1 //===-- AsmPrinterInlineAsm.cpp - AsmPrinter Inline Asm Handling ----------===//
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 implements the inline assembler pieces of the AsmPrinter class.
12 //===----------------------------------------------------------------------===//
14 #define DEBUG_TYPE "asm-printer"
15 #include "llvm/CodeGen/AsmPrinter.h"
16 #include "llvm/ADT/OwningPtr.h"
17 #include "llvm/ADT/SmallString.h"
18 #include "llvm/ADT/Twine.h"
19 #include "llvm/CodeGen/MachineBasicBlock.h"
20 #include "llvm/CodeGen/MachineModuleInfo.h"
21 #include "llvm/IR/Constants.h"
22 #include "llvm/IR/DataLayout.h"
23 #include "llvm/IR/InlineAsm.h"
24 #include "llvm/IR/LLVMContext.h"
25 #include "llvm/IR/Module.h"
26 #include "llvm/MC/MCAsmInfo.h"
27 #include "llvm/MC/MCStreamer.h"
28 #include "llvm/MC/MCSubtargetInfo.h"
29 #include "llvm/MC/MCSymbol.h"
30 #include "llvm/MC/MCTargetAsmParser.h"
31 #include "llvm/Support/ErrorHandling.h"
32 #include "llvm/Support/MemoryBuffer.h"
33 #include "llvm/Support/SourceMgr.h"
34 #include "llvm/Support/TargetRegistry.h"
35 #include "llvm/Support/raw_ostream.h"
36 #include "llvm/Target/TargetMachine.h"
37 #include "llvm/Target/TargetSubtargetInfo.h"
41 struct SrcMgrDiagInfo {
42 const MDNode *LocInfo;
43 LLVMContext::InlineAsmDiagHandlerTy DiagHandler;
48 /// srcMgrDiagHandler - This callback is invoked when the SourceMgr for an
49 /// inline asm has an error in it. diagInfo is a pointer to the SrcMgrDiagInfo
51 static void srcMgrDiagHandler(const SMDiagnostic &Diag, void *diagInfo) {
52 SrcMgrDiagInfo *DiagInfo = static_cast<SrcMgrDiagInfo *>(diagInfo);
53 assert(DiagInfo && "Diagnostic context not passed down?");
55 // If the inline asm had metadata associated with it, pull out a location
56 // cookie corresponding to which line the error occurred on.
57 unsigned LocCookie = 0;
58 if (const MDNode *LocInfo = DiagInfo->LocInfo) {
59 unsigned ErrorLine = Diag.getLineNo()-1;
60 if (ErrorLine >= LocInfo->getNumOperands())
63 if (LocInfo->getNumOperands() != 0)
64 if (const ConstantInt *CI =
65 dyn_cast<ConstantInt>(LocInfo->getOperand(ErrorLine)))
66 LocCookie = CI->getZExtValue();
69 DiagInfo->DiagHandler(Diag, DiagInfo->DiagContext, LocCookie);
72 /// EmitInlineAsm - Emit a blob of inline asm to the output streamer.
73 void AsmPrinter::EmitInlineAsm(StringRef Str, const MDNode *LocMDNode,
74 InlineAsm::AsmDialect Dialect) const {
75 assert(!Str.empty() && "Can't emit empty inline asm block");
77 // Remember if the buffer is nul terminated or not so we can avoid a copy.
78 bool isNullTerminated = Str.back() == 0;
80 Str = Str.substr(0, Str.size()-1);
82 // If the output streamer does not have mature MC support or the integrated
83 // assembler has been disabled, just emit the blob textually.
84 // Otherwise parse the asm and emit it via MC support.
85 // This is useful in case the asm parser doesn't handle something but the
86 // system assembler does.
87 const MCAsmInfo *MCAI = TM.getMCAsmInfo();
88 assert(MCAI && "No MCAsmInfo");
89 if (!MCAI->useIntegratedAssembler() &&
90 !OutStreamer.isIntegratedAssemblerRequired()) {
91 OutStreamer.EmitRawText(Str);
92 emitInlineAsmEnd(TM.getSubtarget<MCSubtargetInfo>(), 0);
97 SrcMgrDiagInfo DiagInfo;
99 // If the current LLVMContext has an inline asm handler, set it in SourceMgr.
100 LLVMContext &LLVMCtx = MMI->getModule()->getContext();
101 bool HasDiagHandler = false;
102 if (LLVMCtx.getInlineAsmDiagnosticHandler() != 0) {
103 // If the source manager has an issue, we arrange for srcMgrDiagHandler
104 // to be invoked, getting DiagInfo passed into it.
105 DiagInfo.LocInfo = LocMDNode;
106 DiagInfo.DiagHandler = LLVMCtx.getInlineAsmDiagnosticHandler();
107 DiagInfo.DiagContext = LLVMCtx.getInlineAsmDiagnosticContext();
108 SrcMgr.setDiagHandler(srcMgrDiagHandler, &DiagInfo);
109 HasDiagHandler = true;
112 MemoryBuffer *Buffer;
113 if (isNullTerminated)
114 Buffer = MemoryBuffer::getMemBuffer(Str, "<inline asm>");
116 Buffer = MemoryBuffer::getMemBufferCopy(Str, "<inline asm>");
118 // Tell SrcMgr about this buffer, it takes ownership of the buffer.
119 SrcMgr.AddNewSourceBuffer(Buffer, SMLoc());
121 OwningPtr<MCAsmParser> Parser(createMCAsmParser(SrcMgr,
122 OutContext, OutStreamer,
125 // Initialize the parser with a fresh subtarget info. It is better to use a
126 // new STI here because the parser may modify it and we do not want those
127 // modifications to persist after parsing the inlineasm. The modifications
128 // made by the parser will be seen by the code emitters because it passes
129 // the current STI down to the EncodeInstruction() method.
130 OwningPtr<MCSubtargetInfo> STI(TM.getTarget().createMCSubtargetInfo(
131 TM.getTargetTriple(), TM.getTargetCPU(), TM.getTargetFeatureString()));
133 // Preserve a copy of the original STI because the parser may modify it. For
134 // example, when switching between arm and thumb mode. If the target needs to
135 // emit code to return to the original state it can do so in
136 // emitInlineAsmEnd().
137 MCSubtargetInfo STIOrig = *STI;
139 OwningPtr<MCTargetAsmParser>
140 TAP(TM.getTarget().createMCAsmParser(*STI, *Parser, *MII));
142 report_fatal_error("Inline asm not supported by this streamer because"
143 " we don't have an asm parser for this target\n");
144 Parser->setAssemblerDialect(Dialect);
145 Parser->setTargetParser(*TAP.get());
147 // Don't implicitly switch to the text section before the asm.
148 int Res = Parser->Run(/*NoInitialTextSection*/ true,
149 /*NoFinalize*/ true);
150 emitInlineAsmEnd(STIOrig, STI.get());
151 if (Res && !HasDiagHandler)
152 report_fatal_error("Error parsing inline asm\n");
155 static void EmitMSInlineAsmStr(const char *AsmStr, const MachineInstr *MI,
156 MachineModuleInfo *MMI, int InlineAsmVariant,
157 AsmPrinter *AP, unsigned LocCookie,
159 // Switch to the inline assembly variant.
160 OS << "\t.intel_syntax\n\t";
162 const char *LastEmitted = AsmStr; // One past the last character emitted.
163 unsigned NumOperands = MI->getNumOperands();
165 while (*LastEmitted) {
166 switch (*LastEmitted) {
168 // Not a special case, emit the string section literally.
169 const char *LiteralEnd = LastEmitted+1;
170 while (*LiteralEnd && *LiteralEnd != '{' && *LiteralEnd != '|' &&
171 *LiteralEnd != '}' && *LiteralEnd != '$' && *LiteralEnd != '\n')
174 OS.write(LastEmitted, LiteralEnd-LastEmitted);
175 LastEmitted = LiteralEnd;
179 ++LastEmitted; // Consume newline character.
180 OS << '\n'; // Indent code with newline.
183 ++LastEmitted; // Consume '$' character.
187 switch (*LastEmitted) {
188 default: Done = false; break;
190 ++LastEmitted; // Consume second '$' character.
195 const char *IDStart = LastEmitted;
196 const char *IDEnd = IDStart;
197 while (*IDEnd >= '0' && *IDEnd <= '9') ++IDEnd;
200 if (StringRef(IDStart, IDEnd-IDStart).getAsInteger(10, Val))
201 report_fatal_error("Bad $ operand number in inline asm string: '" +
202 Twine(AsmStr) + "'");
205 if (Val >= NumOperands-1)
206 report_fatal_error("Invalid $ operand number in inline asm string: '" +
207 Twine(AsmStr) + "'");
209 // Okay, we finally have a value number. Ask the target to print this
211 unsigned OpNo = InlineAsm::MIOp_FirstOperand;
215 // Scan to find the machine operand number for the operand.
217 if (OpNo >= MI->getNumOperands()) break;
218 unsigned OpFlags = MI->getOperand(OpNo).getImm();
219 OpNo += InlineAsm::getNumOperandRegisters(OpFlags) + 1;
222 // We may have a location metadata attached to the end of the
223 // instruction, and at no point should see metadata at any
224 // other point while processing. It's an error if so.
225 if (OpNo >= MI->getNumOperands() ||
226 MI->getOperand(OpNo).isMetadata()) {
229 unsigned OpFlags = MI->getOperand(OpNo).getImm();
230 ++OpNo; // Skip over the ID number.
232 if (InlineAsm::isMemKind(OpFlags)) {
233 Error = AP->PrintAsmMemoryOperand(MI, OpNo, InlineAsmVariant,
236 Error = AP->PrintAsmOperand(MI, OpNo, InlineAsmVariant,
242 raw_string_ostream Msg(msg);
243 Msg << "invalid operand in inline asm: '" << AsmStr << "'";
244 MMI->getModule()->getContext().emitError(LocCookie, Msg.str());
250 OS << "\n\t.att_syntax\n" << (char)0; // null terminate string.
253 static void EmitGCCInlineAsmStr(const char *AsmStr, const MachineInstr *MI,
254 MachineModuleInfo *MMI, int InlineAsmVariant,
255 int AsmPrinterVariant, AsmPrinter *AP,
256 unsigned LocCookie, raw_ostream &OS) {
257 int CurVariant = -1; // The number of the {.|.|.} region we are in.
258 const char *LastEmitted = AsmStr; // One past the last character emitted.
259 unsigned NumOperands = MI->getNumOperands();
263 while (*LastEmitted) {
264 switch (*LastEmitted) {
266 // Not a special case, emit the string section literally.
267 const char *LiteralEnd = LastEmitted+1;
268 while (*LiteralEnd && *LiteralEnd != '{' && *LiteralEnd != '|' &&
269 *LiteralEnd != '}' && *LiteralEnd != '$' && *LiteralEnd != '\n')
271 if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
272 OS.write(LastEmitted, LiteralEnd-LastEmitted);
273 LastEmitted = LiteralEnd;
277 ++LastEmitted; // Consume newline character.
278 OS << '\n'; // Indent code with newline.
281 ++LastEmitted; // Consume '$' character.
285 switch (*LastEmitted) {
286 default: Done = false; break;
288 if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
290 ++LastEmitted; // Consume second '$' character.
292 case '(': // $( -> same as GCC's { character.
293 ++LastEmitted; // Consume '(' character.
294 if (CurVariant != -1)
295 report_fatal_error("Nested variants found in inline asm string: '" +
296 Twine(AsmStr) + "'");
297 CurVariant = 0; // We're in the first variant now.
300 ++LastEmitted; // consume '|' character.
301 if (CurVariant == -1)
302 OS << '|'; // this is gcc's behavior for | outside a variant
304 ++CurVariant; // We're in the next variant.
306 case ')': // $) -> same as GCC's } char.
307 ++LastEmitted; // consume ')' character.
308 if (CurVariant == -1)
309 OS << '}'; // this is gcc's behavior for } outside a variant
316 bool HasCurlyBraces = false;
317 if (*LastEmitted == '{') { // ${variable}
318 ++LastEmitted; // Consume '{' character.
319 HasCurlyBraces = true;
322 // If we have ${:foo}, then this is not a real operand reference, it is a
323 // "magic" string reference, just like in .td files. Arrange to call
325 if (HasCurlyBraces && *LastEmitted == ':') {
327 const char *StrStart = LastEmitted;
328 const char *StrEnd = strchr(StrStart, '}');
330 report_fatal_error("Unterminated ${:foo} operand in inline asm"
331 " string: '" + Twine(AsmStr) + "'");
333 std::string Val(StrStart, StrEnd);
334 AP->PrintSpecial(MI, OS, Val.c_str());
335 LastEmitted = StrEnd+1;
339 const char *IDStart = LastEmitted;
340 const char *IDEnd = IDStart;
341 while (*IDEnd >= '0' && *IDEnd <= '9') ++IDEnd;
344 if (StringRef(IDStart, IDEnd-IDStart).getAsInteger(10, Val))
345 report_fatal_error("Bad $ operand number in inline asm string: '" +
346 Twine(AsmStr) + "'");
349 char Modifier[2] = { 0, 0 };
351 if (HasCurlyBraces) {
352 // If we have curly braces, check for a modifier character. This
353 // supports syntax like ${0:u}, which correspond to "%u0" in GCC asm.
354 if (*LastEmitted == ':') {
355 ++LastEmitted; // Consume ':' character.
356 if (*LastEmitted == 0)
357 report_fatal_error("Bad ${:} expression in inline asm string: '" +
358 Twine(AsmStr) + "'");
360 Modifier[0] = *LastEmitted;
361 ++LastEmitted; // Consume modifier character.
364 if (*LastEmitted != '}')
365 report_fatal_error("Bad ${} expression in inline asm string: '" +
366 Twine(AsmStr) + "'");
367 ++LastEmitted; // Consume '}' character.
370 if (Val >= NumOperands-1)
371 report_fatal_error("Invalid $ operand number in inline asm string: '" +
372 Twine(AsmStr) + "'");
374 // Okay, we finally have a value number. Ask the target to print this
376 if (CurVariant == -1 || CurVariant == AsmPrinterVariant) {
377 unsigned OpNo = InlineAsm::MIOp_FirstOperand;
381 // Scan to find the machine operand number for the operand.
383 if (OpNo >= MI->getNumOperands()) break;
384 unsigned OpFlags = MI->getOperand(OpNo).getImm();
385 OpNo += InlineAsm::getNumOperandRegisters(OpFlags) + 1;
388 // We may have a location metadata attached to the end of the
389 // instruction, and at no point should see metadata at any
390 // other point while processing. It's an error if so.
391 if (OpNo >= MI->getNumOperands() ||
392 MI->getOperand(OpNo).isMetadata()) {
395 unsigned OpFlags = MI->getOperand(OpNo).getImm();
396 ++OpNo; // Skip over the ID number.
398 if (Modifier[0] == 'l') // labels are target independent
399 // FIXME: What if the operand isn't an MBB, report error?
400 OS << *MI->getOperand(OpNo).getMBB()->getSymbol();
402 if (InlineAsm::isMemKind(OpFlags)) {
403 Error = AP->PrintAsmMemoryOperand(MI, OpNo, InlineAsmVariant,
404 Modifier[0] ? Modifier : 0,
407 Error = AP->PrintAsmOperand(MI, OpNo, InlineAsmVariant,
408 Modifier[0] ? Modifier : 0, OS);
414 raw_string_ostream Msg(msg);
415 Msg << "invalid operand in inline asm: '" << AsmStr << "'";
416 MMI->getModule()->getContext().emitError(LocCookie, Msg.str());
423 OS << '\n' << (char)0; // null terminate string.
426 /// EmitInlineAsm - This method formats and emits the specified machine
427 /// instruction that is an inline asm.
428 void AsmPrinter::EmitInlineAsm(const MachineInstr *MI) const {
429 assert(MI->isInlineAsm() && "printInlineAsm only works on inline asms");
431 // Count the number of register definitions to find the asm string.
432 unsigned NumDefs = 0;
433 for (; MI->getOperand(NumDefs).isReg() && MI->getOperand(NumDefs).isDef();
435 assert(NumDefs != MI->getNumOperands()-2 && "No asm string?");
437 assert(MI->getOperand(NumDefs).isSymbol() && "No asm string?");
439 // Disassemble the AsmStr, printing out the literal pieces, the operands, etc.
440 const char *AsmStr = MI->getOperand(NumDefs).getSymbolName();
442 // If this asmstr is empty, just print the #APP/#NOAPP markers.
443 // These are useful to see where empty asm's wound up.
444 if (AsmStr[0] == 0) {
445 OutStreamer.emitRawComment(MAI->getInlineAsmStart());
446 OutStreamer.emitRawComment(MAI->getInlineAsmEnd());
450 // Emit the #APP start marker. This has to happen even if verbose-asm isn't
451 // enabled, so we use emitRawComment.
452 OutStreamer.emitRawComment(MAI->getInlineAsmStart());
454 // Get the !srcloc metadata node if we have it, and decode the loc cookie from
456 unsigned LocCookie = 0;
457 const MDNode *LocMD = 0;
458 for (unsigned i = MI->getNumOperands(); i != 0; --i) {
459 if (MI->getOperand(i-1).isMetadata() &&
460 (LocMD = MI->getOperand(i-1).getMetadata()) &&
461 LocMD->getNumOperands() != 0) {
462 if (const ConstantInt *CI = dyn_cast<ConstantInt>(LocMD->getOperand(0))) {
463 LocCookie = CI->getZExtValue();
469 // Emit the inline asm to a temporary string so we can emit it through
471 SmallString<256> StringData;
472 raw_svector_ostream OS(StringData);
474 // The variant of the current asmprinter.
475 int AsmPrinterVariant = MAI->getAssemblerDialect();
476 InlineAsm::AsmDialect InlineAsmVariant = MI->getInlineAsmDialect();
477 AsmPrinter *AP = const_cast<AsmPrinter*>(this);
478 if (InlineAsmVariant == InlineAsm::AD_ATT)
479 EmitGCCInlineAsmStr(AsmStr, MI, MMI, InlineAsmVariant, AsmPrinterVariant,
482 EmitMSInlineAsmStr(AsmStr, MI, MMI, InlineAsmVariant, AP, LocCookie, OS);
484 EmitInlineAsm(OS.str(), LocMD, MI->getInlineAsmDialect());
486 // Emit the #NOAPP end marker. This has to happen even if verbose-asm isn't
487 // enabled, so we use emitRawComment.
488 OutStreamer.emitRawComment(MAI->getInlineAsmEnd());
492 /// PrintSpecial - Print information related to the specified machine instr
493 /// that is independent of the operand, and may be independent of the instr
494 /// itself. This can be useful for portably encoding the comment character
495 /// or other bits of target-specific knowledge into the asmstrings. The
496 /// syntax used is ${:comment}. Targets can override this to add support
497 /// for their own strange codes.
498 void AsmPrinter::PrintSpecial(const MachineInstr *MI, raw_ostream &OS,
499 const char *Code) const {
500 const DataLayout *DL = TM.getDataLayout();
501 if (!strcmp(Code, "private")) {
502 OS << DL->getPrivateGlobalPrefix();
503 } else if (!strcmp(Code, "comment")) {
504 OS << MAI->getCommentString();
505 } else if (!strcmp(Code, "uid")) {
506 // Comparing the address of MI isn't sufficient, because machineinstrs may
507 // be allocated to the same address across functions.
509 // If this is a new LastFn instruction, bump the counter.
510 if (LastMI != MI || LastFn != getFunctionNumber()) {
513 LastFn = getFunctionNumber();
518 raw_string_ostream Msg(msg);
519 Msg << "Unknown special formatter '" << Code
520 << "' for machine instr: " << *MI;
521 report_fatal_error(Msg.str());
525 /// PrintAsmOperand - Print the specified operand of MI, an INLINEASM
526 /// instruction, using the specified assembler variant. Targets should
527 /// override this to format as appropriate.
528 bool AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
529 unsigned AsmVariant, const char *ExtraCode,
531 // Does this asm operand have a single letter operand modifier?
532 if (ExtraCode && ExtraCode[0]) {
533 if (ExtraCode[1] != 0) return true; // Unknown modifier.
535 const MachineOperand &MO = MI->getOperand(OpNo);
536 switch (ExtraCode[0]) {
538 return true; // Unknown modifier.
539 case 'c': // Substitute immediate value without immediate syntax
540 if (MO.getType() != MachineOperand::MO_Immediate)
544 case 'n': // Negate the immediate constant.
545 if (MO.getType() != MachineOperand::MO_Immediate)
554 bool AsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
556 const char *ExtraCode, raw_ostream &O) {
557 // Target doesn't support this yet!
561 void AsmPrinter::emitInlineAsmEnd(const MCSubtargetInfo &StartInfo,
562 const MCSubtargetInfo *EndInfo) const {}