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 .Default(MIToken::Identifier);
129 static Cursor maybeLexIdentifier(Cursor C, MIToken &Token) {
130 if (!isalpha(C.peek()) && C.peek() != '_')
133 while (isIdentifierChar(C.peek()))
135 auto Identifier = Range.upto(C);
136 Token = MIToken(getIdentifierKind(Identifier), Identifier);
140 static Cursor maybeLexMachineBasicBlock(
141 Cursor C, MIToken &Token,
142 function_ref<void(StringRef::iterator Loc, const Twine &)> ErrorCallback) {
143 if (!C.remaining().startswith("%bb."))
146 C.advance(4); // Skip '%bb.'
147 if (!isdigit(C.peek())) {
148 Token = MIToken(MIToken::Error, C.remaining());
149 ErrorCallback(C.location(), "expected a number after '%bb.'");
152 auto NumberRange = C;
153 while (isdigit(C.peek()))
155 StringRef Number = NumberRange.upto(C);
156 unsigned StringOffset = 4 + Number.size(); // Drop '%bb.<id>'
157 if (C.peek() == '.') {
158 C.advance(); // Skip '.'
160 while (isIdentifierChar(C.peek()))
163 Token = MIToken(MIToken::MachineBasicBlock, Range.upto(C), APSInt(Number),
168 static Cursor maybeLexIndex(Cursor C, MIToken &Token, StringRef Rule,
169 MIToken::TokenKind Kind) {
170 if (!C.remaining().startswith(Rule) || !isdigit(C.peek(Rule.size())))
173 C.advance(Rule.size());
174 auto NumberRange = C;
175 while (isdigit(C.peek()))
177 Token = MIToken(Kind, Range.upto(C), APSInt(NumberRange.upto(C)));
181 static Cursor maybeLexIndexAndName(Cursor C, MIToken &Token, StringRef Rule,
182 MIToken::TokenKind Kind) {
183 if (!C.remaining().startswith(Rule) || !isdigit(C.peek(Rule.size())))
186 C.advance(Rule.size());
187 auto NumberRange = C;
188 while (isdigit(C.peek()))
190 StringRef Number = NumberRange.upto(C);
191 unsigned StringOffset = Rule.size() + Number.size();
192 if (C.peek() == '.') {
195 while (isIdentifierChar(C.peek()))
198 Token = MIToken(Kind, Range.upto(C), APSInt(Number), StringOffset);
202 static Cursor maybeLexJumpTableIndex(Cursor C, MIToken &Token) {
203 return maybeLexIndex(C, Token, "%jump-table.", MIToken::JumpTableIndex);
206 static Cursor maybeLexStackObject(Cursor C, MIToken &Token) {
207 return maybeLexIndexAndName(C, Token, "%stack.", MIToken::StackObject);
210 static Cursor maybeLexFixedStackObject(Cursor C, MIToken &Token) {
211 return maybeLexIndex(C, Token, "%fixed-stack.", MIToken::FixedStackObject);
214 static Cursor lexVirtualRegister(Cursor C, MIToken &Token) {
216 C.advance(); // Skip '%'
217 auto NumberRange = C;
218 while (isdigit(C.peek()))
220 Token = MIToken(MIToken::VirtualRegister, Range.upto(C),
221 APSInt(NumberRange.upto(C)));
225 static Cursor maybeLexRegister(Cursor C, MIToken &Token) {
228 if (isdigit(C.peek(1)))
229 return lexVirtualRegister(C, Token);
231 C.advance(); // Skip '%'
232 while (isIdentifierChar(C.peek()))
234 Token = MIToken(MIToken::NamedRegister, Range.upto(C),
235 /*StringOffset=*/1); // Drop the '%'
239 static Cursor maybeLexGlobalValue(
240 Cursor C, MIToken &Token,
241 function_ref<void(StringRef::iterator Loc, const Twine &)> ErrorCallback) {
245 C.advance(); // Skip the '@'
246 if (C.peek() == '"') {
247 if (Cursor R = lexStringConstant(C, ErrorCallback)) {
248 Token = MIToken(MIToken::QuotedNamedGlobalValue, Range.upto(R),
249 /*StringOffset=*/1); // Drop the '@'
252 Token = MIToken(MIToken::Error, Range.remaining());
255 if (!isdigit(C.peek())) {
256 while (isIdentifierChar(C.peek()))
258 Token = MIToken(MIToken::NamedGlobalValue, Range.upto(C),
259 /*StringOffset=*/1); // Drop the '@'
262 auto NumberRange = C;
263 while (isdigit(C.peek()))
266 MIToken(MIToken::GlobalValue, Range.upto(C), APSInt(NumberRange.upto(C)));
270 static Cursor maybeLexIntegerLiteral(Cursor C, MIToken &Token) {
271 if (!isdigit(C.peek()) && (C.peek() != '-' || !isdigit(C.peek(1))))
275 while (isdigit(C.peek()))
277 StringRef StrVal = Range.upto(C);
278 Token = MIToken(MIToken::IntegerLiteral, StrVal, APSInt(StrVal));
282 static MIToken::TokenKind symbolToken(char C) {
285 return MIToken::comma;
287 return MIToken::equal;
289 return MIToken::colon;
291 return MIToken::Error;
295 static Cursor maybeLexSymbol(Cursor C, MIToken &Token) {
296 auto Kind = symbolToken(C.peek());
297 if (Kind == MIToken::Error)
301 Token = MIToken(Kind, Range.upto(C));
305 StringRef llvm::lexMIToken(
306 StringRef Source, MIToken &Token,
307 function_ref<void(StringRef::iterator Loc, const Twine &)> ErrorCallback) {
308 auto C = skipWhitespace(Cursor(Source));
310 Token = MIToken(MIToken::Eof, C.remaining());
311 return C.remaining();
314 if (Cursor R = maybeLexIdentifier(C, Token))
315 return R.remaining();
316 if (Cursor R = maybeLexMachineBasicBlock(C, Token, ErrorCallback))
317 return R.remaining();
318 if (Cursor R = maybeLexJumpTableIndex(C, Token))
319 return R.remaining();
320 if (Cursor R = maybeLexStackObject(C, Token))
321 return R.remaining();
322 if (Cursor R = maybeLexFixedStackObject(C, Token))
323 return R.remaining();
324 if (Cursor R = maybeLexRegister(C, Token))
325 return R.remaining();
326 if (Cursor R = maybeLexGlobalValue(C, Token, ErrorCallback))
327 return R.remaining();
328 if (Cursor R = maybeLexIntegerLiteral(C, Token))
329 return R.remaining();
330 if (Cursor R = maybeLexSymbol(C, Token))
331 return R.remaining();
333 Token = MIToken(MIToken::Error, C.remaining());
334 ErrorCallback(C.location(),
335 Twine("unexpected character '") + Twine(C.peek()) + "'");
336 return C.remaining();