xref: /llvm-project/llvm/lib/CodeGen/MachineModuleInfo.cpp (revision 9efbbcbe454b16b41e22a5986878c6b6ac925e80) 
1 //===-- llvm/CodeGen/MachineModuleInfo.cpp ----------------------*- 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 #include "llvm/CodeGen/MachineModuleInfo.h"
11 
12 #include "llvm/Constants.h"
13 #include "llvm/DerivedTypes.h"
14 #include "llvm/GlobalVariable.h"
15 #include "llvm/Intrinsics.h"
16 #include "llvm/Instructions.h"
17 #include "llvm/Module.h"
18 #include "llvm/Analysis/ValueTracking.h"
19 #include "llvm/CodeGen/MachineFunctionPass.h"
20 #include "llvm/CodeGen/MachineFunction.h"
21 #include "llvm/CodeGen/Passes.h"
22 #include "llvm/Target/TargetInstrInfo.h"
23 #include "llvm/Target/TargetMachine.h"
24 #include "llvm/Target/TargetOptions.h"
25 #include "llvm/MC/MCSymbol.h"
26 #include "llvm/Support/Dwarf.h"
27 #include "llvm/Support/ErrorHandling.h"
28 using namespace llvm;
29 using namespace llvm::dwarf;
30 
31 // Handle the Pass registration stuff necessary to use TargetData's.
32 static RegisterPass<MachineModuleInfo>
33 X("machinemoduleinfo", "Machine Module Information");
34 char MachineModuleInfo::ID = 0;
35 
36 // Out of line virtual method.
37 MachineModuleInfoImpl::~MachineModuleInfoImpl() {}
38 
39 //===----------------------------------------------------------------------===//
40 
41 MachineModuleInfo::MachineModuleInfo(const MCAsmInfo &MAI)
42 : ImmutablePass(&ID), Context(MAI),
43   ObjFileMMI(0),
44   CurCallSite(0), CallsEHReturn(0), CallsUnwindInit(0), DbgInfoAvailable(false){
45   // Always emit some info, by default "no personality" info.
46   Personalities.push_back(NULL);
47 }
48 
49 MachineModuleInfo::MachineModuleInfo()
50 : ImmutablePass(&ID), Context(*(MCAsmInfo*)0) {
51   assert(0 && "This MachineModuleInfo constructor should never be called, MMI "
52          "should always be explicitly constructed by LLVMTargetMachine");
53   abort();
54 }
55 
56 MachineModuleInfo::~MachineModuleInfo() {
57   delete ObjFileMMI;
58 }
59 
60 /// doInitialization - Initialize the state for a new module.
61 ///
62 bool MachineModuleInfo::doInitialization() {
63   return false;
64 }
65 
66 /// doFinalization - Tear down the state after completion of a module.
67 ///
68 bool MachineModuleInfo::doFinalization() {
69   return false;
70 }
71 
72 /// EndFunction - Discard function meta information.
73 ///
74 void MachineModuleInfo::EndFunction() {
75   // Clean up frame info.
76   FrameMoves.clear();
77 
78   // Clean up exception info.
79   LandingPads.clear();
80   CallSiteMap.clear();
81   TypeInfos.clear();
82   FilterIds.clear();
83   FilterEnds.clear();
84   CallsEHReturn = 0;
85   CallsUnwindInit = 0;
86   VariableDbgInfo.clear();
87 }
88 
89 /// AnalyzeModule - Scan the module for global debug information.
90 ///
91 void MachineModuleInfo::AnalyzeModule(Module &M) {
92   // Insert functions in the llvm.used array (but not llvm.compiler.used) into
93   // UsedFunctions.
94   GlobalVariable *GV = M.getGlobalVariable("llvm.used");
95   if (!GV || !GV->hasInitializer()) return;
96 
97   // Should be an array of 'i8*'.
98   ConstantArray *InitList = dyn_cast<ConstantArray>(GV->getInitializer());
99   if (InitList == 0) return;
100 
101   for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
102     if (Function *F =
103           dyn_cast<Function>(InitList->getOperand(i)->stripPointerCasts()))
104       UsedFunctions.insert(F);
105 }
106 
107 /// getAddrLabelSymbol - Return the symbol to be used for the specified basic
108 /// block when its address is taken.  This cannot be its normal LBB label
109 /// because the block may be accessed outside its containing function.
110 MCSymbol *MachineModuleInfo::getAddrLabelSymbol(const BasicBlock *BB) {
111   assert(BB->hasAddressTaken() &&
112          "Shouldn't get label for block without address taken");
113   MCSymbol *&Entry = AddrLabelSymbols[const_cast<BasicBlock*>(BB)];
114   if (Entry) return Entry;
115   return Entry = Context.CreateTempSymbol();
116 }
117 
118 
119 //===-EH-------------------------------------------------------------------===//
120 
121 /// getOrCreateLandingPadInfo - Find or create an LandingPadInfo for the
122 /// specified MachineBasicBlock.
123 LandingPadInfo &MachineModuleInfo::getOrCreateLandingPadInfo
124     (MachineBasicBlock *LandingPad) {
125   unsigned N = LandingPads.size();
126   for (unsigned i = 0; i < N; ++i) {
127     LandingPadInfo &LP = LandingPads[i];
128     if (LP.LandingPadBlock == LandingPad)
129       return LP;
130   }
131 
132   LandingPads.push_back(LandingPadInfo(LandingPad));
133   return LandingPads[N];
134 }
135 
136 /// addInvoke - Provide the begin and end labels of an invoke style call and
137 /// associate it with a try landing pad block.
138 void MachineModuleInfo::addInvoke(MachineBasicBlock *LandingPad,
139                                   MCSymbol *BeginLabel, MCSymbol *EndLabel) {
140   LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
141   LP.BeginLabels.push_back(BeginLabel);
142   LP.EndLabels.push_back(EndLabel);
143 }
144 
145 /// addLandingPad - Provide the label of a try LandingPad block.
146 ///
147 MCSymbol *MachineModuleInfo::addLandingPad(MachineBasicBlock *LandingPad) {
148   MCSymbol *LandingPadLabel = Context.CreateTempSymbol();
149   LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
150   LP.LandingPadLabel = LandingPadLabel;
151   return LandingPadLabel;
152 }
153 
154 /// addPersonality - Provide the personality function for the exception
155 /// information.
156 void MachineModuleInfo::addPersonality(MachineBasicBlock *LandingPad,
157                                        Function *Personality) {
158   LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
159   LP.Personality = Personality;
160 
161   for (unsigned i = 0; i < Personalities.size(); ++i)
162     if (Personalities[i] == Personality)
163       return;
164 
165   // If this is the first personality we're adding go
166   // ahead and add it at the beginning.
167   if (Personalities[0] == NULL)
168     Personalities[0] = Personality;
169   else
170     Personalities.push_back(Personality);
171 }
172 
173 /// addCatchTypeInfo - Provide the catch typeinfo for a landing pad.
174 ///
175 void MachineModuleInfo::addCatchTypeInfo(MachineBasicBlock *LandingPad,
176                                         std::vector<GlobalVariable *> &TyInfo) {
177   LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
178   for (unsigned N = TyInfo.size(); N; --N)
179     LP.TypeIds.push_back(getTypeIDFor(TyInfo[N - 1]));
180 }
181 
182 /// addFilterTypeInfo - Provide the filter typeinfo for a landing pad.
183 ///
184 void MachineModuleInfo::addFilterTypeInfo(MachineBasicBlock *LandingPad,
185                                         std::vector<GlobalVariable *> &TyInfo) {
186   LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
187   std::vector<unsigned> IdsInFilter(TyInfo.size());
188   for (unsigned I = 0, E = TyInfo.size(); I != E; ++I)
189     IdsInFilter[I] = getTypeIDFor(TyInfo[I]);
190   LP.TypeIds.push_back(getFilterIDFor(IdsInFilter));
191 }
192 
193 /// addCleanup - Add a cleanup action for a landing pad.
194 ///
195 void MachineModuleInfo::addCleanup(MachineBasicBlock *LandingPad) {
196   LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
197   LP.TypeIds.push_back(0);
198 }
199 
200 /// TidyLandingPads - Remap landing pad labels and remove any deleted landing
201 /// pads.
202 void MachineModuleInfo::TidyLandingPads() {
203   for (unsigned i = 0; i != LandingPads.size(); ) {
204     LandingPadInfo &LandingPad = LandingPads[i];
205     if (LandingPad.LandingPadLabel && !LandingPad.LandingPadLabel->isDefined())
206       LandingPad.LandingPadLabel = 0;
207 
208     // Special case: we *should* emit LPs with null LP MBB. This indicates
209     // "nounwind" case.
210     if (!LandingPad.LandingPadLabel && LandingPad.LandingPadBlock) {
211       LandingPads.erase(LandingPads.begin() + i);
212       continue;
213     }
214 
215     for (unsigned j = 0, e = LandingPads[i].BeginLabels.size(); j != e; ++j) {
216       MCSymbol *BeginLabel = LandingPad.BeginLabels[j];
217       MCSymbol *EndLabel = LandingPad.EndLabels[j];
218       if (BeginLabel->isDefined() && EndLabel->isDefined()) continue;
219 
220       LandingPad.BeginLabels.erase(LandingPad.BeginLabels.begin() + j);
221       LandingPad.EndLabels.erase(LandingPad.EndLabels.begin() + j);
222       --j, --e;
223     }
224 
225     // Remove landing pads with no try-ranges.
226     if (LandingPads[i].BeginLabels.empty()) {
227       LandingPads.erase(LandingPads.begin() + i);
228       continue;
229     }
230 
231     // If there is no landing pad, ensure that the list of typeids is empty.
232     // If the only typeid is a cleanup, this is the same as having no typeids.
233     if (!LandingPad.LandingPadBlock ||
234         (LandingPad.TypeIds.size() == 1 && !LandingPad.TypeIds[0]))
235       LandingPad.TypeIds.clear();
236     ++i;
237   }
238 }
239 
240 /// getTypeIDFor - Return the type id for the specified typeinfo.  This is
241 /// function wide.
242 unsigned MachineModuleInfo::getTypeIDFor(GlobalVariable *TI) {
243   for (unsigned i = 0, N = TypeInfos.size(); i != N; ++i)
244     if (TypeInfos[i] == TI) return i + 1;
245 
246   TypeInfos.push_back(TI);
247   return TypeInfos.size();
248 }
249 
250 /// getFilterIDFor - Return the filter id for the specified typeinfos.  This is
251 /// function wide.
252 int MachineModuleInfo::getFilterIDFor(std::vector<unsigned> &TyIds) {
253   // If the new filter coincides with the tail of an existing filter, then
254   // re-use the existing filter.  Folding filters more than this requires
255   // re-ordering filters and/or their elements - probably not worth it.
256   for (std::vector<unsigned>::iterator I = FilterEnds.begin(),
257        E = FilterEnds.end(); I != E; ++I) {
258     unsigned i = *I, j = TyIds.size();
259 
260     while (i && j)
261       if (FilterIds[--i] != TyIds[--j])
262         goto try_next;
263 
264     if (!j)
265       // The new filter coincides with range [i, end) of the existing filter.
266       return -(1 + i);
267 
268 try_next:;
269   }
270 
271   // Add the new filter.
272   int FilterID = -(1 + FilterIds.size());
273   FilterIds.reserve(FilterIds.size() + TyIds.size() + 1);
274   for (unsigned I = 0, N = TyIds.size(); I != N; ++I)
275     FilterIds.push_back(TyIds[I]);
276   FilterEnds.push_back(FilterIds.size());
277   FilterIds.push_back(0); // terminator
278   return FilterID;
279 }
280 
281 /// getPersonality - Return the personality function for the current function.
282 Function *MachineModuleInfo::getPersonality() const {
283   // FIXME: Until PR1414 will be fixed, we're using 1 personality function per
284   // function
285   return !LandingPads.empty() ? LandingPads[0].Personality : NULL;
286 }
287 
288 /// getPersonalityIndex - Return unique index for current personality
289 /// function. NULL/first personality function should always get zero index.
290 unsigned MachineModuleInfo::getPersonalityIndex() const {
291   const Function* Personality = NULL;
292 
293   // Scan landing pads. If there is at least one non-NULL personality - use it.
294   for (unsigned i = 0; i != LandingPads.size(); ++i)
295     if (LandingPads[i].Personality) {
296       Personality = LandingPads[i].Personality;
297       break;
298     }
299 
300   for (unsigned i = 0; i < Personalities.size(); ++i) {
301     if (Personalities[i] == Personality)
302       return i;
303   }
304 
305   // This will happen if the current personality function is
306   // in the zero index.
307   return 0;
308 }
309 
310