[src/trunk]: src/usr.bin/make make(1): improve implementation comment in Var_...

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

details:   https://anonhg.NetBSD.org/src/rev/5572017a7314
branches:  trunk
changeset: 943905:5572017a7314
user:      rillig <rillig%NetBSD.org@localhost>
date:      Sun Sep 13 05:55:39 2020 +0000

description:
make(1): improve implementation comment in Var_Parse

diffstat:

 usr.bin/make/var.c |  24 ++++++++++++------------
 1 files changed, 12 insertions(+), 12 deletions(-)

diffs (52 lines):

diff -r 21ccec8bdefc -r 5572017a7314 usr.bin/make/var.c
--- a/usr.bin/make/var.c        Sun Sep 13 05:36:26 2020 +0000
+++ b/usr.bin/make/var.c        Sun Sep 13 05:55:39 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: var.c,v 1.505 2020/09/12 22:12:17 rillig Exp $ */
+/*     $NetBSD: var.c,v 1.506 2020/09/13 05:55:39 rillig Exp $ */
 
 /*
  * Copyright (c) 1988, 1989, 1990, 1993
@@ -69,14 +69,14 @@
  */
 
 #ifndef MAKE_NATIVE
-static char rcsid[] = "$NetBSD: var.c,v 1.505 2020/09/12 22:12:17 rillig Exp $";
+static char rcsid[] = "$NetBSD: var.c,v 1.506 2020/09/13 05:55:39 rillig Exp $";
 #else
 #include <sys/cdefs.h>
 #ifndef lint
 #if 0
 static char sccsid[] = "@(#)var.c      8.3 (Berkeley) 3/19/94";
 #else
-__RCSID("$NetBSD: var.c,v 1.505 2020/09/12 22:12:17 rillig Exp $");
+__RCSID("$NetBSD: var.c,v 1.506 2020/09/13 05:55:39 rillig Exp $");
 #endif
 #endif /* not lint */
 #endif
@@ -3537,16 +3537,16 @@
            }
 
            /* The variable expression is based on an undefined variable.
-            * Most modifiers leave this expression in the "undefined" state
-            * (VAR_JUNK), only some modifiers like :D, :U, :L, :P turn this
-            * undefined expression into a defined expression.
+            * Nevertheless it needs a Var, for modifiers that access the
+            * variable name, such as :L or :?, and for modifiers that access
+            * the variable flags (VAR_JUNK, VAR_KEEP).
             *
-            * At the end, after applying all modifiers, if the expression is
-            * still undefined after applying all the modifiers, var_Error is
-            * returned.  Until then, the expression needs a variable struct,
-            * for all the modifiers that need access to the variable name,
-            * such as :L or :?.
-            */
+            * Most modifiers leave this expression in the "undefined" state
+            * (VAR_JUNK), only a few modifiers like :D, :U, :L, :P turn this
+            * undefined expression into a defined expression (VAR_KEEP).
+            *
+            * At the end, after applying all modifiers, if the expression
+            * is still !VAR_KEEP, Var_Parse will return var_Error. */
            v = bmake_malloc(sizeof(Var));
            v->name = varname;
            Buf_Init(&v->val, 1);