Re: [PATCH 16/27] tests/tcg/meson.build: introduce expected_output

[Manos Pitsidianakis <manos.pitsidianakis@linaro.org>]

On Wed, 10 Jun 2026 07:30, Pierrick Bouvier <pierrick.bouvier@oss.qualcomm.com> wrote:
>On 6/9/2026 2:47 PM, Pierrick Bouvier wrote:
>> A test can declare it expects a specific output on stdout. In this case,
>> we compare it to a reference file. We implement this instead of relying
>> on a wrapper because we need the flexibility to resolve name of
>> reference file per target.
>> 
>> For instance, multiarch float tests expect different ref files for each
>> target, which is something we can't express with a test wrapper.
>> 
>> Signed-off-by: Pierrick Bouvier <pierrick.bouvier@oss.qualcomm.com>
>> ---
>>  tests/tcg/meson.build             |  9 ++++++++-
>>  tests/tcg/scripts/run_and_diff.sh | 12 ++++++++++++
>>  2 files changed, 20 insertions(+), 1 deletion(-)
>>  create mode 100755 tests/tcg/scripts/run_and_diff.sh
>> 
>> diff --git a/tests/tcg/meson.build b/tests/tcg/meson.build
>> index 5380a360830..3d2c0d6583b 100644
>> --- a/tests/tcg/meson.build
>> +++ b/tests/tcg/meson.build
>> @@ -7,6 +7,7 @@ if config_host.has_key('GDB')
>>  endif
>>  gdb = find_program(gdb_progs, required: false)
>>  prog_gdb_test = find_program('../guest-debug/run-test.py')
>> +prog_run_and_diff = find_program('./scripts/run_and_diff.sh')
>>  
>>  tcg_tests = {}
>>  # tcg_tests is a dictionary with following structure:
>> @@ -24,6 +25,7 @@ tcg_tests = {}
>>  #           'test_name': ['provide an alternative test name'],
>>  #           'cflags': ['cflags to compile test', ...],
>>  #           'qemu_args': ['qemu command line flags', ...],
>> +#           'expected_output': 'file_to_compare_output',
>>  #           'gdb_test': ['gdb test args'],
>>  #           'env_var': ['VAR=value', ...],
>>  #           'wrapper': [program_to_launch_test, 'args'...],
>> @@ -84,7 +86,7 @@ foreach target, plan: tcg_tests
>>      foreach src, setup: t
>>        # return a clear error if user mispell a setup entry
>>        foreach key, _ : setup
>> -        if key not in ['cflags', 'qemu_args', 'gdb_test',
>> +        if key not in ['cflags', 'qemu_args', 'expected_output', 'gdb_test',
>>                         'exe_name', 'test_name', 'env_var', 'plugin_test',
>>                         'wrapper']
>>            error('unknown tcg setup entry \'' + key + '\' for test ' + src)
>> @@ -197,6 +199,11 @@ foreach target, plan: tcg_tests
>>                ]
>>        endif
>>  
>> +      if 'expected_output' in setup
>> +        expected = files(folder / setup['expected_output'])
>> +        cmd = [prog_run_and_diff, expected, cmd]
>> +      endif
>> +
>>        if 'wrapper' in setup
>>          cmd = [setup['wrapper'], cmd]
>>        endif
>> diff --git a/tests/tcg/scripts/run_and_diff.sh b/tests/tcg/scripts/run_and_diff.sh
>> new file mode 100755
>> index 00000000000..d1e9243c49d
>> --- /dev/null
>> +++ b/tests/tcg/scripts/run_and_diff.sh
>> @@ -0,0 +1,12 @@
>> +#!/usr/bin/env bash
>> +# SPDX-License-Identifier: GPL-2.0-or-later
>> +
>> +set -euo pipefail
>> +
>> +if [ $# -lt 2 ]; then
>> +    echo "run_and_diff: expected_output_file cmd [args]..." 1>&2
>> +    exit 1
>> +fi
>> +expected="$1";shift
>> +set -x
>> +diff <("$@") $expected
>
>Fixed this line, since it hides return code of program.
>Write to a temporary file, then diff.

Also, consider if using #!/bin/sh is possible, since it's universally 
portable.