[PATCH v1] treewide: Remove top-level `const` from return types
Barnabás Pőcze
barnabas.pocze at ideasonboard.com
Tue Jun 3 14:51:33 CEST 2025
Hi
2025. 06. 03. 14:36 keltezéssel, Stefan Klug írta:
> Hi Barnabás,
>
> Thank you for the patch.
>
> Quoting Barnabás Pőcze (2025-06-03 13:14:34)
>> Top-level `const` qualifiers are not useful, so avoid them. This is done
>> either by simply removing the top-level `const`, or making the function
>> return a reference to const where that is appropriate.
>>
>> Signed-off-by: Barnabás Pőcze <barnabas.pocze at ideasonboard.com>
>
> Do we need to note somewhere that this breaks the ABI?
I don't know, I can't recall any specific mechanism that was agreed upon.
I believe the itanium abi does not encode the return type of non-template
functions, and as I would expect abi-compliance-checker reports 100% binary
compatibility; am I missing something? It is definitely an API change but I
consider it highly unlikely that anyone's code is affected by this change.
Regards,
Barnabás Pőcze
>
> Reviewed-by: Stefan Klug <stefan.klug at ideasonboard.com>
>
> Best regards,
> Stefan
>
>> ---
>> include/libcamera/base/log.h | 2 +-
>> include/libcamera/geometry.h | 6 +++---
>> include/libcamera/internal/matrix.h | 2 +-
>> include/libcamera/internal/v4l2_subdevice.h | 2 +-
>> include/libcamera/internal/v4l2_videodevice.h | 2 +-
>> src/apps/cam/drm.h | 4 ++--
>> src/ipa/libipa/histogram.h | 2 +-
>> src/libcamera/geometry.cpp | 6 +++---
>> src/libcamera/pipeline/ipu3/ipu3.cpp | 2 +-
>> src/libcamera/pipeline/mali-c55/mali-c55.cpp | 8 ++++----
>> src/libcamera/v4l2_subdevice.cpp | 2 +-
>> src/libcamera/v4l2_videodevice.cpp | 2 +-
>> 12 files changed, 20 insertions(+), 20 deletions(-)
>>
>> diff --git a/include/libcamera/base/log.h b/include/libcamera/base/log.h
>> index 8af74b59d..5a232a650 100644
>> --- a/include/libcamera/base/log.h
>> +++ b/include/libcamera/base/log.h
>> @@ -75,7 +75,7 @@ public:
>> const LogCategory &category() const { return category_; }
>> const std::string &fileInfo() const { return fileInfo_; }
>> const std::string &prefix() const { return prefix_; }
>> - const std::string msg() const { return msgStream_.str(); }
>> + std::string msg() const { return msgStream_.str(); }
>>
>> private:
>> LIBCAMERA_DISABLE_COPY_AND_MOVE(LogMessage)
>> diff --git a/include/libcamera/geometry.h b/include/libcamera/geometry.h
>> index f322e3d5b..d9378efec 100644
>> --- a/include/libcamera/geometry.h
>> +++ b/include/libcamera/geometry.h
>> @@ -31,7 +31,7 @@ public:
>> int x;
>> int y;
>>
>> - const std::string toString() const;
>> + std::string toString() const;
>>
>> constexpr Point operator-() const
>> {
>> @@ -64,7 +64,7 @@ public:
>> unsigned int height;
>>
>> bool isNull() const { return !width && !height; }
>> - const std::string toString() const;
>> + std::string toString() const;
>>
>> Size &alignDownTo(unsigned int hAlignment, unsigned int vAlignment)
>> {
>> @@ -275,7 +275,7 @@ public:
>> unsigned int height;
>>
>> bool isNull() const { return !width && !height; }
>> - const std::string toString() const;
>> + std::string toString() const;
>>
>> Point center() const;
>>
>> diff --git a/include/libcamera/internal/matrix.h b/include/libcamera/internal/matrix.h
>> index 47513b995..1842389f2 100644
>> --- a/include/libcamera/internal/matrix.h
>> +++ b/include/libcamera/internal/matrix.h
>> @@ -56,7 +56,7 @@ public:
>>
>> ~Matrix() = default;
>>
>> - const std::string toString() const
>> + std::string toString() const
>> {
>> std::stringstream out;
>>
>> diff --git a/include/libcamera/internal/v4l2_subdevice.h b/include/libcamera/internal/v4l2_subdevice.h
>> index fa2a4a21e..c1cde1df2 100644
>> --- a/include/libcamera/internal/v4l2_subdevice.h
>> +++ b/include/libcamera/internal/v4l2_subdevice.h
>> @@ -66,7 +66,7 @@ struct V4L2SubdeviceFormat {
>> Size size;
>> std::optional<ColorSpace> colorSpace;
>>
>> - const std::string toString() const;
>> + std::string toString() const;
>> };
>>
>> std::ostream &operator<<(std::ostream &out, const V4L2SubdeviceFormat &f);
>> diff --git a/include/libcamera/internal/v4l2_videodevice.h b/include/libcamera/internal/v4l2_videodevice.h
>> index ae6a76cb0..6caafc4dc 100644
>> --- a/include/libcamera/internal/v4l2_videodevice.h
>> +++ b/include/libcamera/internal/v4l2_videodevice.h
>> @@ -178,7 +178,7 @@ public:
>> std::array<Plane, 3> planes;
>> unsigned int planesCount = 0;
>>
>> - const std::string toString() const;
>> + std::string toString() const;
>> };
>>
>> std::ostream &operator<<(std::ostream &out, const V4L2DeviceFormat &f);
>> diff --git a/src/apps/cam/drm.h b/src/apps/cam/drm.h
>> index 1ba83b6eb..30a916d7e 100644
>> --- a/src/apps/cam/drm.h
>> +++ b/src/apps/cam/drm.h
>> @@ -97,9 +97,9 @@ public:
>>
>> bool isImmutable() const { return flags_ & DRM_MODE_PROP_IMMUTABLE; }
>>
>> - const std::vector<uint64_t> values() const { return values_; }
>> + const std::vector<uint64_t> &values() const { return values_; }
>> const std::map<uint32_t, std::string> &enums() const { return enums_; }
>> - const std::vector<uint32_t> blobs() const { return blobs_; }
>> + const std::vector<uint32_t> &blobs() const { return blobs_; }
>>
>> private:
>> Type type_;
>> diff --git a/src/ipa/libipa/histogram.h b/src/ipa/libipa/histogram.h
>> index a926002c8..8cf8bb6d1 100644
>> --- a/src/ipa/libipa/histogram.h
>> +++ b/src/ipa/libipa/histogram.h
>> @@ -36,7 +36,7 @@ public:
>> }
>>
>> size_t bins() const { return cumulative_.size() - 1; }
>> - const Span<const uint64_t> data() const { return cumulative_; }
>> + Span<const uint64_t> data() const { return cumulative_; }
>> uint64_t total() const { return cumulative_[cumulative_.size() - 1]; }
>> uint64_t cumulativeFrequency(double bin) const;
>> double quantile(double q, uint32_t first = 0, uint32_t last = UINT_MAX) const;
>> diff --git a/src/libcamera/geometry.cpp b/src/libcamera/geometry.cpp
>> index 81cc8cd53..de76d0c12 100644
>> --- a/src/libcamera/geometry.cpp
>> +++ b/src/libcamera/geometry.cpp
>> @@ -53,7 +53,7 @@ namespace libcamera {
>> * \brief Assemble and return a string describing the point
>> * \return A string describing the point
>> */
>> -const std::string Point::toString() const
>> +std::string Point::toString() const
>> {
>> std::stringstream ss;
>> ss << *this;
>> @@ -133,7 +133,7 @@ std::ostream &operator<<(std::ostream &out, const Point &p)
>> * \brief Assemble and return a string describing the size
>> * \return A string describing the size
>> */
>> -const std::string Size::toString() const
>> +std::string Size::toString() const
>> {
>> std::stringstream ss;
>> ss << *this;
>> @@ -676,7 +676,7 @@ std::ostream &operator<<(std::ostream &out, const SizeRange &sr)
>> * \brief Assemble and return a string describing the rectangle
>> * \return A string describing the Rectangle
>> */
>> -const std::string Rectangle::toString() const
>> +std::string Rectangle::toString() const
>> {
>> std::stringstream ss;
>> ss << *this;
>> diff --git a/src/libcamera/pipeline/ipu3/ipu3.cpp b/src/libcamera/pipeline/ipu3/ipu3.cpp
>> index e31e3879d..ad20810e6 100644
>> --- a/src/libcamera/pipeline/ipu3/ipu3.cpp
>> +++ b/src/libcamera/pipeline/ipu3/ipu3.cpp
>> @@ -105,7 +105,7 @@ public:
>> Status validate() override;
>>
>> const StreamConfiguration &cio2Format() const { return cio2Configuration_; }
>> - const ImgUDevice::PipeConfig imguConfig() const { return pipeConfig_; }
>> + const ImgUDevice::PipeConfig &imguConfig() const { return pipeConfig_; }
>>
>> /* Cache the combinedTransform_ that will be applied to the sensor */
>> Transform combinedTransform_;
>> diff --git a/src/libcamera/pipeline/mali-c55/mali-c55.cpp b/src/libcamera/pipeline/mali-c55/mali-c55.cpp
>> index 4acc091bd..28d5da3c8 100644
>> --- a/src/libcamera/pipeline/mali-c55/mali-c55.cpp
>> +++ b/src/libcamera/pipeline/mali-c55/mali-c55.cpp
>> @@ -101,8 +101,8 @@ public:
>> int loadIPA();
>>
>> /* Deflect these functionalities to either TPG or CameraSensor. */
>> - const std::vector<Size> sizes(unsigned int mbusCode) const;
>> - const Size resolution() const;
>> + std::vector<Size> sizes(unsigned int mbusCode) const;
>> + Size resolution() const;
>>
>> int pixfmtToMbusCode(const PixelFormat &pixFmt) const;
>> const PixelFormat &bestRawFormat() const;
>> @@ -195,7 +195,7 @@ void MaliC55CameraData::setSensorControls(const ControlList &sensorControls)
>> delayedCtrls_->push(sensorControls);
>> }
>>
>> -const std::vector<Size> MaliC55CameraData::sizes(unsigned int mbusCode) const
>> +std::vector<Size> MaliC55CameraData::sizes(unsigned int mbusCode) const
>> {
>> if (sensor_)
>> return sensor_->sizes(mbusCode);
>> @@ -218,7 +218,7 @@ const std::vector<Size> MaliC55CameraData::sizes(unsigned int mbusCode) const
>> return sizes;
>> }
>>
>> -const Size MaliC55CameraData::resolution() const
>> +Size MaliC55CameraData::resolution() const
>> {
>> if (sensor_)
>> return sensor_->resolution();
>> diff --git a/src/libcamera/v4l2_subdevice.cpp b/src/libcamera/v4l2_subdevice.cpp
>> index 33279654d..e9c849ac5 100644
>> --- a/src/libcamera/v4l2_subdevice.cpp
>> +++ b/src/libcamera/v4l2_subdevice.cpp
>> @@ -923,7 +923,7 @@ const MediaBusFormatInfo &MediaBusFormatInfo::info(uint32_t code)
>> * \brief Assemble and return a string describing the format
>> * \return A string describing the V4L2SubdeviceFormat
>> */
>> -const std::string V4L2SubdeviceFormat::toString() const
>> +std::string V4L2SubdeviceFormat::toString() const
>> {
>> std::stringstream ss;
>> ss << *this;
>> diff --git a/src/libcamera/v4l2_videodevice.cpp b/src/libcamera/v4l2_videodevice.cpp
>> index d53aa2d3c..58a6704ef 100644
>> --- a/src/libcamera/v4l2_videodevice.cpp
>> +++ b/src/libcamera/v4l2_videodevice.cpp
>> @@ -429,7 +429,7 @@ bool V4L2BufferCache::Entry::operator==(const FrameBuffer &buffer) const
>> * \brief Assemble and return a string describing the format
>> * \return A string describing the V4L2DeviceFormat
>> */
>> -const std::string V4L2DeviceFormat::toString() const
>> +std::string V4L2DeviceFormat::toString() const
>> {
>> std::stringstream ss;
>> ss << *this;
>> --
>> 2.49.0
>>
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