[src/trunk]: src/usr.bin/make make: document parsing of short variable names,...

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

details:   https://anonhg.NetBSD.org/src/rev/896b84a05c9c
branches:  trunk
changeset: 366787:896b84a05c9c
user:      rillig <rillig%NetBSD.org@localhost>
date:      Tue Jun 14 19:57:56 2022 +0000

description:
make: document parsing of short variable names, such as $i

No binary change.

diffstat:

 usr.bin/make/var.c |  11 +++++------
 1 files changed, 5 insertions(+), 6 deletions(-)

diffs (46 lines):

diff -r afbdecb1c7e7 -r 896b84a05c9c usr.bin/make/var.c
--- a/usr.bin/make/var.c        Tue Jun 14 19:43:02 2022 +0000
+++ b/usr.bin/make/var.c        Tue Jun 14 19:57:56 2022 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: var.c,v 1.1024 2022/06/14 19:43:02 rillig Exp $        */
+/*     $NetBSD: var.c,v 1.1025 2022/06/14 19:57:56 rillig Exp $        */
 
 /*
  * Copyright (c) 1988, 1989, 1990, 1993
@@ -139,7 +139,7 @@
 #include "metachar.h"
 
 /*     "@(#)var.c      8.3 (Berkeley) 3/19/94" */
-MAKE_RCSID("$NetBSD: var.c,v 1.1024 2022/06/14 19:43:02 rillig Exp $");
+MAKE_RCSID("$NetBSD: var.c,v 1.1025 2022/06/14 19:57:56 rillig Exp $");
 
 /*
  * Variables are defined using one of the VAR=value assignments.  Their
@@ -4175,7 +4175,7 @@
        const char *val;
 
        if (!IsShortVarnameValid(varname, *pp)) {
-               (*pp)++;
+               (*pp)++;        /* only skip the '$' */
                *out_false_res = VPR_ERR;
                *out_false_val = var_Error;
                return false;
@@ -4185,7 +4185,7 @@
        name[1] = '\0';
        v = VarFind(name, scope, true);
        if (v != NULL) {
-               /* XXX: *pp should be incremented in this case as well. */
+               /* No need to advance *pp, the calling code handles this. */
                *out_true_var = v;
                return true;
        }
@@ -4214,8 +4214,7 @@
         * If undefined expressions are allowed, this should rather
         * be VPR_UNDEF instead of VPR_OK.
         */
-       *out_false_res = emode == VARE_UNDEFERR
-           ? VPR_UNDEF : VPR_OK;
+       *out_false_res = emode == VARE_UNDEFERR ? VPR_UNDEF : VPR_OK;
        *out_false_val = val;
        return false;
 }