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/StringSwitch.h"
16 #include "llvm/ADT/Twine.h"
23 /// This class provides a way to iterate and get characters from the source
30 Cursor(NoneType) : Ptr(nullptr), End(nullptr) {}
32 explicit Cursor(StringRef Str) {
34 End = Ptr + Str.size();
37 bool isEOF() const { return Ptr == End; }
39 char peek(int I = 0) const { return End - Ptr <= I ? 0 : Ptr[I]; }
41 void advance(unsigned I = 1) { Ptr += I; }
43 StringRef remaining() const { return StringRef(Ptr, End - Ptr); }
45 StringRef upto(Cursor C) const {
46 assert(C.Ptr >= Ptr && C.Ptr <= End);
47 return StringRef(Ptr, C.Ptr - Ptr);
50 StringRef::iterator location() const { return Ptr; }
52 operator bool() const { return Ptr != nullptr; }
55 } // end anonymous namespace
57 /// Skip the leading whitespace characters and return the updated cursor.
58 static Cursor skipWhitespace(Cursor C) {
59 while (isspace(C.peek()))
64 static bool isIdentifierChar(char C) {
65 return isalpha(C) || isdigit(C) || C == '_' || C == '-' || C == '.';
68 static MIToken::TokenKind getIdentifierKind(StringRef Identifier) {
69 return StringSwitch<MIToken::TokenKind>(Identifier)
70 .Case("_", MIToken::underscore)
71 .Case("implicit", MIToken::kw_implicit)
72 .Case("implicit-def", MIToken::kw_implicit_define)
73 .Default(MIToken::Identifier);
76 static Cursor maybeLexIdentifier(Cursor C, MIToken &Token) {
77 if (!isalpha(C.peek()) && C.peek() != '_')
80 while (isIdentifierChar(C.peek()))
82 auto Identifier = Range.upto(C);
83 Token = MIToken(getIdentifierKind(Identifier), Identifier);
87 static Cursor maybeLexMachineBasicBlock(
88 Cursor C, MIToken &Token,
89 function_ref<void(StringRef::iterator Loc, const Twine &)> ErrorCallback) {
90 if (!C.remaining().startswith("%bb."))
93 C.advance(4); // Skip '%bb.'
94 if (!isdigit(C.peek())) {
95 Token = MIToken(MIToken::Error, C.remaining());
96 ErrorCallback(C.location(), "expected a number after '%bb.'");
100 while (isdigit(C.peek()))
102 StringRef Number = NumberRange.upto(C);
103 unsigned StringOffset = 4 + Number.size(); // Drop '%bb.<id>'
104 if (C.peek() == '.') {
105 C.advance(); // Skip '.'
107 while (isIdentifierChar(C.peek()))
110 Token = MIToken(MIToken::MachineBasicBlock, Range.upto(C), APSInt(Number),
115 static Cursor maybeLexRegister(Cursor C, MIToken &Token) {
119 C.advance(); // Skip '%'
120 while (isIdentifierChar(C.peek()))
122 Token = MIToken(MIToken::NamedRegister, Range.upto(C),
123 /*StringOffset=*/1); // Drop the '%'
127 static Cursor maybeLexGlobalValue(Cursor C, MIToken &Token) {
131 C.advance(); // Skip the '@'
132 // TODO: add support for quoted names.
133 if (!isdigit(C.peek())) {
134 while (isIdentifierChar(C.peek()))
136 Token = MIToken(MIToken::NamedGlobalValue, Range.upto(C),
137 /*StringOffset=*/1); // Drop the '@'
140 auto NumberRange = C;
141 while (isdigit(C.peek()))
144 MIToken(MIToken::GlobalValue, Range.upto(C), APSInt(NumberRange.upto(C)));
148 static Cursor maybeLexIntegerLiteral(Cursor C, MIToken &Token) {
149 if (!isdigit(C.peek()) && (C.peek() != '-' || !isdigit(C.peek(1))))
153 while (isdigit(C.peek()))
155 StringRef StrVal = Range.upto(C);
156 Token = MIToken(MIToken::IntegerLiteral, StrVal, APSInt(StrVal));
160 static MIToken::TokenKind symbolToken(char C) {
163 return MIToken::comma;
165 return MIToken::equal;
167 return MIToken::Error;
171 static Cursor maybeLexSymbol(Cursor C, MIToken &Token) {
172 auto Kind = symbolToken(C.peek());
173 if (Kind == MIToken::Error)
177 Token = MIToken(Kind, Range.upto(C));
181 StringRef llvm::lexMIToken(
182 StringRef Source, MIToken &Token,
183 function_ref<void(StringRef::iterator Loc, const Twine &)> ErrorCallback) {
184 auto C = skipWhitespace(Cursor(Source));
186 Token = MIToken(MIToken::Eof, C.remaining());
187 return C.remaining();
190 if (Cursor R = maybeLexIdentifier(C, Token))
191 return R.remaining();
192 if (Cursor R = maybeLexMachineBasicBlock(C, Token, ErrorCallback))
193 return R.remaining();
194 if (Cursor R = maybeLexRegister(C, Token))
195 return R.remaining();
196 if (Cursor R = maybeLexGlobalValue(C, Token))
197 return R.remaining();
198 if (Cursor R = maybeLexIntegerLiteral(C, Token))
199 return R.remaining();
200 if (Cursor R = maybeLexSymbol(C, Token))
201 return R.remaining();
203 Token = MIToken(MIToken::Error, C.remaining());
204 ErrorCallback(C.location(),
205 Twine("unexpected character '") + Twine(C.peek()) + "'");
206 return C.remaining();