AsmPrinter.h revision 1da31ee472b9615d7329c656e2cc17c419ed7c95 
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 file contains a class to be used as the base class for target specific
11// asm writers.  This class primarily handles common functionality used by
12// all asm writers.
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 ConstantArray;
25  class GlobalVariable;
26  class MachineConstantPoolEntry;
27  class MachineConstantPoolValue;
28  class Mangler;
29  class TargetAsmInfo;
30
31
32  /// AsmPrinter - This class is intended to be used as a driving class for all
33  /// asm writers.
34  class AsmPrinter : public MachineFunctionPass {
35    /// FunctionNumber - This provides a unique ID for each function emitted in
36    /// this translation unit.  It is autoincremented by SetupMachineFunction,
37    /// and can be accessed with getFunctionNumber() and
38    /// IncrementFunctionNumber().
39    ///
40    unsigned FunctionNumber;
41
42  public:
43    /// Output stream on which we're printing assembly code.
44    ///
45    std::ostream &O;
46
47    /// Target machine description.
48    ///
49    TargetMachine &TM;
50
51    /// Target Asm Printer information.
52    ///
53    const TargetAsmInfo *TAI;
54
55    /// Name-mangler for global names.
56    ///
57    Mangler *Mang;
58
59    /// Cache of mangled name for current function. This is recalculated at the
60    /// beginning of each call to runOnMachineFunction().
61    ///
62    std::string CurrentFnName;
63
64    /// CurrentSection - The current section we are emitting to.  This is
65    /// controlled and used by the SwitchSection method.
66    std::string CurrentSection;
67
68  protected:
69    AsmPrinter(std::ostream &o, TargetMachine &TM, const TargetAsmInfo *T);
70
71  public:
72    /// SwitchToTextSection - Switch to the specified section of the executable
73    /// if we are not already in it!  If GV is non-null and if the global has an
74    /// explicitly requested section, we switch to the section indicated for the
75    /// global instead of NewSection.
76    ///
77    /// If the new section is an empty string, this method forgets what the
78    /// current section is, but does not emit a .section directive.
79    ///
80    /// This method is used when about to emit executable code.
81    ///
82    void SwitchToTextSection(const char *NewSection, const GlobalValue *GV);
83
84    /// SwitchToDataSection - Switch to the specified section of the executable
85    /// if we are not already in it!  If GV is non-null and if the global has an
86    /// explicitly requested section, we switch to the section indicated for the
87    /// global instead of NewSection.
88    ///
89    /// If the new section is an empty string, this method forgets what the
90    /// current section is, but does not emit a .section directive.
91    ///
92    /// This method is used when about to emit data.  For most assemblers, this
93    /// is the same as the SwitchToTextSection method, but not all assemblers
94    /// are the same.
95    ///
96    void SwitchToDataSection(const char *NewSection, const GlobalValue *GV);
97
98    /// getPreferredAlignmentLog - Return the preferred alignment of the
99    /// specified global, returned in log form.  This includes an explicitly
100    /// requested alignment (if the global has one).
101    unsigned getPreferredAlignmentLog(const GlobalVariable *GV) const;
102  protected:
103    /// doInitialization - Set up the AsmPrinter when we are working on a new
104    /// module.  If your pass overrides this, it must make sure to explicitly
105    /// call this implementation.
106    bool doInitialization(Module &M);
107
108    /// doFinalization - Shut down the asmprinter.  If you override this in your
109    /// pass, you must make sure to call it explicitly.
110    bool doFinalization(Module &M);
111
112    /// PrintSpecial - Print information related to the specified machine instr
113    /// that is independent of the operand, and may be independent of the instr
114    /// itself.  This can be useful for portably encoding the comment character
115    /// or other bits of target-specific knowledge into the asmstrings.  The
116    /// syntax used is ${:comment}.  Targets can override this to add support
117    /// for their own strange codes.
118    virtual void PrintSpecial(const MachineInstr *MI, const char *Code);
119
120    /// PrintAsmOperand - Print the specified operand of MI, an INLINEASM
121    /// instruction, using the specified assembler variant.  Targets should
122    /// override this to format as appropriate.  This method can return true if
123    /// the operand is erroneous.
124    virtual bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
125                                 unsigned AsmVariant, const char *ExtraCode);
126
127    /// PrintAsmMemoryOperand - Print the specified operand of MI, an INLINEASM
128    /// instruction, using the specified assembler variant as an address.
129    /// Targets should override this to format as appropriate.  This method can
130    /// return true if the operand is erroneous.
131    virtual bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
132                                       unsigned AsmVariant,
133                                       const char *ExtraCode);
134
135    /// getSectionForFunction - Return the section that we should emit the
136    /// specified function body into.  This defaults to 'TextSection'.  This
137    /// should most likely be overridden by the target to put linkonce/weak
138    /// functions into special sections.
139    virtual std::string getSectionForFunction(const Function &F) const;
140
141    /// SetupMachineFunction - This should be called when a new MachineFunction
142    /// is being processed from runOnMachineFunction.
143    void SetupMachineFunction(MachineFunction &MF);
144
145    /// getFunctionNumber - Return a unique ID for the current function.
146    ///
147    unsigned getFunctionNumber() const { return FunctionNumber; }
148
149    /// IncrementFunctionNumber - Increase Function Number.  AsmPrinters should
150    /// not normally call this, as the counter is automatically bumped by
151    /// SetupMachineFunction.
152    void IncrementFunctionNumber() { FunctionNumber++; }
153
154    /// EmitConstantPool - Print to the current output stream assembly
155    /// representations of the constants in the constant pool MCP. This is
156    /// used to print out constants which have been "spilled to memory" by
157    /// the code generator.
158    ///
159    void EmitConstantPool(MachineConstantPool *MCP);
160
161    /// EmitJumpTableInfo - Print assembly representations of the jump tables
162    /// used by the current function to the current output stream.
163    ///
164    void EmitJumpTableInfo(MachineJumpTableInfo *MJTI, MachineFunction &MF);
165
166    /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
167    /// special global used by LLVM.  If so, emit it and return true, otherwise
168    /// do nothing and return false.
169    bool EmitSpecialLLVMGlobal(const GlobalVariable *GV);
170
171    /// EmitAlignment - Emit an alignment directive to the specified power of
172    /// two boundary.  For example, if you pass in 3 here, you will get an 8
173    /// byte alignment.  If a global value is specified, and if that global has
174    /// an explicit alignment requested, it will override the alignment request.
175    void EmitAlignment(unsigned NumBits, const GlobalValue *GV = 0) const;
176
177    /// EmitZeros - Emit a block of zeros.
178    ///
179    void EmitZeros(uint64_t NumZeros) const;
180
181    /// EmitString - Emit a zero-byte-terminated string constant.
182    ///
183    virtual void EmitString(const ConstantArray *CVA) const;
184
185    /// EmitConstantValueOnly - Print out the specified constant, without a
186    /// storage class.  Only constants of first-class type are allowed here.
187    void EmitConstantValueOnly(const Constant *CV);
188
189    /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
190    ///
191    void EmitGlobalConstant(const Constant* CV);
192
193    virtual void EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV);
194
195    /// printInlineAsm - This method formats and prints the specified machine
196    /// instruction that is an inline asm.
197    void printInlineAsm(const MachineInstr *MI) const;
198
199    /// printBasicBlockLabel - This method prints the label for the specified
200    /// MachineBasicBlock
201    virtual void printBasicBlockLabel(const MachineBasicBlock *MBB,
202                                      bool printColon = false,
203                                      bool printComment = true) const;
204
205    /// printSetLabel - This method prints a set label for the specified
206    /// MachineBasicBlock
207    void printSetLabel(unsigned uid, const MachineBasicBlock *MBB) const;
208
209    /// printDataDirective - This method prints the asm directive for the
210    /// specified type.
211    void printDataDirective(const Type *type);
212
213  private:
214    void EmitLLVMUsedList(Constant *List);
215    void EmitXXStructorList(Constant *List);
216    void EmitConstantPool(unsigned Alignment, const char *Section,
217                std::vector<std::pair<MachineConstantPoolEntry,unsigned> > &CP);
218
219  };
220}
221
222#endif
223