[src/trunk]: src/usr.bin/xlint/lint1 lint: reject _Noreturn if it occurs in i...

[rillig <rillig%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/5ad606bf776b
branches:  trunk
changeset: 377458:5ad606bf776b
user:      rillig <rillig%NetBSD.org@localhost>
date:      Wed Jul 12 18:26:04 2023 +0000

description:
lint: reject _Noreturn if it occurs in invalid places

C11 introduced _Noreturn as a function-specifier, not as a type
attribute.  The latter may occur in more places.

diffstat:

 tests/usr.bin/xlint/lint1/c11.c |  12 ++++++++----
 usr.bin/xlint/lint1/cgram.y     |  10 ++++------
 usr.bin/xlint/lint1/debug.c     |   5 +++--
 usr.bin/xlint/lint1/lex.c       |   6 +++---
 usr.bin/xlint/lint1/lint1.h     |   6 +++---
 5 files changed, 21 insertions(+), 18 deletions(-)

diffs (156 lines):

diff -r ac988a285f34 -r 5ad606bf776b tests/usr.bin/xlint/lint1/c11.c
--- a/tests/usr.bin/xlint/lint1/c11.c   Wed Jul 12 18:13:39 2023 +0000
+++ b/tests/usr.bin/xlint/lint1/c11.c   Wed Jul 12 18:26:04 2023 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: c11.c,v 1.1 2023/07/12 18:13:39 rillig Exp $   */
+/*     $NetBSD: c11.c,v 1.2 2023/07/12 18:26:04 rillig Exp $   */
 # 3 "c11.c"
 
 /*
@@ -11,9 +11,6 @@
 _Noreturn void exit(int);
 void _Noreturn exit(int);
 
-/* XXX: Syntactically invalid, yet lint accepts it. */
-void _Noreturn exit(int) _Noreturn;
-
 _Noreturn void
 noreturn_before_type(void)
 {
@@ -44,3 +41,10 @@ three_times(void)
 {
        exit(0);
 }
+
+/* The '_Noreturn' must not appear after the declarator. */
+void _Noreturn exit(int) _Noreturn;
+/* expect-1: error: formal parameter #1 lacks name [59] */
+/* expect-2: warning: empty declaration [2] */
+/* expect+2: error: syntax error '' [249] */
+/* expect+1: error: cannot recover from previous errors [224] */
diff -r ac988a285f34 -r 5ad606bf776b usr.bin/xlint/lint1/cgram.y
--- a/usr.bin/xlint/lint1/cgram.y       Wed Jul 12 18:13:39 2023 +0000
+++ b/usr.bin/xlint/lint1/cgram.y       Wed Jul 12 18:26:04 2023 +0000
@@ -1,5 +1,5 @@
 %{
-/* $NetBSD: cgram.y,v 1.456 2023/07/12 16:07:35 rillig Exp $ */
+/* $NetBSD: cgram.y,v 1.457 2023/07/12 18:26:04 rillig Exp $ */
 
 /*
  * Copyright (c) 1996 Christopher G. Demetriou.  All Rights Reserved.
@@ -35,7 +35,7 @@
 
 #include <sys/cdefs.h>
 #if defined(__RCSID)
-__RCSID("$NetBSD: cgram.y,v 1.456 2023/07/12 16:07:35 rillig Exp $");
+__RCSID("$NetBSD: cgram.y,v 1.457 2023/07/12 18:26:04 rillig Exp $");
 #endif
 
 #include <limits.h>
@@ -132,7 +132,7 @@ is_either(const char *s, const char *a, 
 
 %}
 
-%expect 132
+%expect 104
 
 %union {
        val_t   *y_val;
@@ -223,7 +223,6 @@ is_either(const char *s, const char *a, 
 %token                 T_REAL
 %token                 T_IMAG
 %token                 T_GENERIC
-%token                 T_NORETURN
 
 /* storage classes (extern, static, auto, register and typedef) */
 %token <y_scl>         T_SCLASS
@@ -932,7 +931,6 @@ type_attribute:                     /* See C11 6.7 declara
 |      T_PACKED {
                dcs_add_packed();
        }
-|      T_NORETURN
 ;
 
 begin_type:
@@ -1969,7 +1967,7 @@ for_exprs:                        /* see C99 6.8.5 */
                c99ism(325);
                stmt_for_exprs(NULL, $6, $8);
                clear_warning_flags();
-           }
+       }
 |      for_start
            expression_opt T_SEMI
            expression_opt T_SEMI
diff -r ac988a285f34 -r 5ad606bf776b usr.bin/xlint/lint1/debug.c
--- a/usr.bin/xlint/lint1/debug.c       Wed Jul 12 18:13:39 2023 +0000
+++ b/usr.bin/xlint/lint1/debug.c       Wed Jul 12 18:26:04 2023 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: debug.c,v 1.50 2023/07/12 16:07:35 rillig Exp $ */
+/* $NetBSD: debug.c,v 1.51 2023/07/12 18:26:04 rillig Exp $ */
 
 /*-
  * Copyright (c) 2021 The NetBSD Foundation, Inc.
@@ -35,7 +35,7 @@
 
 #include <sys/cdefs.h>
 #if defined(__RCSID)
-__RCSID("$NetBSD: debug.c,v 1.50 2023/07/12 16:07:35 rillig Exp $");
+__RCSID("$NetBSD: debug.c,v 1.51 2023/07/12 18:26:04 rillig Exp $");
 #endif
 
 #include <stdlib.h>
@@ -320,6 +320,7 @@ function_specifier_name(function_specifi
 {
        static const char *const name[] = {
                "inline",
+               "_Noreturn",
        };
 
        return name[spec];
diff -r ac988a285f34 -r 5ad606bf776b usr.bin/xlint/lint1/lex.c
--- a/usr.bin/xlint/lint1/lex.c Wed Jul 12 18:13:39 2023 +0000
+++ b/usr.bin/xlint/lint1/lex.c Wed Jul 12 18:26:04 2023 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: lex.c,v 1.176 2023/07/12 16:07:35 rillig Exp $ */
+/* $NetBSD: lex.c,v 1.177 2023/07/12 18:26:04 rillig Exp $ */
 
 /*
  * Copyright (c) 1996 Christopher G. Demetriou.  All Rights Reserved.
@@ -38,7 +38,7 @@
 
 #include <sys/cdefs.h>
 #if defined(__RCSID)
-__RCSID("$NetBSD: lex.c,v 1.176 2023/07/12 16:07:35 rillig Exp $");
+__RCSID("$NetBSD: lex.c,v 1.177 2023/07/12 18:26:04 rillig Exp $");
 #endif
 
 #include <ctype.h>
@@ -148,7 +148,7 @@ static const struct keyword {
        kwdef_type(     "__int128_t",   INT128,                 99),
 #endif
        kwdef_type(     "long",         LONG,                   78),
-       kwdef_token(    "_Noreturn",    T_NORETURN,             11,0,1),
+       kwdef("_Noreturn", T_FUNCTION_SPECIFIER, .u.kw_fs = FS_NORETURN, 11,0,1),
        kwdef_token(    "__packed",     T_PACKED,               78,0,1),
        kwdef_token(    "__real__",     T_REAL,                 78,1,1),
        kwdef_sclass(   "register",     REG,                    78,0,1),
diff -r ac988a285f34 -r 5ad606bf776b usr.bin/xlint/lint1/lint1.h
--- a/usr.bin/xlint/lint1/lint1.h       Wed Jul 12 18:13:39 2023 +0000
+++ b/usr.bin/xlint/lint1/lint1.h       Wed Jul 12 18:26:04 2023 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: lint1.h,v 1.186 2023/07/12 16:07:35 rillig Exp $ */
+/* $NetBSD: lint1.h,v 1.187 2023/07/12 18:26:04 rillig Exp $ */
 
 /*
  * Copyright (c) 1996 Christopher G. Demetriou.  All Rights Reserved.
@@ -210,8 +210,8 @@ typedef enum {
 
 /* C23 6.7.4 */
 typedef enum {
-       FS_INLINE,
-       // TODO: Add FS_NORETURN, for C23.
+       FS_INLINE,              /* since C99 */
+       FS_NORETURN,            /* since C11 */
 } function_specifier;
 
 /*