better (more restrained) error reporting

lang/cem/cemcom/BigPars

@@ -8,8 +8,9 @@
 
 !File: errout.h
 #define	ERROUT		STDERR	/* file pointer for writing messages	*/
-#define	MAXERR_LINE	5	/* maximum number of error messages given
+#define	ERR_SHADOW	5	/* a syntax error overshadows error messages
-					on the same input line.		*/
+					until ERR_SHADOW symbols have been
+					accepted without syntax error */
 
 
 !File: idfsize.h

lang/cem/cemcom/LLlex.c

@@ -25,6 +25,9 @@
 
 /* Data about the token yielded */
 struct token dot, ahead, aside;
+int token_nmb = 0;		/* number of the ahead token */
+int tk_nmb_at_last_syn_err = -5/*ERR_SHADOW*/;
+				/* token number at last syntax error */
 
 #ifndef NOPP
 int ReplaceMacros = 1;		/* replacing macros			*/
@@ -105,6 +108,8 @@ GetToken(ptok)
 	char buf[(IDFSIZE > NUMSIZE ? IDFSIZE : NUMSIZE) + 1];
 	register int ch, nch;
 
+	token_nmb++;
+
 	if (File_Inserted) {
 		File_Inserted = 0;
 		goto firstline;
@@ -219,37 +224,6 @@ firstline:
 		case '=':
 			if (nch == '=')
 				return ptok->tk_symb = EQUAL;
-			/*	The following piece of code tries to recognise
-				old-fashioned assignment operators `=op'
-			*/
-			switch (nch) {
-			case '+':
-				return ptok->tk_symb = PLUSAB;
-			case '-':
-				return ptok->tk_symb = MINAB;
-			case '*':
-				return ptok->tk_symb = TIMESAB;
-			case '/':
-				return ptok->tk_symb = DIVAB;
-			case '%':
-				return ptok->tk_symb = MODAB;
-			case '>':
-			case '<':
-				LoadChar(ch);
-				if (ch != nch) {
-					PushBack();
-					lexerror("illegal operator '=%c%c'",
-						nch, ch);
-				}
-				return ptok->tk_symb = 
-					nch == '<' ? LEFTAB : RIGHTAB;
-			case '&':
-				return ptok->tk_symb = ANDAB;
-			case '^':
-				return ptok->tk_symb = XORAB;
-			case '|':
-				return ptok->tk_symb = ORAB;
-			}
 			PushBack();
 			return ptok->tk_symb = ch;
 		case '>':

lang/cem/cemcom/LLlex.h

@@ -48,6 +48,8 @@ struct token	{
 #endif NOFLOAT
 
 extern struct token dot, ahead, aside;
+extern int token_nmb;			/* number of the ahead token */
+extern int tk_nmb_at_last_syn_err;	/* token number at last syntax error */
 
 #ifndef NOPP
 extern int ReplaceMacros;	/* "LLlex.c"	*/

lang/cem/cemcom/LLmessage.c

@@ -20,11 +20,13 @@ LLmessage(tk)	{
 		error("end of file expected");
 	}
 	else if (tk)	{
-		error("%s missing", symbol2str(tk));
+		error("%s missing before %s", symbol2str(tk), symbol2str(DOT));
 		insert_token(tk);
 	}
-	else
+	else	{
 		error("%s deleted", symbol2str(DOT));
+	}
+	tk_nmb_at_last_syn_err = token_nmb;
 }
 
 insert_token(tk)

lang/cem/cemcom/LintPars

@@ -8,8 +8,9 @@
 
 !File: errout.h
 #define	ERROUT		STDERR	/* file pointer for writing messages	*/
-#define	MAXERR_LINE	5	/* maximum number of error messages given
+#define	ERR_SHADOW	5	/* a syntax error overshadows error messages
-					on the same input line.		*/
+					until ERR_SHADOW symbols have been
+					accepted without syntax error */
 
 
 !File: idfsize.h

lang/cem/cemcom/Makefile

@@ -135,9 +135,6 @@ SRC =	$(CSRC) $(LCSRC) $(GCSRC)
 LINT = /usr/bin/lint
 LINTFLAGS =
 
-MYLINT = ../lpass2/lint
-MYLINTFLAGS = -xh
-
 #EXCLEXCLEXCLEXCL
 
 .SUFFIXES: .str .h
@@ -188,11 +185,7 @@ clean:
 	(cd .. ; rm -rf Xsrc)
 
 lint:	Cfiles
-	sh -c 'if $(CC) nmclash.c > /dev/null 2>&1 ; then make "EMHOME="$(EMHOME) Xlint ; else sh Resolve Xlint ; fi'
+	sh -c 'if $(CC) nmclash.c > /dev/null 2>&1 ; then make "EMHOME="$(EMHOME) LINT=$(LINT) Xlint ; else sh Resolve Xlint ; fi'
-	@rm -f nmclash.o a.out
-
-mylint:	Cfiles
-	sh -c 'if $(CC) nmclash.c > /dev/null 2>&1 ; then make "EMHOME="$(EMHOME) Xmylint ; else sh Resolve Xmylint ; fi'
 	@rm -f nmclash.o a.out
 
 longnames:	$(SRC) $(HFILES)
@@ -274,8 +267,6 @@ $(CURRDIR)lnt:		$(OBJ) $(CURRDIR)Makefile
 Xlint:	$(SRC)
 	$(LINT) $(CDEFS) $(LINTFLAGS) $(SRC)
 
-Xmylint:	$(SRC)
-	$(MYLINT) $(CDEFS) $(MYLINTFLAGS) $(SRC)
 
 #AUTOAUTOAUTOAUTOAUTOAUTOAUTOAUTOAUTOAUTO
 main.o: LLlex.h

lang/cem/cemcom/SmallPars

@@ -8,8 +8,9 @@
 
 !File: errout.h
 #define	ERROUT		STDERR	/* file pointer for writing messages	*/
-#define	MAXERR_LINE	5	/* maximum number of error messages given
+#define	ERR_SHADOW	5	/* a syntax error overshadows error messages
-					on the same input line.		*/
+					until ERR_SHADOW symbols have been
+					accepted without syntax error */
 
 
 !File: idfsize.h

lang/cem/cemcom/ch7bin.c

@@ -77,15 +77,19 @@ ch7bin(expp, oper, expr)
 #endif NOROPTION
 			ch7mon('*', expp);
 		}
-		if ((*expp)->ex_type->tp_fund != FUNCTION)	{
+		switch ((*expp)->ex_type->tp_fund)	{
-			expr_error(*expp, "call of non-function (%s)",
+		case FUNCTION:
-				symbol2str((*expp)->ex_type->tp_fund));
-			/* leave the expression; it may still serve */
-			free_expression(expr);	/* there go the parameters */
-		}
-		else
 			*expp = new_oper((*expp)->ex_type->tp_up,
 					*expp, '(', expr);
+			break;
+		default:		/* uncallable */
+			expr_error(*expp, "calling an object of type %s",
+				symbol2str((*expp)->ex_type->tp_fund));
+		case ERRONEOUS:		/* uncallable but no message */
+			/* leave the expression; it may still serve */
+			free_expression(expr);	/* there go the parameters */
+			break;
+		}
 		(*expp)->ex_flags |= EX_SIDEEFFECTS;
 		break;
 

lang/cem/cemcom/declar.g

@@ -196,15 +196,7 @@ initializer(struct idf *idf; int sc;)
 		if (level == L_FORMAL2)
 			warning("illegal initialization of formal parameter (ignored)");
 	}
-	[
+	'='				/* used to be optional because of V6 */
-		'='
-	|
-		empty
-		{warning("old-fashioned initialization, insert =");}
-		/*	This causes trouble at declarator and at
-			external_definition, q.v.
-		*/
-	]
 	{
 #ifdef	LINT
 		lint_statement();
@@ -247,10 +239,7 @@ declarator(register struct declarator *dc;)
 	}
 :
 	primary_declarator(dc)
-	[%while(1)			/*	int i (M + 2) / 4;
+	[
-						is a function, not an
-						old-fashioned initialization.
-					*/
 		'('
 		formal_list(&fm) ?	/* semantic check later...	*/
 		')'

lang/cem/cemcom/error.c

@@ -236,17 +236,19 @@ _error(class, fn, ln, ap)
 	unsigned int ln;
 	va_list ap;
 {
-	/*	_error attempts to limit the number of error messages
-		for a given line to MAXERR_LINE.
-	*/
-#ifndef	LINT
-	static char *last_fn = 0;
-	static unsigned int last_ln = 0;
-	static int e_seen = 0;
-#endif	LINT
 	char *remark;
 	char *fmt = va_arg(ap, char *);
-	
+
+	/* check visibility of message */
+	switch (class)	{
+	case WARNING:
+	case ERROR:
+		if (token_nmb < tk_nmb_at_last_syn_err + ERR_SHADOW)
+			/* warning or error message overshadowed */
+			return;
+		break;
+	}
+
 	/*	Since name and number are gathered from different places
 		depending on the class, we first collect the relevant
 		values and then decide what to print.
@@ -292,25 +294,6 @@ _error(class, fn, ln, ap)
 		/*NOTREACHED*/;
 	}
 	
-#ifndef	LINT
-	if (ln == last_ln && fn && last_fn && strcmp(fn, last_fn) == 0)	{
-		/* we've seen this place before */
-		e_seen++;
-		if (e_seen == MAXERR_LINE)
-			fmt = "etc ...";
-		else
-		if (e_seen > MAXERR_LINE)
-			/* and too often, I'd say ! */
-			return;
-	}
-	else	{
-		/* brand new place */
-		last_fn = fn;
-		last_ln = ln;
-		e_seen = 0;
-	}
-#endif	LINT
-
 #ifdef	LINT
 	if (	/* there is a file name */
 		fn

lang/cem/cemcom/expression.g

@@ -307,16 +307,6 @@ asgnop(register int *oper;):
 	'^' '=' {*oper = XORAB;}
 |
 	'|' '=' {*oper = ORAB;}
-|
-	[ PLUSAB | MINAB | TIMESAB | DIVAB | MODAB |
-	  LEFTAB | RIGHTAB | ANDAB | XORAB | ORAB ]
-		{
-			char *symbol2str();
-
-			warning("old-fashioned assignment operator, use %s",
-				symbol2str(DOT));
-			*oper = DOT;
-		}
 ;
 
 constant(struct expr **expp;) :

lang/cem/cemcom/program.g

@@ -130,11 +130,7 @@ external_definition
 			lint_ext_def(Dc.dc_idf, Ds.ds_sc);
 #endif	LINT
 		}
-		[%if (Dc.dc_idf->id_def->df_type->tp_fund == FUNCTION)
+		[
-			/*	int i (1) {2, 3}
-				is a function, not an old-fashioned
-				initialization.
-			*/
 			function(&Ds, &Dc)
 		|
 			non_function(&Ds, &Dc)