AsmPrinter.h revision 855a51974134e818232e52d63a2c3b2b48c8e244
1//===-- llvm/CodeGen/AsmPrinter.h - AsmPrinter Framework --------*- C++ -*-===// 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 class is intended to be used as a base class for target-specific 11// asmwriters. This class primarily takes care of printing global constants, 12// which are printed in a very similar way across all targets. 13// 14//===----------------------------------------------------------------------===// 15 16#ifndef LLVM_CODEGEN_ASMPRINTER_H 17#define LLVM_CODEGEN_ASMPRINTER_H 18 19#include "llvm/CodeGen/MachineFunctionPass.h" 20#include "llvm/Support/DataTypes.h" 21 22namespace llvm { 23 class Constant; 24 class Mangler; 25 26 class AsmPrinter : public MachineFunctionPass { 27 protected: 28 /// Output stream on which we're printing assembly code. 29 /// 30 std::ostream &O; 31 32 /// Target machine description. 33 /// 34 TargetMachine &TM; 35 36 /// Name-mangler for global names. 37 /// 38 Mangler *Mang; 39 40 /// Cache of mangled name for current function. This is recalculated at the 41 /// beginning of each call to runOnMachineFunction(). 42 /// 43 std::string CurrentFnName; 44 45 //===------------------------------------------------------------------===// 46 // Properties to be set by the derived class ctor, used to configure the 47 // asmwriter. 48 49 /// CommentString - This indicates the comment character used by the 50 /// assembler. 51 const char *CommentString; // Defaults to "#" 52 53 /// GlobalPrefix - If this is set to a non-empty string, it is prepended 54 /// onto all global symbols. This is often used for "_" or ".". 55 const char *GlobalPrefix; // Defaults to "" 56 57 /// GlobalVarAddrPrefix/Suffix - If these are nonempty, these strings 58 /// will enclose any GlobalVariable (that isn't a function) 59 /// 60 const char *GlobalVarAddrPrefix; // Defaults to "" 61 const char *GlobalVarAddrSuffix; // Defaults to "" 62 63 /// FunctionAddrPrefix/Suffix - If these are nonempty, these strings 64 /// will enclose any GlobalVariable that points to a function. 65 /// For example, this is used by the IA64 backend to materialize 66 /// function descriptors, by decorating the ".data8" object with the 67 /// @fptr( ) link-relocation operator. 68 /// 69 const char *FunctionAddrPrefix; // Defaults to "" 70 const char *FunctionAddrSuffix; // Defaults to "" 71 72 /// ZeroDirective - this should be set to the directive used to get some 73 /// number of zero bytes emitted to the current section. Common cases are 74 /// "\t.zero\t" and "\t.space\t". If this is set to null, the 75 /// Data*bitsDirective's will be used to emit zero bytes. 76 const char *ZeroDirective; // Defaults to "\t.zero\t" 77 78 /// AsciiDirective - This directive allows emission of an ascii string with 79 /// the standard C escape characters embedded into it. 80 const char *AsciiDirective; 81 82 /// DataDirectives - These directives are used to output some unit of 83 /// integer data to the current section. If a data directive is set to 84 /// null, smaller data directives will be used to emit the large sizes. 85 const char *Data8bitsDirective; // Defaults to "\t.byte\t" 86 const char *Data16bitsDirective; // Defaults to "\t.short\t" 87 const char *Data32bitsDirective; // Defaults to "\t.long\t" 88 const char *Data64bitsDirective; // Defaults to "\t.quad\t" 89 90 /// AlignDirective - The directive used to emit round up to an alignment 91 /// boundary. 92 /// 93 const char *AlignDirective; // Defaults to "\t.align\t" 94 95 /// AlignmentIsInBytes - If this is true (the default) then the asmprinter 96 /// emits ".align N" directives, where N is the number of bytes to align to. 97 /// Otherwise, it emits ".align log2(N)", e.g. 3 to align to an 8 byte 98 /// boundary. 99 bool AlignmentIsInBytes; // Defaults to true 100 101 AsmPrinter(std::ostream &o, TargetMachine &tm) 102 : O(o), TM(tm), 103 CommentString("#"), 104 GlobalPrefix(""), 105 GlobalVarAddrPrefix(""), 106 GlobalVarAddrSuffix(""), 107 FunctionAddrPrefix(""), 108 FunctionAddrSuffix(""), 109 ZeroDirective("\t.zero\t"), 110 AsciiDirective("\t.ascii\t"), 111 Data8bitsDirective("\t.byte\t"), 112 Data16bitsDirective("\t.short\t"), 113 Data32bitsDirective("\t.long\t"), 114 Data64bitsDirective("\t.quad\t"), 115 AlignDirective("\t.align\t"), 116 AlignmentIsInBytes(true) { 117 } 118 119 /// doInitialization - Set up the AsmPrinter when we are working on a new 120 /// module. If your pass overrides this, it must make sure to explicitly 121 /// call this implementation. 122 bool doInitialization(Module &M); 123 124 /// doFinalization - Shut down the asmprinter. If you override this in your 125 /// pass, you must make sure to call it explicitly. 126 bool doFinalization(Module &M); 127 128 /// setupMachineFunction - This should be called when a new MachineFunction 129 /// is being processed from runOnMachineFunction. 130 void setupMachineFunction(MachineFunction &MF); 131 132 /// emitAlignment - Emit an alignment directive to the specified power of 133 /// two boundary. For example, if you pass in 3 here, you will get an 8 134 /// byte alignment. 135 void emitAlignment(unsigned NumBits) const; 136 137 /// emitZeros - Emit a block of zeros. 138 /// 139 void emitZeros(uint64_t NumZeros) const; 140 141 /// emitConstantValueOnly - Print out the specified constant, without a 142 /// storage class. Only constants of first-class type are allowed here. 143 void emitConstantValueOnly(const Constant *CV); 144 145 /// emitGlobalConstant - Print a general LLVM constant to the .s file. 146 /// 147 void emitGlobalConstant(const Constant* CV); 148 }; 149} 150 151#endif 152