MachineModuleInfo.cpp revision 4489414d44a8621632e5e97253055452b2c66382 
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"
28using namespace llvm;
29using namespace llvm::dwarf;
30
31// Handle the Pass registration stuff necessary to use TargetData's.
32static RegisterPass<MachineModuleInfo>
33X("machinemoduleinfo", "Machine Module Information");
34char MachineModuleInfo::ID = 0;
35
36// Out of line virtual method.
37MachineModuleInfoImpl::~MachineModuleInfoImpl() {}
38
39//===----------------------------------------------------------------------===//
40
41MachineModuleInfo::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
49MachineModuleInfo::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
56MachineModuleInfo::~MachineModuleInfo() {
57  delete ObjFileMMI;
58}
59
60/// doInitialization - Initialize the state for a new module.
61///
62bool MachineModuleInfo::doInitialization() {
63  return false;
64}
65
66/// doFinalization - Tear down the state after completion of a module.
67///
68bool MachineModuleInfo::doFinalization() {
69  return false;
70}
71
72/// EndFunction - Discard function meta information.
73///
74void 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///
91void 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.
110MCSymbol *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.
123LandingPadInfo &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.
138void 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///
147MCSymbol *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.
156void 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///
175void 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///
184void 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///
195void 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.
202void 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.
242unsigned 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.
252int 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
268try_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.
282Function *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.
290unsigned 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