[src/trunk]: src/usr.bin/make make: fix handling of null bytes in the output ...

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

details:   https://anonhg.NetBSD.org/src/rev/ec881edfc80e
branches:  trunk
changeset: 369842:ec881edfc80e
user:      rillig <rillig%NetBSD.org@localhost>
date:      Sat Sep 03 08:03:27 2022 +0000

description:
make: fix handling of null bytes in the output in jobs mode

The test job-output-null failed occasionally, depending on the exact
timing of the child's write and make's read.

diffstat:

 usr.bin/make/job.c                          |  14 ++++-------
 usr.bin/make/unit-tests/job-output-null.exp |   6 +++-
 usr.bin/make/unit-tests/job-output-null.mk  |  36 ++++++++++++++++++----------
 3 files changed, 32 insertions(+), 24 deletions(-)

diffs (121 lines):

diff -r db72a3a007f7 -r ec881edfc80e usr.bin/make/job.c
--- a/usr.bin/make/job.c        Sat Sep 03 07:45:08 2022 +0000
+++ b/usr.bin/make/job.c        Sat Sep 03 08:03:27 2022 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: job.c,v 1.453 2022/05/07 08:01:20 rillig Exp $ */
+/*     $NetBSD: job.c,v 1.454 2022/09/03 08:03:27 rillig Exp $ */
 
 /*
  * Copyright (c) 1988, 1989, 1990 The Regents of the University of California.
@@ -142,7 +142,7 @@
 #include "trace.h"
 
 /*     "@(#)job.c      8.2 (Berkeley) 3/19/94" */
-MAKE_RCSID("$NetBSD: job.c,v 1.453 2022/05/07 08:01:20 rillig Exp $");
+MAKE_RCSID("$NetBSD: job.c,v 1.454 2022/09/03 08:03:27 rillig Exp $");
 
 /*
  * A shell defines how the commands are run.  All commands for a target are
@@ -1864,18 +1864,14 @@
         * true.
         */
        max = job->curPos + nr;
+       for (i = job->curPos; i < max; i++)
+               if (job->outBuf[i] == '\0')
+                       job->outBuf[i] = ' ';
        for (i = job->curPos + nr - 1;
             i >= job->curPos && i != (size_t)-1; i--) {
                if (job->outBuf[i] == '\n') {
                        gotNL = true;
                        break;
-               } else if (job->outBuf[i] == '\0') {
-                       /*
-                        * FIXME: The null characters are only replaced with
-                        * space _after_ the last '\n'.  Everywhere else they
-                        * hide the rest of the command output.
-                        */
-                       job->outBuf[i] = ' ';
                }
        }
 
diff -r db72a3a007f7 -r ec881edfc80e usr.bin/make/unit-tests/job-output-null.exp
--- a/usr.bin/make/unit-tests/job-output-null.exp       Sat Sep 03 07:45:08 2022 +0000
+++ b/usr.bin/make/unit-tests/job-output-null.exp       Sat Sep 03 08:03:27 2022 +0000
@@ -1,4 +1,6 @@
-1
-2a
+1 trailing
+2a trailing
+2b trailing
+2c trailing
 3a without   newline, 3b without   newline.
 exit status 0
diff -r db72a3a007f7 -r ec881edfc80e usr.bin/make/unit-tests/job-output-null.mk
--- a/usr.bin/make/unit-tests/job-output-null.mk        Sat Sep 03 07:45:08 2022 +0000
+++ b/usr.bin/make/unit-tests/job-output-null.mk        Sat Sep 03 08:03:27 2022 +0000
@@ -1,11 +1,11 @@
-# $NetBSD: job-output-null.mk,v 1.3 2021/09/12 10:26:49 rillig Exp $
+# $NetBSD: job-output-null.mk,v 1.4 2022/09/03 08:03:27 rillig Exp $
 #
 # Test how null bytes in the output of a command are handled.  Make processes
 # them using null-terminated strings, which may cut off some of the output.
 #
-# As of 2021-04-15, make handles null bytes from the child process
-# inconsistently.  It's an edge case though since typically the child
-# processes output text.
+# Before job.c 1.454 from 2022-09-03, make handled null bytes in the output
+# from the child process inconsistently.  It's an edge case though since
+# typically the child processes output text.
 
 # Note: The printf commands used in this test must only use a single format
 # string, without parameters.  This is because it is implementation-dependent
@@ -16,30 +16,40 @@
 #      NetBSD /bin/ksh         3 x write("fmt") (via /bin/printf)
 #      Bash 5                  3 x write("fmt")
 #
-# In the latter case the output may arrive in parts, which in this test makes
-# a crucial difference since the outcome of the test depends on whether there
-# is a '\n' in each of the blocks from the output.
+# In the latter case the output may arrive in 1 to 3 parts, depending on the
+# exact timing, which in this test makes a crucial difference since before
+# job.c 1.454 from 2022-09-03, the outcome of the test depended on whether
+# there was a '\n' in each of the blocks from the output.  Depending on the
+# exact timing, the output of that test varied, its possible values were '2a',
+# '2a 2b', '2a 2c', '2a 2b 2c'.
 
 .MAKEFLAGS: -j1                # force jobs mode
 
 all: .PHONY
-       # The null byte from the command output is kept as-is.
-       # See CollectOutput, which looks like it intended to replace these
-       # null bytes with simple spaces.
+       # The null byte from the command output is replaced with a single
+       # space by CollectOutput.
        @printf '1\0trailing\n'
+       # expect: 1 trailing
 
        # Give the parent process a chance to see the above output, but not
        # yet the output from the next printf command.
        @sleep 1
 
-       # All null bytes from the command output are kept as-is.
+       # Each null byte from the command output is replaced with a single
+       # space.
        @printf '2a\0trailing\n''2b\0trailing\n''2c\0trailing\n'
+       # expect: 2a trailing
+       # expect: 2b trailing
+       # expect: 2c trailing
 
        @sleep 1
 
-       # The null bytes are replaced with spaces since they are not followed
-       # by a newline.
+       # Each null byte from the command output is replaced with a single
+       # space.  Because there is no trailing newline in the output, these
+       # null bytes were replaced with spaces even before job.c 1.454 from
+       # 2022-09-03, unlike in the cases above.
        #
        # The three null bytes in a row test whether this output is
        # compressed to a single space like in DebugFailedTarget.  It isn't.
        @printf '3a\0without\0\0\0newline, 3b\0without\0\0\0newline.'
+       # expect: 3a without   newline, 3b without   newline.