Files
external_libcamera/src/libcamera/control_validator.cpp
Laurent Pinchart 93e72b695e libcamera: Move internal headers to include/libcamera/internal/
The libcamera internal headers are located in src/libcamera/include/.
The directory is added to the compiler headers search path with a meson
include_directories() directive, and internal headers are included with
(e.g. for the internal semaphore.h header)

  #include "semaphore.h"

All was well, until libcxx decided to implement the C++20
synchronization library. The __threading_support header gained a

  #include <semaphore.h>

to include the pthread's semaphore support. As include_directories()
adds src/libcamera/include/ to the compiler search path with -I, the
internal semaphore.h is included instead of the pthread version.
Needless to say, the compiler isn't happy.

Three options have been considered to fix this issue:

- Use -iquote instead of -I. The -iquote option instructs gcc to only
  consider the header search path for headers included with the ""
  version. Meson unfortunately doesn't support this option.

- Rename the internal semaphore.h header. This was deemed to be the
  beginning of a long whack-a-mole game, where namespace clashes with
  system libraries would appear over time (possibly dependent on
  particular system configurations) and would need to be constantly
  fixed.

- Move the internal headers to another directory to create a unique
  namespace through path components. This causes lots of churn in all
  the existing source files through the all project.

The first option would be best, but isn't available to us due to missing
support in meson. Even if -iquote support was added, we would need to
fix the problem before a new version of meson containing the required
support would be released.

The third option is thus the only practical solution available. Bite the
bullet, and do it, moving headers to include/libcamera/internal/.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Jacopo Mondi <jacopo@jmondi.org>
2020-05-16 03:38:11 +03:00

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/* SPDX-License-Identifier: LGPL-2.1-or-later */
/*
* Copyright (C) 2019, Google Inc.
*
* control_validator.cpp - Control validator
*/
#include "libcamera/internal/control_validator.h"
/**
* \file control_validator.h
* \brief Abstract control validator
*/
namespace libcamera {
/**
* \class ControlValidator
* \brief Interface for the control validator
*
* The ControlValidator class is used by the ControlList class to validate
* controls added to the list. It is an abstract class providing an interface
* for object-specific control validation, such a Camera controls and V4L2
* controls.
*/
/**
* \fn ControlValidator::name()
* \brief Retrieve the name of the object associated with the validator
* \return The name of the object associated with the validator
*/
/**
* \fn ControlValidator::validate()
* \brief Validate a control
* \param[in] id The control ID
*
* This method validates the control \a id against the object corresponding to
* the validator. It shall at least validate that the control is applicable to
* the object instance, and may perform additional checks.
*
* \return True if the control is valid, false otherwise
*/
} /* namespace libcamera */