+ assert(0);
+ }
+ }
+
+ return true;
+}
+
+/*
+ * The C grammar leaves ambiguous some cases where parentheses represent a
+ * function declarator or just parentheses. The language uses additional
+ * context (whether or not a typedef is in scope, etc.) to resolve these
+ * ambiguities, but we don't have access to that kind of information.
+ *
+ * The cdecl99 parser uses an unambiguous grammar which treats almost
+ * everything as a function, and thus considers things like 'int (x)' to
+ * be a function type with a single parameter of type 'x' (a typedef name),
+ * returning int. This can result in very complicated types for simple
+ * declarations. Ideally, cdecl99 should try and find the "simplest"
+ * explanation for a given declaration.
+ *
+ * Whether or not it achieves the simplest explanation, we apply a simple rule:
+ * if a declarator could be interpreted as something other than a function,
+ * do that.
+ *
+ * Since cdecl99 supports things like [*] in any context (in C, such constructs
+ * are only valid in function parameter lists), we don't treat them specially
+ * here.
+ */
+
+static struct cdecl_declarator *reduce_function(struct cdecl *param)
+{
+ struct cdecl_declspec *spec = param->specifiers;
+ struct cdecl_declarator *decl = param->declarators;
+ struct cdecl_declarator *last;
+
+ for (last = decl; last && last->type != CDECL_DECL_NULL;)
+ last = last->child;
+
+ if (!last)
+ return NULL;
+
+ last->type = CDECL_DECL_IDENT;
+ last->u.ident = spec->ident;
+ free(param);
+ free(spec);
+
+ return decl;
+}
+
+static bool function_is_reducible(struct cdecl_declarator *d)
+{
+ if (d->type != CDECL_DECL_FUNCTION)
+ return false;
+ if (d->child->type != CDECL_DECL_NULL)
+ return false; /* e.g., int (*)(x) */
+
+ if (!d->u.function.parameters)
+ return false; /* e.g., int f() */
+ if (d->u.function.parameters->next)
+ return false; /* e.g., int (x, y) */
+ if (d->u.function.variadic)
+ return false; /* e.g., int (x, ...) */
+
+ if (d->u.function.parameters->specifiers->type != CDECL_TYPE_IDENT)
+ return false; /* e.g. int (int) */
+ if (d->u.function.parameters->specifiers->next)
+ return false; /* e.g. int (size_t const) */
+ if (d->u.function.parameters->declarators->type == CDECL_DECL_POINTER)
+ return false; /* e.g. int (x *) */
+
+ return true;
+}
+
+static int
+simplify_functions(struct cdecl_declarator **p, struct cdecl_declarator *d)
+{
+ struct cdecl_declarator *new;
+
+ if (!function_is_reducible(d))
+ return 0;
+
+ new = reduce_function(d->u.function.parameters);
+ if (!new)
+ return 0; /* e.g. int (foo bar) */
+ *p = new;
+ free(d->child);
+ free(d);
+
+ return 1;
+}
+
+/*
+ * The parser's bias towards considering things as functions whenever possible
+ * makes nested parentheses tricky. (x) is considered to be part of a function
+ * declarator until simplify_functions converts it. The problem is that
+ * (((x))) is not valid as part of a function declarator, but it *is* valid
+ * as an identifier enclosed 3 times in parentheses. This is complicated by
+ * the fact that things like (((int))) are not valid anywhere.
+ *
+ * To avoid ambiguities, the parser actually emits a "function" declarator for
+ * every pair of parentheses. The ones that can't reasonably be functions
+ * consist of a single "parameter" with no declaration specifiers (note that
+ * every valid function parameter will have at least one type specifier).
+ *
+ * This pass is to remove these fake functions from the parse tree. We take
+ * care to avoid turning invalid things like ((int)) into valid things like
+ * (int) by observing that the only valid function declarators that appear
+ * in these "fake" parentheses are those that have a non-null child declarator
+ * (for instance, int ((*)(int)) *or* those that will be eliminated by the
+ * simplify_functions pass.
+ */
+
+static int
+reduce_parentheses(struct cdecl_declarator **p, struct cdecl_declarator *d)
+{
+ struct cdecl *param;
+
+ if (d->type != CDECL_DECL_FUNCTION)
+ return 0;
+
+ param = d->u.function.parameters;
+ if (param && param->specifiers == NULL) {
+ struct cdecl_declarator *decl;
+
+ assert(!param->next);
+
+ decl = param->declarators;
+ if (decl->type == CDECL_DECL_NULL) {
+ free(decl);
+ free(param);
+ d->u.function.parameters = NULL;
+ return 0;