llvm/tools/llvm-mc/AsmLexer.cpp
2009-08-14 02:18:40 +00:00

333 lines
11 KiB
C++

//===- AsmLexer.cpp - Lexer for Assembly Files ----------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This class implements the lexer for assembly files.
//
//===----------------------------------------------------------------------===//
#include "AsmLexer.h"
#include "llvm/Support/SourceMgr.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Config/config.h" // for strtoull.
#include <cerrno>
#include <cstdio>
#include <cstdlib>
using namespace llvm;
AsmLexer::AsmLexer(SourceMgr &SM) : SrcMgr(SM) {
CurBuffer = 0;
CurBuf = SrcMgr.getMemoryBuffer(CurBuffer);
CurPtr = CurBuf->getBufferStart();
TokStart = 0;
}
AsmLexer::~AsmLexer() {
}
SMLoc AsmLexer::getLoc() const {
return SMLoc::getFromPointer(TokStart);
}
void AsmLexer::PrintMessage(SMLoc Loc, const std::string &Msg,
const char *Type) const {
SrcMgr.PrintMessage(Loc, Msg, Type);
}
/// ReturnError - Set the error to the specified string at the specified
/// location. This is defined to always return AsmToken::Error.
AsmToken AsmLexer::ReturnError(const char *Loc, const std::string &Msg) {
SrcMgr.PrintMessage(SMLoc::getFromPointer(Loc), Msg, "error");
return AsmToken(AsmToken::Error, StringRef(Loc, 0));
}
/// EnterIncludeFile - Enter the specified file. This prints an error and
/// returns true on failure.
bool AsmLexer::EnterIncludeFile(const std::string &Filename) {
int NewBuf = SrcMgr.AddIncludeFile(Filename, SMLoc::getFromPointer(CurPtr));
if (NewBuf == -1)
return true;
// Save the line number and lex buffer of the includer.
CurBuffer = NewBuf;
CurBuf = SrcMgr.getMemoryBuffer(CurBuffer);
CurPtr = CurBuf->getBufferStart();
return false;
}
int AsmLexer::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.
SMLoc ParentIncludeLoc = SrcMgr.getParentIncludeLoc(CurBuffer);
if (ParentIncludeLoc != SMLoc()) {
CurBuffer = SrcMgr.FindBufferContainingLoc(ParentIncludeLoc);
CurBuf = SrcMgr.getMemoryBuffer(CurBuffer);
CurPtr = ParentIncludeLoc.getPointer();
// Reset the token start pointer to the start of the new file.
TokStart = CurPtr;
return getNextChar();
}
// Otherwise, return end of file.
--CurPtr; // Another call to lex will return EOF again.
return EOF;
}
}
}
/// LexIdentifier: [a-zA-Z_.][a-zA-Z0-9_$.@]*
AsmToken AsmLexer::LexIdentifier() {
while (isalnum(*CurPtr) || *CurPtr == '_' || *CurPtr == '$' ||
*CurPtr == '.' || *CurPtr == '@')
++CurPtr;
return AsmToken(AsmToken::Identifier, StringRef(TokStart, CurPtr - TokStart));
}
/// LexPercent: Register: %[a-zA-Z0-9]+
AsmToken AsmLexer::LexPercent() {
if (!isalnum(*CurPtr))
return AsmToken(AsmToken::Percent, StringRef(CurPtr, 1)); // Single %.
while (isalnum(*CurPtr))
++CurPtr;
return AsmToken(AsmToken::Register, StringRef(TokStart, CurPtr - TokStart));
}
/// LexSlash: Slash: /
/// C-Style Comment: /* ... */
AsmToken AsmLexer::LexSlash() {
switch (*CurPtr) {
case '*': break; // C style comment.
case '/': return ++CurPtr, LexLineComment();
default: return AsmToken(AsmToken::Slash, StringRef(CurPtr, 1));
}
// C Style comment.
++CurPtr; // skip the star.
while (1) {
int CurChar = getNextChar();
switch (CurChar) {
case EOF:
return ReturnError(TokStart, "unterminated comment");
case '*':
// End of the comment?
if (CurPtr[0] != '/') break;
++CurPtr; // End the */.
return LexToken();
}
}
}
/// LexLineComment: Comment: #[^\n]*
/// : //[^\n]*
AsmToken AsmLexer::LexLineComment() {
// FIXME: This is broken if we happen to a comment at the end of a file, which
// was .included, and which doesn't end with a newline.
int CurChar = getNextChar();
while (CurChar != '\n' && CurChar != '\n' && CurChar != EOF)
CurChar = getNextChar();
if (CurChar == EOF)
return AsmToken(AsmToken::Eof, StringRef(CurPtr, 0));
return AsmToken(AsmToken::EndOfStatement, StringRef(CurPtr, 0));
}
/// LexDigit: First character is [0-9].
/// Local Label: [0-9][:]
/// Forward/Backward Label: [0-9][fb]
/// Binary integer: 0b[01]+
/// Octal integer: 0[0-7]+
/// Hex integer: 0x[0-9a-fA-F]+
/// Decimal integer: [1-9][0-9]*
/// TODO: FP literal.
AsmToken AsmLexer::LexDigit() {
if (*CurPtr == ':')
return ReturnError(TokStart, "FIXME: local label not implemented");
if (*CurPtr == 'f' || *CurPtr == 'b')
return ReturnError(TokStart, "FIXME: directional label not implemented");
// Decimal integer: [1-9][0-9]*
if (CurPtr[-1] != '0') {
while (isdigit(*CurPtr))
++CurPtr;
return AsmToken(AsmToken::Integer, StringRef(TokStart, CurPtr - TokStart),
strtoll(TokStart, 0, 10));
}
if (*CurPtr == '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");
return AsmToken(AsmToken::Integer, StringRef(TokStart, CurPtr - TokStart),
strtoll(NumStart, 0, 2));
}
if (*CurPtr == '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");
errno = 0;
if (errno == EINVAL)
return ReturnError(CurPtr-2, "Invalid hexadecimal number");
if (errno == ERANGE) {
errno = 0;
if (errno == EINVAL)
return ReturnError(CurPtr-2, "Invalid hexadecimal number");
if (errno == ERANGE)
return ReturnError(CurPtr-2, "Hexadecimal number out of range");
}
return AsmToken(AsmToken::Integer, StringRef(TokStart, CurPtr - TokStart),
(int64_t) strtoull(NumStart, 0, 16));
}
// Must be an octal number, it starts with 0.
while (*CurPtr >= '0' && *CurPtr <= '7')
++CurPtr;
return AsmToken(AsmToken::Integer, StringRef(TokStart, CurPtr - TokStart),
strtoll(TokStart, 0, 8));
}
/// LexQuote: String: "..."
AsmToken AsmLexer::LexQuote() {
int CurChar = getNextChar();
// TODO: does gas allow multiline string constants?
while (CurChar != '"') {
if (CurChar == '\\') {
// Allow \", etc.
CurChar = getNextChar();
}
if (CurChar == EOF)
return ReturnError(TokStart, "unterminated string constant");
CurChar = getNextChar();
}
return AsmToken(AsmToken::String, StringRef(TokStart, CurPtr - TokStart));
}
StringRef AsmLexer::LexUntilEndOfStatement() {
TokStart = CurPtr;
while (*CurPtr != '#' && // Start of line comment.
*CurPtr != ';' && // End of statement marker.
*CurPtr != '\n' &&
*CurPtr != '\r' &&
(*CurPtr != 0 || CurPtr != CurBuf->getBufferEnd()))
++CurPtr;
return StringRef(TokStart, CurPtr-TokStart);
}
AsmToken AsmLexer::LexToken() {
TokStart = CurPtr;
// This always consumes at least one character.
int CurChar = getNextChar();
switch (CurChar) {
default:
// Handle identifier: [a-zA-Z_.][a-zA-Z0-9_$.@]*
if (isalpha(CurChar) || CurChar == '_' || CurChar == '.')
return LexIdentifier();
// Unknown character, emit an error.
return ReturnError(TokStart, "invalid character in input");
case EOF: return AsmToken(AsmToken::Eof, StringRef(TokStart, 0));
case 0:
case ' ':
case '\t':
// Ignore whitespace.
return LexToken();
case '\n': // FALL THROUGH.
case '\r': // FALL THROUGH.
case ';': return AsmToken(AsmToken::EndOfStatement, StringRef(TokStart, 1));
case ':': return AsmToken(AsmToken::Colon, StringRef(TokStart, 1));
case '+': return AsmToken(AsmToken::Plus, StringRef(TokStart, 1));
case '-': return AsmToken(AsmToken::Minus, StringRef(TokStart, 1));
case '~': return AsmToken(AsmToken::Tilde, StringRef(TokStart, 1));
case '(': return AsmToken(AsmToken::LParen, StringRef(TokStart, 1));
case ')': return AsmToken(AsmToken::RParen, StringRef(TokStart, 1));
case '*': return AsmToken(AsmToken::Star, StringRef(TokStart, 1));
case ',': return AsmToken(AsmToken::Comma, StringRef(TokStart, 1));
case '$': return AsmToken(AsmToken::Dollar, StringRef(TokStart, 1));
case '=':
if (*CurPtr == '=')
return ++CurPtr, AsmToken(AsmToken::EqualEqual, StringRef(TokStart, 2));
return AsmToken(AsmToken::Equal, StringRef(TokStart, 1));
case '|':
if (*CurPtr == '|')
return ++CurPtr, AsmToken(AsmToken::PipePipe, StringRef(TokStart, 2));
return AsmToken(AsmToken::Pipe, StringRef(TokStart, 1));
case '^': return AsmToken(AsmToken::Caret, StringRef(TokStart, 1));
case '&':
if (*CurPtr == '&')
return ++CurPtr, AsmToken(AsmToken::AmpAmp, StringRef(TokStart, 2));
return AsmToken(AsmToken::Amp, StringRef(TokStart, 1));
case '!':
if (*CurPtr == '=')
return ++CurPtr, AsmToken(AsmToken::ExclaimEqual, StringRef(TokStart, 2));
return AsmToken(AsmToken::Exclaim, StringRef(TokStart, 1));
case '%': return LexPercent();
case '/': return LexSlash();
case '#': return LexLineComment();
case '"': return LexQuote();
case '0': case '1': case '2': case '3': case '4':
case '5': case '6': case '7': case '8': case '9':
return LexDigit();
case '<':
switch (*CurPtr) {
case '<': return ++CurPtr, AsmToken(AsmToken::LessLess,
StringRef(TokStart, 2));
case '=': return ++CurPtr, AsmToken(AsmToken::LessEqual,
StringRef(TokStart, 2));
case '>': return ++CurPtr, AsmToken(AsmToken::LessGreater,
StringRef(TokStart, 2));
default: return AsmToken(AsmToken::Less, StringRef(TokStart, 1));
}
case '>':
switch (*CurPtr) {
case '>': return ++CurPtr, AsmToken(AsmToken::GreaterGreater,
StringRef(TokStart, 2));
case '=': return ++CurPtr, AsmToken(AsmToken::GreaterEqual,
StringRef(TokStart, 2));
default: return AsmToken(AsmToken::Greater, StringRef(TokStart, 1));
}
// TODO: Quoted identifiers (objc methods etc)
// local labels: [0-9][:]
// Forward/backward labels: [0-9][fb]
// Integers, fp constants, character constants.
}
}