X-Git-Url: https://git.draconx.ca/gitweb/cdecl99.git/blobdiff_plain/bbfdea24b2b940031e86e990bc457785dd378b58..6d601969de9687819347cf27df8ddf6ab026e4b0:/src/parse-decl.c

diff --git a/src/parse-decl.c b/src/parse-decl.c
index 1ad3e8e..f25c4c4 100644
--- a/src/parse-decl.c
+++ b/src/parse-decl.c
@@ -26,6 +26,62 @@
 #include "parse.h"
 #include "scan.h"
 
+/*
+ * We can represent type specifiers as a bitmap, which gives us a finite
+ * list of acceptable bitmap values according to the C standard.  However,
+ * the "long" specifier is allowed to occur more than once, but only at most
+ * 2 times.  Treat it as a special case, assigning an unused bit to represent
+ * the second long.
+ */
+#define MAP_LLONG_BIT 31
+#define MAP_LONG_BIT (CDECL_TYPE_LONG-CDECL_SPEC_TYPE)
+#define CDECL_TYPE_LLONG (CDECL_SPEC_TYPE+MAP_LLONG_BIT)
+
+#include "typemap.h"
+
+/*
+ * Convert the declaration specifiers to a bitmap with each bit
+ * corresponding to one specific type specifier.
+ */
+static int valid_typespec(struct cdecl_declspec *s)
+{
+	unsigned long map = 0;
+
+	for (struct cdecl_declspec *c = s; c; c = c->next) {
+		unsigned long bit;
+
+		if (cdecl_spec_kind(c) != CDECL_SPEC_TYPE)
+			continue;
+
+		bit = c->type - CDECL_SPEC_TYPE;
+		assert(bit < MAP_LLONG_BIT);
+		bit = 1ul << bit;
+
+		/* "long" special case */
+		if ((map & bit) == 1ul << MAP_LONG_BIT)
+			bit = 1ul << MAP_LLONG_BIT;
+
+		if (map & bit) {
+			if (bit == 1ul << MAP_LLONG_BIT)
+				fprintf(stderr, "too many long specifiers\n");
+			else
+				fprintf(stderr, "duplicate type specifier\n");
+			return false;
+		}
+		map |= bit;
+	}
+
+	if (typemap_is_valid(map))
+		return true;
+
+	if (map == 0)
+		fprintf(stderr, "no type specified\n");
+	else
+		fprintf(stderr, "invalid type specified\n");
+
+	return false;
+}
+
 /*
  * Verify the declaration specifiers of a declaration.  If top is true, treat
  * this as a top-level declaration.  Otherwise, treat this as a function
@@ -37,10 +93,8 @@ static bool valid_declspecs(struct cdecl *decl, bool top)
 	struct cdecl_declarator *d   = decl->declarators;
 	bool abstract = cdecl_is_abstract(d);
 	unsigned num_storage = 0;
-	unsigned long typemap;
 
-	typemap = cdecl__build_typemap(specs);
-	if (typemap == -1)
+	if (!valid_typespec(specs))
 		return false;
 
 	for (struct cdecl_declspec *c = specs; c; c = c->next) {