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/Support/DebugLoc.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;
55 class TargetLoweringObjectFile;
60 /// AsmPrinter - This class is intended to be used as a driving class for all
62 class AsmPrinter : public MachineFunctionPass {
64 /// Target machine description.
68 /// Target Asm Printer information.
72 /// OutContext - This is the context for the output file that we are
73 /// streaming. This owns all of the global MC-related objects for the
74 /// generated translation unit.
75 MCContext &OutContext;
77 /// OutStreamer - This is the MCStreamer object for the file we are
78 /// generating. This contains the transient state for the current
79 /// translation unit that we are generating (such as the current section
81 MCStreamer &OutStreamer;
83 /// The current machine function.
84 const MachineFunction *MF;
86 /// MMI - This is a pointer to the current MachineModuleInfo.
87 MachineModuleInfo *MMI;
89 /// Name-mangler for global names.
93 /// The symbol for the current function. This is recalculated at the
94 /// beginning of each call to runOnMachineFunction().
96 MCSymbol *CurrentFnSym;
99 // GCMetadataPrinters - The garbage collection metadata printer table.
100 void *GCMetadataPrinters; // Really a DenseMap.
102 /// VerboseAsm - Emit comments in assembly output if this is true.
107 /// If VerboseAsm is set, a pointer to the loop info for this
111 /// DD - If the target supports dwarf debug info, this pointer is non-null.
114 /// DE - If the target supports dwarf exception info, this pointer is
119 explicit AsmPrinter(TargetMachine &TM, MCStreamer &Streamer);
122 virtual ~AsmPrinter();
124 /// isVerbose - Return true if assembly output should contain comments.
126 bool isVerbose() const { return VerboseAsm; }
128 /// getFunctionNumber - Return a unique ID for the current function.
130 unsigned getFunctionNumber() const;
132 /// getObjFileLowering - Return information about object file lowering.
133 const TargetLoweringObjectFile &getObjFileLowering() const;
135 /// getTargetData - Return information about data layout.
136 const TargetData &getTargetData() const;
138 /// getCurrentSection() - Return the current section we are emitting to.
139 const MCSection *getCurrentSection() const;
142 //===------------------------------------------------------------------===//
143 // MachineFunctionPass Implementation.
144 //===------------------------------------------------------------------===//
146 /// getAnalysisUsage - Record analysis usage.
148 void getAnalysisUsage(AnalysisUsage &AU) const;
150 /// doInitialization - Set up the AsmPrinter when we are working on a new
151 /// module. If your pass overrides this, it must make sure to explicitly
152 /// call this implementation.
153 bool doInitialization(Module &M);
155 /// doFinalization - Shut down the asmprinter. If you override this in your
156 /// pass, you must make sure to call it explicitly.
157 bool doFinalization(Module &M);
159 /// runOnMachineFunction - Emit the specified function out to the
161 virtual bool runOnMachineFunction(MachineFunction &MF) {
162 SetupMachineFunction(MF);
163 EmitFunctionHeader();
168 //===------------------------------------------------------------------===//
169 // Coarse grained IR lowering routines.
170 //===------------------------------------------------------------------===//
172 /// SetupMachineFunction - This should be called when a new MachineFunction
173 /// is being processed from runOnMachineFunction.
174 void SetupMachineFunction(MachineFunction &MF);
176 /// EmitFunctionHeader - This method emits the header for the current
178 void EmitFunctionHeader();
180 /// EmitFunctionBody - This method emits the body and trailer for a
182 void EmitFunctionBody();
184 /// EmitConstantPool - Print to the current output stream assembly
185 /// representations of the constants in the constant pool MCP. This is
186 /// used to print out constants which have been "spilled to memory" by
187 /// the code generator.
189 virtual void EmitConstantPool();
191 /// EmitJumpTableInfo - Print assembly representations of the jump tables
192 /// used by the current function to the current output stream.
194 void EmitJumpTableInfo();
196 /// EmitGlobalVariable - Emit the specified global variable to the .s file.
197 virtual void EmitGlobalVariable(const GlobalVariable *GV);
199 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
200 /// special global used by LLVM. If so, emit it and return true, otherwise
201 /// do nothing and return false.
202 bool EmitSpecialLLVMGlobal(const GlobalVariable *GV);
204 /// EmitAlignment - Emit an alignment directive to the specified power of
205 /// two boundary. For example, if you pass in 3 here, you will get an 8
206 /// byte alignment. If a global value is specified, and if that global has
207 /// an explicit alignment requested, it will override the alignment request
208 /// if required for correctness.
210 void EmitAlignment(unsigned NumBits, const GlobalValue *GV = 0) const;
212 /// EmitBasicBlockStart - This method prints the label for the specified
213 /// MachineBasicBlock, an alignment (if present) and a comment describing
214 /// it if appropriate.
215 void EmitBasicBlockStart(const MachineBasicBlock *MBB) const;
217 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
218 void EmitGlobalConstant(const Constant *CV, unsigned AddrSpace = 0);
221 //===------------------------------------------------------------------===//
223 //===------------------------------------------------------------------===//
225 // Targets can, or in the case of EmitInstruction, must implement these to
228 /// EmitStartOfAsmFile - This virtual method can be overridden by targets
229 /// that want to emit something at the start of their file.
230 virtual void EmitStartOfAsmFile(Module &) {}
232 /// EmitEndOfAsmFile - This virtual method can be overridden by targets that
233 /// want to emit something at the end of their file.
234 virtual void EmitEndOfAsmFile(Module &) {}
236 /// EmitFunctionBodyStart - Targets can override this to emit stuff before
237 /// the first basic block in the function.
238 virtual void EmitFunctionBodyStart() {}
240 /// EmitFunctionBodyEnd - Targets can override this to emit stuff after
241 /// the last basic block in the function.
242 virtual void EmitFunctionBodyEnd() {}
244 /// EmitInstruction - Targets should implement this to emit instructions.
245 virtual void EmitInstruction(const MachineInstr *) {
246 assert(0 && "EmitInstruction not implemented");
249 virtual void EmitFunctionEntryLabel();
251 virtual void EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV);
253 /// isBlockOnlyReachableByFallthough - Return true if the basic block has
254 /// exactly one predecessor and the control transfer mechanism between
255 /// the predecessor and this block is a fall-through.
257 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const;
259 //===------------------------------------------------------------------===//
260 // Symbol Lowering Routines.
261 //===------------------------------------------------------------------===//
264 /// GetTempSymbol - Return the MCSymbol corresponding to the assembler
265 /// temporary label with the specified stem and unique ID.
266 MCSymbol *GetTempSymbol(StringRef Name, unsigned ID) const;
268 /// GetTempSymbol - Return an assembler temporary label with the specified
270 MCSymbol *GetTempSymbol(StringRef Name) const;
273 /// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with
274 /// global value name as its base, with the specified suffix, and where the
275 /// symbol is forced to have private linkage if ForcePrivate is true.
276 MCSymbol *GetSymbolWithGlobalValueBase(const GlobalValue *GV,
278 bool ForcePrivate = true) const;
280 /// GetExternalSymbolSymbol - Return the MCSymbol for the specified
282 MCSymbol *GetExternalSymbolSymbol(StringRef Sym) const;
284 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
285 MCSymbol *GetCPISymbol(unsigned CPID) const;
287 /// GetJTISymbol - Return the symbol for the specified jump table entry.
288 MCSymbol *GetJTISymbol(unsigned JTID, bool isLinkerPrivate = false) const;
290 /// GetJTSetSymbol - Return the symbol for the specified jump table .set
291 /// FIXME: privatize to AsmPrinter.
292 MCSymbol *GetJTSetSymbol(unsigned UID, unsigned MBBID) const;
294 /// GetBlockAddressSymbol - Return the MCSymbol used to satisfy BlockAddress
295 /// uses of the specified basic block.
296 MCSymbol *GetBlockAddressSymbol(const BlockAddress *BA) const;
297 MCSymbol *GetBlockAddressSymbol(const BasicBlock *BB) const;
299 //===------------------------------------------------------------------===//
300 // Emission Helper Routines.
301 //===------------------------------------------------------------------===//
303 /// printOffset - This is just convenient handler for printing offsets.
304 void printOffset(int64_t Offset, raw_ostream &OS) const;
306 /// EmitInt8 - Emit a byte directive and value.
308 void EmitInt8(int Value) const;
310 /// EmitInt16 - Emit a short directive and value.
312 void EmitInt16(int Value) const;
314 /// EmitInt32 - Emit a long directive and value.
316 void EmitInt32(int Value) const;
318 /// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size
319 /// in bytes of the directive is specified by Size and Hi/Lo specify the
320 /// labels. This implicitly uses .set if it is available.
321 void EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
322 unsigned Size) const;
324 /// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo"
325 /// where the size in bytes of the directive is specified by Size and Hi/Lo
326 /// specify the labels. This implicitly uses .set if it is available.
327 void EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset,
328 const MCSymbol *Lo, unsigned Size) const;
330 //===------------------------------------------------------------------===//
331 // Dwarf Emission Helper Routines
332 //===------------------------------------------------------------------===//
334 /// EmitSLEB128 - emit the specified signed leb128 value.
335 void EmitSLEB128(int Value, const char *Desc = 0) const;
337 /// EmitULEB128 - emit the specified unsigned leb128 value.
338 void EmitULEB128(unsigned Value, const char *Desc = 0,
339 unsigned PadTo = 0) const;
341 /// EmitCFAByte - Emit a .byte 42 directive for a DW_CFA_xxx value.
342 void EmitCFAByte(unsigned Val) const;
344 /// EmitEncodingByte - Emit a .byte 42 directive that corresponds to an
345 /// encoding. If verbose assembly output is enabled, we output comments
346 /// describing the encoding. Desc is a string saying what the encoding is
347 /// specifying (e.g. "LSDA").
348 void EmitEncodingByte(unsigned Val, const char *Desc = 0) const;
350 /// GetSizeOfEncodedValue - Return the size of the encoding in bytes.
351 unsigned GetSizeOfEncodedValue(unsigned Encoding) const;
353 /// EmitReference - Emit a reference to a label with a specified encoding.
355 void EmitReference(const MCSymbol *Sym, unsigned Encoding) const;
356 void EmitReference(const GlobalValue *GV, unsigned Encoding) const;
358 /// EmitSectionOffset - Emit the 4-byte offset of Label from the start of
359 /// its section. This can be done with a special directive if the target
360 /// supports it (e.g. cygwin) or by emitting it as an offset from a label at
361 /// the start of the section.
363 /// SectionLabel is a temporary label emitted at the start of the section
364 /// that Label lives in.
365 void EmitSectionOffset(const MCSymbol *Label,
366 const MCSymbol *SectionLabel) const;
368 /// getDebugValueLocation - Get location information encoded by DBG_VALUE
370 virtual MachineLocation getDebugValueLocation(const MachineInstr *MI) const;
372 //===------------------------------------------------------------------===//
373 // Dwarf Lowering Routines
374 //===------------------------------------------------------------------===//
376 /// EmitFrameMoves - Emit frame instructions to describe the layout of the
378 void EmitFrameMoves(const std::vector<MachineMove> &Moves,
379 MCSymbol *BaseLabel, bool isEH) const;
382 //===------------------------------------------------------------------===//
383 // Inline Asm Support
384 //===------------------------------------------------------------------===//
386 // These are hooks that targets can override to implement inline asm
387 // support. These should probably be moved out of AsmPrinter someday.
389 /// PrintSpecial - Print information related to the specified machine instr
390 /// that is independent of the operand, and may be independent of the instr
391 /// itself. This can be useful for portably encoding the comment character
392 /// or other bits of target-specific knowledge into the asmstrings. The
393 /// syntax used is ${:comment}. Targets can override this to add support
394 /// for their own strange codes.
395 virtual void PrintSpecial(const MachineInstr *MI, raw_ostream &OS,
396 const char *Code) const;
398 /// PrintAsmOperand - Print the specified operand of MI, an INLINEASM
399 /// instruction, using the specified assembler variant. Targets should
400 /// override this to format as appropriate. This method can return true if
401 /// the operand is erroneous.
402 virtual bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
403 unsigned AsmVariant, const char *ExtraCode,
406 /// PrintAsmMemoryOperand - Print the specified operand of MI, an INLINEASM
407 /// instruction, using the specified assembler variant as an address.
408 /// Targets should override this to format as appropriate. This method can
409 /// return true if the operand is erroneous.
410 virtual bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
412 const char *ExtraCode,
416 /// Private state for PrintSpecial()
417 // Assign a unique ID to this machine instruction.
418 mutable const MachineInstr *LastMI;
419 mutable unsigned LastFn;
420 mutable unsigned Counter;
421 mutable unsigned SetCounter;
423 /// EmitInlineAsm - Emit a blob of inline asm to the output streamer.
424 void EmitInlineAsm(StringRef Str, unsigned LocCookie) const;
426 /// EmitInlineAsm - This method formats and emits the specified machine
427 /// instruction that is an inline asm.
428 void EmitInlineAsm(const MachineInstr *MI) const;
430 //===------------------------------------------------------------------===//
431 // Internal Implementation Details
432 //===------------------------------------------------------------------===//
434 /// EmitVisibility - This emits visibility information about symbol, if
435 /// this is suported by the target.
436 void EmitVisibility(MCSymbol *Sym, unsigned Visibility) const;
438 void EmitLinkage(unsigned Linkage, MCSymbol *GVSym) const;
440 void EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
441 const MachineBasicBlock *MBB,
443 void EmitLLVMUsedList(Constant *List);
444 void EmitXXStructorList(Constant *List);
445 GCMetadataPrinter *GetOrCreateGCPrinter(GCStrategy *C);