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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/Pass.h"
35 #include "llvm/GlobalValue.h"
36 #include "llvm/Metadata.h"
37 #include "llvm/MC/MachineLocation.h"
38 #include "llvm/MC/MCContext.h"
39 #include "llvm/Support/Dwarf.h"
40 #include "llvm/Support/DebugLoc.h"
41 #include "llvm/Support/ValueHandle.h"
42 #include "llvm/Support/DataTypes.h"
43 #include "llvm/ADT/DenseMap.h"
44 #include "llvm/ADT/PointerIntPair.h"
45 #include "llvm/ADT/SmallPtrSet.h"
46 #include "llvm/ADT/SmallVector.h"
47 
48 namespace llvm {
49 
50 //===----------------------------------------------------------------------===//
51 // Forward declarations.
52 class Constant;
53 class GlobalVariable;
54 class MDNode;
55 class MMIAddrLabelMap;
56 class MachineBasicBlock;
57 class MachineFunction;
58 class Module;
59 class PointerType;
60 class StructType;
61 
62 //===----------------------------------------------------------------------===//
63 /// LandingPadInfo - This structure is used to retain landing pad info for
64 /// the current function.
65 ///
66 struct LandingPadInfo {
67   MachineBasicBlock *LandingPadBlock;    // Landing pad block.
68   SmallVector<MCSymbol*, 1> BeginLabels; // Labels prior to invoke.
69   SmallVector<MCSymbol*, 1> EndLabels;   // Labels after invoke.
70   MCSymbol *LandingPadLabel;             // Label at beginning of landing pad.
71   const Function *Personality;           // Personality function.
72   std::vector<int> TypeIds;              // List of type ids (filters negative)
73 
LandingPadInfoLandingPadInfo74   explicit LandingPadInfo(MachineBasicBlock *MBB)
75     : LandingPadBlock(MBB), LandingPadLabel(0), Personality(0) {}
76 };
77 
78 //===----------------------------------------------------------------------===//
79 /// MachineModuleInfoImpl - This class can be derived from and used by targets
80 /// to hold private target-specific information for each Module.  Objects of
81 /// type are accessed/created with MMI::getInfo and destroyed when the
82 /// MachineModuleInfo is destroyed.
83 ///
84 class MachineModuleInfoImpl {
85 public:
86   typedef PointerIntPair<MCSymbol*, 1, bool> StubValueTy;
87   virtual ~MachineModuleInfoImpl();
88   typedef std::vector<std::pair<MCSymbol*, StubValueTy> > SymbolListTy;
89 protected:
90   static SymbolListTy GetSortedStubs(const DenseMap<MCSymbol*, StubValueTy>&);
91 };
92 
93 //===----------------------------------------------------------------------===//
94 /// MachineModuleInfo - This class contains meta information specific to a
95 /// module.  Queries can be made by different debugging and exception handling
96 /// schemes and reformated for specific use.
97 ///
98 class MachineModuleInfo : public ImmutablePass {
99   /// Context - This is the MCContext used for the entire code generator.
100   MCContext Context;
101 
102   /// TheModule - This is the LLVM Module being worked on.
103   const Module *TheModule;
104 
105   /// ObjFileMMI - This is the object-file-format-specific implementation of
106   /// MachineModuleInfoImpl, which lets targets accumulate whatever info they
107   /// want.
108   MachineModuleInfoImpl *ObjFileMMI;
109 
110   /// FrameMoves - List of moves done by a function's prolog.  Used to construct
111   /// frame maps by debug and exception handling consumers.
112   std::vector<MachineMove> FrameMoves;
113 
114   /// CompactUnwindEncoding - If the target supports it, this is the compact
115   /// unwind encoding. It replaces a function's CIE and FDE.
116   uint32_t CompactUnwindEncoding;
117 
118   /// LandingPads - List of LandingPadInfo describing the landing pad
119   /// information in the current function.
120   std::vector<LandingPadInfo> LandingPads;
121 
122   /// LPadToCallSiteMap - Map a landing pad's EH symbol to the call site
123   /// indexes.
124   DenseMap<MCSymbol*, SmallVector<unsigned, 4> > LPadToCallSiteMap;
125 
126   /// CallSiteMap - Map of invoke call site index values to associated begin
127   /// EH_LABEL for the current function.
128   DenseMap<MCSymbol*, unsigned> CallSiteMap;
129 
130   /// CurCallSite - The current call site index being processed, if any. 0 if
131   /// none.
132   unsigned CurCallSite;
133 
134   /// TypeInfos - List of C++ TypeInfo used in the current function.
135   std::vector<const GlobalVariable *> TypeInfos;
136 
137   /// FilterIds - List of typeids encoding filters used in the current function.
138   std::vector<unsigned> FilterIds;
139 
140   /// FilterEnds - List of the indices in FilterIds corresponding to filter
141   /// terminators.
142   std::vector<unsigned> FilterEnds;
143 
144   /// Personalities - Vector of all personality functions ever seen. Used to
145   /// emit common EH frames.
146   std::vector<const Function *> Personalities;
147 
148   /// UsedFunctions - The functions in the @llvm.used list in a more easily
149   /// searchable format.  This does not include the functions in
150   /// llvm.compiler.used.
151   SmallPtrSet<const Function *, 32> UsedFunctions;
152 
153   /// AddrLabelSymbols - This map keeps track of which symbol is being used for
154   /// the specified basic block's address of label.
155   MMIAddrLabelMap *AddrLabelSymbols;
156 
157   bool CallsEHReturn;
158   bool CallsUnwindInit;
159 
160   /// DbgInfoAvailable - True if debugging information is available
161   /// in this module.
162   bool DbgInfoAvailable;
163 
164   /// CallsExternalVAFunctionWithFloatingPointArguments - True if this module
165   /// calls VarArg function with floating point arguments.  This is used to emit
166   /// an undefined reference to fltused on Windows targets.
167   bool CallsExternalVAFunctionWithFloatingPointArguments;
168 
169 public:
170   static char ID; // Pass identification, replacement for typeid
171 
172   typedef std::pair<unsigned, DebugLoc> UnsignedDebugLocPair;
173   typedef SmallVector<std::pair<TrackingVH<MDNode>, UnsignedDebugLocPair>, 4>
174     VariableDbgInfoMapTy;
175   VariableDbgInfoMapTy VariableDbgInfo;
176 
177   MachineModuleInfo();  // DUMMY CONSTRUCTOR, DO NOT CALL.
178   // Real constructor.
179   MachineModuleInfo(const MCAsmInfo &MAI, const MCRegisterInfo &MRI,
180                     const MCObjectFileInfo *MOFI);
181   ~MachineModuleInfo();
182 
183   bool doInitialization();
184   bool doFinalization();
185 
186   /// EndFunction - Discard function meta information.
187   ///
188   void EndFunction();
189 
getContext()190   const MCContext &getContext() const { return Context; }
getContext()191   MCContext &getContext() { return Context; }
192 
setModule(const Module * M)193   void setModule(const Module *M) { TheModule = M; }
getModule()194   const Module *getModule() const { return TheModule; }
195 
196   /// getInfo - Keep track of various per-function pieces of information for
197   /// backends that would like to do so.
198   ///
199   template<typename Ty>
getObjFileInfo()200   Ty &getObjFileInfo() {
201     if (ObjFileMMI == 0)
202       ObjFileMMI = new Ty(*this);
203     return *static_cast<Ty*>(ObjFileMMI);
204   }
205 
206   template<typename Ty>
getObjFileInfo()207   const Ty &getObjFileInfo() const {
208     return const_cast<MachineModuleInfo*>(this)->getObjFileInfo<Ty>();
209   }
210 
211   /// AnalyzeModule - Scan the module for global debug information.
212   ///
213   void AnalyzeModule(const Module &M);
214 
215   /// hasDebugInfo - Returns true if valid debug info is present.
216   ///
hasDebugInfo()217   bool hasDebugInfo() const { return DbgInfoAvailable; }
setDebugInfoAvailability(bool avail)218   void setDebugInfoAvailability(bool avail) { DbgInfoAvailable = avail; }
219 
callsEHReturn()220   bool callsEHReturn() const { return CallsEHReturn; }
setCallsEHReturn(bool b)221   void setCallsEHReturn(bool b) { CallsEHReturn = b; }
222 
callsUnwindInit()223   bool callsUnwindInit() const { return CallsUnwindInit; }
setCallsUnwindInit(bool b)224   void setCallsUnwindInit(bool b) { CallsUnwindInit = b; }
225 
callsExternalVAFunctionWithFloatingPointArguments()226   bool callsExternalVAFunctionWithFloatingPointArguments() const {
227     return CallsExternalVAFunctionWithFloatingPointArguments;
228   }
229 
setCallsExternalVAFunctionWithFloatingPointArguments(bool b)230   void setCallsExternalVAFunctionWithFloatingPointArguments(bool b) {
231     CallsExternalVAFunctionWithFloatingPointArguments = b;
232   }
233 
234   /// getFrameMoves - Returns a reference to a list of moves done in the current
235   /// function's prologue.  Used to construct frame maps for debug and exception
236   /// handling comsumers.
getFrameMoves()237   std::vector<MachineMove> &getFrameMoves() { return FrameMoves; }
238 
239   /// getCompactUnwindEncoding - Returns the compact unwind encoding for a
240   /// function if the target supports the encoding. This encoding replaces a
241   /// function's CIE and FDE.
getCompactUnwindEncoding()242   uint32_t getCompactUnwindEncoding() const { return CompactUnwindEncoding; }
243 
244   /// setCompactUnwindEncoding - Set the compact unwind encoding for a function
245   /// if the target supports the encoding.
setCompactUnwindEncoding(uint32_t Enc)246   void setCompactUnwindEncoding(uint32_t Enc) { CompactUnwindEncoding = Enc; }
247 
248   /// getAddrLabelSymbol - Return the symbol to be used for the specified basic
249   /// block when its address is taken.  This cannot be its normal LBB label
250   /// because the block may be accessed outside its containing function.
251   MCSymbol *getAddrLabelSymbol(const BasicBlock *BB);
252 
253   /// getAddrLabelSymbolToEmit - Return the symbol to be used for the specified
254   /// basic block when its address is taken.  If other blocks were RAUW'd to
255   /// this one, we may have to emit them as well, return the whole set.
256   std::vector<MCSymbol*> getAddrLabelSymbolToEmit(const BasicBlock *BB);
257 
258   /// takeDeletedSymbolsForFunction - If the specified function has had any
259   /// references to address-taken blocks generated, but the block got deleted,
260   /// return the symbol now so we can emit it.  This prevents emitting a
261   /// reference to a symbol that has no definition.
262   void takeDeletedSymbolsForFunction(const Function *F,
263                                      std::vector<MCSymbol*> &Result);
264 
265 
266   //===- EH ---------------------------------------------------------------===//
267 
268   /// getOrCreateLandingPadInfo - Find or create an LandingPadInfo for the
269   /// specified MachineBasicBlock.
270   LandingPadInfo &getOrCreateLandingPadInfo(MachineBasicBlock *LandingPad);
271 
272   /// addInvoke - Provide the begin and end labels of an invoke style call and
273   /// associate it with a try landing pad block.
274   void addInvoke(MachineBasicBlock *LandingPad,
275                  MCSymbol *BeginLabel, MCSymbol *EndLabel);
276 
277   /// addLandingPad - Add a new panding pad.  Returns the label ID for the
278   /// landing pad entry.
279   MCSymbol *addLandingPad(MachineBasicBlock *LandingPad);
280 
281   /// addPersonality - Provide the personality function for the exception
282   /// information.
283   void addPersonality(MachineBasicBlock *LandingPad,
284                       const Function *Personality);
285 
286   /// getPersonalityIndex - Get index of the current personality function inside
287   /// Personalitites array
288   unsigned getPersonalityIndex() const;
289 
290   /// getPersonalities - Return array of personality functions ever seen.
getPersonalities()291   const std::vector<const Function *>& getPersonalities() const {
292     return Personalities;
293   }
294 
295   /// isUsedFunction - Return true if the functions in the llvm.used list.  This
296   /// does not return true for things in llvm.compiler.used unless they are also
297   /// in llvm.used.
isUsedFunction(const Function * F)298   bool isUsedFunction(const Function *F) {
299     return UsedFunctions.count(F);
300   }
301 
302   /// addCatchTypeInfo - Provide the catch typeinfo for a landing pad.
303   ///
304   void addCatchTypeInfo(MachineBasicBlock *LandingPad,
305                         ArrayRef<const GlobalVariable *> TyInfo);
306 
307   /// addFilterTypeInfo - Provide the filter typeinfo for a landing pad.
308   ///
309   void addFilterTypeInfo(MachineBasicBlock *LandingPad,
310                          ArrayRef<const GlobalVariable *> TyInfo);
311 
312   /// addCleanup - Add a cleanup action for a landing pad.
313   ///
314   void addCleanup(MachineBasicBlock *LandingPad);
315 
316   /// getTypeIDFor - Return the type id for the specified typeinfo.  This is
317   /// function wide.
318   unsigned getTypeIDFor(const GlobalVariable *TI);
319 
320   /// getFilterIDFor - Return the id of the filter encoded by TyIds.  This is
321   /// function wide.
322   int getFilterIDFor(std::vector<unsigned> &TyIds);
323 
324   /// TidyLandingPads - Remap landing pad labels and remove any deleted landing
325   /// pads.
326   void TidyLandingPads(DenseMap<MCSymbol*, uintptr_t> *LPMap = 0);
327 
328   /// getLandingPads - Return a reference to the landing pad info for the
329   /// current function.
getLandingPads()330   const std::vector<LandingPadInfo> &getLandingPads() const {
331     return LandingPads;
332   }
333 
334   /// setCallSiteLandingPad - Map the landing pad's EH symbol to the call
335   /// site indexes.
336   void setCallSiteLandingPad(MCSymbol *Sym, ArrayRef<unsigned> Sites);
337 
338   /// getCallSiteLandingPad - Get the call site indexes for a landing pad EH
339   /// symbol.
getCallSiteLandingPad(MCSymbol * Sym)340   SmallVectorImpl<unsigned> &getCallSiteLandingPad(MCSymbol *Sym) {
341     assert(hasCallSiteLandingPad(Sym) &&
342            "missing call site number for landing pad!");
343     return LPadToCallSiteMap[Sym];
344   }
345 
346   /// hasCallSiteLandingPad - Return true if the landing pad Eh symbol has an
347   /// associated call site.
hasCallSiteLandingPad(MCSymbol * Sym)348   bool hasCallSiteLandingPad(MCSymbol *Sym) {
349     return !LPadToCallSiteMap[Sym].empty();
350   }
351 
352   /// setCallSiteBeginLabel - Map the begin label for a call site.
setCallSiteBeginLabel(MCSymbol * BeginLabel,unsigned Site)353   void setCallSiteBeginLabel(MCSymbol *BeginLabel, unsigned Site) {
354     CallSiteMap[BeginLabel] = Site;
355   }
356 
357   /// getCallSiteBeginLabel - Get the call site number for a begin label.
getCallSiteBeginLabel(MCSymbol * BeginLabel)358   unsigned getCallSiteBeginLabel(MCSymbol *BeginLabel) {
359     assert(hasCallSiteBeginLabel(BeginLabel) &&
360            "Missing call site number for EH_LABEL!");
361     return CallSiteMap[BeginLabel];
362   }
363 
364   /// hasCallSiteBeginLabel - Return true if the begin label has a call site
365   /// number associated with it.
hasCallSiteBeginLabel(MCSymbol * BeginLabel)366   bool hasCallSiteBeginLabel(MCSymbol *BeginLabel) {
367     return CallSiteMap[BeginLabel] != 0;
368   }
369 
370   /// setCurrentCallSite - Set the call site currently being processed.
setCurrentCallSite(unsigned Site)371   void setCurrentCallSite(unsigned Site) { CurCallSite = Site; }
372 
373   /// getCurrentCallSite - Get the call site currently being processed, if any.
374   /// return zero if none.
getCurrentCallSite(void)375   unsigned getCurrentCallSite(void) { return CurCallSite; }
376 
377   /// getTypeInfos - Return a reference to the C++ typeinfo for the current
378   /// function.
getTypeInfos()379   const std::vector<const GlobalVariable *> &getTypeInfos() const {
380     return TypeInfos;
381   }
382 
383   /// getFilterIds - Return a reference to the typeids encoding filters used in
384   /// the current function.
getFilterIds()385   const std::vector<unsigned> &getFilterIds() const {
386     return FilterIds;
387   }
388 
389   /// getPersonality - Return a personality function if available.  The presence
390   /// of one is required to emit exception handling info.
391   const Function *getPersonality() const;
392 
393   /// setVariableDbgInfo - Collect information used to emit debugging
394   /// information of a variable.
setVariableDbgInfo(MDNode * N,unsigned Slot,DebugLoc Loc)395   void setVariableDbgInfo(MDNode *N, unsigned Slot, DebugLoc Loc) {
396     VariableDbgInfo.push_back(std::make_pair(N, std::make_pair(Slot, Loc)));
397   }
398 
getVariableDbgInfo()399   VariableDbgInfoMapTy &getVariableDbgInfo() { return VariableDbgInfo; }
400 
401 }; // End class MachineModuleInfo
402 
403 } // End llvm namespace
404 
405 #endif
406