xref: /openbmc/linux/drivers/staging/media/atomisp/pci/hive_isp_css_include/assert_support.h (revision 9d4fa1a1)

/*
 * Support for Intel Camera Imaging ISP subsystem.
 * Copyright (c) 2015, Intel Corporation.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 */

#ifndef __ASSERT_SUPPORT_H_INCLUDED__
#define __ASSERT_SUPPORT_H_INCLUDED__

/**
 * The following macro can help to test the size of a struct at compile
 * time rather than at run-time. It does not work for all compilers; see
 * below.
 *
 * Depending on the value of 'condition', the following macro is expanded to:
 * - condition==true:
 *     an expression containing an array declaration with negative size,
 *     usually resulting in a compilation error
 * - condition==false:
 *     (void) 1; // C statement with no effect
 *
 * example:
 *  COMPILATION_ERROR_IF( sizeof(struct host_sp_queues) != SIZE_OF_HOST_SP_QUEUES_STRUCT);
 *
 * verify that the macro indeed triggers a compilation error with your compiler:
 *  COMPILATION_ERROR_IF( sizeof(struct host_sp_queues) != (sizeof(struct host_sp_queues)+1) );
 *
 * Not all compilers will trigger an error with this macro; use a search engine to search for
 * BUILD_BUG_ON to find other methods.
 */
#define COMPILATION_ERROR_IF(condition) ((void)sizeof(char[1 - 2 * !!(condition)]))

/* Compile time assertion */
#ifndef CT_ASSERT
#define CT_ASSERT(cnd) ((void)sizeof(char[(cnd) ? 1 :  -1]))
#endif /* CT_ASSERT */

#include <linux/bug.h>

/* TODO: it would be cleaner to use this:
 * #define assert(cnd) BUG_ON(cnd)
 * but that causes many compiler warnings (==errors) under Android
 * because it seems that the BUG_ON() macro is not seen as a check by
 * gcc like the BUG() macro is. */
#define assert(cnd) \
	do { \
		if (!(cnd)) \
			BUG(); \
	} while (0)

#ifndef PIPE_GENERATION
/* Deprecated OP___assert, this is still used in ~1000 places
 * in the code. This will be removed over time.
 * The implementation for the pipe generation tool is in see support.isp.h */
#define OP___assert(cnd) assert(cnd)

static inline void compile_time_assert(unsigned int cond)
{
	/* Call undefined function if cond is false */
	void _compile_time_assert(void);
	if (!cond) _compile_time_assert();
}
#endif /* PIPE_GENERATION */

#endif /* __ASSERT_SUPPORT_H_INCLUDED__ */