llvm-6502/utils/TableGen/TGLexer.cpp

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//===- TGLexer.cpp - Lexer for TableGen -----------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Implement the Lexer for TableGen.
//
//===----------------------------------------------------------------------===//
#include "TGLexer.h"
#include "llvm/Support/Streams.h"
#include "llvm/Support/MemoryBuffer.h"
#include <ostream>
#include "llvm/Config/config.h"
#include <cctype>
#include <cstdlib>
#include <cstring>
using namespace llvm;
TGLexer::TGLexer(MemoryBuffer *StartBuf) : CurLineNo(1), CurBuf(StartBuf) {
CurPtr = CurBuf->getBufferStart();
TokStart = 0;
}
TGLexer::~TGLexer() {
while (!IncludeStack.empty()) {
delete IncludeStack.back().Buffer;
IncludeStack.pop_back();
}
delete CurBuf;
}
/// ReturnError - Set the error to the specified string at the specified
/// location. This is defined to always return tgtok::Error.
tgtok::TokKind TGLexer::ReturnError(const char *Loc, const std::string &Msg) {
PrintError(Loc, Msg);
return tgtok::Error;
}
void TGLexer::PrintIncludeStack(std::ostream &OS) const {
for (unsigned i = 0, e = IncludeStack.size(); i != e; ++i)
OS << "Included from " << IncludeStack[i].Buffer->getBufferIdentifier()
<< ":" << IncludeStack[i].LineNo << ":\n";
OS << "Parsing " << CurBuf->getBufferIdentifier() << ":"
<< CurLineNo << ": ";
}
/// PrintError - Print the error at the specified location.
void TGLexer::PrintError(const char *ErrorLoc, const std::string &Msg) const {
PrintIncludeStack(*cerr.stream());
cerr << Msg << "\n";
assert(ErrorLoc && "Location not specified!");
// Scan backward to find the start of the line.
const char *LineStart = ErrorLoc;
while (LineStart != CurBuf->getBufferStart() &&
LineStart[-1] != '\n' && LineStart[-1] != '\r')
--LineStart;
// Get the end of the line.
const char *LineEnd = ErrorLoc;
while (LineEnd != CurBuf->getBufferEnd() &&
LineEnd[0] != '\n' && LineEnd[0] != '\r')
++LineEnd;
// Print out the line.
cerr << std::string(LineStart, LineEnd) << "\n";
// Print out spaces before the carat.
for (const char *Pos = LineStart; Pos != ErrorLoc; ++Pos)
cerr << (*Pos == '\t' ? '\t' : ' ');
cerr << "^\n";
}
int TGLexer::getNextChar() {
char CurChar = *CurPtr++;
switch (CurChar) {
default:
return (unsigned char)CurChar;
case 0:
// A nul character in the stream is either the end of the current buffer or
// a random nul in the file. Disambiguate that here.
if (CurPtr-1 != CurBuf->getBufferEnd())
return 0; // Just whitespace.
// If this is the end of an included file, pop the parent file off the
// include stack.
if (!IncludeStack.empty()) {
delete CurBuf;
CurBuf = IncludeStack.back().Buffer;
CurLineNo = IncludeStack.back().LineNo;
CurPtr = IncludeStack.back().CurPtr;
IncludeStack.pop_back();
return getNextChar();
}
// Otherwise, return end of file.
--CurPtr; // Another call to lex will return EOF again.
return EOF;
case '\n':
case '\r':
// Handle the newline character by ignoring it and incrementing the line
// count. However, be careful about 'dos style' files with \n\r in them.
// Only treat a \n\r or \r\n as a single line.
if ((*CurPtr == '\n' || (*CurPtr == '\r')) &&
*CurPtr != CurChar)
++CurPtr; // Eat the two char newline sequence.
++CurLineNo;
return '\n';
}
}
tgtok::TokKind TGLexer::LexToken() {
TokStart = CurPtr;
// This always consumes at least one character.
int CurChar = getNextChar();
switch (CurChar) {
default:
// Handle letters: [a-zA-Z_]
if (isalpha(CurChar) || CurChar == '_')
return LexIdentifier();
// Unknown character, emit an error.
return ReturnError(TokStart, "Unexpected character");
case EOF: return tgtok::Eof;
case ':': return tgtok::colon;
case ';': return tgtok::semi;
case '.': return tgtok::period;
case ',': return tgtok::comma;
case '<': return tgtok::less;
case '>': return tgtok::greater;
case ']': return tgtok::r_square;
case '{': return tgtok::l_brace;
case '}': return tgtok::r_brace;
case '(': return tgtok::l_paren;
case ')': return tgtok::r_paren;
case '=': return tgtok::equal;
case '?': return tgtok::question;
case 0:
case ' ':
case '\t':
case '\n':
case '\r':
// Ignore whitespace.
return LexToken();
case '/':
// If this is the start of a // comment, skip until the end of the line or
// the end of the buffer.
if (*CurPtr == '/')
SkipBCPLComment();
else if (*CurPtr == '*') {
if (SkipCComment())
return tgtok::Error;
} else // Otherwise, this is an error.
return ReturnError(TokStart, "Unexpected character");
return LexToken();
case '-': case '+':
case '0': case '1': case '2': case '3': case '4': case '5': case '6':
case '7': case '8': case '9':
return LexNumber();
case '"': return LexString();
case '$': return LexVarName();
case '[': return LexBracket();
case '!': return LexExclaim();
}
}
/// LexString - Lex "[^"]*"
tgtok::TokKind TGLexer::LexString() {
const char *StrStart = CurPtr;
while (*CurPtr != '"') {
// If we hit the end of the buffer, report an error.
if (*CurPtr == 0 && CurPtr == CurBuf->getBufferEnd())
return ReturnError(StrStart, "End of file in string literal");
if (*CurPtr == '\n' || *CurPtr == '\r')
return ReturnError(StrStart, "End of line in string literal");
++CurPtr;
}
CurStrVal.assign(StrStart, CurPtr);
++CurPtr;
return tgtok::StrVal;
}
tgtok::TokKind TGLexer::LexVarName() {
if (!isalpha(CurPtr[0]) && CurPtr[0] != '_')
return ReturnError(TokStart, "Invalid variable name");
// Otherwise, we're ok, consume the rest of the characters.
const char *VarNameStart = CurPtr++;
while (isalpha(*CurPtr) || isdigit(*CurPtr) || *CurPtr == '_')
++CurPtr;
CurStrVal.assign(VarNameStart, CurPtr);
return tgtok::VarName;
}
tgtok::TokKind TGLexer::LexIdentifier() {
// The first letter is [a-zA-Z_].
const char *IdentStart = TokStart;
// Match the rest of the identifier regex: [0-9a-zA-Z_]*
while (isalpha(*CurPtr) || isdigit(*CurPtr) || *CurPtr == '_')
++CurPtr;
// Check to see if this identifier is a keyword.
unsigned Len = CurPtr-IdentStart;
if (Len == 3 && !memcmp(IdentStart, "int", 3)) return tgtok::Int;
if (Len == 3 && !memcmp(IdentStart, "bit", 3)) return tgtok::Bit;
if (Len == 4 && !memcmp(IdentStart, "bits", 4)) return tgtok::Bits;
if (Len == 6 && !memcmp(IdentStart, "string", 6)) return tgtok::String;
if (Len == 4 && !memcmp(IdentStart, "list", 4)) return tgtok::List;
if (Len == 4 && !memcmp(IdentStart, "code", 4)) return tgtok::Code;
if (Len == 3 && !memcmp(IdentStart, "dag", 3)) return tgtok::Dag;
if (Len == 5 && !memcmp(IdentStart, "class", 5)) return tgtok::Class;
if (Len == 3 && !memcmp(IdentStart, "def", 3)) return tgtok::Def;
if (Len == 4 && !memcmp(IdentStart, "defm", 4)) return tgtok::Defm;
if (Len == 10 && !memcmp(IdentStart, "multiclass", 10))
return tgtok::MultiClass;
if (Len == 5 && !memcmp(IdentStart, "field", 5)) return tgtok::Field;
if (Len == 3 && !memcmp(IdentStart, "let", 3)) return tgtok::Let;
if (Len == 2 && !memcmp(IdentStart, "in", 2)) return tgtok::In;
if (Len == 7 && !memcmp(IdentStart, "include", 7)) {
if (LexInclude()) return tgtok::Error;
return Lex();
}
CurStrVal.assign(IdentStart, CurPtr);
return tgtok::Id;
}
/// LexInclude - We just read the "include" token. Get the string token that
/// comes next and enter the include.
bool TGLexer::LexInclude() {
// The token after the include must be a string.
tgtok::TokKind Tok = LexToken();
if (Tok == tgtok::Error) return true;
if (Tok != tgtok::StrVal) {
PrintError(getLoc(), "Expected filename after include");
return true;
}
// Get the string.
std::string Filename = CurStrVal;
// Try to find the file.
MemoryBuffer *NewBuf = MemoryBuffer::getFile(Filename.c_str());
// If the file didn't exist directly, see if it's in an include path.
for (unsigned i = 0, e = IncludeDirectories.size(); i != e && !NewBuf; ++i) {
std::string IncFile = IncludeDirectories[i] + "/" + Filename;
NewBuf = MemoryBuffer::getFile(IncFile.c_str());
}
if (NewBuf == 0) {
PrintError(getLoc(), "Could not find include file '" + Filename + "'");
return true;
}
// Save the line number and lex buffer of the includer.
IncludeStack.push_back(IncludeRec(CurBuf, CurPtr, CurLineNo));
CurLineNo = 1; // Reset line numbering.
CurBuf = NewBuf;
CurPtr = CurBuf->getBufferStart();
return false;
}
void TGLexer::SkipBCPLComment() {
++CurPtr; // skip the second slash.
while (1) {
switch (*CurPtr) {
case '\n':
case '\r':
return; // Newline is end of comment.
case 0:
// If this is the end of the buffer, end the comment.
if (CurPtr == CurBuf->getBufferEnd())
return;
break;
}
// Otherwise, skip the character.
++CurPtr;
}
}
/// SkipCComment - This skips C-style /**/ comments. The only difference from C
/// is that we allow nesting.
bool TGLexer::SkipCComment() {
++CurPtr; // skip the star.
unsigned CommentDepth = 1;
while (1) {
int CurChar = getNextChar();
switch (CurChar) {
case EOF:
PrintError(TokStart, "Unterminated comment!");
return true;
case '*':
// End of the comment?
if (CurPtr[0] != '/') break;
++CurPtr; // End the */.
if (--CommentDepth == 0)
return false;
break;
case '/':
// Start of a nested comment?
if (CurPtr[0] != '*') break;
++CurPtr;
++CommentDepth;
break;
}
}
}
/// LexNumber - Lex:
/// [-+]?[0-9]+
/// 0x[0-9a-fA-F]+
/// 0b[01]+
tgtok::TokKind TGLexer::LexNumber() {
if (CurPtr[-1] == '0') {
if (CurPtr[0] == 'x') {
++CurPtr;
const char *NumStart = CurPtr;
while (isxdigit(CurPtr[0]))
++CurPtr;
// Requires at least one hex digit.
if (CurPtr == NumStart)
return ReturnError(CurPtr-2, "Invalid hexadecimal number");
CurIntVal = strtoll(NumStart, 0, 16);
return tgtok::IntVal;
} else if (CurPtr[0] == 'b') {
++CurPtr;
const char *NumStart = CurPtr;
while (CurPtr[0] == '0' || CurPtr[0] == '1')
++CurPtr;
// Requires at least one binary digit.
if (CurPtr == NumStart)
return ReturnError(CurPtr-2, "Invalid binary number");
CurIntVal = strtoll(NumStart, 0, 2);
return tgtok::IntVal;
}
}
// Check for a sign without a digit.
if (!isdigit(CurPtr[0])) {
if (CurPtr[-1] == '-')
return tgtok::minus;
else if (CurPtr[-1] == '+')
return tgtok::plus;
}
while (isdigit(CurPtr[0]))
++CurPtr;
CurIntVal = strtoll(TokStart, 0, 10);
return tgtok::IntVal;
}
/// LexBracket - We just read '['. If this is a code block, return it,
/// otherwise return the bracket. Match: '[' and '[{ ( [^}]+ | }[^]] )* }]'
tgtok::TokKind TGLexer::LexBracket() {
if (CurPtr[0] != '{')
return tgtok::l_square;
++CurPtr;
const char *CodeStart = CurPtr;
while (1) {
int Char = getNextChar();
if (Char == EOF) break;
if (Char != '}') continue;
Char = getNextChar();
if (Char == EOF) break;
if (Char == ']') {
CurStrVal.assign(CodeStart, CurPtr-2);
return tgtok::CodeFragment;
}
}
return ReturnError(CodeStart-2, "Unterminated Code Block");
}
/// LexExclaim - Lex '!' and '![a-zA-Z]+'.
tgtok::TokKind TGLexer::LexExclaim() {
if (!isalpha(*CurPtr))
return ReturnError(CurPtr-1, "Invalid \"!operator\"");
const char *Start = CurPtr++;
while (isalpha(*CurPtr))
++CurPtr;
// Check to see which operator this is.
unsigned Len = CurPtr-Start;
if (Len == 3 && !memcmp(Start, "con", 3)) return tgtok::XConcat;
if (Len == 3 && !memcmp(Start, "sra", 3)) return tgtok::XSRA;
if (Len == 3 && !memcmp(Start, "srl", 3)) return tgtok::XSRL;
if (Len == 3 && !memcmp(Start, "shl", 3)) return tgtok::XSHL;
if (Len == 9 && !memcmp(Start, "strconcat", 9)) return tgtok::XStrConcat;
return ReturnError(Start-1, "Unknown operator");
}