[src/trunk]: src/usr.bin/xlint/lint1 lint: join grammar rules for initialization

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

details:   https://anonhg.NetBSD.org/src/rev/81ce185849c9
branches:  trunk
changeset: 1019784:81ce185849c9
user:      rillig <rillig%NetBSD.org@localhost>
date:      Sat Mar 20 11:24:49 2021 +0000

description:
lint: join grammar rules for initialization

The '%prec T_COMMA' is necessary to avoid lots of parse errors in the
lint1 unit tests.  Curiously, further down in the grammar, for compound
literals, the '%prec T_COMMA' is not necessary, even though the context
looks very similar.

No functional change.

diffstat:

 tests/usr.bin/xlint/lint1/d_c99_compound_literal_comma.c |  36 +++++++++++----
 usr.bin/xlint/lint1/cgram.y                              |   7 +-
 2 files changed, 29 insertions(+), 14 deletions(-)

diffs (76 lines):

diff -r 4f2a34cb6723 -r 81ce185849c9 tests/usr.bin/xlint/lint1/d_c99_compound_literal_comma.c
--- a/tests/usr.bin/xlint/lint1/d_c99_compound_literal_comma.c  Sat Mar 20 11:05:16 2021 +0000
+++ b/tests/usr.bin/xlint/lint1/d_c99_compound_literal_comma.c  Sat Mar 20 11:24:49 2021 +0000
@@ -1,17 +1,33 @@
-/*     $NetBSD: d_c99_compound_literal_comma.c,v 1.2 2021/01/31 14:39:31 rillig Exp $  */
+/*     $NetBSD: d_c99_compound_literal_comma.c,v 1.3 2021/03/20 11:24:49 rillig Exp $  */
 # 3 "d_c99_compound_literal_comma.c"
 
-struct bintime {
-       unsigned long long sec;
-       unsigned long long frac;
+/*-
+ * Ensure that compound literals can be parsed.
+ *
+ * C99 6.5.2 "Postfix operators" for the syntax.
+ * C99 6.5.2.5 "Compound literals" for the semantics.
+ */
+
+struct point {
+       int x;
+       int y;
 };
 
-struct bintime
-us2bintime(unsigned long long us)
+struct point
+point_abs(struct point point)
 {
+       /* No designators, no trailing comma. */
+       if (point.x >= 0 && point.y >= 0)
+               return (struct point){ point.x, point.y };
 
-       return (struct bintime) {
-               .sec = us / 1000000U,
-               .frac = (((us % 1000000U) >> 32)/1000000U) >> 32,
-       };
+       /* Designators, no trailing comma. */
+       if (point.x >= 0)
+               return (struct point){ .x = point.x, .y = -point.y };
+
+       /* No designators, trailing comma. */
+       if (point.y >= 0)
+               return (struct point){ point.x, point.y, };
+
+       /* Designators, trailing comma. */
+       return (struct point){ .x = point.x, .y = -point.y, };
 }
diff -r 4f2a34cb6723 -r 81ce185849c9 usr.bin/xlint/lint1/cgram.y
--- a/usr.bin/xlint/lint1/cgram.y       Sat Mar 20 11:05:16 2021 +0000
+++ b/usr.bin/xlint/lint1/cgram.y       Sat Mar 20 11:24:49 2021 +0000
@@ -1,5 +1,5 @@
 %{
-/* $NetBSD: cgram.y,v 1.180 2021/03/20 11:05:16 rillig Exp $ */
+/* $NetBSD: cgram.y,v 1.181 2021/03/20 11:24:49 rillig Exp $ */
 
 /*
  * Copyright (c) 1996 Christopher G. Demetriou.  All Rights Reserved.
@@ -35,7 +35,7 @@
 
 #include <sys/cdefs.h>
 #if defined(__RCSID) && !defined(lint)
-__RCSID("$NetBSD: cgram.y,v 1.180 2021/03/20 11:05:16 rillig Exp $");
+__RCSID("$NetBSD: cgram.y,v 1.181 2021/03/20 11:24:49 rillig Exp $");
 #endif
 
 #include <limits.h>
@@ -1332,8 +1332,7 @@
        | init_lbrace init_rbrace {
                /* XXX: Empty braces are not covered by C99 6.7.8. */
          }
-       | init_lbrace initializer_list init_rbrace
-       | init_lbrace initializer_list T_COMMA init_rbrace
+       | init_lbrace initializer_list %prec T_COMMA comma_opt init_rbrace
        | error
        ;