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Fix incorrect lexing of "$ff00+c" (#882)

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Fixes #881 by moving the task from the lexer to the parser.
This both alleviates the need for backtracking in the lexer,
removing what is (was) arguably a hack, and causes tokenization
boundaries to be properly respected, fixing the issue mentioned above.

Co-authored-by: Rangi <remy.oukaour+rangi42@gmail.com>
This commit is contained in:
Eldred Habert
2021-05-05 02:04:19 +02:00
committed by GitHub
parent c502804192
commit c06985a7ad
13 changed files with 31 additions and 28 deletions
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26
src/asm/lexer.c
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@@ -355,7 +355,6 @@ struct LexerState {
uint32_t lineNo;
uint32_t colNo;
int lastToken;
int nextToken;
struct IfStack *ifStack;
@@ -379,7 +378,6 @@ static void initState(struct LexerState *state)
state->mode = LEXER_NORMAL;
state->atLineStart = true; /* yylex() will init colNo due to this */
state->lastToken = T_EOF;
state->nextToken = 0;
state->ifStack = NULL;
@@ -1795,13 +1793,6 @@ static int yylex_NORMAL(void)
dbgPrint("Lexing in normal mode, line=%" PRIu32 ", col=%" PRIu32 "\n",
lexer_GetLineNo(), lexer_GetColNo());
if (lexerState->nextToken) {
int token = lexerState->nextToken;
lexerState->nextToken = 0;
return token;
}
for (;;) {
int c = nextChar();
char secondChar;
@@ -1919,23 +1910,6 @@ static int yylex_NORMAL(void)
case '$':
yylval.constValue = readHexNumber();
/* Attempt to match `$ff00+c` */
if (yylval.constValue == 0xff00) {
/* Whitespace is ignored anyways */
while (isWhitespace(c = peek()))
shiftChar();
if (c == '+') {
shiftChar();
while (isWhitespace(c = peek()))
shiftChar();
if (c == 'c' || c == 'C') {
shiftChar();
return T_MODE_HW_C;
}
/* Retroactively lex the plus after the $ff00 */
lexerState->nextToken = T_OP_ADD;
}
}
return T_NUMBER;
case '0': /* Decimal number */