lint: additional type tests in expressions

lang/cem/cemcom/arith.c

@@ -12,6 +12,7 @@
 */
 
 #include	<alloc.h>
+#include	"lint.h"
 #include	"nofloat.h"
 #include	"nobitfield.h"
 #include	"idf.h"
@@ -163,7 +164,9 @@ any2arith(expp, oper)
 		else
 			expr_warning(*expp, "%s on enum", symbol2str(oper));
 #endif NOROPTION
+#ifndef	LINT
 		int2int(expp, int_type);
+#endif	LINT
 		break;
 #ifndef	NOFLOAT
 	case FLOAT:
@@ -420,53 +423,6 @@ is_test_op(oper)
 	/*NOTREACHED*/
 }
 
-#ifdef ____
-int
-is_arith_op(oper)
-{
-	switch (oper) {
-	case '*':
-	case '/':
-	case '%':
-	case '+':
-	case '-':
-	case LEFT:
-	case RIGHT:
-	case '&':
-	case '^':
-	case '|':
-		return 1;
-	default:
-		return 0;
-	}
-}
-
-int
-is_asgn_op(oper)
-{
-	switch (oper) {
-	case '=':
-	case PLUSAB:
-	case MINAB:
-	case TIMESAB:
-	case DIVAB:
-	case MODAB:
-	case LEFTAB:
-	case RIGHTAB:
-	case ANDAB:
-	case ORAB:
-	case XORAB:
-	case PLUSPLUS:
-	case POSTINCR:
-	case MINMIN:
-	case POSTDECR:
-		return 1;
-	default:
-		return 0;
-	}
-}
-#endif
-
 any2opnd(expp, oper)
 	register struct expr **expp;
 {

lang/cem/cemcom/ch7.c

@@ -163,21 +163,26 @@ ch7cast(expp, oper, tp)
 	if ((*expp)->ex_class == String)
 		string2pointer(*expp);
 	oldtp = (*expp)->ex_type;
+
 #ifndef NOBITFIELD
 	if (oldtp->tp_fund == FIELD)	{
 		field2arith(expp);
 		ch7cast(expp, oper, tp);
 	}
 	else
-	if (tp->tp_fund == FIELD)
+	if (tp->tp_fund == FIELD) {
 		ch7cast(expp, oper, tp->tp_up);
+	}
 	else
 #endif NOBITFIELD
-	if (oldtp == tp)
+	if (oldtp == tp) {
-		{}			/* life is easy */
+		/* life is easy */
+	}
 	else
-	if (tp->tp_fund == VOID)	/* Easy again */
+	if (tp->tp_fund == VOID) {
+		/* Easy again */
 		(*expp)->ex_type = void_type;
+	}
 	else
 	if (is_arith_type(oldtp) && is_arith_type(tp))	{
 		int oldi = is_integral_type(oldtp);
@@ -191,7 +196,14 @@ ch7cast(expp, oper, tp)
 				expr_warning(*expp,
 					"%s on enums of different types",
 					symbol2str(oper));
+#ifdef	LINT
+			if (oper == CAST)
+				(*expp)->ex_type = tp;
+			else
 				int2int(expp, tp);
+#else	LINT
+			int2int(expp, tp);
+#endif	LINT
 		}
 #ifndef NOFLOAT
 		else
@@ -200,13 +212,37 @@ ch7cast(expp, oper, tp)
 				expr_warning(*expp,
 					"conversion of enum to %s\n",
 					symbol2str(tp->tp_fund));
+#ifdef	LINT
+			if (oper == CAST)
+				(*expp)->ex_type = tp;
+			else
 				int2float(expp, tp);
+#else	LINT
+			int2float(expp, tp);
+#endif	LINT
 		}
 		else
-		if (!oldi && i)
+		if (!oldi && i) {
+#ifdef	LINT
+			if (oper == CAST)
+				(*expp)->ex_type = tp;
+			else
 				float2int(expp, tp);
-		else		/* !oldi && !i */
+#else	LINT
+			float2int(expp, tp);
+#endif	LINT
+		}
+		else {
+			/* !oldi && !i */
+#ifdef	LINT
+			if (oper == CAST)
+				(*expp)->ex_type = tp;
+			else
 				float2float(expp, tp);
+#else	LINT
+			float2float(expp, tp);
+#endif	LINT
+		}
 #else NOFLOAT
 		else {
 			crash("(ch7cast) floats not implemented\n");
@@ -269,8 +305,10 @@ ch7cast(expp, oper, tp)
 			(*expp)->ex_type = tp;
 	}
 	else
-	if (oldtp->tp_fund == ERRONEOUS) /* we just won't look */
+	if (oldtp->tp_fund == ERRONEOUS) {
+		/* we just won't look */
 		(*expp)->ex_type = tp;	/* brute force */
+	}
 	else
 	if (oldtp->tp_size == tp->tp_size && oper == CAST)	{
 		expr_warning(*expp, "dubious conversion based on equal size");
@@ -321,6 +359,7 @@ ch7asgn(expp, oper, expr)
 		struct expr *extmp = intexpr((arith)0, INT);
 
 		/* this is really $#@&*%$# ! */
+		/* if you correct this, please correct lint_new_oper() too */
 		extmp->ex_lvalue = 1;
 		extmp->ex_type = exp->ex_type;
 		ch7bin(&extmp, oper, expr);

lang/cem/cemcom/ch7bin.c

@@ -303,7 +303,7 @@ mk_binop(expp, oper, expr, commutative)
 	register struct expr *expr;
 {
 	/*	Constructs in *expp the operation indicated by the operands.
-		"commutative" indicates wether "oper" is a commutative
+		"commutative" indicates whether "oper" is a commutative
 		operator.
 	*/
 	register struct expr *ex = *expp;

lang/cem/cemcom/dumpidf.c

@@ -254,8 +254,8 @@ type2str(tp)
 		sprint(buf, "<NILTYPE>");
 		return buf;
 	}
-	sprint(buf, "(@%lx, #%ld, &%d) ",
+
-			tp, (long)tp->tp_size, tp->tp_align);
+	sprint(buf, "%s(#%ld, &%d) ", buf, (long)tp->tp_size, tp->tp_align);
 	while (ops)	{
 		switch (tp->tp_fund)	{
 		case POINTER:

lang/cem/cemcom/expr.c

@@ -352,6 +352,7 @@ new_oper(tp, e1, oper, e2)
 		expr->ex_file = dot.tk_file;
 		expr->ex_line = dot.tk_line;
 	}
+
 	expr->ex_type = tp;
 	expr->ex_class = Oper;
 	/* combine depths and flags of both expressions */
@@ -368,6 +369,9 @@ new_oper(tp, e1, oper, e2)
 	op->op_oper = oper;
 	op->op_left = e1;
 	op->op_right = e2;
+#ifdef	LINT
+	lint_new_oper(expr);
+#endif	LINT
 	return expr;
 }
 

lang/cem/cemcom/l_brace.str

@@ -4,9 +4,23 @@
  */
 /* $Header$ */
 
+/*	To determine the minimum scope of a local variable, all (braced)
+	scopes are numbered consecutively.  Next we maintain an array which
+	maps the nesting depth (level) onto the scope number; we record
+	the scope number of the first application of a local variable
+	in its definition.  Each further application requires that the
+	level of the variable be at least large enough to comprise both
+	the present scope and that of its first application.  That level
+	number is determined by searching the array and is then recorded in
+	the definition (beacuse it is always equal to or smaller than the
+	level already there).
+
+	The array is implemented as a linked list of struct brace.
+*/
+
 struct brace	{
 	struct brace *next;
-	int br_count;			/* ??? */
+	int br_count;
 	int br_level;
 };
 

lang/cem/cemcom/l_lint.c

@@ -166,7 +166,6 @@ lint_oper(expr, val, used)
 	case ANDAB:
 	case XORAB:
 	case ORAB:
-		lint_conversion(oper, right->ex_type, left->ex_type);
 		/* for cases like i += l; */
 		esp1 = lint_expr(right, RVAL, USED);
 		if (oper != '=') {
@@ -269,7 +268,6 @@ lint_oper(expr, val, used)
 	case INT2FLOAT:
 	case FLOAT2INT:
 	case FLOAT2FLOAT:
-		lint_conversion(oper, right->ex_type, left->ex_type);
 		return lint_expr(right, RVAL, USED);
 
 	case '<':

lang/cem/cemcom/l_misc.c

@@ -27,16 +27,36 @@
 extern char *symbol2str();
 extern struct type *func_type;
 
-lint_conversion(oper, from_type, to_type)
+lint_new_oper(expr)
-	struct type *from_type, *to_type;
+	struct expr *expr;
 {
-	register int from = from_type->tp_fund;
+	/*	Does additional checking on a newly constructed expr node
-	register int to = to_type->tp_fund;
+		of class Oper.
 
+		Some code in this routine could be contracted, but since
+		I am not sure we have covered the entire ground, we'll
+		leave the contracting for some rainy day.
+	*/
+	register struct expr *left = expr->OP_LEFT;
+	register struct expr *right = expr->OP_RIGHT;
+	register int oper = expr->OP_OPER;
+	register int l_fund =
+		left == 0 ? 0 :			/* for monadics */
+		left->ex_type->tp_fund;
+	register int r_fund =
+		right == 0 ? 0 :		/* for ( without parameters */
+		right->ex_type->tp_fund;
+
+	/*	In ch7.c, in ch7asgn(), a combined operator/assignment
+		is hammered into correctness by repeated application of
+		ch7bin(), which calls new_oper(), which calls lint_new_oper().
+		These spurious calls understandably cause spurious error
+		messages, which we don't like.  So we try to suppress these
+		wierd calls here.  This refers to the code marked
+			this is really $#@&*%$# !
+		in ch7asgn().
+	*/
 	switch (oper) {
-	case RETURN:	/* not really an oper, but it works */
-	case INT2INT:
-	case '=':
 	case PLUSAB:
 	case MINAB:
 	case TIMESAB:
@@ -47,19 +67,225 @@ lint_conversion(oper, from_type, to_type)
 	case ANDAB:
 	case XORAB:
 	case ORAB:
-		if (	(from == LONG && to != LONG)
+		/* is the left operand wierd? */
-		||	(from == DOUBLE && to != DOUBLE)
+		if (	left->ex_class == Value
+		&&	left->VL_CLASS == Const
+		&&	left->VL_VALUE == 0
 		) {
-			awarning("conversion from %s to %s may lose accuracy",
+			return;
-				symbol2str(from), symbol2str(to));
 		}
 	}
+
+	switch (oper) {
+	case '=':
+		lint_conversion(right, l_fund);
+		break;
+
+	case PLUSAB:
+		lint_conversion(right, l_fund);
+	case '+':
+		lint_enum_arith(l_fund, oper, r_fund);
+		break;
+
+	case MINAB:
+		lint_conversion(right, l_fund);
+	case '-':
+		if (left == 0) {
+			/* unary */
+			if (r_fund == ENUM)
+				warning("negating an enum");
+		}
+		else {
+			/* binary */
+			if (l_fund == ENUM && r_fund == ENUM) {
+				if (left->ex_type != right->ex_type)
+					warning("subtracting enums of different type");
+				/* update the type, cem does not do it */
+				expr->ex_type = int_type;
+			}
+			lint_enum_arith(l_fund, oper, r_fund);
+		}
+		break;
+
+	case TIMESAB:
+		lint_conversion(right, l_fund);
+	case '*':
+		if (left == 0) {
+			/* unary */
+		}
+		else {
+			/* binary */
+			if (l_fund == ENUM || r_fund == ENUM)
+				warning("multiplying enum");
+		}
+		break;
+
+	case DIVAB:
+		lint_conversion(right, l_fund);
+	case '/':
+		if (l_fund == ENUM || r_fund == ENUM)
+			warning("division on enum");
+		break;
+
+	case MODAB:
+		lint_conversion(right, l_fund);
+	case '%':
+		if (l_fund == ENUM || r_fund == ENUM)
+			warning("modulo on enum");
+		break;
+
+	case '~':
+		if (r_fund == ENUM || r_fund == FLOAT || r_fund == DOUBLE)
+			warning("~ on %s", symbol2str(r_fund));
+		break;
+
+	case '!':
+		if (r_fund == ENUM)
+			warning("! on enum");
+		break;
+
+	case INT2INT:
+	case INT2FLOAT:
+	case FLOAT2INT:
+	case FLOAT2FLOAT:
+		lint_conversion(right, l_fund);
+		break;
+
+	case '<':
+	case '>':
+	case LESSEQ:
+	case GREATEREQ:
+	case EQUAL:
+	case NOTEQUAL:
+		if (	(l_fund == ENUM || r_fund == ENUM)
+		&&	left->ex_type != right->ex_type
+		) {
+			warning("comparing enum with non-enum");
+		}
+		lint_relop(left, right, oper);
+		lint_relop(right, left, 
+			oper == '<' ? '>' :
+			oper == '>' ? '<' :
+			oper == LESSEQ ? GREATEREQ :
+			oper == GREATEREQ ? LESSEQ :
+			oper
+		);
+		break;
+
+	case LEFTAB:
+	case RIGHTAB:
+		lint_conversion(right, l_fund);
+	case LEFT:
+	case RIGHT:
+		if (l_fund == ENUM || r_fund == ENUM)
+			warning("shift on enum");
+		break;
+
+	case ANDAB:
+	case ORAB:
+	case XORAB:
+		lint_conversion(right, l_fund);
+	case '&':
+	case '|':
+	case '^':
+		if (l_fund == ENUM || r_fund == ENUM)
+			warning("bit operations on enum");
+		break;
+
+	case ',':
+	case '?':
+	case ':':
+	case AND:
+	case OR:
+	case POSTINCR:
+	case POSTDECR:
+	case PLUSPLUS:
+	case MINMIN:
+	case '(':
+	case '.':
+	case ARROW:
+	default:
+		/* OK with lint */
+		break;
+	}
 }
 
-lint_ret_conv(from_type)
+lint_enum_arith(l_fund, oper, r_fund)
-	struct type *from_type;
+	int l_fund, oper, r_fund;
 {
-	lint_conversion(RETURN, from_type, func_type);
+	if (	l_fund == ENUM
+	&&	r_fund != CHAR
+	&&	r_fund != SHORT
+	&&	r_fund != INT
+	) {
+		warning("%s on enum and %s",
+			symbol2str(oper), symbol2str(r_fund));
+	}
+	else
+	if (	r_fund == ENUM
+	&&	l_fund != CHAR
+	&&	l_fund != SHORT
+	&&	l_fund != INT
+	) {
+		warning("%s on %s and enum",
+			symbol2str(oper), symbol2str(r_fund));
+	}
+}
+
+lint_conversion(from_expr, to_fund)
+	struct expr *from_expr;
+	int to_fund;
+{
+	register int from_fund = from_expr->ex_type->tp_fund;
+
+	/*	was there an attempt to reduce the type of the from_expr
+		of the form
+			expr & 0377
+		or something like this?
+	*/
+	if (from_expr->ex_class == Oper && from_expr->OP_OPER == INT2INT) {
+		from_expr = from_expr->OP_LEFT;
+	}
+	if (from_expr->ex_class == Oper && from_expr->OP_OPER == '&') {
+		struct expr *bits =
+			is_cp_cst(from_expr->OP_LEFT) ? from_expr->OP_LEFT :
+			is_cp_cst(from_expr->OP_RIGHT) ? from_expr->OP_RIGHT :
+			0;
+
+		if (bits) {
+			arith val = bits->VL_VALUE;
+
+			if (val < 256)
+				from_fund = CHAR;
+			else if (val < 256)
+				from_fund = SHORT;
+		}
+	}
+	if (numsize(from_fund) > numsize(to_fund)) {
+		awarning("conversion from %s to %s may lose accuracy",
+			symbol2str(from_fund), symbol2str(to_fund));
+	}
+}
+
+int
+numsize(fund)
+{
+	switch (fund) {
+	case CHAR:	return 1;
+	case SHORT:	return 2;
+	case INT:	return 3;
+	case ENUM:	return 3;
+	case LONG:	return 4;
+	case FLOAT:	return 5;
+	case DOUBLE:	return 6;
+	default:	return 0;
+	}
+}
+
+lint_ret_conv(from_expr)
+	struct expr *from_expr;
+{
+	lint_conversion(from_expr, func_type->tp_fund);
 }
 
 lint_ptr_conv(from, to)
@@ -117,6 +343,13 @@ lint_relop(left, right, oper)
 	struct expr *left, *right;
 	int oper;	/* '<', '>', LESSEQ, GREATEREQ, EQUAL, NOTEQUAL */
 {
+	/* left operand may be converted */
+	if (	left->ex_class == Oper
+	&&	left->OP_OPER == INT2INT
+	) {
+		left = left->OP_RIGHT;
+	}
+
 	/* <unsigned> <relop> <neg-const|0> is doubtful */
 	if (	left->ex_type->tp_unsigned
 	&&	right->ex_class == Value

lang/cem/cemcom/l_states.c

@@ -964,7 +964,6 @@ lint_label()
 */
 	register struct auto_def *a = top_ls->ls_current->st_auto_list;
 
-	hwarning("all auto variables assumed initialized at label");
 	while (a) {
 		a->ad_maybe_set = 0;
 		a->ad_set = 1;

lang/cem/cemcom/statement.g

@@ -417,7 +417,7 @@ return_statement
 		expression(&expr)
 		{
 #ifdef	LINT
-			lint_ret_conv(expr->ex_type);
+			lint_ret_conv(expr);
 #endif	LINT
 
 			do_return_expr(expr);