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Subject: Re: [PATCH v2 04/17] kunit: test: add kunit_stream a std::stream like
 logger
To:     Brendan Higgins <brendanhiggins@google.com>,
        frowand.list@gmail.com, gregkh@linuxfoundation.org,
        keescook@google.com, kieran.bingham@ideasonboard.com,
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References: <20190501230126.229218-1-brendanhiggins@google.com>
 <20190501230126.229218-5-brendanhiggins@google.com>
From:   shuah <shuah@kernel.org>
Message-ID: <ead23600-eecd-cf74-bdd1-94a6964e29b2@kernel.org>
Date:   Thu, 2 May 2019 19:50:14 -0600
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On 5/1/19 5:01 PM, Brendan Higgins wrote:
> A lot of the expectation and assertion infrastructure prints out fairly
> complicated test failure messages, so add a C++ style log library for
> for logging test results.
> 
> Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
> ---
>   include/kunit/kunit-stream.h |  85 ++++++++++++++++++++
>   include/kunit/test.h         |   2 +
>   kunit/Makefile               |   3 +-
>   kunit/kunit-stream.c         | 149 +++++++++++++++++++++++++++++++++++
>   kunit/test.c                 |   8 ++
>   5 files changed, 246 insertions(+), 1 deletion(-)
>   create mode 100644 include/kunit/kunit-stream.h
>   create mode 100644 kunit/kunit-stream.c
> 
> diff --git a/include/kunit/kunit-stream.h b/include/kunit/kunit-stream.h
> new file mode 100644
> index 0000000000000..d457a54fe0100
> --- /dev/null
> +++ b/include/kunit/kunit-stream.h
> @@ -0,0 +1,85 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * C++ stream style string formatter and printer used in KUnit for outputting
> + * KUnit messages.
> + *
> + * Copyright (C) 2019, Google LLC.
> + * Author: Brendan Higgins <brendanhiggins@google.com>
> + */
> +
> +#ifndef _KUNIT_KUNIT_STREAM_H
> +#define _KUNIT_KUNIT_STREAM_H
> +
> +#include <linux/types.h>
> +#include <kunit/string-stream.h>
> +
> +struct kunit;
> +
> +/**
> + * struct kunit_stream - a std::stream style string builder.
> + *
> + * A std::stream style string builder. Allows messages to be built up and
> + * printed all at once.
> + */
> +struct kunit_stream {
> +	/* private: internal use only. */
> +	struct kunit *test;
> +	spinlock_t lock; /* Guards level. */
> +	const char *level;
> +	struct string_stream *internal_stream;
> +};
> +
> +/**
> + * kunit_new_stream() - constructs a new &struct kunit_stream.
> + * @test: The test context object.
> + *
> + * Constructs a new test managed &struct kunit_stream.
> + */
> +struct kunit_stream *kunit_new_stream(struct kunit *test);
> +
> +/**
> + * kunit_stream_set_level(): sets the level that string should be printed at.
> + * @this: the stream being operated on.
> + * @level: the print level the stream is set to output to.
> + *
> + * Sets the print level at which the stream outputs.
> + */
> +void kunit_stream_set_level(struct kunit_stream *this, const char *level);
> +
> +/**
> + * kunit_stream_add(): adds the formatted input to the internal buffer.
> + * @this: the stream being operated on.
> + * @fmt: printf style format string to append to stream.
> + *
> + * Appends the formatted string, @fmt, to the internal buffer.
> + */
> +void __printf(2, 3) kunit_stream_add(struct kunit_stream *this,
> +				     const char *fmt, ...);
> +
> +/**
> + * kunit_stream_append(): appends the contents of @other to @this.
> + * @this: the stream to which @other is appended.
> + * @other: the stream whose contents are appended to @this.
> + *
> + * Appends the contents of @other to @this.
> + */
> +void kunit_stream_append(struct kunit_stream *this, struct kunit_stream *other);
> +
> +/**
> + * kunit_stream_commit(): prints out the internal buffer to the user.
> + * @this: the stream being operated on.
> + *
> + * Outputs the contents of the internal buffer as a kunit_printk formatted
> + * output.
> + */
> +void kunit_stream_commit(struct kunit_stream *this);
> +
> +/**
> + * kunit_stream_clear(): clears the internal buffer.
> + * @this: the stream being operated on.
> + *
> + * Clears the contents of the internal buffer.
> + */
> +void kunit_stream_clear(struct kunit_stream *this);
> +
> +#endif /* _KUNIT_KUNIT_STREAM_H */
> diff --git a/include/kunit/test.h b/include/kunit/test.h
> index 819edd8db4e81..4668e8a635954 100644
> --- a/include/kunit/test.h
> +++ b/include/kunit/test.h
> @@ -11,6 +11,7 @@
>   
>   #include <linux/types.h>
>   #include <linux/slab.h>
> +#include <kunit/kunit-stream.h>
>   
>   struct kunit_resource;
>   
> @@ -171,6 +172,7 @@ struct kunit {
>   	void (*vprintk)(const struct kunit *test,
>   			const char *level,
>   			struct va_format *vaf);
> +	void (*fail)(struct kunit *test, struct kunit_stream *stream);
>   };
>   
>   int kunit_init_test(struct kunit *test, const char *name);
> diff --git a/kunit/Makefile b/kunit/Makefile
> index 275b565a0e81f..6ddc622ee6b1c 100644
> --- a/kunit/Makefile
> +++ b/kunit/Makefile
> @@ -1,2 +1,3 @@
>   obj-$(CONFIG_KUNIT) +=			test.o \
> -					string-stream.o
> +					string-stream.o \
> +					kunit-stream.o
> diff --git a/kunit/kunit-stream.c b/kunit/kunit-stream.c
> new file mode 100644
> index 0000000000000..93c14eec03844
> --- /dev/null
> +++ b/kunit/kunit-stream.c
> @@ -0,0 +1,149 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * C++ stream style string formatter and printer used in KUnit for outputting
> + * KUnit messages.
> + *
> + * Copyright (C) 2019, Google LLC.
> + * Author: Brendan Higgins <brendanhiggins@google.com>
> + */
> +
> +#include <kunit/test.h>
> +#include <kunit/kunit-stream.h>
> +#include <kunit/string-stream.h>
> +
> +const char *kunit_stream_get_level(struct kunit_stream *this)
> +{
> +	unsigned long flags;
> +	const char *level;
> +
> +	spin_lock_irqsave(&this->lock, flags);
> +	level = this->level;
> +	spin_unlock_irqrestore(&this->lock, flags);
> +
> +	return level;
> +}
> +
> +void kunit_stream_set_level(struct kunit_stream *this, const char *level)
> +{
> +	unsigned long flags;
> +
> +	spin_lock_irqsave(&this->lock, flags);
> +	this->level = level;
> +	spin_unlock_irqrestore(&this->lock, flags);
> +}
> +
> +void kunit_stream_add(struct kunit_stream *this, const char *fmt, ...)
> +{
> +	va_list args;
> +	struct string_stream *stream = this->internal_stream;
> +
> +	va_start(args, fmt);
> +
> +	if (string_stream_vadd(stream, fmt, args) < 0)
> +		kunit_err(this->test, "Failed to allocate fragment: %s\n", fmt);
> +
> +	va_end(args);
> +}
> +
> +void kunit_stream_append(struct kunit_stream *this,
> +				struct kunit_stream *other)
> +{
> +	struct string_stream *other_stream = other->internal_stream;
> +	const char *other_content;
> +
> +	other_content = string_stream_get_string(other_stream);
> +
> +	if (!other_content) {
> +		kunit_err(this->test,
> +			  "Failed to get string from second argument for appending.\n");
> +		return;
> +	}
> +
> +	kunit_stream_add(this, other_content);
> +}
> +
> +void kunit_stream_clear(struct kunit_stream *this)
> +{
> +	string_stream_clear(this->internal_stream);
> +}
> +
> +void kunit_stream_commit(struct kunit_stream *this)
> +{
> +	struct string_stream *stream = this->internal_stream;
> +	struct string_stream_fragment *fragment;
> +	const char *level;
> +	char *buf;
> +
> +	level = kunit_stream_get_level(this);
> +	if (!level) {
> +		kunit_err(this->test,
> +			  "Stream was committed without a specified log level.\n");
> +		level = KERN_ERR;
> +		kunit_stream_set_level(this, level);
> +	}
> +
> +	buf = string_stream_get_string(stream);
> +	if (!buf) {
> +		kunit_err(this->test,
> +			 "Could not allocate buffer, dumping stream:\n");
> +		list_for_each_entry(fragment, &stream->fragments, node) {
> +			kunit_err(this->test, fragment->fragment);
> +		}
> +		kunit_err(this->test, "\n");
> +		goto cleanup;
> +	}
> +
> +	kunit_printk(level, this->test, buf);
> +	kfree(buf);
> +
> +cleanup:
> +	kunit_stream_clear(this);
> +}
> +
> +static int kunit_stream_init(struct kunit_resource *res, void *context)
> +{
> +	struct kunit *test = context;
> +	struct kunit_stream *stream;
> +
> +	stream = kzalloc(sizeof(*stream), GFP_KERNEL);
> +	if (!stream)
> +		return -ENOMEM;
> +	res->allocation = stream;
> +	stream->test = test;
> +	spin_lock_init(&stream->lock);
> +	stream->internal_stream = new_string_stream();
> +
> +	if (!stream->internal_stream)
> +		return -ENOMEM;

What happens to stream? Don't you want to free that?

> +
> +	return 0;
> +}
> +
> +static void kunit_stream_free(struct kunit_resource *res)
> +{
> +	struct kunit_stream *stream = res->allocation;
> +
> +	if (!string_stream_is_empty(stream->internal_stream)) {
> +		kunit_err(stream->test,
> +			 "End of test case reached with uncommitted stream entries.\n");
> +		kunit_stream_commit(stream);
> +	}
> +
> +	destroy_string_stream(stream->internal_stream);
> +	kfree(stream);
> +}
> +
> +struct kunit_stream *kunit_new_stream(struct kunit *test)
> +{
> +	struct kunit_resource *res;
> +
> +	res = kunit_alloc_resource(test,
> +				   kunit_stream_init,
> +				   kunit_stream_free,
> +				   test);
> +
> +	if (res)
> +		return res->allocation;
> +	else
> +		return NULL;
> +}
> diff --git a/kunit/test.c b/kunit/test.c
> index 541f9adb1608c..f7575b127e2df 100644
> --- a/kunit/test.c
> +++ b/kunit/test.c
> @@ -63,12 +63,20 @@ static void kunit_vprintk(const struct kunit *test,
>   			  "kunit %s: %pV", test->name, vaf);
>   }
>   
> +static void kunit_fail(struct kunit *test, struct kunit_stream *stream)
> +{
> +	kunit_set_success(test, false);
> +	kunit_stream_set_level(stream, KERN_ERR);
> +	kunit_stream_commit(stream);
> +}
> +
>   int kunit_init_test(struct kunit *test, const char *name)
>   {
>   	spin_lock_init(&test->lock);
>   	INIT_LIST_HEAD(&test->resources);
>   	test->name = name;
>   	test->vprintk = kunit_vprintk;
> +	test->fail = kunit_fail;
>   
>   	return 0;
>   }
> 

thanks,
-- Shuah