shithub: scc

Info  •  Files  •  Log  •  Branches

Add bit fields

Bit fields are small integers with a varible size of bits. C99
defines that bit fields can be of type int or type bool.

--- a/decl.c

+++ b/decl.c

@@ -122,6 +122,18 @@

 	do {

 		declarator(base, ns);

 		tp = decl_type(base);

+		if (accept(':')) {

+			expect(CONSTANT);

+			switch (tp->type) {

+			case INT: case BOOL:

+				tp = btype(NULL, BITFLD);

+				tp->len = yyval.sym->val;

+				break;

+			default:

+				error("bit-field '%s' has invalid type",

+				      cursym->name);

+			}

+		}

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

 	} while (accept(','));

--- a/tokens.h

+++ b/tokens.h

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

 	/* types */

 	INT = 1, CHAR, FLOAT, LONG, LLONG, SHORT, VOID, DOUBLE,

 	LDOUBLE, STRUCT, UNION, ENUM, BOOL, ARY, PTR, FTN,

-	COMPLEX, IMAGINARY,

+	COMPLEX, IMAGINARY, BITFLD,

 	/* storage specifier */

 	TYPEDEF, EXTERN, STATIC, AUTO, REGISTER,

 	/* type qualifier */

--- a/types.c

+++ b/types.c

@@ -93,7 +93,7 @@

 	type = tp->type;

 	switch (tok) {

-	case VOID: case BOOL: case STRUCT: case UNION: case ENUM:

+	case VOID: case BOOL: case STRUCT: case UNION: case ENUM: case BITFLD:

 		if (type)

 			goto two_or_more;;

 		type = tok;