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 if (const MDNode *SrcLoc = MI->getOperand(NumOperands-1).getMetadata()) {
131 if (SrcLoc->getNumOperands() != 0)
132 if (const ConstantInt *CI = dyn_cast<ConstantInt>(SrcLoc->getOperand(0)))
133 LocCookie = CI->getZExtValue();
136 // Emit the inline asm to a temporary string so we can emit it through
138 SmallString<256> StringData;
139 raw_svector_ostream OS(StringData);
143 // The variant of the current asmprinter.
144 int AsmPrinterVariant = MAI->getAssemblerDialect();
146 int CurVariant = -1; // The number of the {.|.|.} region we are in.
147 const char *LastEmitted = AsmStr; // One past the last character emitted.
149 while (*LastEmitted) {
150 switch (*LastEmitted) {
152 // Not a special case, emit the string section literally.
153 const char *LiteralEnd = LastEmitted+1;
154 while (*LiteralEnd && *LiteralEnd != '{' && *LiteralEnd != '|' &&
155 *LiteralEnd != '}' && *LiteralEnd != '$' && *LiteralEnd != '\n')
157 if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
158 OS.write(LastEmitted, LiteralEnd-LastEmitted);
159 LastEmitted = LiteralEnd;
163 ++LastEmitted; // Consume newline character.
164 OS << '\n'; // Indent code with newline.
167 ++LastEmitted; // Consume '$' character.
171 switch (*LastEmitted) {
172 default: Done = false; break;
174 if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
176 ++LastEmitted; // Consume second '$' character.
178 case '(': // $( -> same as GCC's { character.
179 ++LastEmitted; // Consume '(' character.
180 if (CurVariant != -1)
181 report_fatal_error("Nested variants found in inline asm string: '"
182 + std::string(AsmStr) + "'");
183 CurVariant = 0; // We're in the first variant now.
186 ++LastEmitted; // consume '|' character.
187 if (CurVariant == -1)
188 OS << '|'; // this is gcc's behavior for | outside a variant
190 ++CurVariant; // We're in the next variant.
192 case ')': // $) -> same as GCC's } char.
193 ++LastEmitted; // consume ')' character.
194 if (CurVariant == -1)
195 OS << '}'; // this is gcc's behavior for } outside a variant
202 bool HasCurlyBraces = false;
203 if (*LastEmitted == '{') { // ${variable}
204 ++LastEmitted; // Consume '{' character.
205 HasCurlyBraces = true;
208 // If we have ${:foo}, then this is not a real operand reference, it is a
209 // "magic" string reference, just like in .td files. Arrange to call
211 if (HasCurlyBraces && *LastEmitted == ':') {
213 const char *StrStart = LastEmitted;
214 const char *StrEnd = strchr(StrStart, '}');
216 report_fatal_error(Twine("Unterminated ${:foo} operand in inline asm"
217 " string: '") + Twine(AsmStr) + "'");
219 std::string Val(StrStart, StrEnd);
220 PrintSpecial(MI, OS, Val.c_str());
221 LastEmitted = StrEnd+1;
225 const char *IDStart = LastEmitted;
226 const char *IDEnd = IDStart;
227 while (*IDEnd >= '0' && *IDEnd <= '9') ++IDEnd;
230 if (StringRef(IDStart, IDEnd-IDStart).getAsInteger(10, Val))
231 report_fatal_error("Bad $ operand number in inline asm string: '"
232 + std::string(AsmStr) + "'");
235 char Modifier[2] = { 0, 0 };
237 if (HasCurlyBraces) {
238 // If we have curly braces, check for a modifier character. This
239 // supports syntax like ${0:u}, which correspond to "%u0" in GCC asm.
240 if (*LastEmitted == ':') {
241 ++LastEmitted; // Consume ':' character.
242 if (*LastEmitted == 0)
243 report_fatal_error("Bad ${:} expression in inline asm string: '" +
244 std::string(AsmStr) + "'");
246 Modifier[0] = *LastEmitted;
247 ++LastEmitted; // Consume modifier character.
250 if (*LastEmitted != '}')
251 report_fatal_error("Bad ${} expression in inline asm string: '"
252 + std::string(AsmStr) + "'");
253 ++LastEmitted; // Consume '}' character.
256 if (Val >= NumOperands-1)
257 report_fatal_error("Invalid $ operand number in inline asm string: '"
258 + std::string(AsmStr) + "'");
260 // Okay, we finally have a value number. Ask the target to print this
262 if (CurVariant == -1 || CurVariant == AsmPrinterVariant) {
267 // Scan to find the machine operand number for the operand.
269 if (OpNo >= MI->getNumOperands()) break;
270 unsigned OpFlags = MI->getOperand(OpNo).getImm();
271 OpNo += InlineAsm::getNumOperandRegisters(OpFlags) + 1;
274 if (OpNo >= MI->getNumOperands()) {
277 unsigned OpFlags = MI->getOperand(OpNo).getImm();
278 ++OpNo; // Skip over the ID number.
280 if (Modifier[0] == 'l') // labels are target independent
281 // FIXME: What if the operand isn't an MBB, report error?
282 OS << *MI->getOperand(OpNo).getMBB()->getSymbol();
284 AsmPrinter *AP = const_cast<AsmPrinter*>(this);
285 if (InlineAsm::isMemKind(OpFlags)) {
286 Error = AP->PrintAsmMemoryOperand(MI, OpNo, AsmPrinterVariant,
287 Modifier[0] ? Modifier : 0,
290 Error = AP->PrintAsmOperand(MI, OpNo, AsmPrinterVariant,
291 Modifier[0] ? Modifier : 0, OS);
297 raw_string_ostream Msg(msg);
298 Msg << "invalid operand in inline asm: '" << AsmStr << "'";
299 MMI->getModule()->getContext().emitError(LocCookie, Msg.str());
306 OS << '\n' << (char)0; // null terminate string.
307 EmitInlineAsm(OS.str(), LocCookie);
309 // Emit the #NOAPP end marker. This has to happen even if verbose-asm isn't
310 // enabled, so we use EmitRawText.
311 if (OutStreamer.hasRawTextSupport())
312 OutStreamer.EmitRawText(Twine("\t")+MAI->getCommentString()+
313 MAI->getInlineAsmEnd());
317 /// PrintSpecial - Print information related to the specified machine instr
318 /// that is independent of the operand, and may be independent of the instr
319 /// itself. This can be useful for portably encoding the comment character
320 /// or other bits of target-specific knowledge into the asmstrings. The
321 /// syntax used is ${:comment}. Targets can override this to add support
322 /// for their own strange codes.
323 void AsmPrinter::PrintSpecial(const MachineInstr *MI, raw_ostream &OS,
324 const char *Code) const {
325 if (!strcmp(Code, "private")) {
326 OS << MAI->getPrivateGlobalPrefix();
327 } else if (!strcmp(Code, "comment")) {
328 OS << MAI->getCommentString();
329 } else if (!strcmp(Code, "uid")) {
330 // Comparing the address of MI isn't sufficient, because machineinstrs may
331 // be allocated to the same address across functions.
333 // If this is a new LastFn instruction, bump the counter.
334 if (LastMI != MI || LastFn != getFunctionNumber()) {
337 LastFn = getFunctionNumber();
342 raw_string_ostream Msg(msg);
343 Msg << "Unknown special formatter '" << Code
344 << "' for machine instr: " << *MI;
345 report_fatal_error(Msg.str());
349 /// PrintAsmOperand - Print the specified operand of MI, an INLINEASM
350 /// instruction, using the specified assembler variant. Targets should
351 /// override this to format as appropriate.
352 bool AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
353 unsigned AsmVariant, const char *ExtraCode,
355 // Target doesn't support this yet!
359 bool AsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
361 const char *ExtraCode, raw_ostream &O) {
362 // Target doesn't support this yet!