scc

commit 893e56b36a5d1da429dd01ca703adbedff2898e5
parent 15b5db8b6c5c767cf9c538f3cdafa8926b4b7430
Author: Roberto E. Vargas Caballero <k0ga@shike2.com>
Date:   Wed,  9 Oct 2013 22:47:09 +0200

Use symbolic constants for namespaces and lookup values

We were using some ugly rules in namespace (positive, negative or zero),
and it was no clear when you were calling the function what was happening.
So this patch add symbolic names.

Diffstat:
M
decl.c
 | 
19
+++++++++++--------
M
symbol.h
 | 
2
++

2 files changed, 13 insertions(+), 8 deletions(-)
diff --git a/decl.c b/decl.c
@@ -8,6 +8,9 @@
 #include "syntax.h"
 #include "symbol.h"
 
+#define NOALLOC_NS    0
+#define ALLOCDUP_NS   1
+#define ALLOC_NS      2
 char parser_out_home;
 
 static struct symbol *cursym;
@@ -17,24 +20,24 @@ static unsigned char structbuf[NR_STRUCT_LEVEL], *structp = &structbuf[0];
 static void declarator(struct ctype *tp, unsigned char ns);
 
 static struct symbol *
-namespace(register unsigned char ns, signed char alloc)
+namespace(register unsigned char ns, char alloc)
 {
 	register struct symbol *sym = yyval.sym;
 	unsigned char yyns = sym->ns;
 
-	if (!alloc) {
+	if (alloc == NOALLOC_NS) {
 		if (yyns == NS_ANY)
 			return NULL;
 		else if (yyns == ns)
 			return sym;
 		else                        /* don't create new symbol */
-			return lookup(yytext, -ns);
+			return lookup(yytext, NOINSERT(ns));
 	} else {
 		if (yyns == NS_ANY) {
 			sym->ns = ns;
 			return sym;
 		} else if (yyns == ns && sym->ctx == curctx) {
-			if (alloc < 0)
+			if (alloc == ALLOCDUP_NS)
 				return sym;
 			error("redeclaration of '%s'", yytext);
 		}
@@ -49,7 +52,7 @@ dirdcl(register struct ctype *tp, unsigned char ns)
 		declarator(tp, ns);
 		expect(')');
 	} else if (yytoken == IDEN) {
-		cursym = namespace(ns, 1);
+		cursym = namespace(ns, ALLOC_NS);
 		next();
 	} else {
 		error("expected '(' or identifier before of '%s'", yytext);
@@ -88,7 +91,7 @@ new_struct(register struct ctype *tp)
 	struct symbol *sym = NULL;
 
 	if (yytoken == IDEN) {
-		sym = namespace(NS_STRUCT, -1);
+		sym = namespace(NS_STRUCT, ALLOCDUP_NS);
 		sym->ctype = tp;
 		next();
 	}
@@ -175,7 +178,7 @@ enum_dcl(struct ctype *base)
 			break;
 
 		expect(IDEN);
-		sym = namespace(NS_IDEN, 1);
+		sym = namespace(NS_IDEN, ALLOC_NS);
 		sym->ctype = tp;
 		if (accept('=')) {
 			expect(CONSTANT);
@@ -220,7 +223,7 @@ spec(void)
 				struct symbol *sym;
 				unsigned char tok = ahead();
 
-				sym = namespace(NS_TYPEDEF, 0);
+				sym = namespace(NS_TYPEDEF, NOALLOC_NS);
 				if (sym && tok != ';' && tok != ',') {
 					if (!tp)
 						tp = newctype();
diff --git a/symbol.h b/symbol.h
@@ -11,6 +11,8 @@
 #define CTX_FUNC  2
 #define CTX_ANY   0
 
+#define NOINSERT(x) (-x)
+
 enum {
 	NS_IDEN,
 	NS_KEYWORD,