lib/VMCore/IntrinsicInst.cpp

   1 //===-- InstrinsicInst.cpp - Intrinsic Instruction Wrappers -----*- C++ -*-===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file was developed by James M. Laskey and is distributed under
   6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file implements methods that make it really easy to deal with intrinsic
  11 // functions with the isa/dyncast family of functions.  In particular, this
  12 // allows you to do things like:
  13 //
  14 //     if (DbgStopPointInst *SPI = dyn_cast<DbgStopPointInst>(Inst))
  15 //        ... SPI->getFileName() ... SPI->getDirectory() ...
  16 //
  17 // All intrinsic function calls are instances of the call instruction, so these
  18 // are all subclasses of the CallInst class.  Note that none of these classes
  19 // has state or virtual methods, which is an important part of this gross/neat
  20 // hack working.
  21 //
  22 // In some cases, arguments to intrinsics need to be generic and are defined as
  23 // type pointer to empty struct { }*.  To access the real item of interest the
  24 // cast instruction needs to be stripped away.
  25 //
  26 //===----------------------------------------------------------------------===//
  27
  28 #include "llvm/IntrinsicInst.h"
  29 #include "llvm/Constants.h"
  30 #include "llvm/GlobalVariable.h"
  31 #include "llvm/CodeGen/MachineModuleInfo.h"
  32 using namespace llvm;
  33
  34 //===----------------------------------------------------------------------===//
  35 /// DbgInfoIntrinsic - This is the common base class for debug info intrinsics
  36 ///
  37
  38 static Value *CastOperand(Value *C) {
  39   if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C))
  40     if (CE->isCast())
  41       return CE->getOperand(0);
  42   return NULL;
  43 }
  44
  45 Value *DbgInfoIntrinsic::StripCast(Value *C) {
  46   if (Value *CO = CastOperand(C)) {
  47     C = StripCast(CO);
  48   } else if (GlobalVariable *GV = dyn_cast<GlobalVariable>(C)) {
  49     if (GV->hasInitializer())
  50       if (Value *CO = CastOperand(GV->getInitializer()))
  51         C = StripCast(CO);
  52   }
  53   return dyn_cast<GlobalVariable>(C);
  54 }
  55
  56 //===----------------------------------------------------------------------===//
  57 /// DbgStopPointInst - This represents the llvm.dbg.stoppoint instruction.
  58 ///
  59
  60 std::string DbgStopPointInst::getFileName() const {
  61   // Once the operand indices are verified, update this assert
  62   assert(LLVMDebugVersion == (6 << 16) && "Verify operand indices");
  63   GlobalVariable *GV = cast<GlobalVariable>(getContext());
  64   if (!GV->hasInitializer()) return "";
  65   ConstantStruct *CS = cast<ConstantStruct>(GV->getInitializer());
  66   return CS->getOperand(3)->getStringValue();
  67 }
  68
  69 std::string DbgStopPointInst::getDirectory() const {
  70   // Once the operand indices are verified, update this assert
  71   assert(LLVMDebugVersion == (6 << 16) && "Verify operand indices");
  72   GlobalVariable *GV = cast<GlobalVariable>(getContext());
  73   if (!GV->hasInitializer()) return "";
  74   ConstantStruct *CS = cast<ConstantStruct>(GV->getInitializer());
  75   return CS->getOperand(4)->getStringValue();
  76 }
  77
  78 //===----------------------------------------------------------------------===//
  79 /// Ensure that users of IntrinsicInst.h will link with this module.
  80 DEFINING_FILE_FOR(IntrinsicInst)