MachineModuleInfo.cpp revision 1db5d985d6cc883ad90073f979c483aa7c1b8955 
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, CallsEHReturn(0)
44, CallsUnwindInit(0)
45, DbgInfoAvailable(false) {
46  // Always emit some info, by default "no personality" info.
47  Personalities.push_back(NULL);
48}
49
50MachineModuleInfo::~MachineModuleInfo() {
51  delete ObjFileMMI;
52}
53
54/// doInitialization - Initialize the state for a new module.
55///
56bool MachineModuleInfo::doInitialization() {
57  return false;
58}
59
60/// doFinalization - Tear down the state after completion of a module.
61///
62bool MachineModuleInfo::doFinalization() {
63  return false;
64}
65
66/// EndFunction - Discard function meta information.
67///
68void MachineModuleInfo::EndFunction() {
69  // Clean up frame info.
70  FrameMoves.clear();
71
72  // Clean up exception info.
73  LandingPads.clear();
74  CallSiteMap.clear();
75  TypeInfos.clear();
76  FilterIds.clear();
77  FilterEnds.clear();
78  CallsEHReturn = 0;
79  CallsUnwindInit = 0;
80  VariableDbgInfo.clear();
81}
82
83/// AnalyzeModule - Scan the module for global debug information.
84///
85void MachineModuleInfo::AnalyzeModule(Module &M) {
86  // Insert functions in the llvm.used array (but not llvm.compiler.used) into
87  // UsedFunctions.
88  GlobalVariable *GV = M.getGlobalVariable("llvm.used");
89  if (!GV || !GV->hasInitializer()) return;
90
91  // Should be an array of 'i8*'.
92  ConstantArray *InitList = dyn_cast<ConstantArray>(GV->getInitializer());
93  if (InitList == 0) return;
94
95  for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
96    if (Function *F =
97          dyn_cast<Function>(InitList->getOperand(i)->stripPointerCasts()))
98      UsedFunctions.insert(F);
99}
100
101//===-EH-------------------------------------------------------------------===//
102
103/// getOrCreateLandingPadInfo - Find or create an LandingPadInfo for the
104/// specified MachineBasicBlock.
105LandingPadInfo &MachineModuleInfo::getOrCreateLandingPadInfo
106    (MachineBasicBlock *LandingPad) {
107  unsigned N = LandingPads.size();
108  for (unsigned i = 0; i < N; ++i) {
109    LandingPadInfo &LP = LandingPads[i];
110    if (LP.LandingPadBlock == LandingPad)
111      return LP;
112  }
113
114  LandingPads.push_back(LandingPadInfo(LandingPad));
115  return LandingPads[N];
116}
117
118/// addInvoke - Provide the begin and end labels of an invoke style call and
119/// associate it with a try landing pad block.
120void MachineModuleInfo::addInvoke(MachineBasicBlock *LandingPad,
121                                  unsigned BeginLabel, unsigned EndLabel) {
122  LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
123  LP.BeginLabels.push_back(BeginLabel);
124  LP.EndLabels.push_back(EndLabel);
125}
126
127/// addLandingPad - Provide the label of a try LandingPad block.
128///
129unsigned MachineModuleInfo::addLandingPad(MachineBasicBlock *LandingPad) {
130  unsigned LandingPadLabel = NextLabelID();
131  LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
132  LP.LandingPadLabel = LandingPadLabel;
133  return LandingPadLabel;
134}
135
136/// addPersonality - Provide the personality function for the exception
137/// information.
138void MachineModuleInfo::addPersonality(MachineBasicBlock *LandingPad,
139                                       Function *Personality) {
140  LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
141  LP.Personality = Personality;
142
143  for (unsigned i = 0; i < Personalities.size(); ++i)
144    if (Personalities[i] == Personality)
145      return;
146
147  // If this is the first personality we're adding go
148  // ahead and add it at the beginning.
149  if (Personalities[0] == NULL)
150    Personalities[0] = Personality;
151  else
152    Personalities.push_back(Personality);
153}
154
155/// addCatchTypeInfo - Provide the catch typeinfo for a landing pad.
156///
157void MachineModuleInfo::addCatchTypeInfo(MachineBasicBlock *LandingPad,
158                                        std::vector<GlobalVariable *> &TyInfo) {
159  LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
160  for (unsigned N = TyInfo.size(); N; --N)
161    LP.TypeIds.push_back(getTypeIDFor(TyInfo[N - 1]));
162}
163
164/// addFilterTypeInfo - Provide the filter typeinfo for a landing pad.
165///
166void MachineModuleInfo::addFilterTypeInfo(MachineBasicBlock *LandingPad,
167                                        std::vector<GlobalVariable *> &TyInfo) {
168  LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
169  std::vector<unsigned> IdsInFilter(TyInfo.size());
170  for (unsigned I = 0, E = TyInfo.size(); I != E; ++I)
171    IdsInFilter[I] = getTypeIDFor(TyInfo[I]);
172  LP.TypeIds.push_back(getFilterIDFor(IdsInFilter));
173}
174
175/// addCleanup - Add a cleanup action for a landing pad.
176///
177void MachineModuleInfo::addCleanup(MachineBasicBlock *LandingPad) {
178  LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad);
179  LP.TypeIds.push_back(0);
180}
181
182/// TidyLandingPads - Remap landing pad labels and remove any deleted landing
183/// pads.
184void MachineModuleInfo::TidyLandingPads() {
185  for (unsigned i = 0; i != LandingPads.size(); ) {
186    LandingPadInfo &LandingPad = LandingPads[i];
187    LandingPad.LandingPadLabel = MappedLabel(LandingPad.LandingPadLabel);
188
189    // Special case: we *should* emit LPs with null LP MBB. This indicates
190    // "nounwind" case.
191    if (!LandingPad.LandingPadLabel && LandingPad.LandingPadBlock) {
192      LandingPads.erase(LandingPads.begin() + i);
193      continue;
194    }
195
196    for (unsigned j=0; j != LandingPads[i].BeginLabels.size(); ) {
197      unsigned BeginLabel = MappedLabel(LandingPad.BeginLabels[j]);
198      unsigned EndLabel = MappedLabel(LandingPad.EndLabels[j]);
199
200      if (!BeginLabel || !EndLabel) {
201        LandingPad.BeginLabels.erase(LandingPad.BeginLabels.begin() + j);
202        LandingPad.EndLabels.erase(LandingPad.EndLabels.begin() + j);
203        continue;
204      }
205
206      LandingPad.BeginLabels[j] = BeginLabel;
207      LandingPad.EndLabels[j] = EndLabel;
208      ++j;
209    }
210
211    // Remove landing pads with no try-ranges.
212    if (LandingPads[i].BeginLabels.empty()) {
213      LandingPads.erase(LandingPads.begin() + i);
214      continue;
215    }
216
217    // If there is no landing pad, ensure that the list of typeids is empty.
218    // If the only typeid is a cleanup, this is the same as having no typeids.
219    if (!LandingPad.LandingPadBlock ||
220        (LandingPad.TypeIds.size() == 1 && !LandingPad.TypeIds[0]))
221      LandingPad.TypeIds.clear();
222
223    ++i;
224  }
225}
226
227/// getTypeIDFor - Return the type id for the specified typeinfo.  This is
228/// function wide.
229unsigned MachineModuleInfo::getTypeIDFor(GlobalVariable *TI) {
230  for (unsigned i = 0, N = TypeInfos.size(); i != N; ++i)
231    if (TypeInfos[i] == TI) return i + 1;
232
233  TypeInfos.push_back(TI);
234  return TypeInfos.size();
235}
236
237/// getFilterIDFor - Return the filter id for the specified typeinfos.  This is
238/// function wide.
239int MachineModuleInfo::getFilterIDFor(std::vector<unsigned> &TyIds) {
240  // If the new filter coincides with the tail of an existing filter, then
241  // re-use the existing filter.  Folding filters more than this requires
242  // re-ordering filters and/or their elements - probably not worth it.
243  for (std::vector<unsigned>::iterator I = FilterEnds.begin(),
244       E = FilterEnds.end(); I != E; ++I) {
245    unsigned i = *I, j = TyIds.size();
246
247    while (i && j)
248      if (FilterIds[--i] != TyIds[--j])
249        goto try_next;
250
251    if (!j)
252      // The new filter coincides with range [i, end) of the existing filter.
253      return -(1 + i);
254
255try_next:;
256  }
257
258  // Add the new filter.
259  int FilterID = -(1 + FilterIds.size());
260  FilterIds.reserve(FilterIds.size() + TyIds.size() + 1);
261  for (unsigned I = 0, N = TyIds.size(); I != N; ++I)
262    FilterIds.push_back(TyIds[I]);
263  FilterEnds.push_back(FilterIds.size());
264  FilterIds.push_back(0); // terminator
265  return FilterID;
266}
267
268/// getPersonality - Return the personality function for the current function.
269Function *MachineModuleInfo::getPersonality() const {
270  // FIXME: Until PR1414 will be fixed, we're using 1 personality function per
271  // function
272  return !LandingPads.empty() ? LandingPads[0].Personality : NULL;
273}
274
275/// getPersonalityIndex - Return unique index for current personality
276/// function. NULL/first personality function should always get zero index.
277unsigned MachineModuleInfo::getPersonalityIndex() const {
278  const Function* Personality = NULL;
279
280  // Scan landing pads. If there is at least one non-NULL personality - use it.
281  for (unsigned i = 0; i != LandingPads.size(); ++i)
282    if (LandingPads[i].Personality) {
283      Personality = LandingPads[i].Personality;
284      break;
285    }
286
287  for (unsigned i = 0; i < Personalities.size(); ++i) {
288    if (Personalities[i] == Personality)
289      return i;
290  }
291
292  // This will happen if the current personality function is
293  // in the zero index.
294  return 0;
295}
296
297