86 lines
2.2 KiB
Plaintext
86 lines
2.2 KiB
Plaintext
/****************************************************/
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/* File: tiny.l */
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/* Lex specification for TINY */
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/* Compiler Construction: Principles and Practice */
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/* Kenneth C. Louden */
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/****************************************************/
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%{
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#include "globals.h"
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#include "util.h"
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#include "scan.h"
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/* lexeme of identifier or reserved word */
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char tokenString[MAXTOKENLEN+1];
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%}
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digit [0-9]
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number {digit}+
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letter [a-zA-Z]
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identifier {letter}+
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newline \n
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whitespace [ \t]+
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%%
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"if" {return IF;}
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"else" {return ELSE;}
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"while" {return WHILE;}
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"return" {return RETURN;}
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"int" {return INT;}
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"void" {return VOID;}
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"=" {return ASSIGN;}
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"==" {return EQ;}
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"!=" {return NE;}
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"<" {return LT;}
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"<=" {return LE;}
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">" {return GT;}
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">=" {return GE;}
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"+" {return PLUS;}
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"-" {return MINUS;}
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"*" {return TIMES;}
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"/" {return OVER;}
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"(" {return LPAREN;}
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")" {return RPAREN;}
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"[" {return LBRACE;}
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"]" {return RBRACE;}
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"{" {return LCURLY;}
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"}" {return RCURLY;}
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";" {return SEMI;}
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"," {return COMMA;}
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{number} {return NUM;}
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{identifier} {return ID;}
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{newline} {lineno++;}
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{whitespace} {/* skip whitespace */}
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"/*" { char now, prev;
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do
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{ now = input();
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if (now == EOF) break;
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else if (now == '\n') lineno++;
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else if (now == '/' && prev == '*') break;
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prev = now;
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} while (1);
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}
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. {return ERROR;}
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%%
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TokenType getToken(void)
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{ static int firstTime = TRUE;
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TokenType currentToken;
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if (firstTime)
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{ firstTime = FALSE;
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lineno++;
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yyin = source;
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yyout = listing;
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}
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currentToken = yylex();
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strncpy(tokenString,yytext,MAXTOKENLEN);
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if (TraceScan) {
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fprintf(listing,"\t%d: ",lineno);
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printToken(currentToken,tokenString);
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}
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return currentToken;
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}
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