[src/trunk]: src/usr.bin/xlint/lint1 lint: remove shift/reduce conflict for s...

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

details:   https://anonhg.NetBSD.org/src/rev/50cbdd60353a
branches:  trunk
changeset: 1022286:50cbdd60353a
user:      rillig <rillig%NetBSD.org@localhost>
date:      Sun Jul 11 17:38:55 2021 +0000

description:
lint: remove shift/reduce conflict for sizeof

According to the grammar, the expression 'sizeof(int)x' was ambiguous.
Since 'sizeof(int)' is a valid term, that could have been reduced,
which would have resulted in a parse error when trying to parse 'x'.

Now 'sizeof' takes a unary_expression instead of a term.

No functional change.

diffstat:

 usr.bin/xlint/lint1/cgram.y |  41 +++++++++++++++++++++++------------------
 1 files changed, 23 insertions(+), 18 deletions(-)

diffs (97 lines):

diff -r 36fd60245fc4 -r 50cbdd60353a usr.bin/xlint/lint1/cgram.y
--- a/usr.bin/xlint/lint1/cgram.y       Sun Jul 11 16:57:21 2021 +0000
+++ b/usr.bin/xlint/lint1/cgram.y       Sun Jul 11 17:38:55 2021 +0000
@@ -1,5 +1,5 @@
 %{
-/* $NetBSD: cgram.y,v 1.307 2021/07/11 16:57:21 rillig Exp $ */
+/* $NetBSD: cgram.y,v 1.308 2021/07/11 17:38:55 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 1.307 2021/07/11 16:57:21 rillig Exp $");
+__RCSID("$NetBSD: cgram.y,v 1.308 2021/07/11 17:38:55 rillig Exp $");
 #endif
 
 #include <limits.h>
@@ -124,7 +124,7 @@
 
 %}
 
-%expect 173
+%expect 172
 
 %union {
        val_t   *y_val;
@@ -280,6 +280,7 @@
 
 %type  <y_tnode>       primary_expression
 %type  <y_tnode>       postfix_expression
+%type  <y_tnode>       unary_expression
 
 %type  <y_sym>         func_decl
 %type  <y_sym>         notype_decl
@@ -1806,19 +1807,16 @@
         }
        ;
 
-term:                          /* see C99 6.5.1 */
+unary_expression:              /* C99 6.5.3 */
          postfix_expression
-       | T_INCDEC term {
+       | T_INCDEC unary_expression {
                $$ = build($1 == INC ? INCBEF : DECBEF, $2, NULL);
          }
-       | T_ASTERISK term {
-               $$ = build(INDIR, $2, NULL);
-         }
        | T_AMPER term {
                $$ = build(ADDR, $2, NULL);
          }
-       | T_UNARY term {
-               $$ = build($1, $2, NULL);
+       | T_ASTERISK term {
+               $$ = build(INDIR, $2, NULL);
          }
        | T_ADDITIVE term {
                if (tflag && $1 == PLUS) {
@@ -1827,6 +1825,21 @@
                }
                $$ = build($1 == PLUS ? UPLUS : UMINUS, $2, NULL);
          }
+       | T_UNARY term {
+               $$ = build($1, $2, NULL);
+         }
+       | T_SIZEOF unary_expression {
+               $$ = $2 == NULL ? NULL : build_sizeof($2->tn_type);
+               if ($$ != NULL)
+                       check_expr_misc($2, false, false, false, false, false, true);
+         }
+       | T_SIZEOF T_LPAREN type_name T_RPAREN %prec T_SIZEOF {
+               $$ = build_sizeof($3);
+         }
+       ;
+
+term:                          /* see C99 6.5.1 */
+         unary_expression
        | T_REAL term {
                $$ = build(REAL, $2, NULL);
          }
@@ -1846,14 +1859,6 @@
                symtyp = FMEMBER;
                $$ = build_offsetof($3, getsym($5));
          }
-       | T_SIZEOF term {
-               $$ = $2 == NULL ? NULL : build_sizeof($2->tn_type);
-               if ($$ != NULL)
-                       check_expr_misc($2, false, false, false, false, false, true);
-         }
-       | T_SIZEOF T_LPAREN type_name T_RPAREN %prec T_SIZEOF {
-               $$ = build_sizeof($3);
-         }
        | T_ALIGNOF T_LPAREN type_name T_RPAREN {
                $$ = build_alignof($3);
          }