  /// indexes.
123  DenseMap<MCSymbol*, SmallVector<unsigned, 4> > LPadToCallSiteMap;
124
125  /// CallSiteMap - Map of invoke call site index values to associated begin
126  /// EH_LABEL for the current function.
127  DenseMap<MCSymbol*, unsigned> CallSiteMap;
128
129  /// CurCallSite - The current call site index being processed, if any. 0 if
130  /// none.
131  unsigned CurCallSite;
132
133  /// TypeInfos - List of C++ TypeInfo used in the current function.
134  std::vector<const GlobalVariable *> TypeInfos;
135
136  /// FilterIds - List of typeids encoding filters used in the current function.
137  std::vector<unsigned> FilterIds;
138
139  /// FilterEnds - List of the indices in FilterIds corresponding to filter
140  /// terminators.
141  std::vector<unsigned> FilterEnds;
142
143  /// Personalities - Vector of all personality functions ever seen. Used to
144  /// emit common EH frames.
145  std::vector<const Function *> Personalities;
146
147  /// UsedFunctions - The functions in the @llvm.used list in a more easily
148  /// searchable format.  This does not include the functions in
149  /// llvm.compiler.used.
150  SmallPtrSet<const Function *, 32> UsedFunctions;
151
152  /// AddrLabelSymbols - This map keeps track of which symbol is being used for
153  /// the specified basic block's address of label.
154  MMIAddrLabelMap *AddrLabelSymbols;
155
156  bool CallsEHReturn;
157  bool CallsUnwindInit;
158
159  /// DbgInfoAvailable - True if debugging information is available
160  /// in this module.
161  bool DbgInfoAvailable;
162
163  /// UsesVAFloatArgument - True if this module calls VarArg function with
164  /// floating-point arguments.  This is used to emit an undefined reference
165  /// to _fltused on Windows targets.
166  bool UsesVAFloatArgument;
167
168public:
169  static char ID; // Pass identification, replacement for typeid
170
171  struct VariableDbgInfo {
172    TrackingVH<MDNode> Var;
173    unsigned Slot;
174    DebugLoc Loc;
175  };
176  typedef SmallVector<VariableDbgInfo, 4> VariableDbgInfoMapTy;
177  VariableDbgInfoMapTy VariableDbgInfos;
178
179  MachineModuleInfo();  // DUMMY CONSTRUCTOR, DO NOT CALL.
180  // Real constructor.
181  MachineModuleInfo(const MCAsmInfo &MAI, const MCRegisterInfo &MRI,
182                    const MCObjectFileInfo *MOFI);
183  ~MachineModuleInfo();
184
185  // Initialization and Finalization
186  bool doInitialization(Module &) override;
187  bool doFinalization(Module &) override;
188
189  /// EndFunction - Discard function meta information.
190  ///
191  void EndFunction();
192
193  const MCContext &getContext() const { return Context; }
194  MCContext &getContext() { return Context; }
195
196  void setModule(const Module *M) { TheModule = M; }
197  const Module *getModule() const { return TheModule; }
198
199  /// getInfo - Keep track of various per-function pieces of information for
200  /// backends that would like to do so.
201  ///
202  template<typename Ty>
203  Ty &getObjFileInfo() {
204    if (ObjFileMMI == nullptr)
205      ObjFileMMI = new Ty(*this);
206    return *static_cast<Ty*>(ObjFileMMI);
207  }
208
209  template<typename Ty>
210  const Ty &getObjFileInfo() const {
211    return const_cast<MachineModuleInfo*>(this)->getObjFileInfo<Ty>();
212  }
213
214  /// AnalyzeModule - Scan the module for global debug information.
215  ///
216  void AnalyzeModule(const Module &M);
217
218  /// hasDebugInfo - Returns true if valid debug info is present.
219  ///
220  bool hasDebugInfo() const { return DbgInfoAvailable; }
221  void setDebugInfoAvailability(bool avail) { DbgInfoAvailable = avail; }
222
223  bool callsEHReturn() const { return CallsEHReturn; }
224  void setCallsEHReturn(bool b) { CallsEHReturn = b; }
225
226  bool callsUnwindInit() const { return CallsUnwindInit; }
227  void setCallsUnwindInit(bool b) { CallsUnwindInit = b; }
228
229  bool usesVAFloatArgument() const {
230    return UsesVAFloatArgument;
231  }
232
233  void setUsesVAFloatArgument(bool b) {
234    UsesVAFloatArgument = b;
235  }
236
237  /// \brief Returns a reference to a list of cfi instructions in the current
238  /// function's prologue.  Used to construct frame maps for debug and exception
239  /// handling comsumers.
240  const std::vector<MCCFIInstruction> &getFrameInstructions() const {
241    return FrameInstructions;
242  }
243
244  unsigned LLVM_ATTRIBUTE_UNUSED_RESULT
245  addFrameInst(const MCCFIInstruction &Inst) {
246    FrameInstructions.push_back(Inst);
247    return FrameInstructions.size() - 1;
248  }
249
250  /// getCompactUnwindEncoding - Returns the compact unwind encoding for a
251  /// function if the target supports the encoding. This encoding replaces a
252  /// function's CIE and FDE.
253  uint32_t getCompactUnwindEncoding() const { return CompactUnwindEncoding; }
254
255  /// setCompactUnwindEncoding - Set the compact unwind encoding for a function
256  /// if the target supports the encoding.
257  void setCompactUnwindEncoding(uint32_t Enc) { CompactUnwindEncoding = Enc; }
258
259  /// getAddrLabelSymbol - Return the symbol to be used for the specified basic
260  /// block when its address is taken.  This cannot be its normal LBB label
261  /// because the block may be accessed outside its containing function.
262  MCSymbol *getAddrLabelSymbol(const BasicBlock *BB);
263
264  /// getAddrLabelSymbolToEmit - Return the symbol to be used for the specified
265  /// basic block when its address is taken.  If other blocks were RAUW'd to
266  /// this one, we may have to emit them as well, return the whole set.
267  std::vector<MCSymbol*> getAddrLabelSymbolToEmit(const BasicBlock *BB);
268
269  /// takeDeletedSymbolsForFunction - If the specified function has had any
270  /// references to address-taken blocks generated, but the block got deleted,
271  /// return the symbol now so we can emit it.  This prevents emitting a
272  /// reference to a symbol that has no definition.
273  void takeDeletedSymbolsForFunction(const Function *F,
274                                     std::vector<MCSymbol*> &Result);
275
276
277  //===- EH ---------------------------------------------------------------===//
278
279  /// getOrCreateLandingPadInfo - Find or create an LandingPadInfo for the
280  /// specified MachineBasicBlock.
281  LandingPadInfo &getOrCreateLandingPadInfo(MachineBasicBlock *LandingPad);
282
283  /// addInvoke - Provide the begin and end labels of an invoke style call and
284  /// associate it with a try landing pad block.
285  void addInvoke(MachineBasicBlock *LandingPad,
286                 MCSymbol *BeginLabel, MCSymbol *EndLabel);
287
288  /// addLandingPad - Add a new panding pad.  Returns the label ID for the
289  /// landing pad entry.
290  MCSymbol *addLandingPad(MachineBasicBlock *LandingPad);
291
292  /// addPersonality - Provide the personality function for the exception
293  /// information.
294  void addPersonality(MachineBasicBlock *LandingPad,
295                      const Function *Personality);
296
297  /// getPersonalityIndex - Get index of the current personality function inside
298  /// Personalitites array
299  unsigned getPersonalityIndex() const;
300
301  /// getPersonalities - Return array of personality functions ever seen.
302  const std::vector<const Function *>& getPersonalities() const {
303    return Personalities;
304  }
305
306  /// isUsedFunction - Return true if the functions in the llvm.used list.  This
307  /// does not return true for things in llvm.compiler.used unless they are also
308  /// in llvm.used.
309  bool isUsedFunction(const Function *F) const {
310    return UsedFunctions.count(F);
311  }
312
313  /// addCatchTypeInfo - Provide the catch typeinfo for a landing pad.
314  ///
315  void addCatchTypeInfo(MachineBasicBlock *LandingPad,
316                        ArrayRef<const GlobalVariable *> TyInfo);
317
318  /// addFilterTypeInfo - Provide the filter typeinfo for a landing pad.
319  ///
320  void addFilterTypeInfo(MachineBasicBlock *LandingPad,
321                         ArrayRef<const GlobalVariable *> TyInfo);
322
323  /// addCleanup - Add a cleanup action for a landing pad.
324  ///
325  void addCleanup(MachineBasicBlock *LandingPad);
326
327  /// getTypeIDFor - Return the type id for the specified typeinfo.  This is
328  /// function wide.
329  unsigned getTypeIDFor(const GlobalVariable *TI);
330
331  /// getFilterIDFor - Return the id of the filter encoded by TyIds.  This is
332  /// function wide.
333  int getFilterIDFor(std::vector<unsigned> &TyIds);
334
335  /// TidyLandingPads - Remap landing pad labels and remove any deleted landing
336  /// pads.
337  void TidyLandingPads(DenseMap<MCSymbol*, uintptr_t> *LPMap = nullptr);
338
339  /// getLandingPads - Return a reference to the landing pad info for the
340  /// current function.
341  const std::vector<LandingPadInfo> &getLandingPads() const {
342    return LandingPads;
343  }
344
345  /// setCallSiteLandingPad - Map the landing pad's EH symbol to the call
346  /// site indexes.
347  void setCallSiteLandingPad(MCSymbol *Sym, ArrayRef<unsigned> Sites);
348
349  /// getCallSiteLandingPad - Get the call site indexes for a landing pad EH
350  /// symbol.
351  SmallVectorImpl<unsigned> &getCallSiteLandingPad(MCSymbol *Sym) {
352    assert(hasCallSiteLandingPad(Sym) &&
353           "missing call site number for landing pad!");
354    return LPadToCallSiteMap[Sym];
355  }
356
357  /// hasCallSiteLandingPad - Return true if the landing pad Eh symbol has an
358  /// associated call site.
359  bool hasCallSiteLandingPad(MCSymbol *Sym) {
360    return !LPadToCallSiteMap[Sym].empty();
361  }
362
363  /// setCallSiteBeginLabel - Map the begin label for a call site.
364  void setCallSiteBeginLabel(MCSymbol *BeginLabel, unsigned Site) {
365    CallSiteMap[BeginLabel] = Site;
366  }
367
368  /// getCallSiteBeginLabel - Get the call site number for a begin label.
369  unsigned getCallSiteBeginLabel(MCSymbol *BeginLabel) {
370    assert(hasCallSiteBeginLabel(BeginLabel) &&
371           "Missing call site number for EH_LABEL!");
372    return CallSiteMap[BeginLabel];
373  }
374
375  /// hasCallSiteBeginLabel - Return true if the begin label has a call site
376  /// number associated with it.
377  bool hasCallSiteBeginLabel(MCSymbol *BeginLabel) {
378    return CallSiteMap[BeginLabel] != 0;
379  }
380
381  /// setCurrentCallSite - Set the call site currently being processed.
382  void setCurrentCallSite(unsigned Site) { CurCallSite = Site; }
383
384  /// getCurrentCallSite - Get the call site currently being processed, if any.
385  /// return zero if none.
386  unsigned getCurrentCallSite() { return CurCallSite; }
387
388  /// getTypeInfos - Return a reference to the C++ typeinfo for the current
389  /// function.
390  const std::vector<const GlobalVariable *> &getTypeInfos() const {
391    return TypeInfos;
392  }
393
394  /// getFilterIds - Return a reference to the typeids encoding filters used in
395  /// the current function.
396  const std::vector<unsigned> &getFilterIds() const {
397    return FilterIds;
398  }
399
400  /// getPersonality - Return a personality function if available.  The presence
401  /// of one is required to emit exception handling info.
402  const Function *getPersonality() const;
403
404  /// setVariableDbgInfo - Collect information used to emit debugging
405  /// information of a variable.
406  void setVariableDbgInfo(MDNode *N, unsigned Slot, DebugLoc Loc) {
407    VariableDbgInfo Info = { N, Slot, Loc };
408    VariableDbgInfos.push_back(std::move(Info));
409  }
410
411  VariableDbgInfoMapTy &getVariableDbgInfo() { return VariableDbgInfos; }
412
413}; // End class MachineModuleInfo
414
415} // End llvm namespace
416
417#endif
418