X-Git-Url: https://git.draconx.ca/gitweb/cdecl99.git/blobdiff_plain/a41aa156f28753613f38924fc856d3dc992cfc56..23bee8f66fbd14c308d3c509a59024768bc2feef:/src/parse-decl.c

diff --git a/src/parse-decl.c b/src/parse-decl.c
index 8f0bd38..3c60dd2 100644
--- a/src/parse-decl.c
+++ b/src/parse-decl.c
@@ -1,6 +1,6 @@
 /*
  * Parse and validate C declarations.
- * Copyright © 2011-2012, 2020-2021, 2023 Nick Bowler
+ * Copyright © 2011-2012, 2020-2021, 2023-2024 Nick Bowler
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -27,6 +27,8 @@
 #include "scan.h"
 #include "errmsg.h"
 
+static struct cdecl *fake_function_param(struct cdecl_declarator *);
+
 /*
  * Allocate a "parse item", which is a union of several parse tree
  * structure types, together with a string buffer.  The s_sz argument
@@ -177,6 +179,36 @@ static bool valid_declspecs(struct cdecl *decl, bool top)
 	return true;
 }
 
+/*
+ * Find the tree pointer which leads to the parameter's leaf node.
+ *
+ * Return a null pointer if the traversal locates a syntactic element which
+ * prevents function reduction.  This occurs if the leaf node declares an
+ * identifier, or for nontrivial fake function parameters (see below).
+ */
+static struct cdecl_declarator **leaf_pointer(struct cdecl *param)
+{
+	struct cdecl_declarator *d, **p = &param->declarators;
+
+	if ((param = fake_function_param(param->declarators))) {
+		if (param->declarators->type != CDECL_DECL_NULL)
+			return NULL; /* e.g. int (x (*)) */
+	}
+
+	while ((d = *p)->child) {
+		p = &d->child;
+
+		if (fake_function_param(d->child))
+			return NULL; /* e.g. int (x (*)[][1]) */
+	}
+
+	if (d->type != CDECL_DECL_NULL)
+		return NULL; /* e.g. int (x y) */
+
+	return p;
+}
+
+
 /*
  * The C grammar leaves ambiguous some cases where parentheses represent a
  * function declarator or just parentheses.  The language uses additional
@@ -201,13 +233,10 @@ static bool valid_declspecs(struct cdecl *decl, bool top)
 
 static struct cdecl_declarator *reduce_function(struct cdecl *param)
 {
-	struct cdecl_declarator *d, **p = &param->declarators;
 	struct parse_item *spec = (void *)param->specifiers;
+	struct cdecl_declarator *d, **p;
 
-	while ((d = *p)->child)
-		p = &d->child;
-
-	if (d->type != CDECL_DECL_NULL)
+	if (!(p = leaf_pointer(param)))
 		return NULL;
 
 	/*
@@ -260,7 +289,7 @@ simplify_functions(struct cdecl_declarator **p, struct cdecl_declarator *d)
 
 	new = reduce_function(d->u.function.parameters);
 	if (!new)
-		return 0; /* e.g. int (foo bar) */
+		return 0;
 	*p = new;
 	free(d);