llvm-6502/utils/TableGen/TGLexer.cpp
Chris Lattner a805874422 reimplement the tblgen lexer with a simple hand-written lexer. This eliminates
one dependency on flex and gets rid of two ".cvs" files.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44210 91177308-0d34-0410-b5e6-96231b3b80d8
2007-11-18 02:57:27 +00:00

440 lines
12 KiB
C++

//===- TGLexer.cpp - Lexer for TableGen -----------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by Chris Lattner and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Implement the Lexer for TableGen.
//
//===----------------------------------------------------------------------===//
#include "Record.h"
#include "llvm/Support/Streams.h"
#include "Record.h"
#include "TGLexer.h"
#include "llvm/Support/MemoryBuffer.h"
typedef std::pair<llvm::Record*, std::vector<llvm::Init*>*> SubClassRefTy;
#include "FileParser.h"
#include <cctype>
using namespace llvm;
// FIXME: REMOVE THIS.
#define YYEOF 0
#define YYERROR -2
TGLexer::TGLexer(MemoryBuffer *StartBuf) : CurLineNo(1), CurBuf(StartBuf) {
CurPtr = CurBuf->getBufferStart();
}
TGLexer::~TGLexer() {
while (!IncludeStack.empty()) {
delete IncludeStack.back().Buffer;
IncludeStack.pop_back();
}
delete CurBuf;
}
std::ostream &TGLexer::err() {
PrintIncludeStack(*cerr.stream());
return *cerr.stream();
}
void TGLexer::PrintIncludeStack(std::ostream &OS) {
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 << ": ";
}
int TGLexer::getNextChar() {
char CurChar = *CurPtr++;
switch (CurChar) {
default:
return 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; // Each the two char newline sequence.
++CurLineNo;
return '\n';
}
}
int TGLexer::LexToken() {
// 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, return the char itself.
return (unsigned char)CurChar;
case EOF: return YYEOF;
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 YYERROR;
} else // Otherwise, return this / as a token.
return CurChar;
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 '$': return LexVarName();
case '[': return LexBracket();
case '!': return LexExclaim();
}
}
/// LexString - Lex "[^"]*"
int TGLexer::LexString() {
const char *StrStart = CurPtr;
while (*CurPtr != '"') {
// If we hit the end of the buffer, report an error.
if (*CurPtr == 0 && CurPtr == CurBuf->getBufferEnd()) {
TheError = "End of file in string literal";
return YYERROR;
} else if (*CurPtr == '\n' || *CurPtr == '\r') {
TheError = "End of line in string literal";
return YYERROR;
}
++CurPtr;
}
Filelval.StrVal = new std::string(StrStart, CurPtr);
++CurPtr;
return STRVAL;
}
int TGLexer::LexVarName() {
if (!isalpha(CurPtr[0]) && CurPtr[0] != '_')
return '$'; // Invalid varname.
// Otherwise, we're ok, consume the rest of the characters.
const char *VarNameStart = CurPtr++;
while (isalpha(*CurPtr) || isdigit(*CurPtr) || *CurPtr == '_')
++CurPtr;
Filelval.StrVal = new std::string(VarNameStart, CurPtr);
return VARNAME;
}
int TGLexer::LexIdentifier() {
// The first letter is [a-zA-Z_].
const char *IdentStart = CurPtr-1;
// 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 INT;
if (Len == 3 && !memcmp(IdentStart, "bit", 3)) return BIT;
if (Len == 4 && !memcmp(IdentStart, "bits", 4)) return BITS;
if (Len == 6 && !memcmp(IdentStart, "string", 6)) return STRING;
if (Len == 4 && !memcmp(IdentStart, "list", 4)) return LIST;
if (Len == 4 && !memcmp(IdentStart, "code", 4)) return CODE;
if (Len == 3 && !memcmp(IdentStart, "dag", 3)) return DAG;
if (Len == 5 && !memcmp(IdentStart, "class", 5)) return CLASS;
if (Len == 3 && !memcmp(IdentStart, "def", 3)) return DEF;
if (Len == 4 && !memcmp(IdentStart, "defm", 4)) return DEFM;
if (Len == 10 && !memcmp(IdentStart, "multiclass", 10)) return MULTICLASS;
if (Len == 5 && !memcmp(IdentStart, "field", 5)) return FIELD;
if (Len == 3 && !memcmp(IdentStart, "let", 3)) return LET;
if (Len == 2 && !memcmp(IdentStart, "in", 2)) return IN;
if (Len == 7 && !memcmp(IdentStart, "include", 7)) {
if (LexInclude()) return YYERROR;
return LexToken();
}
Filelval.StrVal = new std::string(IdentStart, CurPtr);
return 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.
int Tok = LexToken();
if (Tok == YYERROR) return true;
if (Tok != STRVAL) {
TheError = "Expected filename after include";
return true;
}
// Get the string.
std::string Filename = *Filelval.StrVal;
delete Filelval.StrVal;
// Try to find the file.
MemoryBuffer *NewBuf = MemoryBuffer::getFile(&Filename[0], Filename.size());
// 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[0], IncFile.size());
}
if (NewBuf == 0) {
TheError = "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:
TheError = "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]+
int TGLexer::LexNumber() {
const char *NumStart = CurPtr-1;
if (CurPtr[-1] == '0') {
if (CurPtr[0] == 'x') {
++CurPtr;
NumStart = CurPtr;
while (isxdigit(CurPtr[0]))
++CurPtr;
if (CurPtr == NumStart) {
TheError = "Invalid hexadecimal number";
return YYERROR;
}
Filelval.IntVal = strtoll(NumStart, 0, 16);
return INTVAL;
} else if (CurPtr[0] == 'b') {
++CurPtr;
NumStart = CurPtr;
while (CurPtr[0] == '0' || CurPtr[0] == '1')
++CurPtr;
if (CurPtr == NumStart) {
TheError = "Invalid binary number";
return YYERROR;
}
Filelval.IntVal = strtoll(NumStart, 0, 2);
return INTVAL;
}
}
// Check for a sign without a digit.
if (CurPtr[-1] == '-' || CurPtr[-1] == '+') {
if (!isdigit(CurPtr[0]))
return CurPtr[-1];
}
while (isdigit(CurPtr[0]))
++CurPtr;
Filelval.IntVal = strtoll(NumStart, 0, 10);
return INTVAL;
}
/// LexBracket - We just read '['. If this is a code block, return it,
/// otherwise return the bracket. Match: '[' and '[{ ( [^}]+ | }[^]] )* }]'
int TGLexer::LexBracket() {
if (CurPtr[0] != '{')
return '[';
++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 == ']') {
Filelval.StrVal = new std::string(CodeStart, CurPtr-2);
return CODEFRAGMENT;
}
}
TheError = "Invalid Code Block";
return YYERROR;
}
/// LexExclaim - Lex '!' and '![a-zA-Z]+'.
int TGLexer::LexExclaim() {
if (!isalpha(*CurPtr))
return '!';
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 CONCATTOK;
if (Len == 3 && !memcmp(Start, "sra", 3)) return SRATOK;
if (Len == 3 && !memcmp(Start, "srl", 3)) return SRLTOK;
if (Len == 3 && !memcmp(Start, "shl", 3)) return SHLTOK;
if (Len == 9 && !memcmp(Start, "strconcat", 9)) return STRCONCATTOK;
TheError = "Unknown operator";
return YYERROR;
}
//===----------------------------------------------------------------------===//
// Interfaces used by the Bison parser.
//===----------------------------------------------------------------------===//
int Fileparse();
static TGLexer *TheLexer;
namespace llvm {
std::ostream &err() {
return TheLexer->err();
}
/// ParseFile - this function begins the parsing of the specified tablegen
/// file.
///
void ParseFile(const std::string &Filename,
const std::vector<std::string> &IncludeDirs) {
std::string ErrorStr;
MemoryBuffer *F = MemoryBuffer::getFileOrSTDIN(&Filename[0], Filename.size(),
&ErrorStr);
if (F == 0) {
cerr << "Could not open input file '" + Filename + "': " << ErrorStr <<"\n";
exit(1);
}
assert(!TheLexer && "Lexer isn't reentrant yet!");
TheLexer = new TGLexer(F);
// Record the location of the include directory so that the lexer can find
// it later.
TheLexer->setIncludeDirs(IncludeDirs);
Fileparse();
// Cleanup
delete TheLexer;
TheLexer = 0;
}
} // End llvm namespace
int Filelex() {
assert(TheLexer && "No lexer setup yet!");
int Tok = TheLexer->LexToken();
if (Tok == YYERROR) {
err() << TheLexer->getError() << "\n";
exit(1);
}
return Tok;
}