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/InlineAsm.h"
17 #include "llvm/LLVMContext.h"
18 #include "llvm/Module.h"
19 #include "llvm/CodeGen/MachineBasicBlock.h"
20 #include "llvm/CodeGen/MachineModuleInfo.h"
21 #include "llvm/MC/MCAsmInfo.h"
22 #include "llvm/MC/MCStreamer.h"
23 #include "llvm/MC/MCSymbol.h"
24 #include "llvm/MC/MCParser/AsmParser.h"
25 #include "llvm/Target/TargetAsmParser.h"
26 #include "llvm/Target/TargetMachine.h"
27 #include "llvm/Target/TargetRegistry.h"
28 #include "llvm/ADT/OwningPtr.h"
29 #include "llvm/ADT/SmallString.h"
30 #include "llvm/ADT/Twine.h"
31 #include "llvm/Support/ErrorHandling.h"
32 #include "llvm/Support/MemoryBuffer.h"
33 #include "llvm/Support/SourceMgr.h"
34 #include "llvm/Support/raw_ostream.h"
37 /// EmitInlineAsm - Emit a blob of inline asm to the output streamer.
38 void AsmPrinter::EmitInlineAsm(StringRef Str, unsigned LocCookie) const {
39 assert(!Str.empty() && "Can't emit empty inline asm block");
41 // Remember if the buffer is nul terminated or not so we can avoid a copy.
42 bool isNullTerminated = Str.back() == 0;
44 Str = Str.substr(0, Str.size()-1);
46 // If the output streamer is actually a .s file, just emit the blob textually.
47 // This is useful in case the asm parser doesn't handle something but the
48 // system assembler does.
49 if (OutStreamer.hasRawTextSupport()) {
50 OutStreamer.EmitRawText(Str);
56 // If the current LLVMContext has an inline asm handler, set it in SourceMgr.
57 LLVMContext &LLVMCtx = MMI->getModule()->getContext();
58 bool HasDiagHandler = false;
59 if (void *DiagHandler = LLVMCtx.getInlineAsmDiagnosticHandler()) {
60 SrcMgr.setDiagHandler((SourceMgr::DiagHandlerTy)(intptr_t)DiagHandler,
61 LLVMCtx.getInlineAsmDiagnosticContext(), LocCookie);
62 HasDiagHandler = true;
67 Buffer = MemoryBuffer::getMemBuffer(Str, "<inline asm>");
69 Buffer = MemoryBuffer::getMemBufferCopy(Str, "<inline asm>");
71 // Tell SrcMgr about this buffer, it takes ownership of the buffer.
72 SrcMgr.AddNewSourceBuffer(Buffer, SMLoc());
74 AsmParser Parser(SrcMgr, OutContext, OutStreamer, *MAI);
75 OwningPtr<TargetAsmParser> TAP(TM.getTarget().createAsmParser(Parser));
77 llvm_report_error("Inline asm not supported by this streamer because"
78 " we don't have an asm parser for this target\n");
79 Parser.setTargetParser(*TAP.get());
81 // Don't implicitly switch to the text section before the asm.
82 int Res = Parser.Run(/*NoInitialTextSection*/ true,
84 if (Res && !HasDiagHandler)
85 llvm_report_error("Error parsing inline asm\n");
89 /// EmitInlineAsm - This method formats and emits the specified machine
90 /// instruction that is an inline asm.
91 void AsmPrinter::EmitInlineAsm(const MachineInstr *MI) const {
92 assert(MI->isInlineAsm() && "printInlineAsm only works on inline asms");
94 unsigned NumOperands = MI->getNumOperands();
96 // Count the number of register definitions to find the asm string.
98 for (; MI->getOperand(NumDefs).isReg() && MI->getOperand(NumDefs).isDef();
100 assert(NumDefs != NumOperands-1 && "No asm string?");
102 assert(MI->getOperand(NumDefs).isSymbol() && "No asm string?");
104 // Disassemble the AsmStr, printing out the literal pieces, the operands, etc.
105 const char *AsmStr = MI->getOperand(NumDefs).getSymbolName();
107 // If this asmstr is empty, just print the #APP/#NOAPP markers.
108 // These are useful to see where empty asm's wound up.
109 if (AsmStr[0] == 0) {
110 // Don't emit the comments if writing to a .o file.
111 if (!OutStreamer.hasRawTextSupport()) return;
113 OutStreamer.EmitRawText(Twine("\t")+MAI->getCommentString()+
114 MAI->getInlineAsmStart());
115 OutStreamer.EmitRawText(Twine("\t")+MAI->getCommentString()+
116 MAI->getInlineAsmEnd());
120 // Emit the #APP start marker. This has to happen even if verbose-asm isn't
121 // enabled, so we use EmitRawText.
122 if (OutStreamer.hasRawTextSupport())
123 OutStreamer.EmitRawText(Twine("\t")+MAI->getCommentString()+
124 MAI->getInlineAsmStart());
126 // Emit the inline asm to a temporary string so we can emit it through
128 SmallString<256> StringData;
129 raw_svector_ostream OS(StringData);
133 // The variant of the current asmprinter.
134 int AsmPrinterVariant = MAI->getAssemblerDialect();
136 int CurVariant = -1; // The number of the {.|.|.} region we are in.
137 const char *LastEmitted = AsmStr; // One past the last character emitted.
139 while (*LastEmitted) {
140 switch (*LastEmitted) {
142 // Not a special case, emit the string section literally.
143 const char *LiteralEnd = LastEmitted+1;
144 while (*LiteralEnd && *LiteralEnd != '{' && *LiteralEnd != '|' &&
145 *LiteralEnd != '}' && *LiteralEnd != '$' && *LiteralEnd != '\n')
147 if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
148 OS.write(LastEmitted, LiteralEnd-LastEmitted);
149 LastEmitted = LiteralEnd;
153 ++LastEmitted; // Consume newline character.
154 OS << '\n'; // Indent code with newline.
157 ++LastEmitted; // Consume '$' character.
161 switch (*LastEmitted) {
162 default: Done = false; break;
164 if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
166 ++LastEmitted; // Consume second '$' character.
168 case '(': // $( -> same as GCC's { character.
169 ++LastEmitted; // Consume '(' character.
170 if (CurVariant != -1) {
171 llvm_report_error("Nested variants found in inline asm string: '"
172 + std::string(AsmStr) + "'");
174 CurVariant = 0; // We're in the first variant now.
177 ++LastEmitted; // consume '|' character.
178 if (CurVariant == -1)
179 OS << '|'; // this is gcc's behavior for | outside a variant
181 ++CurVariant; // We're in the next variant.
183 case ')': // $) -> same as GCC's } char.
184 ++LastEmitted; // consume ')' character.
185 if (CurVariant == -1)
186 OS << '}'; // this is gcc's behavior for } outside a variant
193 bool HasCurlyBraces = false;
194 if (*LastEmitted == '{') { // ${variable}
195 ++LastEmitted; // Consume '{' character.
196 HasCurlyBraces = true;
199 // If we have ${:foo}, then this is not a real operand reference, it is a
200 // "magic" string reference, just like in .td files. Arrange to call
202 if (HasCurlyBraces && *LastEmitted == ':') {
204 const char *StrStart = LastEmitted;
205 const char *StrEnd = strchr(StrStart, '}');
207 llvm_report_error(Twine("Unterminated ${:foo} operand in inline asm"
208 " string: '") + Twine(AsmStr) + "'");
210 std::string Val(StrStart, StrEnd);
211 PrintSpecial(MI, OS, Val.c_str());
212 LastEmitted = StrEnd+1;
216 const char *IDStart = LastEmitted;
217 const char *IDEnd = IDStart;
218 while (*IDEnd >= '0' && *IDEnd <= '9') ++IDEnd;
221 if (StringRef(IDStart, IDEnd-IDStart).getAsInteger(10, Val))
222 llvm_report_error("Bad $ operand number in inline asm string: '"
223 + std::string(AsmStr) + "'");
226 char Modifier[2] = { 0, 0 };
228 if (HasCurlyBraces) {
229 // If we have curly braces, check for a modifier character. This
230 // supports syntax like ${0:u}, which correspond to "%u0" in GCC asm.
231 if (*LastEmitted == ':') {
232 ++LastEmitted; // Consume ':' character.
233 if (*LastEmitted == 0)
234 llvm_report_error("Bad ${:} expression in inline asm string: '" +
235 std::string(AsmStr) + "'");
237 Modifier[0] = *LastEmitted;
238 ++LastEmitted; // Consume modifier character.
241 if (*LastEmitted != '}')
242 llvm_report_error("Bad ${} expression in inline asm string: '"
243 + std::string(AsmStr) + "'");
244 ++LastEmitted; // Consume '}' character.
247 if (Val >= NumOperands-1)
248 llvm_report_error("Invalid $ operand number in inline asm string: '"
249 + std::string(AsmStr) + "'");
251 // Okay, we finally have a value number. Ask the target to print this
253 if (CurVariant == -1 || CurVariant == AsmPrinterVariant) {
258 // Scan to find the machine operand number for the operand.
260 if (OpNo >= MI->getNumOperands()) break;
261 unsigned OpFlags = MI->getOperand(OpNo).getImm();
262 OpNo += InlineAsm::getNumOperandRegisters(OpFlags) + 1;
265 if (OpNo >= MI->getNumOperands()) {
268 unsigned OpFlags = MI->getOperand(OpNo).getImm();
269 ++OpNo; // Skip over the ID number.
271 if (Modifier[0] == 'l') // labels are target independent
272 // FIXME: What if the operand isn't an MBB, report error?
273 OS << *MI->getOperand(OpNo).getMBB()->getSymbol();
275 AsmPrinter *AP = const_cast<AsmPrinter*>(this);
276 if ((OpFlags & 7) == 4) {
277 Error = AP->PrintAsmMemoryOperand(MI, OpNo, AsmPrinterVariant,
278 Modifier[0] ? Modifier : 0,
281 Error = AP->PrintAsmOperand(MI, OpNo, AsmPrinterVariant,
282 Modifier[0] ? Modifier : 0, OS);
288 raw_string_ostream Msg(msg);
289 Msg << "Invalid operand found in inline asm: '" << AsmStr << "'\n";
291 llvm_report_error(Msg.str());
298 OS << '\n' << (char)0; // null terminate string.
299 EmitInlineAsm(OS.str(), 0/*no loc cookie*/);
301 // Emit the #NOAPP end marker. This has to happen even if verbose-asm isn't
302 // enabled, so we use EmitRawText.
303 if (OutStreamer.hasRawTextSupport())
304 OutStreamer.EmitRawText(Twine("\t")+MAI->getCommentString()+
305 MAI->getInlineAsmEnd());
309 /// PrintSpecial - Print information related to the specified machine instr
310 /// that is independent of the operand, and may be independent of the instr
311 /// itself. This can be useful for portably encoding the comment character
312 /// or other bits of target-specific knowledge into the asmstrings. The
313 /// syntax used is ${:comment}. Targets can override this to add support
314 /// for their own strange codes.
315 void AsmPrinter::PrintSpecial(const MachineInstr *MI, raw_ostream &OS,
316 const char *Code) const {
317 if (!strcmp(Code, "private")) {
318 OS << MAI->getPrivateGlobalPrefix();
319 } else if (!strcmp(Code, "comment")) {
320 OS << MAI->getCommentString();
321 } else if (!strcmp(Code, "uid")) {
322 // Comparing the address of MI isn't sufficient, because machineinstrs may
323 // be allocated to the same address across functions.
325 // If this is a new LastFn instruction, bump the counter.
326 if (LastMI != MI || LastFn != getFunctionNumber()) {
329 LastFn = getFunctionNumber();
334 raw_string_ostream Msg(msg);
335 Msg << "Unknown special formatter '" << Code
336 << "' for machine instr: " << *MI;
337 llvm_report_error(Msg.str());
341 /// PrintAsmOperand - Print the specified operand of MI, an INLINEASM
342 /// instruction, using the specified assembler variant. Targets should
343 /// override this to format as appropriate.
344 bool AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
345 unsigned AsmVariant, const char *ExtraCode,
347 // Target doesn't support this yet!
351 bool AsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
353 const char *ExtraCode, raw_ostream &O) {
354 // Target doesn't support this yet!