Add original unix v6

2018-01-27 22:35:41 +09:00
commit 2c7099ee50
664 changed files with 106254 additions and 0 deletions
@@ -0,0 +1,125 @@
+# define _maxdepth 150
+
+/*	parser for yacc output	*/
+extern int yyval; /* defined in the table file */
+extern int yylval; /* defined in the table file */
+extern int *yypv; /* defined in the table file */
+
+
+int yydebug 0; /* 1 for debugging */
+int yyv[_maxdepth]; /* where the values are stored */
+int yystate 0; /* current parser state */
+int yychar -1; /* current input token number */
+int yynerrs 0;  /* number of errors */
+int yyerrflag 0;  /* error recovery flag */
+
+
+yyparse() {
+
+   extern int yygo[], yypgo[], yyr1[], yyr2[], yyact[], yypact[];
+   auto int *ps, s[_maxdepth];
+   auto int ac, n, *p;
+
+   yystate = 0;
+   yychar = -1;
+   yynerrs = 0;
+   yyerrflag = 0;
+   ps= &s[0]-1;
+   yypv= &yyv[0]-1;
+
+ stack:    /* put a state and value onto the stack */
+
+   if( yydebug  ) printf( "state %d, value %d, char %d\n",yystate,yyval,yychar );
+   *++ps = yystate;
+   *++yypv = yyval;
+
+ newstate:      /* set ap to point to the parsing actions for the new state */
+
+   p = &yyact[ yypact[yystate+1] ]; 
+
+ actn:       /* get the next action, and perform it */
+
+   n = ( ac = *p++ ) & 07777;  /* n is the "address" of the action */
+
+   switch( ac>>12 ) { /* switch on operation */
+
+   case 1:		/* skip on test */
+      if( yydebug && (yychar<0) ){
+        yychar = yylex();
+        printf( "character %d read\n", yychar );
+        }
+      if( n != ( (yychar<0) ? ( yychar=yylex() ) : yychar ) ) ++p;
+      goto actn;  /* get next action */
+
+   case 2:		/* shift */
+
+      yystate=n;
+      yyval=yylval;
+      yychar= -1;
+      if( yyerrflag ) --yyerrflag;
+      goto stack;   /* stack new state */
+
+   case 3:		/* reduce */
+
+      if( yydebug ) printf("reduce %d\n",n);
+      ps =- yyr2[n];
+      yypv =- yyr2[n];
+      yyval=yypv[1];
+      yyactr(n);
+         /* consult goto table to find next state */
+      for( p= &yygo[yypgo[yyr1[n]]]; *p != *ps && *p >= 0 ; p =+ 2 ) ;
+      yystate = p[1];
+      goto stack;  /* stack new state and value */
+
+   case 4:		/* accept */
+      return(0);
+
+   case 0:   /* error ... attempt to resume parsing */
+
+      switch( yyerrflag ){
+
+      case 0:   /* brand new error */
+
+         ++yynerrs;
+         yyerror( "syntax error" );
+
+      case 1:
+      case 2: /* incompletely recovered error ... try again */
+
+         yyerrflag = 3;
+
+         /* find a state where "error" is a legal shift action */
+
+         while ( ps >= s ) {
+            for( p= &yyact[ yypact[*ps+1] ] ; (*p>>12) == 1 ; p =+ 2 ) /* search ps actions */
+                if( *p == 4352 ) goto found;
+
+            /* the current ps has no shift onn "error", pop stack */
+
+            if( yydebug ) printf( "error recovery pops state %d, uncovers %d\n", *ps, ps[-1] );
+            --ps;
+            --yypv;
+            }
+
+         /* there is no state on the stack with an error shift ... abort */
+
+    abort:
+         return(1);
+
+      found:   /* we have a state with a shift on "error", resume parsing */
+
+         yystate = p[1] & 07777;
+         goto stack;
+
+      case 3:  /* no shift yet; clobber input char */
+
+         if( yydebug ) printf( "error recovery discards char %d\n", yychar );
+
+         if( yychar == 0 ) goto abort; /* don't discard EOF, quit */
+         yychar = -1;
+         goto newstate;   /* try again in the same state */
+
+         }
+
+      }
+   }