1 //===-- llvm/CodeGen/AsmPrinter.h - AsmPrinter Framework --------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
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.
8 //===----------------------------------------------------------------------===//
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
14 //===----------------------------------------------------------------------===//
16 #ifndef LLVM_CODEGEN_ASMPRINTER_H
17 #define LLVM_CODEGEN_ASMPRINTER_H
19 #include "llvm/CodeGen/MachineFunctionPass.h"
20 #include "llvm/Support/DataTypes.h"
28 class MachineConstantPoolEntry;
29 class MachineConstantPoolValue;
34 /// AsmPrinter - This class is intended to be used as a driving class for all
36 class AsmPrinter : public MachineFunctionPass {
39 /// FunctionNumber - This provides a unique ID for each function emitted in
40 /// this translation unit. It is autoincremented by SetupMachineFunction,
41 /// and can be accessed with getFunctionNumber() and
42 /// IncrementFunctionNumber().
44 unsigned FunctionNumber;
47 // Necessary for external weak linkage support
48 std::set<const GlobalValue*> ExtWeakSymbols;
51 /// Output stream on which we're printing assembly code.
55 /// Target machine description.
59 /// Target Asm Printer information.
61 const TargetAsmInfo *TAI;
63 /// Name-mangler for global names.
67 /// Cache of mangled name for current function. This is recalculated at the
68 /// beginning of each call to runOnMachineFunction().
70 std::string CurrentFnName;
72 /// CurrentSection - The current section we are emitting to. This is
73 /// controlled and used by the SwitchSection method.
74 std::string CurrentSection;
77 AsmPrinter(std::ostream &o, TargetMachine &TM, const TargetAsmInfo *T);
80 /// SwitchToTextSection - Switch to the specified section of the executable
81 /// if we are not already in it! If GV is non-null and if the global has an
82 /// explicitly requested section, we switch to the section indicated for the
83 /// global instead of NewSection.
85 /// If the new section is an empty string, this method forgets what the
86 /// current section is, but does not emit a .section directive.
88 /// This method is used when about to emit executable code.
90 void SwitchToTextSection(const char *NewSection, const GlobalValue *GV = NULL);
92 /// SwitchToDataSection - Switch to the specified section of the executable
93 /// if we are not already in it! If GV is non-null and if the global has an
94 /// explicitly requested section, we switch to the section indicated for the
95 /// global instead of NewSection.
97 /// If the new section is an empty string, this method forgets what the
98 /// current section is, but does not emit a .section directive.
100 /// This method is used when about to emit data. For most assemblers, this
101 /// is the same as the SwitchToTextSection method, but not all assemblers
104 void SwitchToDataSection(const char *NewSection, const GlobalValue *GV = NULL);
106 /// getGlobalLinkName - Returns the asm/link name of of the specified
107 /// global variable. Should be overridden by each target asm printer to
108 /// generate the appropriate value.
109 virtual const std::string getGlobalLinkName(const GlobalVariable *GV) const;
111 /// EmitExternalGlobal - Emit the external reference to a global variable.
112 /// Should be overridden if an indirect reference should be used.
113 virtual void EmitExternalGlobal(const GlobalVariable *GV);
116 /// doInitialization - Set up the AsmPrinter when we are working on a new
117 /// module. If your pass overrides this, it must make sure to explicitly
118 /// call this implementation.
119 bool doInitialization(Module &M);
121 /// doFinalization - Shut down the asmprinter. If you override this in your
122 /// pass, you must make sure to call it explicitly.
123 bool doFinalization(Module &M);
125 /// PrintSpecial - Print information related to the specified machine instr
126 /// that is independent of the operand, and may be independent of the instr
127 /// itself. This can be useful for portably encoding the comment character
128 /// or other bits of target-specific knowledge into the asmstrings. The
129 /// syntax used is ${:comment}. Targets can override this to add support
130 /// for their own strange codes.
131 virtual void PrintSpecial(const MachineInstr *MI, const char *Code);
133 /// PrintAsmOperand - Print the specified operand of MI, an INLINEASM
134 /// instruction, using the specified assembler variant. Targets should
135 /// override this to format as appropriate. This method can return true if
136 /// the operand is erroneous.
137 virtual bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
138 unsigned AsmVariant, const char *ExtraCode);
140 /// PrintAsmMemoryOperand - Print the specified operand of MI, an INLINEASM
141 /// instruction, using the specified assembler variant as an address.
142 /// Targets should override this to format as appropriate. This method can
143 /// return true if the operand is erroneous.
144 virtual bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
146 const char *ExtraCode);
148 /// getSectionForFunction - Return the section that we should emit the
149 /// specified function body into. This defaults to 'TextSection'. This
150 /// should most likely be overridden by the target to put linkonce/weak
151 /// functions into special sections.
152 virtual std::string getSectionForFunction(const Function &F) const;
154 /// SetupMachineFunction - This should be called when a new MachineFunction
155 /// is being processed from runOnMachineFunction.
156 void SetupMachineFunction(MachineFunction &MF);
158 /// getFunctionNumber - Return a unique ID for the current function.
160 unsigned getFunctionNumber() const { return FunctionNumber; }
162 /// IncrementFunctionNumber - Increase Function Number. AsmPrinters should
163 /// not normally call this, as the counter is automatically bumped by
164 /// SetupMachineFunction.
165 void IncrementFunctionNumber() { FunctionNumber++; }
167 /// EmitConstantPool - Print to the current output stream assembly
168 /// representations of the constants in the constant pool MCP. This is
169 /// used to print out constants which have been "spilled to memory" by
170 /// the code generator.
172 void EmitConstantPool(MachineConstantPool *MCP);
174 /// EmitJumpTableInfo - Print assembly representations of the jump tables
175 /// used by the current function to the current output stream.
177 void EmitJumpTableInfo(MachineJumpTableInfo *MJTI, MachineFunction &MF);
179 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
180 /// special global used by LLVM. If so, emit it and return true, otherwise
181 /// do nothing and return false.
182 bool EmitSpecialLLVMGlobal(const GlobalVariable *GV);
185 //===------------------------------------------------------------------===//
186 /// LEB 128 number encoding.
188 /// PrintULEB128 - Print a series of hexidecimal values(separated by commas)
189 /// representing an unsigned leb128 value.
190 void PrintULEB128(unsigned Value) const;
192 /// SizeULEB128 - Compute the number of bytes required for an unsigned
194 static unsigned SizeULEB128(unsigned Value);
196 /// PrintSLEB128 - Print a series of hexidecimal values(separated by commas)
197 /// representing a signed leb128 value.
198 void PrintSLEB128(int Value) const;
200 /// SizeSLEB128 - Compute the number of bytes required for a signed leb128
202 static unsigned SizeSLEB128(int Value);
204 //===------------------------------------------------------------------===//
205 // Emission and print routines
208 /// PrintHex - Print a value as a hexidecimal value.
210 void PrintHex(int Value) const;
212 /// EOL - Print a newline character to asm stream. If a comment is present
213 /// then it will be printed first. Comments should not contain '\n'.
215 void EOL(const std::string &Comment) const;
217 /// EmitULEB128Bytes - Emit an assembler byte data directive to compose an
218 /// unsigned leb128 value.
219 void EmitULEB128Bytes(unsigned Value) const;
221 /// EmitSLEB128Bytes - print an assembler byte data directive to compose a
222 /// signed leb128 value.
223 void EmitSLEB128Bytes(int Value) const;
225 /// EmitInt8 - Emit a byte directive and value.
227 void EmitInt8(int Value) const;
229 /// EmitInt16 - Emit a short directive and value.
231 void EmitInt16(int Value) const;
233 /// EmitInt32 - Emit a long directive and value.
235 void EmitInt32(int Value) const;
237 /// EmitInt64 - Emit a long long directive and value.
239 void EmitInt64(uint64_t Value) const;
241 /// EmitString - Emit a string with quotes and a null terminator.
242 /// Special characters are emitted properly.
243 /// \literal (Eg. '\t') \endliteral
244 void EmitString(const std::string &String) const;
246 //===------------------------------------------------------------------===//
248 /// EmitAlignment - Emit an alignment directive to the specified power of
249 /// two boundary. For example, if you pass in 3 here, you will get an 8
250 /// byte alignment. If a global value is specified, and if that global has
251 /// an explicit alignment requested, it will unconditionally override the
252 /// alignment request. However, if ForcedAlignBits is specified, this value
253 /// has final say: the ultimate alignment will be the max of ForcedAlignBits
254 /// and the alignment computed with NumBits and the global. If UseFillExpr
255 /// is true, it also emits an optional second value FillValue which the
256 /// assembler uses to fill gaps to match alignment.
258 /// The algorithm is:
260 /// if (GV && GV->hasalignment) Align = GV->getalignment();
261 /// Align = std::max(Align, ForcedAlignBits);
263 void EmitAlignment(unsigned NumBits, const GlobalValue *GV = 0,
264 unsigned ForcedAlignBits = 0, bool UseFillExpr = false,
265 unsigned FillValue = 0) const;
268 /// EmitZeros - Emit a block of zeros.
270 void EmitZeros(uint64_t NumZeros) const;
272 /// EmitString - Emit a zero-byte-terminated string constant.
274 virtual void EmitString(const ConstantArray *CVA) const;
276 /// EmitConstantValueOnly - Print out the specified constant, without a
277 /// storage class. Only constants of first-class type are allowed here.
278 void EmitConstantValueOnly(const Constant *CV);
280 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
282 void EmitGlobalConstant(const Constant* CV);
284 virtual void EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV);
286 /// printInlineAsm - This method formats and prints the specified machine
287 /// instruction that is an inline asm.
288 void printInlineAsm(const MachineInstr *MI) const;
290 /// printLabel - This method prints a local label used by debug and
291 /// exception handling tables.
292 void printLabel(const MachineInstr *MI) const;
294 /// printBasicBlockLabel - This method prints the label for the specified
295 /// MachineBasicBlock
296 virtual void printBasicBlockLabel(const MachineBasicBlock *MBB,
297 bool printColon = false,
298 bool printComment = true) const;
300 /// printSetLabel - This method prints a set label for the specified
301 /// MachineBasicBlock
302 void printSetLabel(unsigned uid, const MachineBasicBlock *MBB) const;
303 void printSetLabel(unsigned uid, unsigned uid2,
304 const MachineBasicBlock *MBB) const;
306 /// printDataDirective - This method prints the asm directive for the
308 void printDataDirective(const Type *type);
311 void EmitLLVMUsedList(Constant *List);
312 void EmitXXStructorList(Constant *List);
313 void EmitConstantPool(unsigned Alignment, const char *Section,
314 std::vector<std::pair<MachineConstantPoolEntry,unsigned> > &CP);