1 //===- MILexer.cpp - Machine instructions lexer implementation ----------===//
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 lexing of machine instructions.
12 //===----------------------------------------------------------------------===//
15 #include "llvm/ADT/StringExtras.h"
16 #include "llvm/ADT/StringSwitch.h"
17 #include "llvm/ADT/Twine.h"
24 /// This class provides a way to iterate and get characters from the source
31 Cursor(NoneType) : Ptr(nullptr), End(nullptr) {}
33 explicit Cursor(StringRef Str) {
35 End = Ptr + Str.size();
38 bool isEOF() const { return Ptr == End; }
40 char peek(int I = 0) const { return End - Ptr <= I ? 0 : Ptr[I]; }
42 void advance(unsigned I = 1) { Ptr += I; }
44 StringRef remaining() const { return StringRef(Ptr, End - Ptr); }
46 StringRef upto(Cursor C) const {
47 assert(C.Ptr >= Ptr && C.Ptr <= End);
48 return StringRef(Ptr, C.Ptr - Ptr);
51 StringRef::iterator location() const { return Ptr; }
53 operator bool() const { return Ptr != nullptr; }
56 } // end anonymous namespace
58 /// Skip the leading whitespace characters and return the updated cursor.
59 static Cursor skipWhitespace(Cursor C) {
60 while (isspace(C.peek()))
65 /// Return true if the given character satisfies the following regular
66 /// expression: [-a-zA-Z$._0-9]
67 static bool isIdentifierChar(char C) {
68 return isalpha(C) || isdigit(C) || C == '_' || C == '-' || C == '.' ||
72 void MIToken::unescapeQuotedStringValue(std::string &Str) const {
73 assert(isStringValueQuoted() && "String value isn't quoted");
74 StringRef Value = Range.drop_front(StringOffset);
75 assert(Value.front() == '"' && Value.back() == '"');
76 Cursor C = Cursor(Value.substr(1, Value.size() - 2));
79 Str.reserve(C.remaining().size());
83 if (C.peek(1) == '\\') {
89 if (isxdigit(C.peek(1)) && isxdigit(C.peek(2))) {
90 Str += hexDigitValue(C.peek(1)) * 16 + hexDigitValue(C.peek(2));
100 /// Lex a string constant using the following regular expression: \"[^\"]*\"
101 static Cursor lexStringConstant(
103 function_ref<void(StringRef::iterator Loc, const Twine &)> ErrorCallback) {
104 assert(C.peek() == '"');
105 for (C.advance(); C.peek() != '"'; C.advance()) {
109 "end of machine instruction reached before the closing '\"'");
117 static MIToken::TokenKind getIdentifierKind(StringRef Identifier) {
118 return StringSwitch<MIToken::TokenKind>(Identifier)
119 .Case("_", MIToken::underscore)
120 .Case("implicit", MIToken::kw_implicit)
121 .Case("implicit-def", MIToken::kw_implicit_define)
122 .Case("dead", MIToken::kw_dead)
123 .Case("killed", MIToken::kw_killed)
124 .Case("undef", MIToken::kw_undef)
125 .Case("frame-setup", MIToken::kw_frame_setup)
126 .Case(".cfi_def_cfa_offset", MIToken::kw_cfi_def_cfa_offset)
127 .Default(MIToken::Identifier);
130 static Cursor maybeLexIdentifier(Cursor C, MIToken &Token) {
131 if (!isalpha(C.peek()) && C.peek() != '_' && C.peek() != '.')
134 while (isIdentifierChar(C.peek()))
136 auto Identifier = Range.upto(C);
137 Token = MIToken(getIdentifierKind(Identifier), Identifier);
141 static Cursor maybeLexMachineBasicBlock(
142 Cursor C, MIToken &Token,
143 function_ref<void(StringRef::iterator Loc, const Twine &)> ErrorCallback) {
144 if (!C.remaining().startswith("%bb."))
147 C.advance(4); // Skip '%bb.'
148 if (!isdigit(C.peek())) {
149 Token = MIToken(MIToken::Error, C.remaining());
150 ErrorCallback(C.location(), "expected a number after '%bb.'");
153 auto NumberRange = C;
154 while (isdigit(C.peek()))
156 StringRef Number = NumberRange.upto(C);
157 unsigned StringOffset = 4 + Number.size(); // Drop '%bb.<id>'
158 if (C.peek() == '.') {
159 C.advance(); // Skip '.'
161 while (isIdentifierChar(C.peek()))
164 Token = MIToken(MIToken::MachineBasicBlock, Range.upto(C), APSInt(Number),
169 static Cursor maybeLexIndex(Cursor C, MIToken &Token, StringRef Rule,
170 MIToken::TokenKind Kind) {
171 if (!C.remaining().startswith(Rule) || !isdigit(C.peek(Rule.size())))
174 C.advance(Rule.size());
175 auto NumberRange = C;
176 while (isdigit(C.peek()))
178 Token = MIToken(Kind, Range.upto(C), APSInt(NumberRange.upto(C)));
182 static Cursor maybeLexIndexAndName(Cursor C, MIToken &Token, StringRef Rule,
183 MIToken::TokenKind Kind) {
184 if (!C.remaining().startswith(Rule) || !isdigit(C.peek(Rule.size())))
187 C.advance(Rule.size());
188 auto NumberRange = C;
189 while (isdigit(C.peek()))
191 StringRef Number = NumberRange.upto(C);
192 unsigned StringOffset = Rule.size() + Number.size();
193 if (C.peek() == '.') {
196 while (isIdentifierChar(C.peek()))
199 Token = MIToken(Kind, Range.upto(C), APSInt(Number), StringOffset);
203 static Cursor maybeLexJumpTableIndex(Cursor C, MIToken &Token) {
204 return maybeLexIndex(C, Token, "%jump-table.", MIToken::JumpTableIndex);
207 static Cursor maybeLexStackObject(Cursor C, MIToken &Token) {
208 return maybeLexIndexAndName(C, Token, "%stack.", MIToken::StackObject);
211 static Cursor maybeLexFixedStackObject(Cursor C, MIToken &Token) {
212 return maybeLexIndex(C, Token, "%fixed-stack.", MIToken::FixedStackObject);
215 static Cursor maybeLexConstantPoolItem(Cursor C, MIToken &Token) {
216 return maybeLexIndex(C, Token, "%const.", MIToken::ConstantPoolItem);
219 static Cursor lexVirtualRegister(Cursor C, MIToken &Token) {
221 C.advance(); // Skip '%'
222 auto NumberRange = C;
223 while (isdigit(C.peek()))
225 Token = MIToken(MIToken::VirtualRegister, Range.upto(C),
226 APSInt(NumberRange.upto(C)));
230 static Cursor maybeLexRegister(Cursor C, MIToken &Token) {
233 if (isdigit(C.peek(1)))
234 return lexVirtualRegister(C, Token);
236 C.advance(); // Skip '%'
237 while (isIdentifierChar(C.peek()))
239 Token = MIToken(MIToken::NamedRegister, Range.upto(C),
240 /*StringOffset=*/1); // Drop the '%'
244 static Cursor lexName(
245 Cursor C, MIToken &Token, MIToken::TokenKind Type,
246 MIToken::TokenKind QuotedType, unsigned PrefixLength,
247 function_ref<void(StringRef::iterator Loc, const Twine &)> ErrorCallback) {
249 C.advance(PrefixLength);
250 if (C.peek() == '"') {
251 if (Cursor R = lexStringConstant(C, ErrorCallback)) {
252 Token = MIToken(QuotedType, Range.upto(R), PrefixLength);
255 Token = MIToken(MIToken::Error, Range.remaining());
258 while (isIdentifierChar(C.peek()))
260 Token = MIToken(Type, Range.upto(C), PrefixLength);
264 static Cursor maybeLexGlobalValue(
265 Cursor C, MIToken &Token,
266 function_ref<void(StringRef::iterator Loc, const Twine &)> ErrorCallback) {
269 if (!isdigit(C.peek(1)))
270 return lexName(C, Token, MIToken::NamedGlobalValue,
271 MIToken::QuotedNamedGlobalValue, /*PrefixLength=*/1,
274 C.advance(1); // Skip the '@'
275 auto NumberRange = C;
276 while (isdigit(C.peek()))
279 MIToken(MIToken::GlobalValue, Range.upto(C), APSInt(NumberRange.upto(C)));
283 static Cursor maybeLexExternalSymbol(
284 Cursor C, MIToken &Token,
285 function_ref<void(StringRef::iterator Loc, const Twine &)> ErrorCallback) {
288 return lexName(C, Token, MIToken::ExternalSymbol,
289 MIToken::QuotedExternalSymbol,
290 /*PrefixLength=*/1, ErrorCallback);
293 static Cursor maybeLexIntegerLiteral(Cursor C, MIToken &Token) {
294 if (!isdigit(C.peek()) && (C.peek() != '-' || !isdigit(C.peek(1))))
298 while (isdigit(C.peek()))
300 StringRef StrVal = Range.upto(C);
301 Token = MIToken(MIToken::IntegerLiteral, StrVal, APSInt(StrVal));
305 static MIToken::TokenKind symbolToken(char C) {
308 return MIToken::comma;
310 return MIToken::equal;
312 return MIToken::colon;
314 return MIToken::Error;
318 static Cursor maybeLexSymbol(Cursor C, MIToken &Token) {
319 auto Kind = symbolToken(C.peek());
320 if (Kind == MIToken::Error)
324 Token = MIToken(Kind, Range.upto(C));
328 StringRef llvm::lexMIToken(
329 StringRef Source, MIToken &Token,
330 function_ref<void(StringRef::iterator Loc, const Twine &)> ErrorCallback) {
331 auto C = skipWhitespace(Cursor(Source));
333 Token = MIToken(MIToken::Eof, C.remaining());
334 return C.remaining();
337 if (Cursor R = maybeLexIdentifier(C, Token))
338 return R.remaining();
339 if (Cursor R = maybeLexMachineBasicBlock(C, Token, ErrorCallback))
340 return R.remaining();
341 if (Cursor R = maybeLexJumpTableIndex(C, Token))
342 return R.remaining();
343 if (Cursor R = maybeLexStackObject(C, Token))
344 return R.remaining();
345 if (Cursor R = maybeLexFixedStackObject(C, Token))
346 return R.remaining();
347 if (Cursor R = maybeLexConstantPoolItem(C, Token))
348 return R.remaining();
349 if (Cursor R = maybeLexRegister(C, Token))
350 return R.remaining();
351 if (Cursor R = maybeLexGlobalValue(C, Token, ErrorCallback))
352 return R.remaining();
353 if (Cursor R = maybeLexExternalSymbol(C, Token, ErrorCallback))
354 return R.remaining();
355 if (Cursor R = maybeLexIntegerLiteral(C, Token))
356 return R.remaining();
357 if (Cursor R = maybeLexSymbol(C, Token))
358 return R.remaining();
360 Token = MIToken(MIToken::Error, C.remaining());
361 ErrorCallback(C.location(),
362 Twine("unexpected character '") + Twine(C.peek()) + "'");
363 return C.remaining();