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 .Case("dead", MIToken::kw_dead)
74 .Case("killed", MIToken::kw_killed)
75 .Case("undef", MIToken::kw_undef)
76 .Default(MIToken::Identifier);
79 static Cursor maybeLexIdentifier(Cursor C, MIToken &Token) {
80 if (!isalpha(C.peek()) && C.peek() != '_')
83 while (isIdentifierChar(C.peek()))
85 auto Identifier = Range.upto(C);
86 Token = MIToken(getIdentifierKind(Identifier), Identifier);
90 static Cursor maybeLexMachineBasicBlock(
91 Cursor C, MIToken &Token,
92 function_ref<void(StringRef::iterator Loc, const Twine &)> ErrorCallback) {
93 if (!C.remaining().startswith("%bb."))
96 C.advance(4); // Skip '%bb.'
97 if (!isdigit(C.peek())) {
98 Token = MIToken(MIToken::Error, C.remaining());
99 ErrorCallback(C.location(), "expected a number after '%bb.'");
102 auto NumberRange = C;
103 while (isdigit(C.peek()))
105 StringRef Number = NumberRange.upto(C);
106 unsigned StringOffset = 4 + Number.size(); // Drop '%bb.<id>'
107 if (C.peek() == '.') {
108 C.advance(); // Skip '.'
110 while (isIdentifierChar(C.peek()))
113 Token = MIToken(MIToken::MachineBasicBlock, Range.upto(C), APSInt(Number),
118 static Cursor maybeLexIndex(Cursor C, MIToken &Token, StringRef Rule,
119 MIToken::TokenKind Kind) {
120 if (!C.remaining().startswith(Rule) || !isdigit(C.peek(Rule.size())))
123 C.advance(Rule.size());
124 auto NumberRange = C;
125 while (isdigit(C.peek()))
127 Token = MIToken(Kind, Range.upto(C), APSInt(NumberRange.upto(C)));
131 static Cursor maybeLexJumpTableIndex(Cursor C, MIToken &Token) {
132 return maybeLexIndex(C, Token, "%jump-table.", MIToken::JumpTableIndex);
135 static Cursor lexVirtualRegister(Cursor C, MIToken &Token) {
137 C.advance(); // Skip '%'
138 auto NumberRange = C;
139 while (isdigit(C.peek()))
141 Token = MIToken(MIToken::VirtualRegister, Range.upto(C),
142 APSInt(NumberRange.upto(C)));
146 static Cursor maybeLexRegister(Cursor C, MIToken &Token) {
149 if (isdigit(C.peek(1)))
150 return lexVirtualRegister(C, Token);
152 C.advance(); // Skip '%'
153 while (isIdentifierChar(C.peek()))
155 Token = MIToken(MIToken::NamedRegister, Range.upto(C),
156 /*StringOffset=*/1); // Drop the '%'
160 static Cursor maybeLexGlobalValue(Cursor C, MIToken &Token) {
164 C.advance(); // Skip the '@'
165 // TODO: add support for quoted names.
166 if (!isdigit(C.peek())) {
167 while (isIdentifierChar(C.peek()))
169 Token = MIToken(MIToken::NamedGlobalValue, Range.upto(C),
170 /*StringOffset=*/1); // Drop the '@'
173 auto NumberRange = C;
174 while (isdigit(C.peek()))
177 MIToken(MIToken::GlobalValue, Range.upto(C), APSInt(NumberRange.upto(C)));
181 static Cursor maybeLexIntegerLiteral(Cursor C, MIToken &Token) {
182 if (!isdigit(C.peek()) && (C.peek() != '-' || !isdigit(C.peek(1))))
186 while (isdigit(C.peek()))
188 StringRef StrVal = Range.upto(C);
189 Token = MIToken(MIToken::IntegerLiteral, StrVal, APSInt(StrVal));
193 static MIToken::TokenKind symbolToken(char C) {
196 return MIToken::comma;
198 return MIToken::equal;
200 return MIToken::colon;
202 return MIToken::Error;
206 static Cursor maybeLexSymbol(Cursor C, MIToken &Token) {
207 auto Kind = symbolToken(C.peek());
208 if (Kind == MIToken::Error)
212 Token = MIToken(Kind, Range.upto(C));
216 StringRef llvm::lexMIToken(
217 StringRef Source, MIToken &Token,
218 function_ref<void(StringRef::iterator Loc, const Twine &)> ErrorCallback) {
219 auto C = skipWhitespace(Cursor(Source));
221 Token = MIToken(MIToken::Eof, C.remaining());
222 return C.remaining();
225 if (Cursor R = maybeLexIdentifier(C, Token))
226 return R.remaining();
227 if (Cursor R = maybeLexMachineBasicBlock(C, Token, ErrorCallback))
228 return R.remaining();
229 if (Cursor R = maybeLexJumpTableIndex(C, Token))
230 return R.remaining();
231 if (Cursor R = maybeLexRegister(C, Token))
232 return R.remaining();
233 if (Cursor R = maybeLexGlobalValue(C, Token))
234 return R.remaining();
235 if (Cursor R = maybeLexIntegerLiteral(C, Token))
236 return R.remaining();
237 if (Cursor R = maybeLexSymbol(C, Token))
238 return R.remaining();
240 Token = MIToken(MIToken::Error, C.remaining());
241 ErrorCallback(C.location(),
242 Twine("unexpected character '") + Twine(C.peek()) + "'");
243 return C.remaining();