1 //===-- llvm/CodeGen/AsmPrinter.h - AsmPrinter Framework --------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // 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/System/DataTypes.h"
31 class GCMetadataPrinter;
34 class MachineBasicBlock;
35 class MachineFunction;
37 class MachineLocation;
38 class MachineLoopInfo;
40 class MachineConstantPool;
41 class MachineConstantPoolEntry;
42 class MachineConstantPoolValue;
43 class MachineJumpTableInfo;
44 class MachineModuleInfo;
56 class TargetLoweringObjectFile;
62 /// AsmPrinter - This class is intended to be used as a driving class for all
64 class AsmPrinter : public MachineFunctionPass {
66 /// Target machine description.
70 /// Target Asm Printer information.
74 /// OutContext - This is the context for the output file that we are
75 /// streaming. This owns all of the global MC-related objects for the
76 /// generated translation unit.
77 MCContext &OutContext;
79 /// OutStreamer - This is the MCStreamer object for the file we are
80 /// generating. This contains the transient state for the current
81 /// translation unit that we are generating (such as the current section
83 MCStreamer &OutStreamer;
85 /// The current machine function.
86 const MachineFunction *MF;
88 /// MMI - This is a pointer to the current MachineModuleInfo.
89 MachineModuleInfo *MMI;
91 /// Name-mangler for global names.
95 /// The symbol for the current function. This is recalculated at the
96 /// beginning of each call to runOnMachineFunction().
98 MCSymbol *CurrentFnSym;
101 // GCMetadataPrinters - The garbage collection metadata printer table.
102 void *GCMetadataPrinters; // Really a DenseMap.
104 /// VerboseAsm - Emit comments in assembly output if this is true.
109 /// If VerboseAsm is set, a pointer to the loop info for this
113 /// DD - If the target supports dwarf debug info, this pointer is non-null.
116 /// DE - If the target supports dwarf exception info, this pointer is
121 explicit AsmPrinter(TargetMachine &TM, MCStreamer &Streamer);
124 virtual ~AsmPrinter();
126 /// isVerbose - Return true if assembly output should contain comments.
128 bool isVerbose() const { return VerboseAsm; }
130 /// getFunctionNumber - Return a unique ID for the current function.
132 unsigned getFunctionNumber() const;
134 /// getObjFileLowering - Return information about object file lowering.
135 const TargetLoweringObjectFile &getObjFileLowering() const;
137 /// getTargetData - Return information about data layout.
138 const TargetData &getTargetData() const;
140 /// getCurrentSection() - Return the current section we are emitting to.
141 const MCSection *getCurrentSection() const;
144 //===------------------------------------------------------------------===//
145 // MachineFunctionPass Implementation.
146 //===------------------------------------------------------------------===//
148 /// getAnalysisUsage - Record analysis usage.
150 void getAnalysisUsage(AnalysisUsage &AU) const;
152 /// doInitialization - Set up the AsmPrinter when we are working on a new
153 /// module. If your pass overrides this, it must make sure to explicitly
154 /// call this implementation.
155 bool doInitialization(Module &M);
157 /// doFinalization - Shut down the asmprinter. If you override this in your
158 /// pass, you must make sure to call it explicitly.
159 bool doFinalization(Module &M);
161 /// runOnMachineFunction - Emit the specified function out to the
163 virtual bool runOnMachineFunction(MachineFunction &MF) {
164 SetupMachineFunction(MF);
165 EmitFunctionHeader();
170 //===------------------------------------------------------------------===//
171 // Coarse grained IR lowering routines.
172 //===------------------------------------------------------------------===//
174 /// SetupMachineFunction - This should be called when a new MachineFunction
175 /// is being processed from runOnMachineFunction.
176 void SetupMachineFunction(MachineFunction &MF);
178 /// EmitFunctionHeader - This method emits the header for the current
180 void EmitFunctionHeader();
182 /// EmitFunctionBody - This method emits the body and trailer for a
184 void EmitFunctionBody();
186 /// EmitConstantPool - Print to the current output stream assembly
187 /// representations of the constants in the constant pool MCP. This is
188 /// used to print out constants which have been "spilled to memory" by
189 /// the code generator.
191 virtual void EmitConstantPool();
193 /// EmitJumpTableInfo - Print assembly representations of the jump tables
194 /// used by the current function to the current output stream.
196 void EmitJumpTableInfo();
198 /// EmitGlobalVariable - Emit the specified global variable to the .s file.
199 virtual void EmitGlobalVariable(const GlobalVariable *GV);
201 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
202 /// special global used by LLVM. If so, emit it and return true, otherwise
203 /// do nothing and return false.
204 bool EmitSpecialLLVMGlobal(const GlobalVariable *GV);
206 /// EmitAlignment - Emit an alignment directive to the specified power of
207 /// two boundary. For example, if you pass in 3 here, you will get an 8
208 /// byte alignment. If a global value is specified, and if that global has
209 /// an explicit alignment requested, it will override the alignment request
210 /// if required for correctness.
212 void EmitAlignment(unsigned NumBits, const GlobalValue *GV = 0) const;
214 /// EmitBasicBlockStart - This method prints the label for the specified
215 /// MachineBasicBlock, an alignment (if present) and a comment describing
216 /// it if appropriate.
217 void EmitBasicBlockStart(const MachineBasicBlock *MBB) const;
219 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
220 void EmitGlobalConstant(const Constant *CV, unsigned AddrSpace = 0);
223 //===------------------------------------------------------------------===//
225 //===------------------------------------------------------------------===//
227 // Targets can, or in the case of EmitInstruction, must implement these to
230 /// EmitStartOfAsmFile - This virtual method can be overridden by targets
231 /// that want to emit something at the start of their file.
232 virtual void EmitStartOfAsmFile(Module &) {}
234 /// EmitEndOfAsmFile - This virtual method can be overridden by targets that
235 /// want to emit something at the end of their file.
236 virtual void EmitEndOfAsmFile(Module &) {}
238 /// EmitFunctionBodyStart - Targets can override this to emit stuff before
239 /// the first basic block in the function.
240 virtual void EmitFunctionBodyStart() {}
242 /// EmitFunctionBodyEnd - Targets can override this to emit stuff after
243 /// the last basic block in the function.
244 virtual void EmitFunctionBodyEnd() {}
246 /// EmitInstruction - Targets should implement this to emit instructions.
247 virtual void EmitInstruction(const MachineInstr *) {
248 assert(0 && "EmitInstruction not implemented");
251 virtual void EmitFunctionEntryLabel();
253 virtual void EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV);
255 /// isBlockOnlyReachableByFallthough - Return true if the basic block has
256 /// exactly one predecessor and the control transfer mechanism between
257 /// the predecessor and this block is a fall-through.
259 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const;
261 //===------------------------------------------------------------------===//
262 // Symbol Lowering Routines.
263 //===------------------------------------------------------------------===//
266 /// GetTempSymbol - Return the MCSymbol corresponding to the assembler
267 /// temporary label with the specified stem and unique ID.
268 MCSymbol *GetTempSymbol(StringRef Name, unsigned ID) const;
270 /// GetTempSymbol - Return an assembler temporary label with the specified
272 MCSymbol *GetTempSymbol(StringRef Name) const;
275 /// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with
276 /// global value name as its base, with the specified suffix, and where the
277 /// symbol is forced to have private linkage if ForcePrivate is true.
278 MCSymbol *GetSymbolWithGlobalValueBase(const GlobalValue *GV,
280 bool ForcePrivate = true) const;
282 /// GetExternalSymbolSymbol - Return the MCSymbol for the specified
284 MCSymbol *GetExternalSymbolSymbol(StringRef Sym) const;
286 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
287 MCSymbol *GetCPISymbol(unsigned CPID) const;
289 /// GetJTISymbol - Return the symbol for the specified jump table entry.
290 MCSymbol *GetJTISymbol(unsigned JTID, bool isLinkerPrivate = false) const;
292 /// GetJTSetSymbol - Return the symbol for the specified jump table .set
293 /// FIXME: privatize to AsmPrinter.
294 MCSymbol *GetJTSetSymbol(unsigned UID, unsigned MBBID) const;
296 /// GetBlockAddressSymbol - Return the MCSymbol used to satisfy BlockAddress
297 /// uses of the specified basic block.
298 MCSymbol *GetBlockAddressSymbol(const BlockAddress *BA) const;
299 MCSymbol *GetBlockAddressSymbol(const BasicBlock *BB) const;
301 //===------------------------------------------------------------------===//
302 // Emission Helper Routines.
303 //===------------------------------------------------------------------===//
305 /// printOffset - This is just convenient handler for printing offsets.
306 void printOffset(int64_t Offset, raw_ostream &OS) const;
308 /// EmitInt8 - Emit a byte directive and value.
310 void EmitInt8(int Value) const;
312 /// EmitInt16 - Emit a short directive and value.
314 void EmitInt16(int Value) const;
316 /// EmitInt32 - Emit a long directive and value.
318 void EmitInt32(int Value) const;
320 /// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size
321 /// in bytes of the directive is specified by Size and Hi/Lo specify the
322 /// labels. This implicitly uses .set if it is available.
323 void EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
324 unsigned Size) const;
326 /// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo"
327 /// where the size in bytes of the directive is specified by Size and Hi/Lo
328 /// specify the labels. This implicitly uses .set if it is available.
329 void EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset,
330 const MCSymbol *Lo, unsigned Size) const;
332 /// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
333 /// where the size in bytes of the directive is specified by Size and Label
334 /// specifies the label. This implicitly uses .set if it is available.
335 void EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
336 unsigned Size) const;
338 //===------------------------------------------------------------------===//
339 // Dwarf Emission Helper Routines
340 //===------------------------------------------------------------------===//
342 /// EmitSLEB128 - emit the specified signed leb128 value.
343 void EmitSLEB128(int Value, const char *Desc = 0) const;
345 /// EmitULEB128 - emit the specified unsigned leb128 value.
346 void EmitULEB128(unsigned Value, const char *Desc = 0,
347 unsigned PadTo = 0) const;
349 /// EmitCFAByte - Emit a .byte 42 directive for a DW_CFA_xxx value.
350 void EmitCFAByte(unsigned Val) const;
352 /// EmitEncodingByte - Emit a .byte 42 directive that corresponds to an
353 /// encoding. If verbose assembly output is enabled, we output comments
354 /// describing the encoding. Desc is a string saying what the encoding is
355 /// specifying (e.g. "LSDA").
356 void EmitEncodingByte(unsigned Val, const char *Desc = 0) const;
358 /// GetSizeOfEncodedValue - Return the size of the encoding in bytes.
359 unsigned GetSizeOfEncodedValue(unsigned Encoding) const;
361 /// EmitReference - Emit a reference to a label with a specified encoding.
363 void EmitReference(const MCSymbol *Sym, unsigned Encoding) const;
364 void EmitReference(const GlobalValue *GV, unsigned Encoding) const;
366 /// EmitSectionOffset - Emit the 4-byte offset of Label from the start of
367 /// its section. This can be done with a special directive if the target
368 /// supports it (e.g. cygwin) or by emitting it as an offset from a label at
369 /// the start of the section.
371 /// SectionLabel is a temporary label emitted at the start of the section
372 /// that Label lives in.
373 void EmitSectionOffset(const MCSymbol *Label,
374 const MCSymbol *SectionLabel) const;
376 /// getDebugValueLocation - Get location information encoded by DBG_VALUE
378 virtual MachineLocation getDebugValueLocation(const MachineInstr *MI) const;
380 /// getISAEncoding - Get the value for DW_AT_APPLE_isa. Zero if no isa
381 /// encoding specified.
382 virtual unsigned getISAEncoding() { return 0; }
384 //===------------------------------------------------------------------===//
385 // Dwarf Lowering Routines
386 //===------------------------------------------------------------------===//
388 /// EmitFrameMoves - Emit frame instructions to describe the layout of the
390 void EmitFrameMoves(const std::vector<MachineMove> &Moves,
391 MCSymbol *BaseLabel, bool isEH) const;
394 //===------------------------------------------------------------------===//
395 // Inline Asm Support
396 //===------------------------------------------------------------------===//
398 // These are hooks that targets can override to implement inline asm
399 // support. These should probably be moved out of AsmPrinter someday.
401 /// PrintSpecial - Print information related to the specified machine instr
402 /// that is independent of the operand, and may be independent of the instr
403 /// itself. This can be useful for portably encoding the comment character
404 /// or other bits of target-specific knowledge into the asmstrings. The
405 /// syntax used is ${:comment}. Targets can override this to add support
406 /// for their own strange codes.
407 virtual void PrintSpecial(const MachineInstr *MI, raw_ostream &OS,
408 const char *Code) const;
410 /// PrintAsmOperand - Print the specified operand of MI, an INLINEASM
411 /// instruction, using the specified assembler variant. Targets should
412 /// override this to format as appropriate. This method can return true if
413 /// the operand is erroneous.
414 virtual bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
415 unsigned AsmVariant, const char *ExtraCode,
418 /// PrintAsmMemoryOperand - Print the specified operand of MI, an INLINEASM
419 /// instruction, using the specified assembler variant as an address.
420 /// Targets should override this to format as appropriate. This method can
421 /// return true if the operand is erroneous.
422 virtual bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
424 const char *ExtraCode,
428 /// Private state for PrintSpecial()
429 // Assign a unique ID to this machine instruction.
430 mutable const MachineInstr *LastMI;
431 mutable unsigned LastFn;
432 mutable unsigned Counter;
433 mutable unsigned SetCounter;
435 /// EmitInlineAsm - Emit a blob of inline asm to the output streamer.
436 void EmitInlineAsm(StringRef Str, const MDNode *LocMDNode = 0) const;
438 /// EmitInlineAsm - This method formats and emits the specified machine
439 /// instruction that is an inline asm.
440 void EmitInlineAsm(const MachineInstr *MI) const;
442 //===------------------------------------------------------------------===//
443 // Internal Implementation Details
444 //===------------------------------------------------------------------===//
446 /// EmitVisibility - This emits visibility information about symbol, if
447 /// this is suported by the target.
448 void EmitVisibility(MCSymbol *Sym, unsigned Visibility) const;
450 void EmitLinkage(unsigned Linkage, MCSymbol *GVSym) const;
452 void EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
453 const MachineBasicBlock *MBB,
455 void EmitLLVMUsedList(Constant *List);
456 void EmitXXStructorList(Constant *List);
457 GCMetadataPrinter *GetOrCreateGCPrinter(GCStrategy *C);