From: Nick Bowler <nbowler@draconx.ca>
Date: Thu, 7 Jul 2011 00:51:31 +0000 (-0400)
Subject: Validate declspecs in function parameters.
X-Git-Tag: v1~146
X-Git-Url: https://git.draconx.ca/gitweb/cdecl99.git/commitdiff_plain/34d65b55a47f66bb907d30ae2b65c4fb64f38cc5

Validate declspecs in function parameters.
---

diff --git a/src/parse-decl.c b/src/parse-decl.c
index b5212ec..c210f7c 100644
--- a/src/parse-decl.c
+++ b/src/parse-decl.c
@@ -25,9 +25,11 @@
 #include "scan.h"
 
 /*
- * Verify the declaration specifiers of a declaration.
+ * Verify the declaration specifiers of a declaration.  If top is true, treat
+ * this as a top-level declaration.  Otherwise, treat this as a function
+ * parameter (which carries additional constraints).
  */
-static bool valid_declspecs(struct cdecl *decl)
+static bool valid_declspecs(struct cdecl *decl, bool top)
 {
 	struct cdecl_declspec *specs = decl->specifiers;
 	struct cdecl_declarator *d   = decl->declarators;
@@ -49,6 +51,11 @@ static bool valid_declspecs(struct cdecl *decl)
 			}
 			continue;
 		case CDECL_SPEC_STOR:
+			if (!top && c->type != CDECL_STOR_REGISTER) {
+				fprintf(stderr, "function parameters may only have register storage\n");
+				return false;
+			}
+
 			if (++num_storage > 1) {
 				fprintf(stderr, "too many storage-class specifiers\n");
 				return false;
@@ -65,7 +72,7 @@ static bool valid_declspecs(struct cdecl *decl)
 			}
 			break;
 		case CDECL_SPEC_FUNC:
-			if (d->type != CDECL_DECL_FUNCTION) {
+			if (!top || d->type != CDECL_DECL_FUNCTION) {
 				fprintf(stderr, "only function declarations may have function specifiers.\n");
 				return false;
 			}
@@ -244,6 +251,38 @@ reduce_parentheses(struct cdecl_declarator **p, struct cdecl_declarator *d)
 	return 0;
 }
 
+static int
+check_parameters(struct cdecl_declarator **p, struct cdecl_declarator *d)
+{
+	struct cdecl_declspec *spec;
+	struct cdecl *param;
+	bool has_void = false;
+
+	if (d->type != CDECL_DECL_FUNCTION)
+		return 0;
+
+	for (param = d->u.function.parameters; param; param = param->next) {
+		if (!valid_declspecs(param, false))
+			return -1;
+
+		for (spec = param->specifiers; spec; spec = spec->next) {
+			if (spec->type == CDECL_TYPE_VOID
+			    && param->declarators->type == CDECL_DECL_NULL)
+				has_void = true;
+		}
+	}
+
+	if (has_void && d->u.function.parameters->next) {
+		fprintf(stderr, "a void parameter must stand alone\n");
+		return -1;
+	} else if (has_void && d->u.function.variadic) {
+		fprintf(stderr, "variadic functions cannot have a void parameter\n");
+		return -1;
+	}
+
+	return 0;
+}
+
 /*
  * Traverse the parse tree, calling a function on every declarator in a
  * depth-first preorder traversal.  The function is given a pointer to the
@@ -299,8 +338,10 @@ struct cdecl *cdecl_parse_decl(const char *declstr)
 			goto err;
 		if (!forall_declarators(i, simplify_functions))
 			goto err;
+		if (!forall_declarators(i, check_parameters))
+			goto err;
 
-		if (!valid_declspecs(i))
+		if (!valid_declspecs(i, true))
 			goto err;
 	}