[src/trunk]: src/usr.bin/make make: simplify parsing of '||' in conditions

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

details:   https://anonhg.NetBSD.org/src/rev/f5b1e6ee3096
branches:  trunk
changeset: 1027545:f5b1e6ee3096
user:      rillig <rillig%NetBSD.org@localhost>
date:      Fri Dec 10 19:47:20 2021 +0000

description:
make: simplify parsing of '||' in conditions

Previously, the grammar said 'Or -> Or || And', while the code looked
more like 'Or -> And || Or'.  Make the code look like the grammar and
keep track of the resulting value of the condition explicitly.

No functional change intended.

diffstat:

 usr.bin/make/cond.c |  31 +++++++++++++------------------
 1 files changed, 13 insertions(+), 18 deletions(-)

diffs (62 lines):

diff -r 335ae400ba74 -r f5b1e6ee3096 usr.bin/make/cond.c
--- a/usr.bin/make/cond.c       Fri Dec 10 19:30:05 2021 +0000
+++ b/usr.bin/make/cond.c       Fri Dec 10 19:47:20 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: cond.c,v 1.284 2021/12/09 23:02:46 rillig Exp $        */
+/*     $NetBSD: cond.c,v 1.285 2021/12/10 19:47:20 rillig Exp $        */
 
 /*
  * Copyright (c) 1988, 1989, 1990 The Regents of the University of California.
@@ -95,12 +95,11 @@
 #include "dir.h"
 
 /*     "@(#)cond.c     8.2 (Berkeley) 1/2/94"  */
-MAKE_RCSID("$NetBSD: cond.c,v 1.284 2021/12/09 23:02:46 rillig Exp $");
+MAKE_RCSID("$NetBSD: cond.c,v 1.285 2021/12/10 19:47:20 rillig Exp $");
 
 /*
  * The parsing of conditional expressions is based on this grammar:
- *     Or -> And
- *     Or -> Or '||' And
+ *     Or -> And ('||' And)*
  *     And -> Term
  *     And -> And '&&' Term
  *     Term -> Function '(' Argument ')'
@@ -1002,27 +1001,23 @@
 }
 
 /*
- * Or -> And
- * Or -> Or '||' And
+ * Or -> And ('||' And)*
  */
 static CondResult
 CondParser_Or(CondParser *par, bool doEval)
 {
-       CondResult res;
+       CondResult res, rhs;
        Token op;
 
-       res = CondParser_And(par, doEval);
-       if (res == CR_ERROR)
-               return CR_ERROR;
-
-       op = CondParser_Token(par, doEval);
-       if (op == TOK_OR) {
-               if (res == CR_FALSE)
-                       return CondParser_Or(par, doEval);
-               if (CondParser_Or(par, false) == CR_ERROR)
+       res = CR_FALSE;
+       do {
+               if ((rhs = CondParser_And(par, doEval)) == CR_ERROR)
                        return CR_ERROR;
-               return res;
-       }
+               if (rhs == CR_TRUE) {
+                       res = CR_TRUE;
+                       doEval = false;
+               }
+       } while ((op = CondParser_Token(par, doEval)) == TOK_OR);
 
        CondParser_PushBack(par, op);
        return res;