shithub: scc

Info  •  Files  •  Log  •  Branches

Add struct and unions declarators

These declarators are very diferents of the previous due to
they define a new namespace, so the thecniques used previously
cannot be applied here. We have to define a new namespace with
each new struct declared. We defined the first struct namespace
as NS_ANY+1, so we will not have any collision with the anothers
namespaces.

--- a/decl.c

+++ b/decl.c

@@ -11,6 +11,9 @@

 char parser_out_home;

 static struct symbol *cursym;

+static unsigned char nr_structs = NS_ANY + 1;

+static unsigned char structbuf[NR_STRUCT_LEVEL], *structp = &structbuf[0];

+

 static void declarator(struct ctype *tp, unsigned char ns);

 static struct symbol *

@@ -79,6 +82,9 @@

 	}

 }

+

+static struct ctype *struct_spec(register struct ctype *);

+

 struct ctype *

 spec(void)

 {

@@ -95,10 +101,13 @@

 		case FLOAT:    case DOUBLE: case BOOL:

 		case VOID:     case CHAR:   case SHORT:

 		case INT:      case ENUM:   case LONG:

-		case STRUCT:   case UNION:

 			tp = btype(tp, yytoken);

 			break;

-			/* TODO: ENUM, STRUCT, UNION */

+			/* TODO: ENUM */

+		case STRUCT:   case UNION:

+			tp = btype(tp, yytoken);

+			next();

+			return struct_spec(tp);

 		case IDEN:

 			if (!tp || !tp->type) {

 				struct symbol *sym;

@@ -138,6 +147,60 @@

 	}

 }

+static struct ctype *

+struct_dcl(unsigned char ns)

+{

+	register struct ctype *tp, *base;

+

+	if (!(base = spec())) {

+		base = newctype();

+		base->type = INT;

+		warning_error(options.implicit,

+		              "data definition has no type or storage class");

+	}

+	if (base->c_typedef  || base->c_static || base->c_auto ||

+	    base->c_register || base->c_extern) {

+		error("storage specifier in a struct/union field declaration");

+	}

+

+	do {                      /* TODO: detect unnamed structs */

+		declarator(base, ns);

+		tp = decl_type(base);

+		(cursym->ctype = tp)->refcnt++;

+	} while (accept(','));

+

+	expect(';');

+	return tp;

+}

+

+static struct ctype *

+struct_spec(register struct ctype *tp)

+{

+	if (yytoken == IDEN) {

+		(namespace(NS_STRUCT, -1)->ctype = tp)->refcnt++;

+		next();

+	}

+

+	if (nr_structs == NR_MAXSTRUCTS)

+		error("too much structs/unions defined");

+	if (structp == &structbuf[NR_STRUCT_LEVEL])

+		error("too much nested structs/unions");

+	tp->c_struct = *structp++ = nr_structs;

+

+	if (!accept('{'))

+		return tp;

+

+	if (!tp->forward)

+		error("struct/union already defined");

+

+	do

+		struct_dcl(tp->c_struct);

+	while (!accept('}'));

+	tp->forward = 0;

+

+	return tp;

+}

+

 static void

 declarator(struct ctype *tp, unsigned char ns)

 {

@@ -201,6 +264,9 @@

 		declarator(base, base->c_typedef ? NS_TYPEDEF : NS_IDEN);

 		tp = decl_type(base);

 		(cursym->ctype = tp)->refcnt++;

+		if ((tp->type == STRUCT || tp->type == UNION) && tp->forward)

+			error("declaration of variable with incomplete type");

+

 		sp = nodesym(cursym);

 		if (tp->type == FTN && yytoken == '{') {

 			np  = node2(ODEF, sp, function(cursym));

@@ -227,8 +293,18 @@

 		warning_error(options.implicit,

 		              "data definition has no type or storage class");

 	} else if (accept(';')) {

-		warning_error(options.useless,

-			      "useless type name in empty declaration");

+		register unsigned char type = tp->type;

+

+		if (type == STRUCT || type == UNION) {

+			if (tp->c_extern || tp->c_static || tp->c_auto ||

+			    tp->c_register || tp->c_const || tp->c_volatile) {

+				warning_error(options.useless,

+				              "useless storage class specifier in empty declaration");

+			}

+		} else {

+			warning_error(options.useless,

+			              "useless type name in empty declaration");

+		}

 		delctype(tp);

 		goto repeat;

 	}

--- a/sizes.h

+++ b/sizes.h

@@ -11,6 +11,10 @@

  */

 #define NR_COND   8

 /*

+ * number of defined structs/unions in one translation unit

+ */

+#define NR_MAXSTRUCTS 127

+/*

  * 12 pointer, array, and function declarators (in any combinations)

  *  modifying an arithmetic, a structure, a union, or an incomplete type

  *  in a declaration

--- a/symbol.h

+++ b/symbol.h

@@ -32,7 +32,11 @@

 	bool c_restrict : 1;

 	bool c_unsigned : 1;

 	bool c_signed : 1;

-	unsigned len;

+	bool forward : 1;

+	union {

+		unsigned len;

+		unsigned char c_struct;

+	};

 	struct ctype *base;

 	unsigned char refcnt;

 };

--- a/types.c

+++ b/types.c

@@ -17,7 +17,7 @@

 {

 	register struct ctype *tp = xcalloc(sizeof(*tp), 1);

-	tp->refcnt = 1;

+	tp->forward = tp->refcnt = 1;

 	return tp;

 }

-- 

⑨