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/CodeGen/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/System/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 MachineBasicBlock;
56 class MachineFunction;
57 class Module;
58 class PointerType;
59 class StructType;
60 
61 /// MachineModuleInfoImpl - This class can be derived from and used by targets
62 /// to hold private target-specific information for each Module.  Objects of
63 /// type are accessed/created with MMI::getInfo and destroyed when the
64 /// MachineModuleInfo is destroyed.
65 class MachineModuleInfoImpl {
66 public:
67   typedef PointerIntPair<MCSymbol*, 1, bool> StubValueTy;
68   virtual ~MachineModuleInfoImpl();
69   typedef std::vector<std::pair<MCSymbol*, StubValueTy> > SymbolListTy;
70 protected:
71   static SymbolListTy GetSortedStubs(const DenseMap<MCSymbol*, StubValueTy>&);
72 };
73 
74 
75 
76 //===----------------------------------------------------------------------===//
77 /// LandingPadInfo - This structure is used to retain landing pad info for
78 /// the current function.
79 ///
80 struct LandingPadInfo {
81   MachineBasicBlock *LandingPadBlock;    // Landing pad block.
82   SmallVector<MCSymbol*, 1> BeginLabels; // Labels prior to invoke.
83   SmallVector<MCSymbol*, 1> EndLabels;   // Labels after invoke.
84   MCSymbol *LandingPadLabel;             // Label at beginning of landing pad.
85   const Function *Personality;           // Personality function.
86   std::vector<int> TypeIds;              // List of type ids (filters negative)
87 
LandingPadInfoLandingPadInfo88   explicit LandingPadInfo(MachineBasicBlock *MBB)
89     : LandingPadBlock(MBB), LandingPadLabel(0), Personality(0) {}
90 };
91 
92 class MMIAddrLabelMap;
93 
94 //===----------------------------------------------------------------------===//
95 /// MachineModuleInfo - This class contains meta information specific to a
96 /// module.  Queries can be made by different debugging and exception handling
97 /// schemes and reformated for specific use.
98 ///
99 class MachineModuleInfo : public ImmutablePass {
100   /// Context - This is the MCContext used for the entire code generator.
101   MCContext Context;
102 
103   /// TheModule - This is the LLVM Module being worked on.
104   const Module *TheModule;
105 
106   /// ObjFileMMI - This is the object-file-format-specific implementation of
107   /// MachineModuleInfoImpl, which lets targets accumulate whatever info they
108   /// want.
109   MachineModuleInfoImpl *ObjFileMMI;
110 
111   // FrameMoves - List of moves done by a function's prolog.  Used to construct
112   // frame maps by debug and exception handling consumers.
113   std::vector<MachineMove> FrameMoves;
114 
115   // LandingPads - List of LandingPadInfo describing the landing pad information
116   // in the current function.
117   std::vector<LandingPadInfo> LandingPads;
118 
119   // Map of invoke call site index values to associated begin EH_LABEL for
120   // the current function.
121   DenseMap<MCSymbol*, unsigned> CallSiteMap;
122 
123   // The current call site index being processed, if any. 0 if none.
124   unsigned CurCallSite;
125 
126   // TypeInfos - List of C++ TypeInfo used in the current function.
127   //
128   std::vector<const GlobalVariable *> TypeInfos;
129 
130   // FilterIds - List of typeids encoding filters used in the current function.
131   //
132   std::vector<unsigned> FilterIds;
133 
134   // FilterEnds - List of the indices in FilterIds corresponding to filter
135   // terminators.
136   //
137   std::vector<unsigned> FilterEnds;
138 
139   // Personalities - Vector of all personality functions ever seen. Used to emit
140   // common EH frames.
141   std::vector<const Function *> Personalities;
142 
143   /// UsedFunctions - The functions in the @llvm.used list in a more easily
144   /// searchable format.  This does not include the functions in
145   /// llvm.compiler.used.
146   SmallPtrSet<const Function *, 32> UsedFunctions;
147 
148 
149   /// AddrLabelSymbols - This map keeps track of which symbol is being used for
150   /// the specified basic block's address of label.
151   MMIAddrLabelMap *AddrLabelSymbols;
152 
153   bool CallsEHReturn;
154   bool CallsUnwindInit;
155 
156   /// DbgInfoAvailable - True if debugging information is available
157   /// in this module.
158   bool DbgInfoAvailable;
159 
160 public:
161   static char ID; // Pass identification, replacement for typeid
162 
163   typedef std::pair<unsigned, DebugLoc> UnsignedDebugLocPair;
164   typedef SmallVector<std::pair<TrackingVH<MDNode>, UnsignedDebugLocPair>, 4>
165     VariableDbgInfoMapTy;
166   VariableDbgInfoMapTy VariableDbgInfo;
167 
168   MachineModuleInfo();  // DUMMY CONSTRUCTOR, DO NOT CALL.
169   MachineModuleInfo(const MCAsmInfo &MAI);  // Real constructor.
170   ~MachineModuleInfo();
171 
172   bool doInitialization();
173   bool doFinalization();
174 
175   /// EndFunction - Discard function meta information.
176   ///
177   void EndFunction();
178 
getContext()179   const MCContext &getContext() const { return Context; }
getContext()180   MCContext &getContext() { return Context; }
181 
setModule(const Module * M)182   void setModule(const Module *M) { TheModule = M; }
getModule()183   const Module *getModule() const { return TheModule; }
184 
185   /// getInfo - Keep track of various per-function pieces of information for
186   /// backends that would like to do so.
187   ///
188   template<typename Ty>
getObjFileInfo()189   Ty &getObjFileInfo() {
190     if (ObjFileMMI == 0)
191       ObjFileMMI = new Ty(*this);
192     return *static_cast<Ty*>(ObjFileMMI);
193   }
194 
195   template<typename Ty>
getObjFileInfo()196   const Ty &getObjFileInfo() const {
197     return const_cast<MachineModuleInfo*>(this)->getObjFileInfo<Ty>();
198   }
199 
200   /// AnalyzeModule - Scan the module for global debug information.
201   ///
202   void AnalyzeModule(const Module &M);
203 
204   /// hasDebugInfo - Returns true if valid debug info is present.
205   ///
hasDebugInfo()206   bool hasDebugInfo() const { return DbgInfoAvailable; }
setDebugInfoAvailability(bool avail)207   void setDebugInfoAvailability(bool avail) { DbgInfoAvailable = true; }
208 
callsEHReturn()209   bool callsEHReturn() const { return CallsEHReturn; }
setCallsEHReturn(bool b)210   void setCallsEHReturn(bool b) { CallsEHReturn = b; }
211 
callsUnwindInit()212   bool callsUnwindInit() const { return CallsUnwindInit; }
setCallsUnwindInit(bool b)213   void setCallsUnwindInit(bool b) { CallsUnwindInit = b; }
214 
215   /// getFrameMoves - Returns a reference to a list of moves done in the current
216   /// function's prologue.  Used to construct frame maps for debug and exception
217   /// handling comsumers.
getFrameMoves()218   std::vector<MachineMove> &getFrameMoves() { return FrameMoves; }
219 
220   /// getAddrLabelSymbol - Return the symbol to be used for the specified basic
221   /// block when its address is taken.  This cannot be its normal LBB label
222   /// because the block may be accessed outside its containing function.
223   MCSymbol *getAddrLabelSymbol(const BasicBlock *BB);
224 
225   /// getAddrLabelSymbolToEmit - Return the symbol to be used for the specified
226   /// basic block when its address is taken.  If other blocks were RAUW'd to
227   /// this one, we may have to emit them as well, return the whole set.
228   std::vector<MCSymbol*> getAddrLabelSymbolToEmit(const BasicBlock *BB);
229 
230   /// takeDeletedSymbolsForFunction - If the specified function has had any
231   /// references to address-taken blocks generated, but the block got deleted,
232   /// return the symbol now so we can emit it.  This prevents emitting a
233   /// reference to a symbol that has no definition.
234   void takeDeletedSymbolsForFunction(const Function *F,
235                                      std::vector<MCSymbol*> &Result);
236 
237 
238   //===- EH ---------------------------------------------------------------===//
239 
240   /// getOrCreateLandingPadInfo - Find or create an LandingPadInfo for the
241   /// specified MachineBasicBlock.
242   LandingPadInfo &getOrCreateLandingPadInfo(MachineBasicBlock *LandingPad);
243 
244   /// addInvoke - Provide the begin and end labels of an invoke style call and
245   /// associate it with a try landing pad block.
246   void addInvoke(MachineBasicBlock *LandingPad,
247                  MCSymbol *BeginLabel, MCSymbol *EndLabel);
248 
249   /// addLandingPad - Add a new panding pad.  Returns the label ID for the
250   /// landing pad entry.
251   MCSymbol *addLandingPad(MachineBasicBlock *LandingPad);
252 
253   /// addPersonality - Provide the personality function for the exception
254   /// information.
255   void addPersonality(MachineBasicBlock *LandingPad,
256                       const Function *Personality);
257 
258   /// getPersonalityIndex - Get index of the current personality function inside
259   /// Personalitites array
260   unsigned getPersonalityIndex() const;
261 
262   /// getPersonalities - Return array of personality functions ever seen.
getPersonalities()263   const std::vector<const Function *>& getPersonalities() const {
264     return Personalities;
265   }
266 
267   /// isUsedFunction - Return true if the functions in the llvm.used list.  This
268   /// does not return true for things in llvm.compiler.used unless they are also
269   /// in llvm.used.
isUsedFunction(const Function * F)270   bool isUsedFunction(const Function *F) {
271     return UsedFunctions.count(F);
272   }
273 
274   /// addCatchTypeInfo - Provide the catch typeinfo for a landing pad.
275   ///
276   void addCatchTypeInfo(MachineBasicBlock *LandingPad,
277                         std::vector<const GlobalVariable *> &TyInfo);
278 
279   /// addFilterTypeInfo - Provide the filter typeinfo for a landing pad.
280   ///
281   void addFilterTypeInfo(MachineBasicBlock *LandingPad,
282                          std::vector<const GlobalVariable *> &TyInfo);
283 
284   /// addCleanup - Add a cleanup action for a landing pad.
285   ///
286   void addCleanup(MachineBasicBlock *LandingPad);
287 
288   /// getTypeIDFor - Return the type id for the specified typeinfo.  This is
289   /// function wide.
290   unsigned getTypeIDFor(const GlobalVariable *TI);
291 
292   /// getFilterIDFor - Return the id of the filter encoded by TyIds.  This is
293   /// function wide.
294   int getFilterIDFor(std::vector<unsigned> &TyIds);
295 
296   /// TidyLandingPads - Remap landing pad labels and remove any deleted landing
297   /// pads.
298   void TidyLandingPads(DenseMap<MCSymbol*, uintptr_t> *LPMap = 0);
299 
300   /// getLandingPads - Return a reference to the landing pad info for the
301   /// current function.
getLandingPads()302   const std::vector<LandingPadInfo> &getLandingPads() const {
303     return LandingPads;
304   }
305 
306   /// setCallSiteBeginLabel - Map the begin label for a call site
setCallSiteBeginLabel(MCSymbol * BeginLabel,unsigned Site)307   void setCallSiteBeginLabel(MCSymbol *BeginLabel, unsigned Site) {
308     CallSiteMap[BeginLabel] = Site;
309   }
310 
311   /// getCallSiteBeginLabel - Get the call site number for a begin label
getCallSiteBeginLabel(MCSymbol * BeginLabel)312   unsigned getCallSiteBeginLabel(MCSymbol *BeginLabel) {
313     assert(CallSiteMap.count(BeginLabel) &&
314            "Missing call site number for EH_LABEL!");
315     return CallSiteMap[BeginLabel];
316   }
317 
318   /// setCurrentCallSite - Set the call site currently being processed.
setCurrentCallSite(unsigned Site)319   void setCurrentCallSite(unsigned Site) { CurCallSite = Site; }
320 
321   /// getCurrentCallSite - Get the call site currently being processed, if any.
322   /// return zero if none.
getCurrentCallSite(void)323   unsigned getCurrentCallSite(void) { return CurCallSite; }
324 
325   /// getTypeInfos - Return a reference to the C++ typeinfo for the current
326   /// function.
getTypeInfos()327   const std::vector<const GlobalVariable *> &getTypeInfos() const {
328     return TypeInfos;
329   }
330 
331   /// getFilterIds - Return a reference to the typeids encoding filters used in
332   /// the current function.
getFilterIds()333   const std::vector<unsigned> &getFilterIds() const {
334     return FilterIds;
335   }
336 
337   /// getPersonality - Return a personality function if available.  The presence
338   /// of one is required to emit exception handling info.
339   const Function *getPersonality() const;
340 
341   /// setVariableDbgInfo - Collect information used to emit debugging
342   /// information of a variable.
setVariableDbgInfo(MDNode * N,unsigned Slot,DebugLoc Loc)343   void setVariableDbgInfo(MDNode *N, unsigned Slot, DebugLoc Loc) {
344     VariableDbgInfo.push_back(std::make_pair(N, std::make_pair(Slot, Loc)));
345   }
346 
getVariableDbgInfo()347   VariableDbgInfoMapTy &getVariableDbgInfo() { return VariableDbgInfo; }
348 
349 }; // End class MachineModuleInfo
350 
351 } // End llvm namespace
352 
353 #endif
354