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) 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 unsigned Cookie = 0; // no cookie yet.
61 SrcMgr.setDiagHandler((SourceMgr::DiagHandlerTy)(intptr_t)DiagHandler,
62 LLVMCtx.getInlineAsmDiagnosticContext(), Cookie);
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 llvm_report_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 llvm_report_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-1 && "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 // Emit the inline asm to a temporary string so we can emit it through
129 SmallString<256> StringData;
130 raw_svector_ostream OS(StringData);
134 // The variant of the current asmprinter.
135 int AsmPrinterVariant = MAI->getAssemblerDialect();
137 int CurVariant = -1; // The number of the {.|.|.} region we are in.
138 const char *LastEmitted = AsmStr; // One past the last character emitted.
140 while (*LastEmitted) {
141 switch (*LastEmitted) {
143 // Not a special case, emit the string section literally.
144 const char *LiteralEnd = LastEmitted+1;
145 while (*LiteralEnd && *LiteralEnd != '{' && *LiteralEnd != '|' &&
146 *LiteralEnd != '}' && *LiteralEnd != '$' && *LiteralEnd != '\n')
148 if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
149 OS.write(LastEmitted, LiteralEnd-LastEmitted);
150 LastEmitted = LiteralEnd;
154 ++LastEmitted; // Consume newline character.
155 OS << '\n'; // Indent code with newline.
158 ++LastEmitted; // Consume '$' character.
162 switch (*LastEmitted) {
163 default: Done = false; break;
165 if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
167 ++LastEmitted; // Consume second '$' character.
169 case '(': // $( -> same as GCC's { character.
170 ++LastEmitted; // Consume '(' character.
171 if (CurVariant != -1) {
172 llvm_report_error("Nested variants found in inline asm string: '"
173 + std::string(AsmStr) + "'");
175 CurVariant = 0; // We're in the first variant now.
178 ++LastEmitted; // consume '|' character.
179 if (CurVariant == -1)
180 OS << '|'; // this is gcc's behavior for | outside a variant
182 ++CurVariant; // We're in the next variant.
184 case ')': // $) -> same as GCC's } char.
185 ++LastEmitted; // consume ')' character.
186 if (CurVariant == -1)
187 OS << '}'; // this is gcc's behavior for } outside a variant
194 bool HasCurlyBraces = false;
195 if (*LastEmitted == '{') { // ${variable}
196 ++LastEmitted; // Consume '{' character.
197 HasCurlyBraces = true;
200 // If we have ${:foo}, then this is not a real operand reference, it is a
201 // "magic" string reference, just like in .td files. Arrange to call
203 if (HasCurlyBraces && *LastEmitted == ':') {
205 const char *StrStart = LastEmitted;
206 const char *StrEnd = strchr(StrStart, '}');
208 llvm_report_error(Twine("Unterminated ${:foo} operand in inline asm"
209 " string: '") + Twine(AsmStr) + "'");
211 std::string Val(StrStart, StrEnd);
212 PrintSpecial(MI, OS, Val.c_str());
213 LastEmitted = StrEnd+1;
217 const char *IDStart = LastEmitted;
218 const char *IDEnd = IDStart;
219 while (*IDEnd >= '0' && *IDEnd <= '9') ++IDEnd;
222 if (StringRef(IDStart, IDEnd-IDStart).getAsInteger(10, Val))
223 llvm_report_error("Bad $ operand number in inline asm string: '"
224 + std::string(AsmStr) + "'");
227 char Modifier[2] = { 0, 0 };
229 if (HasCurlyBraces) {
230 // If we have curly braces, check for a modifier character. This
231 // supports syntax like ${0:u}, which correspond to "%u0" in GCC asm.
232 if (*LastEmitted == ':') {
233 ++LastEmitted; // Consume ':' character.
234 if (*LastEmitted == 0)
235 llvm_report_error("Bad ${:} expression in inline asm string: '" +
236 std::string(AsmStr) + "'");
238 Modifier[0] = *LastEmitted;
239 ++LastEmitted; // Consume modifier character.
242 if (*LastEmitted != '}')
243 llvm_report_error("Bad ${} expression in inline asm string: '"
244 + std::string(AsmStr) + "'");
245 ++LastEmitted; // Consume '}' character.
248 if (Val >= NumOperands-1)
249 llvm_report_error("Invalid $ operand number in inline asm string: '"
250 + std::string(AsmStr) + "'");
252 // Okay, we finally have a value number. Ask the target to print this
254 if (CurVariant == -1 || CurVariant == AsmPrinterVariant) {
259 // Scan to find the machine operand number for the operand.
261 if (OpNo >= MI->getNumOperands()) break;
262 unsigned OpFlags = MI->getOperand(OpNo).getImm();
263 OpNo += InlineAsm::getNumOperandRegisters(OpFlags) + 1;
266 if (OpNo >= MI->getNumOperands()) {
269 unsigned OpFlags = MI->getOperand(OpNo).getImm();
270 ++OpNo; // Skip over the ID number.
272 if (Modifier[0] == 'l') // labels are target independent
273 // FIXME: What if the operand isn't an MBB, report error?
274 OS << *MI->getOperand(OpNo).getMBB()->getSymbol();
276 AsmPrinter *AP = const_cast<AsmPrinter*>(this);
277 if ((OpFlags & 7) == 4) {
278 Error = AP->PrintAsmMemoryOperand(MI, OpNo, AsmPrinterVariant,
279 Modifier[0] ? Modifier : 0,
282 Error = AP->PrintAsmOperand(MI, OpNo, AsmPrinterVariant,
283 Modifier[0] ? Modifier : 0, OS);
289 raw_string_ostream Msg(msg);
290 Msg << "Invalid operand found in inline asm: '" << AsmStr << "'\n";
292 llvm_report_error(Msg.str());
299 OS << '\n' << (char)0; // null terminate string.
300 EmitInlineAsm(OS.str());
302 // Emit the #NOAPP end marker. This has to happen even if verbose-asm isn't
303 // enabled, so we use EmitRawText.
304 if (OutStreamer.hasRawTextSupport())
305 OutStreamer.EmitRawText(Twine("\t")+MAI->getCommentString()+
306 MAI->getInlineAsmEnd());
310 /// PrintSpecial - Print information related to the specified machine instr
311 /// that is independent of the operand, and may be independent of the instr
312 /// itself. This can be useful for portably encoding the comment character
313 /// or other bits of target-specific knowledge into the asmstrings. The
314 /// syntax used is ${:comment}. Targets can override this to add support
315 /// for their own strange codes.
316 void AsmPrinter::PrintSpecial(const MachineInstr *MI, raw_ostream &OS,
317 const char *Code) const {
318 if (!strcmp(Code, "private")) {
319 OS << MAI->getPrivateGlobalPrefix();
320 } else if (!strcmp(Code, "comment")) {
321 OS << MAI->getCommentString();
322 } else if (!strcmp(Code, "uid")) {
323 // Comparing the address of MI isn't sufficient, because machineinstrs may
324 // be allocated to the same address across functions.
326 // If this is a new LastFn instruction, bump the counter.
327 if (LastMI != MI || LastFn != getFunctionNumber()) {
330 LastFn = getFunctionNumber();
335 raw_string_ostream Msg(msg);
336 Msg << "Unknown special formatter '" << Code
337 << "' for machine instr: " << *MI;
338 llvm_report_error(Msg.str());
342 /// PrintAsmOperand - Print the specified operand of MI, an INLINEASM
343 /// instruction, using the specified assembler variant. Targets should
344 /// override this to format as appropriate.
345 bool AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
346 unsigned AsmVariant, const char *ExtraCode,
348 // Target doesn't support this yet!
352 bool AsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
354 const char *ExtraCode, raw_ostream &O) {
355 // Target doesn't support this yet!