[src/trunk]: src/usr.bin/make make(1): add debugging output for :@ modifier

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

details:   https://anonhg.NetBSD.org/src/rev/e7c179240c47
branches:  trunk
changeset: 935522:e7c179240c47
user:      rillig <rillig%NetBSD.org@localhost>
date:      Sat Jul 04 17:10:33 2020 +0000

description:
make(1): add debugging output for :@ modifier

The inner working of the :@ modifier is quite tricky.  To understand what
really happens, it helps to look at each word as it is being modified.

diffstat:

 usr.bin/make/unit-tests/modmisc.exp |   1 +
 usr.bin/make/unit-tests/modmisc.mk  |  14 ++++++++++++--
 usr.bin/make/var.c                  |  12 +++++++++---
 3 files changed, 22 insertions(+), 5 deletions(-)

diffs (80 lines):

diff -r d30a1d46963b -r e7c179240c47 usr.bin/make/unit-tests/modmisc.exp
--- a/usr.bin/make/unit-tests/modmisc.exp       Sat Jul 04 16:58:11 2020 +0000
+++ b/usr.bin/make/unit-tests/modmisc.exp       Sat Jul 04 17:10:33 2020 +0000
@@ -31,4 +31,5 @@
 :a c:
 :x__ 3 x__ 3:
 :+one+ +two+ +three+:
+mod-at-resolve:w1a2w w1b2w w1a2 1b${RES2}w:
 exit status 0
diff -r d30a1d46963b -r e7c179240c47 usr.bin/make/unit-tests/modmisc.mk
--- a/usr.bin/make/unit-tests/modmisc.mk        Sat Jul 04 16:58:11 2020 +0000
+++ b/usr.bin/make/unit-tests/modmisc.mk        Sat Jul 04 17:10:33 2020 +0000
@@ -1,4 +1,4 @@
-# $Id: modmisc.mk,v 1.9 2020/07/04 16:15:21 rillig Exp $
+# $Id: modmisc.mk,v 1.10 2020/07/04 17:10:33 rillig Exp $
 #
 # miscellaneous modifier tests
 
@@ -16,7 +16,7 @@
 MOD_SEP=S,:, ,g
 
 all:   modvar modvarloop modsysv mod-HTE emptyvar undefvar
-all:   mod-S mod-C mod-at-varname
+all:   mod-S mod-C mod-at-varname mod-at-resolve
 
 modsysv:
        @echo "The answer is ${libfoo.a:L:libfoo.a=42}"
@@ -80,3 +80,13 @@
 # will ever depend on this, but technically it's possible.
 mod-at-varname:
        @echo :${:Uone two three:@${:Ubar:S,b,v,}@+${var}+@:Q}:
+
+# The :@ modifier resolves the variables a little more often than expected.
+# In particular, it resolves _all_ variables from the context, and not only
+# the loop variable (in this case v).
+RESOLVE=       ${RES1} $${RES1}
+RES1=          1a${RES2} 1b$${RES2}
+RES2=          2
+
+mod-at-resolve:
+       @echo $@:${RESOLVE:@v@w${v}w@:Q}:
diff -r d30a1d46963b -r e7c179240c47 usr.bin/make/var.c
--- a/usr.bin/make/var.c        Sat Jul 04 16:58:11 2020 +0000
+++ b/usr.bin/make/var.c        Sat Jul 04 17:10:33 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: var.c,v 1.253 2020/07/04 16:30:47 rillig Exp $ */
+/*     $NetBSD: var.c,v 1.254 2020/07/04 17:10:33 rillig Exp $ */
 
 /*
  * Copyright (c) 1988, 1989, 1990, 1993
@@ -69,14 +69,14 @@
  */
 
 #ifndef MAKE_NATIVE
-static char rcsid[] = "$NetBSD: var.c,v 1.253 2020/07/04 16:30:47 rillig Exp $";
+static char rcsid[] = "$NetBSD: var.c,v 1.254 2020/07/04 17:10:33 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 1.253 2020/07/04 16:30:47 rillig Exp $");
+__RCSID("$NetBSD: var.c,v 1.254 2020/07/04 17:10:33 rillig Exp $");
 #endif
 #endif /* not lint */
 #endif
@@ -1567,6 +1567,12 @@
     if (*word) {
        Var_Set_with_flags(loop->tvar, word, loop->ctxt, VAR_NO_EXPORT);
        s = Var_Subst(NULL, loop->str, loop->ctxt, loop->flags);
+       if (DEBUG(VAR)) {
+           fprintf(debug_file,
+                   "VarLoopExpand: in \"%s\", replace \"%s\" with \"%s\" "
+                   "to \"%s\"\n",
+                   word, loop->tvar, loop->str, s ? s : "(null)");
+       }
        if (s != NULL && *s != '\0') {
            if (addSpace && *s != '\n')
                Buf_AddByte(buf, ' ');