LLVM API Documentation

InlineAsm.h

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00001 //===-- llvm/InlineAsm.h - Class to represent inline asm strings-*- C++ -*-===//
00002 //
00003 //                     The LLVM Compiler Infrastructure
00004 //
00005 // This file was developed by Chris Lattner and is distributed under
00006 // the University of Illinois Open Source License. See LICENSE.TXT for details.
00007 //
00008 //===----------------------------------------------------------------------===//
00009 //
00010 // This class represents the inline asm strings, which are Value*'s that are
00011 // used as the callee operand of call instructions.  InlineAsm's are uniqued
00012 // like constants, and created via InlineAsm::get(...).
00013 //
00014 //===----------------------------------------------------------------------===//
00015 
00016 #ifndef LLVM_INLINEASM_H
00017 #define LLVM_INLINEASM_H
00018 
00019 #include "llvm/Value.h"
00020 #include "llvm/System/IncludeFile.h"
00021 #include <vector>
00022 
00023 namespace llvm {
00024 
00025 struct AssemblyAnnotationWriter;
00026 class PointerType;
00027 class FunctionType;
00028 class Module;
00029 
00030 class InlineAsm : public Value {
00031   InlineAsm(const InlineAsm &);             // do not implement
00032   void operator=(const InlineAsm&);         // do not implement
00033 
00034   std::string AsmString, Constraints;
00035   bool HasSideEffects;
00036   
00037   InlineAsm(const FunctionType *Ty, const std::string &AsmString,
00038             const std::string &Constraints, bool hasSideEffects);
00039   virtual ~InlineAsm();
00040 public:
00041 
00042   /// InlineAsm::get - Return the the specified uniqued inline asm string.
00043   ///
00044   static InlineAsm *get(const FunctionType *Ty, const std::string &AsmString,
00045                         const std::string &Constraints, bool hasSideEffects);
00046   
00047   bool hasSideEffects() const { return HasSideEffects; }
00048   
00049   /// getType - InlineAsm's are always pointers.
00050   ///
00051   const PointerType *getType() const {
00052     return reinterpret_cast<const PointerType*>(Value::getType());
00053   }
00054   
00055   /// getFunctionType - InlineAsm's are always pointers to functions.
00056   ///
00057   const FunctionType *getFunctionType() const;
00058   
00059   const std::string &getAsmString() const { return AsmString; }
00060   const std::string &getConstraintString() const { return Constraints; }
00061 
00062   virtual void print(std::ostream &O) const { print(O, 0); }
00063   void print(std::ostream &OS, AssemblyAnnotationWriter *AAW) const;
00064 
00065   /// Verify - This static method can be used by the parser to check to see if
00066   /// the specified constraint string is legal for the type.  This returns true
00067   /// if legal, false if not.
00068   ///
00069   static bool Verify(const FunctionType *Ty, const std::string &Constraints);
00070 
00071   // Constraint String Parsing 
00072   enum ConstraintPrefix {
00073     isInput,            // 'x'
00074     isOutput,           // '=x'
00075     isClobber           // '~x'
00076   };
00077   
00078   struct ConstraintInfo {
00079     /// Type - The basic type of the constraint: input/output/clobber
00080     ///
00081     ConstraintPrefix Type;
00082     
00083     /// isEarlyClobber - "&": output operand writes result before inputs are all
00084     /// read.  This is only ever set for an output operand.
00085     bool isEarlyClobber; 
00086     
00087     /// isIndirectOutput - If this is true for an output constraint, the address
00088     /// to store the output result is passed as an operand to the call.
00089     bool isIndirectOutput;
00090     
00091     /// hasMatchingInput - This is set to true for an output constraint iff
00092     /// there is an input constraint that is required to match it (e.g. "0").
00093     bool hasMatchingInput;
00094     
00095     /// isCommutative - This is set to true for a constraint that is commutative
00096     /// with the next operand.
00097     bool isCommutative;
00098     
00099     /// Code - The constraint code, either the register name (in braces) or the
00100     /// constraint letter/number.
00101     std::vector<std::string> Codes;
00102     
00103     /// Parse - Analyze the specified string (e.g. "==&{eax}") and fill in the
00104     /// fields in this structure.  If the constraint string is not understood,
00105     /// return true, otherwise return false.
00106     bool Parse(const std::string &Str, 
00107                std::vector<InlineAsm::ConstraintInfo> &ConstraintsSoFar);
00108   };
00109   
00110   /// ParseConstraints - Split up the constraint string into the specific
00111   /// constraints and their prefixes.  If this returns an empty vector, and if
00112   /// the constraint string itself isn't empty, there was an error parsing.
00113   static std::vector<ConstraintInfo> 
00114     ParseConstraints(const std::string &ConstraintString);
00115   
00116   /// ParseConstraints - Parse the constraints of this inlineasm object, 
00117   /// returning them the same way that ParseConstraints(str) does.
00118   std::vector<ConstraintInfo> 
00119   ParseConstraints() const {
00120     return ParseConstraints(Constraints);
00121   }
00122   
00123   // Methods for support type inquiry through isa, cast, and dyn_cast:
00124   static inline bool classof(const InlineAsm *) { return true; }
00125   static inline bool classof(const Value *V) {
00126     return V->getValueType() == Value::InlineAsmVal;
00127   }
00128 };
00129 
00130 } // End llvm namespace
00131 
00132 // Make sure the InlineAsm.cpp file is linked when this one is #included.
00133 FORCE_DEFINING_FILE_TO_BE_LINKED(InlineAsm)
00134 
00135 #endif