MachineModuleInfo.cpp revision 5e42343a7b40d2fc6be5516fdcb033b3be025889 
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/Analysis/ValueTracking.h"
14#include "llvm/CodeGen/MachineFunctionPass.h"
15#include "llvm/CodeGen/MachineFunction.h"
16#include "llvm/CodeGen/Passes.h"
17#include "llvm/Target/TargetInstrInfo.h"
18#include "llvm/Target/TargetMachine.h"
19#include "llvm/Target/TargetOptions.h"
20#include "llvm/DerivedTypes.h"
21#include "llvm/GlobalVariable.h"
22#include "llvm/Intrinsics.h"
23#include "llvm/Instructions.h"
24#include "llvm/Module.h"
25#include "llvm/Support/Dwarf.h"
26#include "llvm/Support/ErrorHandling.h"
27using namespace llvm;
28using namespace llvm::dwarf;
29
30// Handle the Pass registration stuff necessary to use TargetData's.
31static RegisterPass<MachineModuleInfo>
32X("machinemoduleinfo", "Module Information");
33char MachineModuleInfo::ID = 0;
34
35// Out of line virtual method.
36MachineModuleInfoImpl::~MachineModuleInfoImpl() {}
37
38//===----------------------------------------------------------------------===//
39
40MachineModuleInfo::MachineModuleInfo()
41: ImmutablePass(&ID)
42, ObjFileMMI(0)
43, CurCallSite(0)
44, CallsEHReturn(0)
45, CallsUnwindInit(0)
46, DbgInfoAvailable(false) {
47  // Always emit some info, by default "no personality" info.
48  Personalities.push_back(NULL);
49}
50
51MachineModuleInfo::~MachineModuleInfo() {
52  delete ObjFileMMI;
53}
54
55/// doInitialization - Initialize the state for a new module.
56///
57bool MachineModuleInfo::doInitialization() {
58  return false;
59}
60
61/// doFinalization - Tear down the state after completion of a module.
62///
63bool MachineModuleInfo::doFinalization() {
64  return false;
65}
66
67/// EndFunction - Discard function meta information.
68///
69void MachineModuleInfo::EndFunction() {
70  // Clean up frame info.
71  FrameMoves.clear();
72
73  // Clean up exception info.
74  LandingPads.clear();
75  CallSiteMap.clear();
76  TypeInfos.clear();
77  FilterIds.clear();
78  FilterEnds.clear();
79  CallsEHReturn = 0;
80  CallsUnwindInit = 0;
81  VariableDbgInfo.clear();
82}
83
84/// AnalyzeModule - Scan the module for global debug information.
85///
86void MachineModuleInfo::AnalyzeModule(Module &M) {
87  // Insert functions in the llvm.used array (but not llvm.compiler.used) into
88  // UsedFunctions.
89  GlobalVariable *GV = M.getGlobalVariable("llvm.used");
90  if (!GV || !GV->hasInitializer()) return;
91
92  // Should be an array of 'i8*'.
93  ConstantArray *InitList = dyn_cast<ConstantArray>(GV->getInitializer());
94  if (InitList == 0) return;
95
96  for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
97    if (Function *F =
98          dyn_cast<Function>(InitList->getOperand(i)->stripPointerCasts()))
99      UsedFunctions.insert(F);
100}
101
102//===-EH-------------------------------------------------------------------===//
103
104/// getOrCreateLandingPadInfo - Find or create an LandingPadInfo for the
105/// specified MachineBasicBlock.
106LandingPadInfo &MachineModuleInfo::getOrCreateLandingPadInfo
107    (MachineBasicBlock *LandingPad) {
108  unsigned N = LandingPads.size();
109  for (unsigned i = 0; i < N; ++i) {
110    LandingPadInfo &LP = LandingPads[i];
111    if (LP.LandingPadBlock == LandingPad)
112      return LP;
113  }
114
115  LandingPads.push_back(LandingPadInfo(LandingPad));
116  return LandingPads[N];
117}
118
119/// addInvoke - Provide the begin and end labels of an invoke style call and
120/// associate it with a try landing pad block.
121void MachineModuleInfo::addInvoke(MachineBasicBlock *LandingPad,
122                                  unsigned BeginLabel, unsigned EndLabel) {
123  LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
124  LP.BeginLabels.push_back(BeginLabel);
125  LP.EndLabels.push_back(EndLabel);
126}
127
128/// addLandingPad - Provide the label of a try LandingPad block.
129///
130unsigned MachineModuleInfo::addLandingPad(MachineBasicBlock *LandingPad) {
131  unsigned LandingPadLabel = NextLabelID();
132  LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
133  LP.LandingPadLabel = LandingPadLabel;
134  return LandingPadLabel;
135}
136
137/// addPersonality - Provide the personality function for the exception
138/// information.
139void MachineModuleInfo::addPersonality(MachineBasicBlock *LandingPad,
140                                       Function *Personality) {
141  LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
142  LP.Personality = Personality;
143
144  for (unsigned i = 0; i < Personalities.size(); ++i)
145    if (Personalities[i] == Personality)
146      return;
147
148  // If this is the first personality we're adding go
149  // ahead and add it at the beginning.
150  if (Personalities[0] == NULL)
151    Personalities[0] = Personality;
152  else
153    Personalities.push_back(Personality);
154}
155
156/// addCatchTypeInfo - Provide the catch typeinfo for a landing pad.
157///
158void MachineModuleInfo::addCatchTypeInfo(MachineBasicBlock *LandingPad,
159                                        std::vector<GlobalVariable *> &TyInfo) {
160  LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
161  for (unsigned N = TyInfo.size(); N; --N)
162    LP.TypeIds.push_back(getTypeIDFor(TyInfo[N - 1]));
163}
164
165/// addFilterTypeInfo - Provide the filter typeinfo for a landing pad.
166///
167void MachineModuleInfo::addFilterTypeInfo(MachineBasicBlock *LandingPad,
168                                        std::vector<GlobalVariable *> &TyInfo) {
169  LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
170  std::vector<unsigned> IdsInFilter(TyInfo.size());
171  for (unsigned I = 0, E = TyInfo.size(); I != E; ++I)
172    IdsInFilter[I] = getTypeIDFor(TyInfo[I]);
173  LP.TypeIds.push_back(getFilterIDFor(IdsInFilter));
174}
175
176/// addCleanup - Add a cleanup action for a landing pad.
177///
178void MachineModuleInfo::addCleanup(MachineBasicBlock *LandingPad) {
179  LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
180  LP.TypeIds.push_back(0);
181}
182
183/// TidyLandingPads - Remap landing pad labels and remove any deleted landing
184/// pads.
185void MachineModuleInfo::TidyLandingPads() {
186  for (unsigned i = 0; i != LandingPads.size(); ) {
187    LandingPadInfo &LandingPad = LandingPads[i];
188    if (isLabelDeleted(LandingPad.LandingPadLabel))
189      LandingPad.LandingPadLabel = 0;
190
191    // Special case: we *should* emit LPs with null LP MBB. This indicates
192    // "nounwind" case.
193    if (!LandingPad.LandingPadLabel && LandingPad.LandingPadBlock) {
194      LandingPads.erase(LandingPads.begin() + i);
195      continue;
196    }
197
198    for (unsigned j=0; j != LandingPads[i].BeginLabels.size(); ) {
199      unsigned BeginLabel = LandingPad.BeginLabels[j];
200      unsigned EndLabel = LandingPad.EndLabels[j];
201      if (isLabelDeleted(BeginLabel) || isLabelDeleted(EndLabel)) {
202        LandingPad.BeginLabels.erase(LandingPad.BeginLabels.begin() + j);
203        LandingPad.EndLabels.erase(LandingPad.EndLabels.begin() + j);
204        continue;
205      }
206
207      ++j;
208    }
209
210    // Remove landing pads with no try-ranges.
211    if (LandingPads[i].BeginLabels.empty()) {
212      LandingPads.erase(LandingPads.begin() + i);
213      continue;
214    }
215
216    // If there is no landing pad, ensure that the list of typeids is empty.
217    // If the only typeid is a cleanup, this is the same as having no typeids.
218    if (!LandingPad.LandingPadBlock ||
219        (LandingPad.TypeIds.size() == 1 && !LandingPad.TypeIds[0]))
220      LandingPad.TypeIds.clear();
221
222    ++i;
223  }
224}
225
226/// getTypeIDFor - Return the type id for the specified typeinfo.  This is
227/// function wide.
228unsigned MachineModuleInfo::getTypeIDFor(GlobalVariable *TI) {
229  for (unsigned i = 0, N = TypeInfos.size(); i != N; ++i)
230    if (TypeInfos[i] == TI) return i + 1;
231
232  TypeInfos.push_back(TI);
233  return TypeInfos.size();
234}
235
236/// getFilterIDFor - Return the filter id for the specified typeinfos.  This is
237/// function wide.
238int MachineModuleInfo::getFilterIDFor(std::vector<unsigned> &TyIds) {
239  // If the new filter coincides with the tail of an existing filter, then
240  // re-use the existing filter.  Folding filters more than this requires
241  // re-ordering filters and/or their elements - probably not worth it.
242  for (std::vector<unsigned>::iterator I = FilterEnds.begin(),
243       E = FilterEnds.end(); I != E; ++I) {
244    unsigned i = *I, j = TyIds.size();
245
246    while (i && j)
247      if (FilterIds[--i] != TyIds[--j])
248        goto try_next;
249
250    if (!j)
251      // The new filter coincides with range [i, end) of the existing filter.
252      return -(1 + i);
253
254try_next:;
255  }
256
257  // Add the new filter.
258  int FilterID = -(1 + FilterIds.size());
259  FilterIds.reserve(FilterIds.size() + TyIds.size() + 1);
260  for (unsigned I = 0, N = TyIds.size(); I != N; ++I)
261    FilterIds.push_back(TyIds[I]);
262  FilterEnds.push_back(FilterIds.size());
263  FilterIds.push_back(0); // terminator
264  return FilterID;
265}
266
267/// getPersonality - Return the personality function for the current function.
268Function *MachineModuleInfo::getPersonality() const {
269  // FIXME: Until PR1414 will be fixed, we're using 1 personality function per
270  // function
271  return !LandingPads.empty() ? LandingPads[0].Personality : NULL;
272}
273
274/// getPersonalityIndex - Return unique index for current personality
275/// function. NULL/first personality function should always get zero index.
276unsigned MachineModuleInfo::getPersonalityIndex() const {
277  const Function* Personality = NULL;
278
279  // Scan landing pads. If there is at least one non-NULL personality - use it.
280  for (unsigned i = 0; i != LandingPads.size(); ++i)
281    if (LandingPads[i].Personality) {
282      Personality = LandingPads[i].Personality;
283      break;
284    }
285
286  for (unsigned i = 0; i < Personalities.size(); ++i) {
287    if (Personalities[i] == Personality)
288      return i;
289  }
290
291  // This will happen if the current personality function is
292  // in the zero index.
293  return 0;
294}
295
296