Module Name: src
Committed By: rillig
Date: Sat Dec 18 13:23:09 UTC 2021
Modified Files:
src/usr.bin/xlint/lint1: init.c
Log Message:
lint: document wrong data structures for modelling initializations
No functional change.
To generate a diff of this commit:
cvs rdiff -u -r1.219 -r1.220 src/usr.bin/xlint/lint1/init.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/usr.bin/xlint/lint1/init.c
diff -u src/usr.bin/xlint/lint1/init.c:1.219 src/usr.bin/xlint/lint1/init.c:1.220
--- src/usr.bin/xlint/lint1/init.c:1.219 Sat Dec 18 13:06:33 2021
+++ src/usr.bin/xlint/lint1/init.c Sat Dec 18 13:23:09 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: init.c,v 1.219 2021/12/18 13:06:33 rillig Exp $ */
+/* $NetBSD: init.c,v 1.220 2021/12/18 13:23:09 rillig Exp $ */
/*
* Copyright (c) 1994, 1995 Jochen Pohl
@@ -38,7 +38,7 @@
#include <sys/cdefs.h>
#if defined(__RCSID) && !defined(lint)
-__RCSID("$NetBSD: init.c,v 1.219 2021/12/18 13:06:33 rillig Exp $");
+__RCSID("$NetBSD: init.c,v 1.220 2021/12/18 13:23:09 rillig Exp $");
#endif
#include <stdlib.h>
@@ -60,11 +60,10 @@ __RCSID("$NetBSD: init.c,v 1.219 2021/12
* struct { int x, y; } point = { 3, 4 };
* struct { int x, y; } point = { .y = 4, .x = 3 };
*
- * Any scalar expression in the initializer may be surrounded by arbitrarily
- * many extra pairs of braces, like in the example 'number_with_braces' (C99
- * 6.7.8p11).
+ * Any scalar expression or string in the initializer may be surrounded by
+ * additional pairs of braces.
*
- * For multi-dimensional arrays, the inner braces may be omitted like in
+ * For nested aggregate objects, the inner braces may be omitted like in
* array_flat or spelled out like in array_nested. This is unusual in
* practice and therefore only supported very basically.
*
@@ -84,6 +83,7 @@ __RCSID("$NetBSD: init.c,v 1.219 2021/12
*
* See also:
* C99 6.7.8 "Initialization"
+ * C11 6.7.9 "Initialization"
* d_c99_init.c for more examples
*/
@@ -100,44 +100,66 @@ struct designator {
};
/*
- * The optional designation for an initializer, saying which sub-object to
- * initialize. Examples for designations are '.member' or
- * '.member[123].member.member[1][1]'.
+ * The path from the "current object" of a brace level to the sub-object that
+ * will be initialized by the next expression. Examples for designations are
+ * '.member' or '.member[123].member.member[1][1]'.
*
* C99 6.7.8p6, 6.7.8p7
*/
struct designation {
struct designator *dn_items;
- size_t dn_len;
- size_t dn_cap;
+ size_t dn_len;
+ size_t dn_cap;
};
/*
- * Describes a single brace level of an ongoing initialization.
+ * Everything that happens between a '{' and the corresponding '}' of an
+ * initialization.
*
- * See C99 6.7.8p17.
+ * C99 6.7.8p17
*/
struct brace_level {
- /*
- * The type of the current object that is initialized at this brace
- * level.
- */
+ /* The type of the "current object". */
const type_t *bl_type;
- struct designation bl_designation; /* .member[123].member */
+ /*
+ * The path to the sub-object of the "current object" that is
+ * initialized by the next expression.
+ *
+ * TODO: use this not only for explicit designations but also for
+ * implicit designations, like in C90.
+ */
+ struct designation bl_designation;
/*
* The next member of the struct or union that is to be initialized,
* unless a specific member is selected by a designator.
+ *
+ * TODO: use bl_designation instead.
*/
const sym_t *bl_member;
/*
* The subscript of the next array element that is to be initialized,
* unless a specific subscript is selected by a designator.
+ *
+ * TODO: use bl_designation instead.
*/
size_t bl_subscript;
- bool bl_scalar_done: 1; /* for scalars */
- bool bl_confused: 1; /* skip further checks */
+
+ /*
+ * Whether the designation is used up, that is, there is no next
+ * sub-object left to be initialized.
+ */
+ bool bl_scalar_done:1; /* for scalars */
+
+ /*
+ * Whether lint has been confused by allowed but extra or omitted
+ * braces. In such a case, lint skips further type checks on the
+ * initializer expressions.
+ *
+ * TODO: properly handle the omitted braces.
+ */
+ bool bl_confused:1;
struct brace_level *bl_enclosing;
};
