FindUsedTypes.cpp revision b576c94c15af9a440f69d9d03c2afead7971118c 
1//===- FindUsedTypes.cpp - Find all Types used by a module ----------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file was developed by the LLVM research group and is distributed under
6// the University of Illinois Open Source License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This pass is used to seek out all of the types in use by the program.
11//
12//===----------------------------------------------------------------------===//
13
14#include "llvm/Analysis/FindUsedTypes.h"
15#include "llvm/Assembly/CachedWriter.h"
16#include "llvm/SymbolTable.h"
17#include "llvm/DerivedTypes.h"
18#include "llvm/Module.h"
19#include "llvm/Support/InstIterator.h"
20
21static RegisterAnalysis<FindUsedTypes>
22X("printusedtypes", "Find Used Types");
23
24// stub to help linkage
25void FindUsedTypes::stub() {}
26
27// IncorporateType - Incorporate one type and all of its subtypes into the
28// collection of used types.
29//
30void FindUsedTypes::IncorporateType(const Type *Ty) {
31  if (UsedTypes.count(Ty)) return;  // Already contain Ty.
32
33  // If ty doesn't already exist in the used types map, add it now.
34  //
35  UsedTypes.insert(Ty);
36
37  // Make sure to add any types this type references now.
38  //
39  for (Type::subtype_iterator I = Ty->subtype_begin(), E = Ty->subtype_end();
40       I != E; ++I)
41    IncorporateType(*I);
42}
43
44
45// run - This incorporates all types used by the specified module
46//
47bool FindUsedTypes::run(Module &m) {
48  UsedTypes.clear();  // reset if run multiple times...
49
50  // Loop over global variables, incorporating their types
51  for (Module::const_giterator I = m.gbegin(), E = m.gend(); I != E; ++I)
52    IncorporateType(I->getType());
53
54  for (Module::iterator MI = m.begin(), ME = m.end(); MI != ME; ++MI) {
55    IncorporateType(MI->getType());
56    const Function &F = *MI;
57
58    // Loop over all of the instructions in the function, adding their return
59    // type as well as the types of their operands.
60    //
61    for (const_inst_iterator II = inst_begin(F), IE = inst_end(F);
62         II != IE; ++II) {
63      const Instruction *I = *II;
64      const Type *Ty = I->getType();
65
66      IncorporateType(Ty);  // Incorporate the type of the instruction
67      for (User::const_op_iterator OI = I->op_begin(), OE = I->op_end();
68           OI != OE; ++OI)
69        if ((*OI)->getType() != Ty)         // Avoid set lookup in common case
70          IncorporateType((*OI)->getType());// Insert inst operand types as well
71    }
72  }
73
74  return false;
75}
76
77// Print the types found in the module.  If the optional Module parameter is
78// passed in, then the types are printed symbolically if possible, using the
79// symbol table from the module.
80//
81void FindUsedTypes::print(std::ostream &o, const Module *M) const {
82  o << "Types in use by this module:\n";
83  if (M) {
84    CachedWriter CW(M, o);
85    for (std::set<const Type *>::const_iterator I = UsedTypes.begin(),
86           E = UsedTypes.end(); I != E; ++I)
87      CW << "  " << *I << "\n";
88  } else
89    for (std::set<const Type *>::const_iterator I = UsedTypes.begin(),
90           E = UsedTypes.end(); I != E; ++I)
91      o << "  " << *I << "\n";
92}
93