Subversion Repositories eco32

%{
#include <stdio.h>
#include <stdlib.h>
#include "lburg.h"
static char rcsid[] = "$Id: gram.y,v 2.5 1997/11/21 18:59:34 drh Exp $";
/*lint -e616 -e527 -e652 -esym(552,yynerrs) -esym(563,yynewstate,yyerrlab) */
static int yylineno = 0;
int yylex(void);
%}
%union {
        int n;
        char *string;
        Tree tree;
}
%term TERMINAL
%term START
%term PPERCENT

%token  <string>        ID TEMPLATE CODE
%token  <n>             INT
%type   <string>        nonterm cost
%type   <tree>          tree
%%
spec    : decls PPERCENT rules          { yylineno = 0; }
        | decls                         { yylineno = 0; }
        ;

decls   : /* lambda */
        | decls decl
        ;

decl    : TERMINAL  blist '\n'
        | START nonterm '\n'            {
                if (nonterm($2)->number != 1)
                        yyerror("redeclaration of the start symbol\n");
                }
        | '\n'
        | error '\n'                    { yyerrok; }
        ;

blist   : /* lambda */
        | blist ID '=' INT              { term($2, $4); }
        ;

rules   : /* lambda */
        | rules nonterm ':' tree TEMPLATE cost '\n'     { rule($2, $4, $5, $6); }
        | rules '\n'
        | rules error '\n'              { yyerrok; }
        ;

nonterm : ID                            { nonterm($$ = $1); }
        ;

tree    : ID                            { $$ = tree($1,  0,  0); }
        | ID '(' tree ')'               { $$ = tree($1, $3,  0); }
        | ID '(' tree ',' tree ')'      { $$ = tree($1, $3, $5); }
        ;

cost    : CODE                          { if (*$1 == 0) $$ = "0"; }
        ;
%%
#include <assert.h>
#include <stdarg.h>
#include <ctype.h>
#include <string.h>
#include <limits.h>

int errcnt = 0;
FILE *infp = NULL;
FILE *outfp = NULL;
static char buf[BUFSIZ], *bp = buf;
static int ppercent = 0;
static int code = 0;

static int get(void) {
        if (*bp == 0) {
                bp = buf;
                *bp = 0;
                if (fgets(buf, sizeof buf, infp) == NULL)
                        return EOF;
                yylineno++;
                while (buf[0] == '%' && buf[1] == '{' && buf[2] == '\n') {
                        for (;;) {
                                if (fgets(buf, sizeof buf, infp) == NULL) {
                                        yywarn("unterminated %{...%}\n");
                                        return EOF;
                                }
                                yylineno++;
                                if (strcmp(buf, "%}\n") == 0)
                                        break;
                                fputs(buf, outfp);
                        }
                        if (fgets(buf, sizeof buf, infp) == NULL)
                                return EOF;
                        yylineno++;
                }
        }
        return *bp++;
}

void yyerror(char *fmt, ...) {
        va_list ap;

        va_start(ap, fmt);
        if (yylineno > 0)
                fprintf(stderr, "line %d: ", yylineno);
        vfprintf(stderr, fmt, ap);
        if (fmt[strlen(fmt)-1] != '\n')
                 fprintf(stderr, "\n");
        errcnt++;
        va_end(ap);
}

int yylex(void) {
        int c;

        if (code) {
                char *p;
                bp += strspn(bp, " \t\f");
                p = strchr(bp, '\n');
                if (p == NULL)
                        p = strchr(bp, '\n');
                while (p > bp && isspace(p[-1]))
                        p--;
                yylval.string = alloc(p - bp + 1);
                strncpy(yylval.string, bp, p - bp);
                yylval.string[p - bp] = 0;
                bp = p;
                code--;
                return CODE;
        }
        while ((c = get()) != EOF) {
                switch (c) {
                case ' ': case '\f': case '\t':
                        continue;
                case '\n':
                case '(': case ')': case ',':
                case ':': case '=':
                        return c;
                }
                if (c == '%' && *bp == '%') {
                        bp++;
                        return ppercent++ ? 0 : PPERCENT;
                } else if (c == '%' && strncmp(bp, "term", 4) == 0
                && isspace(bp[4])) {
                        bp += 4;
                        return TERMINAL;
                } else if (c == '%' && strncmp(bp, "start", 5) == 0
                && isspace(bp[5])) {
                        bp += 5;
                        return START;
                } else if (c == '"') {
                        char *p = strchr(bp, '"');
                        if (p == NULL) {
                                yyerror("missing \" in assembler template\n");
                                p = strchr(bp, '\n');
                                if (p == NULL)
                                        p = strchr(bp, '\0');
                        }
                        assert(p);
                        yylval.string = alloc(p - bp + 1);
                        strncpy(yylval.string, bp, p - bp);
                        yylval.string[p - bp] = 0;
                        bp = *p == '"' ? p + 1 : p;
                        code++;
                        return TEMPLATE;
                } else if (isdigit(c)) {
                        int n = 0;
                        do {
                                int d = c - '0';
                                if (n > (INT_MAX - d)/10)
                                        yyerror("integer greater than %d\n", INT_MAX);
                                else
                                        n = 10*n + d;
                                c = get();
                        } while (c != EOF && isdigit(c));
                        bp--;
                        yylval.n = n;
                        return INT;
                } else if (isalpha(c)) {
                        char *p = bp - 1;
                        while (isalpha(*bp) || isdigit(*bp) || *bp == '_')
                                bp++;
                        yylval.string = alloc(bp - p + 1);
                        strncpy(yylval.string, p, bp - p);
                        yylval.string[bp - p] = 0;
                        return ID;
                } else if (isprint(c))
                        yyerror("invalid character `%c'\n", c);
                else
                        yyerror("invalid character `\\%03o'\n", (unsigned char)c);
        }
        return 0;
}

void yywarn(char *fmt, ...) {
        va_list ap;

        va_start(ap, fmt);
        if (yylineno > 0)
                fprintf(stderr, "line %d: ", yylineno);
        fprintf(stderr, "warning: ");
        vfprintf(stderr, fmt, ap);
}