freebsd-dev/contrib/bmake/unit-tests/job-output-null.mk
2023-01-27 16:33:01 -08:00

56 lines
2.2 KiB
Makefile

# $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.
#
# 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
# how many times the command 'printf "fmt%s" "" "" ""' calls write(2).
#
# NetBSD /bin/sh 1 x write("fmtfmtfmt")
# Dash 1 x write("fmtfmtfmt")
# 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 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 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
# 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
# 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.