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/CodeGen/MachineBasicBlock.h"
18 #include "llvm/MC/MCAsmInfo.h"
19 #include "llvm/MC/MCStreamer.h"
20 #include "llvm/MC/MCSymbol.h"
21 #include "llvm/ADT/SmallString.h"
22 #include "llvm/ADT/Twine.h"
23 #include "llvm/Support/ErrorHandling.h"
24 #include "llvm/Support/raw_ostream.h"
27 /// EmitInlineAsm - Emit a blob of inline asm to the output streamer.
28 void AsmPrinter::EmitInlineAsm(StringRef Str) const {
29 assert(!Str.empty() && "Can't emit empty inline asm block");
31 // If the output streamer is actually a .s file, just emit the blob textually.
32 // This is useful in case the asm parser doesn't handle something but the
33 // system assembler does.
34 if (OutStreamer.hasRawTextSupport()) {
35 OutStreamer.EmitRawText(Str);
39 errs() << "Inline asm not supported by this streamer!\n";
43 /// EmitInlineAsm - This method formats and emits the specified machine
44 /// instruction that is an inline asm.
45 void AsmPrinter::EmitInlineAsm(const MachineInstr *MI) const {
46 assert(MI->isInlineAsm() && "printInlineAsm only works on inline asms");
48 unsigned NumOperands = MI->getNumOperands();
50 // Count the number of register definitions to find the asm string.
52 for (; MI->getOperand(NumDefs).isReg() && MI->getOperand(NumDefs).isDef();
54 assert(NumDefs != NumOperands-1 && "No asm string?");
56 assert(MI->getOperand(NumDefs).isSymbol() && "No asm string?");
58 // Disassemble the AsmStr, printing out the literal pieces, the operands, etc.
59 const char *AsmStr = MI->getOperand(NumDefs).getSymbolName();
61 // If this asmstr is empty, just print the #APP/#NOAPP markers.
62 // These are useful to see where empty asm's wound up.
64 // Don't emit the comments if writing to a .o file.
65 if (!OutStreamer.hasRawTextSupport()) return;
67 OutStreamer.EmitRawText(Twine("\t")+MAI->getCommentString()+
68 MAI->getInlineAsmStart());
69 OutStreamer.EmitRawText(Twine("\t")+MAI->getCommentString()+
70 MAI->getInlineAsmEnd());
74 // Emit the #APP start marker. This has to happen even if verbose-asm isn't
75 // enabled, so we use EmitRawText.
76 if (OutStreamer.hasRawTextSupport())
77 OutStreamer.EmitRawText(Twine("\t")+MAI->getCommentString()+
78 MAI->getInlineAsmStart());
80 // Emit the inline asm to a temporary string so we can emit it through
82 SmallString<256> StringData;
83 raw_svector_ostream OS(StringData);
87 // The variant of the current asmprinter.
88 int AsmPrinterVariant = MAI->getAssemblerDialect();
90 int CurVariant = -1; // The number of the {.|.|.} region we are in.
91 const char *LastEmitted = AsmStr; // One past the last character emitted.
93 while (*LastEmitted) {
94 switch (*LastEmitted) {
96 // Not a special case, emit the string section literally.
97 const char *LiteralEnd = LastEmitted+1;
98 while (*LiteralEnd && *LiteralEnd != '{' && *LiteralEnd != '|' &&
99 *LiteralEnd != '}' && *LiteralEnd != '$' && *LiteralEnd != '\n')
101 if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
102 OS.write(LastEmitted, LiteralEnd-LastEmitted);
103 LastEmitted = LiteralEnd;
107 ++LastEmitted; // Consume newline character.
108 OS << '\n'; // Indent code with newline.
111 ++LastEmitted; // Consume '$' character.
115 switch (*LastEmitted) {
116 default: Done = false; break;
118 if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
120 ++LastEmitted; // Consume second '$' character.
122 case '(': // $( -> same as GCC's { character.
123 ++LastEmitted; // Consume '(' character.
124 if (CurVariant != -1) {
125 llvm_report_error("Nested variants found in inline asm string: '"
126 + std::string(AsmStr) + "'");
128 CurVariant = 0; // We're in the first variant now.
131 ++LastEmitted; // consume '|' character.
132 if (CurVariant == -1)
133 OS << '|'; // this is gcc's behavior for | outside a variant
135 ++CurVariant; // We're in the next variant.
137 case ')': // $) -> same as GCC's } char.
138 ++LastEmitted; // consume ')' character.
139 if (CurVariant == -1)
140 OS << '}'; // this is gcc's behavior for } outside a variant
147 bool HasCurlyBraces = false;
148 if (*LastEmitted == '{') { // ${variable}
149 ++LastEmitted; // Consume '{' character.
150 HasCurlyBraces = true;
153 // If we have ${:foo}, then this is not a real operand reference, it is a
154 // "magic" string reference, just like in .td files. Arrange to call
156 if (HasCurlyBraces && *LastEmitted == ':') {
158 const char *StrStart = LastEmitted;
159 const char *StrEnd = strchr(StrStart, '}');
161 llvm_report_error(Twine("Unterminated ${:foo} operand in inline asm"
162 " string: '") + Twine(AsmStr) + "'");
164 std::string Val(StrStart, StrEnd);
165 PrintSpecial(MI, OS, Val.c_str());
166 LastEmitted = StrEnd+1;
170 const char *IDStart = LastEmitted;
171 const char *IDEnd = IDStart;
172 while (*IDEnd >= '0' && *IDEnd <= '9') ++IDEnd;
175 if (StringRef(IDStart, IDEnd-IDStart).getAsInteger(10, Val))
176 llvm_report_error("Bad $ operand number in inline asm string: '"
177 + std::string(AsmStr) + "'");
180 char Modifier[2] = { 0, 0 };
182 if (HasCurlyBraces) {
183 // If we have curly braces, check for a modifier character. This
184 // supports syntax like ${0:u}, which correspond to "%u0" in GCC asm.
185 if (*LastEmitted == ':') {
186 ++LastEmitted; // Consume ':' character.
187 if (*LastEmitted == 0)
188 llvm_report_error("Bad ${:} expression in inline asm string: '" +
189 std::string(AsmStr) + "'");
191 Modifier[0] = *LastEmitted;
192 ++LastEmitted; // Consume modifier character.
195 if (*LastEmitted != '}')
196 llvm_report_error("Bad ${} expression in inline asm string: '"
197 + std::string(AsmStr) + "'");
198 ++LastEmitted; // Consume '}' character.
201 if (Val >= NumOperands-1)
202 llvm_report_error("Invalid $ operand number in inline asm string: '"
203 + std::string(AsmStr) + "'");
205 // Okay, we finally have a value number. Ask the target to print this
207 if (CurVariant == -1 || CurVariant == AsmPrinterVariant) {
212 // Scan to find the machine operand number for the operand.
214 if (OpNo >= MI->getNumOperands()) break;
215 unsigned OpFlags = MI->getOperand(OpNo).getImm();
216 OpNo += InlineAsm::getNumOperandRegisters(OpFlags) + 1;
219 if (OpNo >= MI->getNumOperands()) {
222 unsigned OpFlags = MI->getOperand(OpNo).getImm();
223 ++OpNo; // Skip over the ID number.
225 if (Modifier[0] == 'l') // labels are target independent
226 // FIXME: What if the operand isn't an MBB, report error?
227 OS << *MI->getOperand(OpNo).getMBB()->getSymbol();
229 AsmPrinter *AP = const_cast<AsmPrinter*>(this);
230 if ((OpFlags & 7) == 4) {
231 Error = AP->PrintAsmMemoryOperand(MI, OpNo, AsmPrinterVariant,
232 Modifier[0] ? Modifier : 0,
235 Error = AP->PrintAsmOperand(MI, OpNo, AsmPrinterVariant,
236 Modifier[0] ? Modifier : 0, OS);
242 raw_string_ostream Msg(msg);
243 Msg << "Invalid operand found in inline asm: '" << AsmStr << "'\n";
245 llvm_report_error(Msg.str());
254 EmitInlineAsm(OS.str());
256 // Emit the #NOAPP end marker. This has to happen even if verbose-asm isn't
257 // enabled, so we use EmitRawText.
258 if (OutStreamer.hasRawTextSupport())
259 OutStreamer.EmitRawText(Twine("\t")+MAI->getCommentString()+
260 MAI->getInlineAsmEnd());
264 /// PrintSpecial - Print information related to the specified machine instr
265 /// that is independent of the operand, and may be independent of the instr
266 /// itself. This can be useful for portably encoding the comment character
267 /// or other bits of target-specific knowledge into the asmstrings. The
268 /// syntax used is ${:comment}. Targets can override this to add support
269 /// for their own strange codes.
270 void AsmPrinter::PrintSpecial(const MachineInstr *MI, raw_ostream &OS,
271 const char *Code) const {
272 if (!strcmp(Code, "private")) {
273 OS << MAI->getPrivateGlobalPrefix();
274 } else if (!strcmp(Code, "comment")) {
275 OS << MAI->getCommentString();
276 } else if (!strcmp(Code, "uid")) {
277 // Comparing the address of MI isn't sufficient, because machineinstrs may
278 // be allocated to the same address across functions.
280 // If this is a new LastFn instruction, bump the counter.
281 if (LastMI != MI || LastFn != getFunctionNumber()) {
284 LastFn = getFunctionNumber();
289 raw_string_ostream Msg(msg);
290 Msg << "Unknown special formatter '" << Code
291 << "' for machine instr: " << *MI;
292 llvm_report_error(Msg.str());
296 /// PrintAsmOperand - Print the specified operand of MI, an INLINEASM
297 /// instruction, using the specified assembler variant. Targets should
298 /// override this to format as appropriate.
299 bool AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
300 unsigned AsmVariant, const char *ExtraCode,
302 // Target doesn't support this yet!
306 bool AsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
308 const char *ExtraCode, raw_ostream &O) {
309 // Target doesn't support this yet!