[src/trunk]: src/usr.bin/make make(1): replace emptyString with allocated emp...

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

details:   https://anonhg.NetBSD.org/src/rev/b9adf1b0cf2d
branches:  trunk
changeset: 1015916:b9adf1b0cf2d
user:      rillig <rillig%NetBSD.org@localhost>
date:      Wed Nov 04 02:26:21 2020 +0000

description:
make(1): replace emptyString with allocated empty string

Special-casing this variable only made the code more complicated.
Furthermore, it is not related to error handling in any way and
therefore distracted the reader from this topic.

diffstat:

 usr.bin/make/var.c |  19 ++++++-------------
 1 files changed, 6 insertions(+), 13 deletions(-)

diffs (69 lines):

diff -r 094c581e8f67 -r b9adf1b0cf2d usr.bin/make/var.c
--- a/usr.bin/make/var.c        Wed Nov 04 01:37:55 2020 +0000
+++ b/usr.bin/make/var.c        Wed Nov 04 02:26:21 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: var.c,v 1.652 2020/11/02 21:34:40 rillig Exp $ */
+/*     $NetBSD: var.c,v 1.653 2020/11/04 02:26:21 rillig Exp $ */
 
 /*
  * Copyright (c) 1988, 1989, 1990, 1993
@@ -130,7 +130,7 @@
 #include "metachar.h"
 
 /*     "@(#)var.c      8.3 (Berkeley) 3/19/94" */
-MAKE_RCSID("$NetBSD: var.c,v 1.652 2020/11/02 21:34:40 rillig Exp $");
+MAKE_RCSID("$NetBSD: var.c,v 1.653 2020/11/04 02:26:21 rillig Exp $");
 
 #define VAR_DEBUG1(fmt, arg1) DEBUG1(VAR, fmt, arg1)
 #define VAR_DEBUG2(fmt, arg1, arg2) DEBUG2(VAR, fmt, arg1, arg2)
@@ -157,11 +157,6 @@
  * be deferred until it is defined in an actual target. */
 static char varUndefined[] = "";
 
-/* Special return value for Var_Parse, just to avoid allocating empty strings.
- * In contrast to var_Error and varUndefined, this is not an error marker but
- * just an ordinary successful return value. */
-static char emptyString[] = "";
-
 /*
  * Traditionally this make consumed $$ during := like any other expansion.
  * Other make's do not, and this make follows straight since 2016-01-09.
@@ -2299,7 +2294,7 @@
     if (st->eflags & VARE_WANTRES)
        st->newVal = Cmd_Exec(cmd, &errfmt);
     else
-       st->newVal = emptyString;
+       st->newVal = bmake_strdup("");
     free(cmd);
 
     if (errfmt != NULL)
@@ -3014,7 +3009,7 @@
        }
     }
     free(val);
-    st->newVal = emptyString;
+    st->newVal = bmake_strdup("");
     return AMR_OK;
 }
 
@@ -3138,7 +3133,7 @@
            if (errfmt)
                Error(errfmt, st->val);
        } else
-           st->newVal = emptyString;
+           st->newVal = bmake_strdup("");
        *pp = p + 2;
        return AMR_OK;
     } else
@@ -3412,10 +3407,8 @@
                *out_freeIt = NULL;
            }
            st.val = st.newVal;
-           if (st.val != var_Error && st.val != varUndefined &&
-               st.val != emptyString) {
+           if (st.val != var_Error && st.val != varUndefined)
                *out_freeIt = st.val;
-           }
        }
        if (*p == '\0' && st.endc != '\0') {
            Error("Unclosed variable specification (expecting '%c') "