Re: [LTP] [PATCH 1/3] Add support for mixing C and shell code

[Richard Palethorpe <io@richiejp.com>]

Cyril Hrubis <chrubis@suse.cz> writes:

Hello Cyril,

In general I like the idea except that it will encourage more shell
usage, but I'm guessing that is a battle that has already been
lost. Also if a suitable embedded scripting language were found this is
a starting point for that.

> This is a proof of a concept of a seamless C and shell integration. The
> idea is that with this you can mix shell and C code as much as as you
> wish to get the best of the two worlds.
>
> Signed-off-by: Cyril Hrubis <chrubis@suse.cz>
> ---
>  include/tst_test.h                           | 38 +++++++++++++
>  lib/tst_test.c                               | 51 +++++++++++++++++
>  testcases/lib/.gitignore                     |  1 +
>  testcases/lib/Makefile                       |  4 +-
>  testcases/lib/run_tests.sh                   | 11 ++++
>  testcases/lib/tests/.gitignore               |  6 ++
>  testcases/lib/tests/Makefile                 | 11 ++++
>  testcases/lib/tests/shell_test01.c           | 17 ++++++
>  testcases/lib/tests/shell_test02.c           | 18 ++++++
>  testcases/lib/tests/shell_test03.c           | 25 +++++++++
>  testcases/lib/tests/shell_test04.c           | 18 ++++++
>  testcases/lib/tests/shell_test05.c           | 27 +++++++++
>  testcases/lib/tests/shell_test06.c           | 16 ++++++
>  testcases/lib/tests/shell_test_brk.sh        |  6 ++
>  testcases/lib/tests/shell_test_check_argv.sh | 23 ++++++++
>  testcases/lib/tests/shell_test_checkpoint.sh |  7 +++
>  testcases/lib/tests/shell_test_pass.sh       |  6 ++
>  testcases/lib/tst_env.sh                     | 21 +++++++
>  testcases/lib/tst_res_.c                     | 58 ++++++++++++++++++++
>  19 files changed, 362 insertions(+), 2 deletions(-)
>  create mode 100755 testcases/lib/run_tests.sh
>  create mode 100644 testcases/lib/tests/.gitignore
>  create mode 100644 testcases/lib/tests/Makefile
>  create mode 100644 testcases/lib/tests/shell_test01.c
>  create mode 100644 testcases/lib/tests/shell_test02.c
>  create mode 100644 testcases/lib/tests/shell_test03.c
>  create mode 100644 testcases/lib/tests/shell_test04.c
>  create mode 100644 testcases/lib/tests/shell_test05.c
>  create mode 100644 testcases/lib/tests/shell_test06.c
>  create mode 100755 testcases/lib/tests/shell_test_brk.sh
>  create mode 100755 testcases/lib/tests/shell_test_check_argv.sh
>  create mode 100755 testcases/lib/tests/shell_test_checkpoint.sh
>  create mode 100755 testcases/lib/tests/shell_test_pass.sh
>  create mode 100644 testcases/lib/tst_env.sh
>  create mode 100644 testcases/lib/tst_res_.c
>
> diff --git a/include/tst_test.h b/include/tst_test.h
> index 6c76f043d..a334195ac 100644
> --- a/include/tst_test.h
> +++ b/include/tst_test.h
> @@ -331,6 +331,8 @@ struct tst_fs {
>   * @child_needs_reinit: Has to be set if the test needs to call tst_reinit()
>   *                      from a process started by exec().
>   *
> + * @runs_script: Implies child_needs_reinit and forks_child at the moment.
> + *
>   * @needs_devfs: If set the devfs is mounted at tst_test.mntpoint. This is
>   *               needed for tests that need to create device files since tmpfs
>   *               at /tmp is usually mounted with 'nodev' option.
> @@ -518,6 +520,7 @@ struct tst_fs {
>  	unsigned int mount_device:1;
>  	unsigned int needs_rofs:1;
>  	unsigned int child_needs_reinit:1;
> +	unsigned int runs_script:1;

This could be a string constant instead of a flag if you want to future
proof against multiple scripting languages or you could change it to runs_shell.

>  	unsigned int needs_devfs:1;
>  	unsigned int restore_wallclock:1;
>  
> @@ -526,6 +529,8 @@ struct tst_fs {
>  	unsigned int skip_in_lockdown:1;
>  	unsigned int skip_in_secureboot:1;
>  	unsigned int skip_in_compat:1;
> +
> +
>  	int needs_abi_bits;
>  
>  	unsigned int needs_hugetlbfs:1;
> @@ -611,6 +616,39 @@ void tst_run_tcases(int argc, char *argv[], struct tst_test *self)
>   */
>  void tst_reinit(void);
>  
> +/**
> + * tst_run_shell() - Prepare the environment and execute a shell script.
> + *
> + * @script_name: A filename of the script.
> + * @params: A NULL terminated array of shell script parameters, pass NULL if
> + *          none are needed. This what is passed starting from argv[1].
> + *
> + * The shell script is executed with LTP_IPC_PATH in environment so that the
> + * binary helpers such as tst_res_ or tst_checkpoint work properly when executed
> + * from the script. This also means that the tst_test.runs_script flag needs to
> + * be set.
> + *
> + * The shell script itself has to source the tst_env.sh shell script at the
> + * start and after that it's free to use tst_res in the same way C code would
> + * use.
> + *
> + * Example shell script that reports success::
> + *
> + *   #!/bin/sh
> + *   . tst_env.sh
> + *
> + *   tst_res TPASS "Example test works"
> + *
> + * The call returns a pid in a case that you want to examine the return value
> + * of the script yourself. If you do not need to check the return value
> + * yourself you can use tst_reap_children() to wait for the completion. Or let
> + * the test library collect the child automatically, just be wary that the
> + * script and the test both runs concurently at the same time in this case.
> + *
> + * Return: A pid of the shell process.
> + */
> +int tst_run_shell(char *script_name, char *const params[]);
> +
>  unsigned int tst_multiply_timeout(unsigned int timeout);
>  
>  /*
> diff --git a/lib/tst_test.c b/lib/tst_test.c
> index e5bc5bf4d..7e1075fdf 100644
> --- a/lib/tst_test.c
> +++ b/lib/tst_test.c
> @@ -4,6 +4,8 @@
>   * Copyright (c) Linux Test Project, 2016-2024
>   */
>  
> +#define _GNU_SOURCE
> +
>  #include <limits.h>
>  #include <stdio.h>
>  #include <stdarg.h>
> @@ -173,6 +175,50 @@ void tst_reinit(void)
>  	SAFE_CLOSE(fd);
>  }
>  
> +extern char **environ;
> +
> +static unsigned int params_array_len(char *const array[])
> +{
> +	unsigned int ret = 0;
> +
> +	if (!array)
> +		return 0;
> +
> +	while (*(array++))
> +		ret++;
> +
> +	return ret;
> +}
> +
> +int tst_run_shell(char *script_name, char *const params[])
script_name should really be const as this is an API
> +{
> +	int pid;
> +	unsigned int i, params_len = params_array_len(params);
> +	char *argv[params_len + 2];
> +
> +	if (!tst_test->runs_script)
> +		tst_brk(TBROK, "runs_script flag must be set!");
> +
> +	argv[0] = script_name;
maybe you'd have to cast it here or something, but IMO worth it

Reviewed-by: Richard Palethorpe <io@richiejp.com>

-- 
Thank you,
Richard,
richiejp.com.

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