lib/Analysis/IPA/FindUsedTypes.cpp

   1 //===- FindUsedTypes.cpp - Find all Types used by a module ----------------===//
   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 // This pass is used to seek out all of the types in use by the program.  Note
  11 // that this analysis explicitly does not include types only used by the symbol
  12 // table.
  13 //
  14 //===----------------------------------------------------------------------===//
  15
  16 #include "llvm/Analysis/FindUsedTypes.h"
  17 #include "llvm/Constants.h"
  18 #include "llvm/DerivedTypes.h"
  19 #include "llvm/Module.h"
  20 #include "llvm/Assembly/Writer.h"
  21 #include "llvm/Support/InstIterator.h"
  22 #include "llvm/Support/raw_ostream.h"
  23 using namespace llvm;
  24
  25 char FindUsedTypes::ID = 0;
  26 INITIALIZE_PASS(FindUsedTypes, "print-used-types",
  27                 "Find Used Types", false, true)
  28
  29 // IncorporateType - Incorporate one type and all of its subtypes into the
  30 // collection of used types.
  31 //
  32 void FindUsedTypes::IncorporateType(const Type *Ty) {
  33   // If ty doesn't already exist in the used types map, add it now, otherwise
  34   // return.
  35   if (!UsedTypes.insert(Ty).second) return;  // Already contain 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 void FindUsedTypes::IncorporateValue(const Value *V) {
  45   IncorporateType(V->getType());
  46
  47   // If this is a constant, it could be using other types...
  48   if (const Constant *C = dyn_cast<Constant>(V)) {
  49     if (!isa<GlobalValue>(C))
  50       for (User::const_op_iterator OI = C->op_begin(), OE = C->op_end();
  51            OI != OE; ++OI)
  52         IncorporateValue(*OI);
  53   }
  54 }
  55
  56
  57 // run - This incorporates all types used by the specified module
  58 //
  59 bool FindUsedTypes::runOnModule(Module &m) {
  60   UsedTypes.clear();  // reset if run multiple times...
  61
  62   // Loop over global variables, incorporating their types
  63   for (Module::const_global_iterator I = m.global_begin(), E = m.global_end();
  64        I != E; ++I) {
  65     IncorporateType(I->getType());
  66     if (I->hasInitializer())
  67       IncorporateValue(I->getInitializer());
  68   }
  69
  70   for (Module::iterator MI = m.begin(), ME = m.end(); MI != ME; ++MI) {
  71     IncorporateType(MI->getType());
  72     const Function &F = *MI;
  73
  74     // Loop over all of the instructions in the function, adding their return
  75     // type as well as the types of their operands.
  76     //
  77     for (const_inst_iterator II = inst_begin(F), IE = inst_end(F);
  78          II != IE; ++II) {
  79       const Instruction &I = *II;
  80
  81       IncorporateType(I.getType());  // Incorporate the type of the instruction
  82       for (User::const_op_iterator OI = I.op_begin(), OE = I.op_end();
  83            OI != OE; ++OI)
  84         IncorporateValue(*OI);  // Insert inst operand types as well
  85     }
  86   }
  87
  88   return false;
  89 }
  90
  91 // Print the types found in the module.  If the optional Module parameter is
  92 // passed in, then the types are printed symbolically if possible, using the
  93 // symbol table from the module.
  94 //
  95 void FindUsedTypes::print(raw_ostream &OS, const Module *M) const {
  96   OS << "Types in use by this module:\n";
  97   for (std::set<const Type *>::const_iterator I = UsedTypes.begin(),
  98        E = UsedTypes.end(); I != E; ++I) {
  99     OS << "   ";
 100     WriteTypeSymbolic(OS, *I, M);
 101     OS << '\n';
 102   }
 103 }