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/Constants.h"
17 #include "llvm/InlineAsm.h"
18 #include "llvm/LLVMContext.h"
19 #include "llvm/Module.h"
20 #include "llvm/CodeGen/MachineBasicBlock.h"
21 #include "llvm/CodeGen/MachineModuleInfo.h"
22 #include "llvm/MC/MCAsmInfo.h"
23 #include "llvm/MC/MCStreamer.h"
24 #include "llvm/MC/MCSymbol.h"
25 #include "llvm/MC/MCParser/AsmParser.h"
26 #include "llvm/Target/TargetAsmParser.h"
27 #include "llvm/Target/TargetMachine.h"
28 #include "llvm/Target/TargetRegistry.h"
29 #include "llvm/ADT/OwningPtr.h"
30 #include "llvm/ADT/SmallString.h"
31 #include "llvm/ADT/Twine.h"
32 #include "llvm/Support/ErrorHandling.h"
33 #include "llvm/Support/MemoryBuffer.h"
34 #include "llvm/Support/SourceMgr.h"
35 #include "llvm/Support/raw_ostream.h"
38 /// EmitInlineAsm - Emit a blob of inline asm to the output streamer.
39 void AsmPrinter::EmitInlineAsm(StringRef Str, unsigned LocCookie) const {
40 assert(!Str.empty() && "Can't emit empty inline asm block");
42 // Remember if the buffer is nul terminated or not so we can avoid a copy.
43 bool isNullTerminated = Str.back() == 0;
45 Str = Str.substr(0, Str.size()-1);
47 // If the output streamer is actually a .s file, just emit the blob textually.
48 // This is useful in case the asm parser doesn't handle something but the
49 // system assembler does.
50 if (OutStreamer.hasRawTextSupport()) {
51 OutStreamer.EmitRawText(Str);
57 // If the current LLVMContext has an inline asm handler, set it in SourceMgr.
58 LLVMContext &LLVMCtx = MMI->getModule()->getContext();
59 bool HasDiagHandler = false;
60 if (void *DiagHandler = LLVMCtx.getInlineAsmDiagnosticHandler()) {
61 SrcMgr.setDiagHandler((SourceMgr::DiagHandlerTy)(intptr_t)DiagHandler,
62 LLVMCtx.getInlineAsmDiagnosticContext(), LocCookie);
63 HasDiagHandler = true;
68 Buffer = MemoryBuffer::getMemBuffer(Str, "<inline asm>");
70 Buffer = MemoryBuffer::getMemBufferCopy(Str, "<inline asm>");
72 // Tell SrcMgr about this buffer, it takes ownership of the buffer.
73 SrcMgr.AddNewSourceBuffer(Buffer, SMLoc());
75 AsmParser Parser(SrcMgr, OutContext, OutStreamer, *MAI);
76 OwningPtr<TargetAsmParser> TAP(TM.getTarget().createAsmParser(Parser));
78 report_fatal_error("Inline asm not supported by this streamer because"
79 " we don't have an asm parser for this target\n");
80 Parser.setTargetParser(*TAP.get());
82 // Don't implicitly switch to the text section before the asm.
83 int Res = Parser.Run(/*NoInitialTextSection*/ true,
85 if (Res && !HasDiagHandler)
86 report_fatal_error("Error parsing inline asm\n");
90 /// EmitInlineAsm - This method formats and emits the specified machine
91 /// instruction that is an inline asm.
92 void AsmPrinter::EmitInlineAsm(const MachineInstr *MI) const {
93 assert(MI->isInlineAsm() && "printInlineAsm only works on inline asms");
95 unsigned NumOperands = MI->getNumOperands();
97 // Count the number of register definitions to find the asm string.
99 for (; MI->getOperand(NumDefs).isReg() && MI->getOperand(NumDefs).isDef();
101 assert(NumDefs != NumOperands-2 && "No asm string?");
103 assert(MI->getOperand(NumDefs).isSymbol() && "No asm string?");
105 // Disassemble the AsmStr, printing out the literal pieces, the operands, etc.
106 const char *AsmStr = MI->getOperand(NumDefs).getSymbolName();
108 // If this asmstr is empty, just print the #APP/#NOAPP markers.
109 // These are useful to see where empty asm's wound up.
110 if (AsmStr[0] == 0) {
111 // Don't emit the comments if writing to a .o file.
112 if (!OutStreamer.hasRawTextSupport()) return;
114 OutStreamer.EmitRawText(Twine("\t")+MAI->getCommentString()+
115 MAI->getInlineAsmStart());
116 OutStreamer.EmitRawText(Twine("\t")+MAI->getCommentString()+
117 MAI->getInlineAsmEnd());
121 // Emit the #APP start marker. This has to happen even if verbose-asm isn't
122 // enabled, so we use EmitRawText.
123 if (OutStreamer.hasRawTextSupport())
124 OutStreamer.EmitRawText(Twine("\t")+MAI->getCommentString()+
125 MAI->getInlineAsmStart());
127 // Get the !srcloc metadata node if we have it, and decode the loc cookie from
129 unsigned LocCookie = 0;
130 for (unsigned i = MI->getNumOperands(); i != 0; --i) {
131 if (MI->getOperand(i-1).isMetadata())
132 if (const MDNode *SrcLoc = MI->getOperand(i-1).getMetadata())
133 if (SrcLoc->getNumOperands() != 0)
134 if (const ConstantInt *CI =
135 dyn_cast<ConstantInt>(SrcLoc->getOperand(0))) {
136 LocCookie = CI->getZExtValue();
141 // Emit the inline asm to a temporary string so we can emit it through
143 SmallString<256> StringData;
144 raw_svector_ostream OS(StringData);
148 // The variant of the current asmprinter.
149 int AsmPrinterVariant = MAI->getAssemblerDialect();
151 int CurVariant = -1; // The number of the {.|.|.} region we are in.
152 const char *LastEmitted = AsmStr; // One past the last character emitted.
154 while (*LastEmitted) {
155 switch (*LastEmitted) {
157 // Not a special case, emit the string section literally.
158 const char *LiteralEnd = LastEmitted+1;
159 while (*LiteralEnd && *LiteralEnd != '{' && *LiteralEnd != '|' &&
160 *LiteralEnd != '}' && *LiteralEnd != '$' && *LiteralEnd != '\n')
162 if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
163 OS.write(LastEmitted, LiteralEnd-LastEmitted);
164 LastEmitted = LiteralEnd;
168 ++LastEmitted; // Consume newline character.
169 OS << '\n'; // Indent code with newline.
172 ++LastEmitted; // Consume '$' character.
176 switch (*LastEmitted) {
177 default: Done = false; break;
179 if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
181 ++LastEmitted; // Consume second '$' character.
183 case '(': // $( -> same as GCC's { character.
184 ++LastEmitted; // Consume '(' character.
185 if (CurVariant != -1)
186 report_fatal_error("Nested variants found in inline asm string: '" +
187 Twine(AsmStr) + "'");
188 CurVariant = 0; // We're in the first variant now.
191 ++LastEmitted; // consume '|' character.
192 if (CurVariant == -1)
193 OS << '|'; // this is gcc's behavior for | outside a variant
195 ++CurVariant; // We're in the next variant.
197 case ')': // $) -> same as GCC's } char.
198 ++LastEmitted; // consume ')' character.
199 if (CurVariant == -1)
200 OS << '}'; // this is gcc's behavior for } outside a variant
207 bool HasCurlyBraces = false;
208 if (*LastEmitted == '{') { // ${variable}
209 ++LastEmitted; // Consume '{' character.
210 HasCurlyBraces = true;
213 // If we have ${:foo}, then this is not a real operand reference, it is a
214 // "magic" string reference, just like in .td files. Arrange to call
216 if (HasCurlyBraces && *LastEmitted == ':') {
218 const char *StrStart = LastEmitted;
219 const char *StrEnd = strchr(StrStart, '}');
221 report_fatal_error("Unterminated ${:foo} operand in inline asm"
222 " string: '" + Twine(AsmStr) + "'");
224 std::string Val(StrStart, StrEnd);
225 PrintSpecial(MI, OS, Val.c_str());
226 LastEmitted = StrEnd+1;
230 const char *IDStart = LastEmitted;
231 const char *IDEnd = IDStart;
232 while (*IDEnd >= '0' && *IDEnd <= '9') ++IDEnd;
235 if (StringRef(IDStart, IDEnd-IDStart).getAsInteger(10, Val))
236 report_fatal_error("Bad $ operand number in inline asm string: '" +
237 Twine(AsmStr) + "'");
240 char Modifier[2] = { 0, 0 };
242 if (HasCurlyBraces) {
243 // If we have curly braces, check for a modifier character. This
244 // supports syntax like ${0:u}, which correspond to "%u0" in GCC asm.
245 if (*LastEmitted == ':') {
246 ++LastEmitted; // Consume ':' character.
247 if (*LastEmitted == 0)
248 report_fatal_error("Bad ${:} expression in inline asm string: '" +
249 Twine(AsmStr) + "'");
251 Modifier[0] = *LastEmitted;
252 ++LastEmitted; // Consume modifier character.
255 if (*LastEmitted != '}')
256 report_fatal_error("Bad ${} expression in inline asm string: '" +
257 Twine(AsmStr) + "'");
258 ++LastEmitted; // Consume '}' character.
261 if (Val >= NumOperands-1)
262 report_fatal_error("Invalid $ operand number in inline asm string: '" +
263 Twine(AsmStr) + "'");
265 // Okay, we finally have a value number. Ask the target to print this
267 if (CurVariant == -1 || CurVariant == AsmPrinterVariant) {
272 // Scan to find the machine operand number for the operand.
274 if (OpNo >= MI->getNumOperands()) break;
275 unsigned OpFlags = MI->getOperand(OpNo).getImm();
276 OpNo += InlineAsm::getNumOperandRegisters(OpFlags) + 1;
279 if (OpNo >= MI->getNumOperands()) {
282 unsigned OpFlags = MI->getOperand(OpNo).getImm();
283 ++OpNo; // Skip over the ID number.
285 if (Modifier[0] == 'l') // labels are target independent
286 // FIXME: What if the operand isn't an MBB, report error?
287 OS << *MI->getOperand(OpNo).getMBB()->getSymbol();
289 AsmPrinter *AP = const_cast<AsmPrinter*>(this);
290 if (InlineAsm::isMemKind(OpFlags)) {
291 Error = AP->PrintAsmMemoryOperand(MI, OpNo, AsmPrinterVariant,
292 Modifier[0] ? Modifier : 0,
295 Error = AP->PrintAsmOperand(MI, OpNo, AsmPrinterVariant,
296 Modifier[0] ? Modifier : 0, OS);
302 raw_string_ostream Msg(msg);
303 Msg << "invalid operand in inline asm: '" << AsmStr << "'";
304 MMI->getModule()->getContext().emitError(LocCookie, Msg.str());
311 OS << '\n' << (char)0; // null terminate string.
312 EmitInlineAsm(OS.str(), LocCookie);
314 // Emit the #NOAPP end marker. This has to happen even if verbose-asm isn't
315 // enabled, so we use EmitRawText.
316 if (OutStreamer.hasRawTextSupport())
317 OutStreamer.EmitRawText(Twine("\t")+MAI->getCommentString()+
318 MAI->getInlineAsmEnd());
322 /// PrintSpecial - Print information related to the specified machine instr
323 /// that is independent of the operand, and may be independent of the instr
324 /// itself. This can be useful for portably encoding the comment character
325 /// or other bits of target-specific knowledge into the asmstrings. The
326 /// syntax used is ${:comment}. Targets can override this to add support
327 /// for their own strange codes.
328 void AsmPrinter::PrintSpecial(const MachineInstr *MI, raw_ostream &OS,
329 const char *Code) const {
330 if (!strcmp(Code, "private")) {
331 OS << MAI->getPrivateGlobalPrefix();
332 } else if (!strcmp(Code, "comment")) {
333 OS << MAI->getCommentString();
334 } else if (!strcmp(Code, "uid")) {
335 // Comparing the address of MI isn't sufficient, because machineinstrs may
336 // be allocated to the same address across functions.
338 // If this is a new LastFn instruction, bump the counter.
339 if (LastMI != MI || LastFn != getFunctionNumber()) {
342 LastFn = getFunctionNumber();
347 raw_string_ostream Msg(msg);
348 Msg << "Unknown special formatter '" << Code
349 << "' for machine instr: " << *MI;
350 report_fatal_error(Msg.str());
354 /// PrintAsmOperand - Print the specified operand of MI, an INLINEASM
355 /// instruction, using the specified assembler variant. Targets should
356 /// override this to format as appropriate.
357 bool AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
358 unsigned AsmVariant, const char *ExtraCode,
360 // Target doesn't support this yet!
364 bool AsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
366 const char *ExtraCode, raw_ostream &O) {
367 // Target doesn't support this yet!