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/Analysis/EHPersonalities.h"
39#include "llvm/IR/DebugLoc.h"
40#include "llvm/IR/Metadata.h"
41#include "llvm/IR/ValueHandle.h"
42#include "llvm/MC/MCContext.h"
43#include "llvm/MC/MCSymbol.h"
44#include "llvm/MC/MachineLocation.h"
45#include "llvm/Pass.h"
46#include "llvm/Support/DataTypes.h"
47#include "llvm/Support/Dwarf.h"
48
49namespace llvm {
50
51//===----------------------------------------------------------------------===//
52// Forward declarations.
53class Constant;
54class GlobalVariable;
55class BlockAddress;
56class MDNode;
57class MMIAddrLabelMap;
58class MachineBasicBlock;
59class MachineFunction;
60class Module;
61class PointerType;
62class StructType;
63
64struct SEHHandler {
65  // Filter or finally function. Null indicates a catch-all.
66  const Function *FilterOrFinally;
67
68  // Address of block to recover at. Null for a finally handler.
69  const BlockAddress *RecoverBA;
70};
71
72//===----------------------------------------------------------------------===//
73/// LandingPadInfo - This structure is used to retain landing pad info for
74/// the current function.
75///
76struct LandingPadInfo {
77  MachineBasicBlock *LandingPadBlock;      // Landing pad block.
78  SmallVector<MCSymbol *, 1> BeginLabels;  // Labels prior to invoke.
79  SmallVector<MCSymbol *, 1> EndLabels;    // Labels after invoke.
80  SmallVector<SEHHandler, 1> SEHHandlers;  // SEH handlers active at this lpad.
81  MCSymbol *LandingPadLabel;               // Label at beginning of landing pad.
82  std::vector<int> TypeIds;               // List of type ids (filters negative).
83
84  explicit LandingPadInfo(MachineBasicBlock *MBB)
85      : LandingPadBlock(MBB), LandingPadLabel(nullptr) {}
86};
87
88//===----------------------------------------------------------------------===//
89/// MachineModuleInfoImpl - This class can be derived from and used by targets
90/// to hold private target-specific information for each Module.  Objects of
91/// type are accessed/created with MMI::getInfo and destroyed when the
92/// MachineModuleInfo is destroyed.
93///
94class MachineModuleInfoImpl {
95public:
96  typedef PointerIntPair<MCSymbol*, 1, bool> StubValueTy;
97  virtual ~MachineModuleInfoImpl();
98  typedef std::vector<std::pair<MCSymbol*, StubValueTy> > SymbolListTy;
99protected:
100
101  /// Return the entries from a DenseMap in a deterministic sorted orer.
102  /// Clears the map.
103  static SymbolListTy getSortedStubs(DenseMap<MCSymbol*, StubValueTy>&);
104};
105
106//===----------------------------------------------------------------------===//
107/// MachineModuleInfo - This class contains meta information specific to a
108/// module.  Queries can be made by different debugging and exception handling
109/// schemes and reformated for specific use.
110///
111class MachineModuleInfo : public ImmutablePass {
112  /// Context - This is the MCContext used for the entire code generator.
113  MCContext Context;
114
115  /// TheModule - This is the LLVM Module being worked on.
116  const Module *TheModule;
117
118  /// ObjFileMMI - This is the object-file-format-specific implementation of
119  /// MachineModuleInfoImpl, which lets targets accumulate whatever info they
120  /// want.
121  MachineModuleInfoImpl *ObjFileMMI;
122
123  /// List of moves done by a function's prolog.  Used to construct frame maps
124  /// by debug and exception handling consumers.
125  std::vector<MCCFIInstruction> FrameInstructions;
126
127  /// LandingPads - List of LandingPadInfo describing the landing pad
128  /// information in the current function.
129  std::vector<LandingPadInfo> LandingPads;
130
131  /// LPadToCallSiteMap - Map a landing pad's EH symbol to the call site
132  /// indexes.
133  DenseMap<MCSymbol*, SmallVector<unsigned, 4> > LPadToCallSiteMap;
134
135  /// CallSiteMap - Map of invoke call site index values to associated begin
136  /// EH_LABEL for the current function.
137  DenseMap<MCSymbol*, unsigned> CallSiteMap;
138
139  /// CurCallSite - The current call site index being processed, if any. 0 if
140  /// none.
141  unsigned CurCallSite;
142
143  /// TypeInfos - List of C++ TypeInfo used in the current function.
144  std::vector<const GlobalValue *> TypeInfos;
145
146  /// FilterIds - List of typeids encoding filters used in the current function.
147  std::vector<unsigned> FilterIds;
148
149  /// FilterEnds - List of the indices in FilterIds corresponding to filter
150  /// terminators.
151  std::vector<unsigned> FilterEnds;
152
153  /// Personalities - Vector of all personality functions ever seen. Used to
154  /// emit common EH frames.
155  std::vector<const Function *> Personalities;
156
157  /// AddrLabelSymbols - This map keeps track of which symbol is being used for
158  /// the specified basic block's address of label.
159  MMIAddrLabelMap *AddrLabelSymbols;
160
161  bool CallsEHReturn;
162  bool CallsUnwindInit;
163  bool HasEHFunclets;
164
165  // TODO: Ideally, what we'd like is to have a switch that allows emitting
166  // synchronous (precise at call-sites only) CFA into .eh_frame. However,
167  // even under this switch, we'd like .debug_frame to be precise when using.
168  // -g. At this moment, there's no way to specify that some CFI directives
169  // go into .eh_frame only, while others go into .debug_frame only.
170
171  /// DbgInfoAvailable - True if debugging information is available
172  /// in this module.
173  bool DbgInfoAvailable;
174
175  /// UsesVAFloatArgument - True if this module calls VarArg function with
176  /// floating-point arguments.  This is used to emit an undefined reference
177  /// to _fltused on Windows targets.
178  bool UsesVAFloatArgument;
179
180  /// UsesMorestackAddr - True if the module calls the __morestack function
181  /// indirectly, as is required under the large code model on x86. This is used
182  /// to emit a definition of a symbol, __morestack_addr, containing the
183  /// address. See comments in lib/Target/X86/X86FrameLowering.cpp for more
184  /// details.
185  bool UsesMorestackAddr;
186
187  EHPersonality PersonalityTypeCache;
188
189public:
190  static char ID; // Pass identification, replacement for typeid
191
192  struct VariableDbgInfo {
193    const DILocalVariable *Var;
194    const DIExpression *Expr;
195    unsigned Slot;
196    const DILocation *Loc;
197
198    VariableDbgInfo(const DILocalVariable *Var, const DIExpression *Expr,
199                    unsigned Slot, const DILocation *Loc)
200        : Var(Var), Expr(Expr), Slot(Slot), Loc(Loc) {}
201  };
202  typedef SmallVector<VariableDbgInfo, 4> VariableDbgInfoMapTy;
203  VariableDbgInfoMapTy VariableDbgInfos;
204
205  MachineModuleInfo();  // DUMMY CONSTRUCTOR, DO NOT CALL.
206  // Real constructor.
207  MachineModuleInfo(const MCAsmInfo &MAI, const MCRegisterInfo &MRI,
208                    const MCObjectFileInfo *MOFI);
209  ~MachineModuleInfo() override;
210
211  // Initialization and Finalization
212  bool doInitialization(Module &) override;
213  bool doFinalization(Module &) override;
214
215  /// EndFunction - Discard function meta information.
216  ///
217  void EndFunction();
218
219  const MCContext &getContext() const { return Context; }
220  MCContext &getContext() { return Context; }
221
222  void setModule(const Module *M) { TheModule = M; }
223  const Module *getModule() const { return TheModule; }
224
225  /// getInfo - Keep track of various per-function pieces of information for
226  /// backends that would like to do so.
227  ///
228  template<typename Ty>
229  Ty &getObjFileInfo() {
230    if (ObjFileMMI == nullptr)
231      ObjFileMMI = new Ty(*this);
232    return *static_cast<Ty*>(ObjFileMMI);
233  }
234
235  template<typename Ty>
236  const Ty &getObjFileInfo() const {
237    return const_cast<MachineModuleInfo*>(this)->getObjFileInfo<Ty>();
238  }
239
240  /// hasDebugInfo - Returns true if valid debug info is present.
241  ///
242  bool hasDebugInfo() const { return DbgInfoAvailable; }
243  void setDebugInfoAvailability(bool avail) { DbgInfoAvailable = avail; }
244
245  bool callsEHReturn() const { return CallsEHReturn; }
246  void setCallsEHReturn(bool b) { CallsEHReturn = b; }
247
248  bool callsUnwindInit() const { return CallsUnwindInit; }
249  void setCallsUnwindInit(bool b) { CallsUnwindInit = b; }
250
251  bool hasEHFunclets() const { return HasEHFunclets; }
252  void setHasEHFunclets(bool V) { HasEHFunclets = V; }
253
254  bool usesVAFloatArgument() const {
255    return UsesVAFloatArgument;
256  }
257
258  void setUsesVAFloatArgument(bool b) {
259    UsesVAFloatArgument = b;
260  }
261
262  bool usesMorestackAddr() const {
263    return UsesMorestackAddr;
264  }
265
266  void setUsesMorestackAddr(bool b) {
267    UsesMorestackAddr = b;
268  }
269
270  /// \brief Returns a reference to a list of cfi instructions in the current
271  /// function's prologue.  Used to construct frame maps for debug and exception
272  /// handling comsumers.
273  const std::vector<MCCFIInstruction> &getFrameInstructions() const {
274    return FrameInstructions;
275  }
276
277  unsigned LLVM_ATTRIBUTE_UNUSED_RESULT
278  addFrameInst(const MCCFIInstruction &Inst) {
279    FrameInstructions.push_back(Inst);
280    return FrameInstructions.size() - 1;
281  }
282
283  /// getAddrLabelSymbol - Return the symbol to be used for the specified basic
284  /// block when its address is taken.  This cannot be its normal LBB label
285  /// because the block may be accessed outside its containing function.
286  MCSymbol *getAddrLabelSymbol(const BasicBlock *BB) {
287    return getAddrLabelSymbolToEmit(BB).front();
288  }
289
290  /// getAddrLabelSymbolToEmit - Return the symbol to be used for the specified
291  /// basic block when its address is taken.  If other blocks were RAUW'd to
292  /// this one, we may have to emit them as well, return the whole set.
293  ArrayRef<MCSymbol *> getAddrLabelSymbolToEmit(const BasicBlock *BB);
294
295  /// takeDeletedSymbolsForFunction - If the specified function has had any
296  /// references to address-taken blocks generated, but the block got deleted,
297  /// return the symbol now so we can emit it.  This prevents emitting a
298  /// reference to a symbol that has no definition.
299  void takeDeletedSymbolsForFunction(const Function *F,
300                                     std::vector<MCSymbol*> &Result);
301
302
303  //===- EH ---------------------------------------------------------------===//
304
305  /// getOrCreateLandingPadInfo - Find or create an LandingPadInfo for the
306  /// specified MachineBasicBlock.
307  LandingPadInfo &getOrCreateLandingPadInfo(MachineBasicBlock *LandingPad);
308
309  /// addInvoke - Provide the begin and end labels of an invoke style call and
310  /// associate it with a try landing pad block.
311  void addInvoke(MachineBasicBlock *LandingPad,
312                 MCSymbol *BeginLabel, MCSymbol *EndLabel);
313
314  /// addLandingPad - Add a new panding pad.  Returns the label ID for the
315  /// landing pad entry.
316  MCSymbol *addLandingPad(MachineBasicBlock *LandingPad);
317
318  /// addPersonality - Provide the personality function for the exception
319  /// information.
320  void addPersonality(const Function *Personality);
321
322  /// getPersonalities - Return array of personality functions ever seen.
323  const std::vector<const Function *>& getPersonalities() const {
324    return Personalities;
325  }
326
327  /// addCatchTypeInfo - Provide the catch typeinfo for a landing pad.
328  ///
329  void addCatchTypeInfo(MachineBasicBlock *LandingPad,
330                        ArrayRef<const GlobalValue *> TyInfo);
331
332  /// addFilterTypeInfo - Provide the filter typeinfo for a landing pad.
333  ///
334  void addFilterTypeInfo(MachineBasicBlock *LandingPad,
335                         ArrayRef<const GlobalValue *> TyInfo);
336
337  /// addCleanup - Add a cleanup action for a landing pad.
338  ///
339  void addCleanup(MachineBasicBlock *LandingPad);
340
341  void addSEHCatchHandler(MachineBasicBlock *LandingPad, const Function *Filter,
342                          const BlockAddress *RecoverLabel);
343
344  void addSEHCleanupHandler(MachineBasicBlock *LandingPad,
345                            const Function *Cleanup);
346
347  /// getTypeIDFor - Return the type id for the specified typeinfo.  This is
348  /// function wide.
349  unsigned getTypeIDFor(const GlobalValue *TI);
350
351  /// getFilterIDFor - Return the id of the filter encoded by TyIds.  This is
352  /// function wide.
353  int getFilterIDFor(std::vector<unsigned> &TyIds);
354
355  /// TidyLandingPads - Remap landing pad labels and remove any deleted landing
356  /// pads.
357  void TidyLandingPads(DenseMap<MCSymbol*, uintptr_t> *LPMap = nullptr);
358
359  /// getLandingPads - Return a reference to the landing pad info for the
360  /// current function.
361  const std::vector<LandingPadInfo> &getLandingPads() const {
362    return LandingPads;
363  }
364
365  /// setCallSiteLandingPad - Map the landing pad's EH symbol to the call
366  /// site indexes.
367  void setCallSiteLandingPad(MCSymbol *Sym, ArrayRef<unsigned> Sites);
368
369  /// getCallSiteLandingPad - Get the call site indexes for a landing pad EH
370  /// symbol.
371  SmallVectorImpl<unsigned> &getCallSiteLandingPad(MCSymbol *Sym) {
372    assert(hasCallSiteLandingPad(Sym) &&
373           "missing call site number for landing pad!");
374    return LPadToCallSiteMap[Sym];
375  }
376
377  /// hasCallSiteLandingPad - Return true if the landing pad Eh symbol has an
378  /// associated call site.
379  bool hasCallSiteLandingPad(MCSymbol *Sym) {
380    return !LPadToCallSiteMap[Sym].empty();
381  }
382
383  /// setCallSiteBeginLabel - Map the begin label for a call site.
384  void setCallSiteBeginLabel(MCSymbol *BeginLabel, unsigned Site) {
385    CallSiteMap[BeginLabel] = Site;
386  }
387
388  /// getCallSiteBeginLabel - Get the call site number for a begin label.
389  unsigned getCallSiteBeginLabel(MCSymbol *BeginLabel) {
390    assert(hasCallSiteBeginLabel(BeginLabel) &&
391           "Missing call site number for EH_LABEL!");
392    return CallSiteMap[BeginLabel];
393  }
394
395  /// hasCallSiteBeginLabel - Return true if the begin label has a call site
396  /// number associated with it.
397  bool hasCallSiteBeginLabel(MCSymbol *BeginLabel) {
398    return CallSiteMap[BeginLabel] != 0;
399  }
400
401  /// setCurrentCallSite - Set the call site currently being processed.
402  void setCurrentCallSite(unsigned Site) { CurCallSite = Site; }
403
404  /// getCurrentCallSite - Get the call site currently being processed, if any.
405  /// return zero if none.
406  unsigned getCurrentCallSite() { return CurCallSite; }
407
408  /// getTypeInfos - Return a reference to the C++ typeinfo for the current
409  /// function.
410  const std::vector<const GlobalValue *> &getTypeInfos() const {
411    return TypeInfos;
412  }
413
414  /// getFilterIds - Return a reference to the typeids encoding filters used in
415  /// the current function.
416  const std::vector<unsigned> &getFilterIds() const {
417    return FilterIds;
418  }
419
420  /// setVariableDbgInfo - Collect information used to emit debugging
421  /// information of a variable.
422  void setVariableDbgInfo(const DILocalVariable *Var, const DIExpression *Expr,
423                          unsigned Slot, const DILocation *Loc) {
424    VariableDbgInfos.emplace_back(Var, Expr, Slot, Loc);
425  }
426
427  VariableDbgInfoMapTy &getVariableDbgInfo() { return VariableDbgInfos; }
428
429}; // End class MachineModuleInfo
430
431} // End llvm namespace
432
433#endif
434