[libcamera-devel] [PATCH v5 2/9] libcamera: yaml_parser: Replace ok flag to get() with std::optional
Christian Rauch
Rauch.Christian at gmx.de
Wed Aug 3 21:10:19 CEST 2022
Hi Laurent,
Am 03.08.22 um 00:01 schrieb Laurent Pinchart:
> Hi Christian,
>
> On Tue, Aug 02, 2022 at 10:47:52PM +0200, Christian Rauch via libcamera-devel wrote:
>> Dear Laurent,
>>
>> The "return {};" in this patch cause "maybe-uninitialized" warnings in
>> my CI pipeline:
>
> Thank you for the report. We have CI pipelines too, but clearly, there
> are way more compiler/platform combinations out there that we test at
> the moment :-)
>
> Could you report the compiler, compiler version and platform, for my
> information ?
It's an arm64 corss compile workflow with gcc 9 [1]. See the full log at
[2].
[1]
https://github.com/christianrauch/libcamera-ci/blob/ci/.github/workflows/main_cross.yml
[2]
https://github.com/christianrauch/libcamera-ci/runs/7639256594?check_suite_focus=true
>
>> ../src/libcamera/yaml_parser.cpp: In member function ‘std::optional<_Tp>
>> libcamera::YamlObject::get() const [with T = short unsigned int;
>> std::enable_if_t<(((((((is_same_v<bool, T> || is_same_v<double, T>) ||
>> is_same_v<short int, T>) || is_same_v<short unsigned int, T>) ||
>> is_same_v<int, T>) || is_same_v<unsigned int, T>) ||
>> is_same_v<std::__cxx11::basic_string<char, std::char_traits<char>,
>> std::allocator<char> >, T>) || is_same_v<libcamera::Size, T>)>*
>> <anonymous> = 0]’:
>> ../src/libcamera/yaml_parser.cpp:184:11: error: ‘<anonymous>’ may be
>> used uninitialized in this function [-Werror=maybe-uninitialized]
>> 184 | return {};
>> | ^
>>
>> ... and a couple more in "yaml_parser.cpp".
>>
>> Since your intention is here to notify the user of invalid values,
>> wouldn't it be better to "return nullptr;" instead?
>
> The would be std::nullopt as the function returns a std::optional<>, but
> yes, that would make sense. I was expecting {} to do the same.
>
> As I can't test if this would fix the compilation warning given that I
> can't reproduce them, would you be able to test that change with your CI
> pipeline ? If std::nullopt fixes the errors, I can send a patch, or you
> can send one directly if you prefer.
>
>> Am 28.07.22 um 00:21 schrieb Laurent Pinchart via libcamera-devel:
>>> The YamlObject::get() function takes a default value and an optional
>>> bool ok flag to handle parsing errors. This ad-hoc mechanism complicates
>>> error handling in callers.
>>>
>>> A better API is possible by dropping the default value and ok flag and
>>> returning an std::optional. Not only does it simplify the calls, it also
>>> lets callers handle errors through the standard std::optional class
>>> instead of the current ad-hoc mechanism.
>>>
>>> Provide a get() wrapper around std::optional::value_or() to further
>>> simplify callers that don't need any specific error handling.
>>>
>>> Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
>>> Reviewed-by: Naushir Patuck <naush at raspberrypi.com>
>>> Tested-by: Naushir Patuck <naush at raspberrypi.com>
>>> ---
>>> include/libcamera/internal/yaml_parser.h | 9 +-
>>> src/libcamera/yaml_parser.cpp | 138 +++++++++--------------
>>> test/yaml-parser.cpp | 71 ++++++------
>>> 3 files changed, 96 insertions(+), 122 deletions(-)
>>>
>>> diff --git a/include/libcamera/internal/yaml_parser.h b/include/libcamera/internal/yaml_parser.h
>>> index 064cf44381d7..61f2223223a7 100644
>>> --- a/include/libcamera/internal/yaml_parser.h
>>> +++ b/include/libcamera/internal/yaml_parser.h
>>> @@ -9,6 +9,7 @@
>>>
>>> #include <iterator>
>>> #include <map>
>>> +#include <optional>
>>> #include <string>
>>> #include <vector>
>>>
>>> @@ -165,7 +166,13 @@ public:
>>> #else
>>> template<typename T>
>>> #endif
>>> - T get(const T &defaultValue, bool *ok = nullptr) const;
>>> + std::optional<T> get() const;
>>> +
>>> + template<typename T>
>>> + T get(const T &defaultValue) const
>>> + {
>>> + return get<T>().value_or(defaultValue);
>>> + }
>>>
>>> DictAdapter asDict() const { return DictAdapter{ dictionary_ }; }
>>> ListAdapter asList() const { return ListAdapter{ list_ }; }
>>> diff --git a/src/libcamera/yaml_parser.cpp b/src/libcamera/yaml_parser.cpp
>>> index 5c45e44e49c3..4299f5abd38a 100644
>>> --- a/src/libcamera/yaml_parser.cpp
>>> +++ b/src/libcamera/yaml_parser.cpp
>>> @@ -31,12 +31,6 @@ namespace {
>>> /* Empty static YamlObject as a safe result for invalid operations */
>>> static const YamlObject empty;
>>>
>>> -void setOk(bool *ok, bool result)
>>> -{
>>> - if (ok)
>>> - *ok = result;
>>> -}
>>> -
>>> } /* namespace */
>>>
>>> /**
>>> @@ -100,54 +94,52 @@ std::size_t YamlObject::size() const
>>> }
>>>
>>> /**
>>> - * \fn template<typename T> YamlObject::get<T>(
>>> - * const T &defaultValue, bool *ok) const
>>> + * \fn template<typename T> YamlObject::get<T>() const
>>> + * \brief Parse the YamlObject as a \a T value
>>> + *
>>> + * This function parses the value of the YamlObject as a \a T object, and
>>> + * returns the value. If parsing fails (usually because the YamlObject doesn't
>>> + * store a \a T value), std::nullopt is returned.
>>> + *
>>> + * \return The YamlObject value, or std::nullopt if parsing failed
>>> + */
>>> +
>>> +/**
>>> + * \fn template<typename T> YamlObject::get<T>(const T &defaultValue) const
>>> * \brief Parse the YamlObject as a \a T value
>>> * \param[in] defaultValue The default value when failing to parse
>>> - * \param[out] ok The result of whether the parse succeeded
>>> *
>>> * This function parses the value of the YamlObject as a \a T object, and
>>> * returns the value. If parsing fails (usually because the YamlObject doesn't
>>> - * store a \a T value), the \a defaultValue is returned, and \a ok is set to
>>> - * false. Otherwise, the YamlObject value is returned, and \a ok is set to true.
>>> + * store a \a T value), the \a defaultValue is returned.
>>> *
>>> - * The \a ok pointer is optional and can be a nullptr if the caller doesn't
>>> - * need to know if parsing succeeded.
>>> - *
>>> - * \return Value as a bool type
>>> + * \return The YamlObject value, or \a defaultValue if parsing failed
>>> */
>>>
>>> #ifndef __DOXYGEN__
>>>
>>> template<>
>>> -bool YamlObject::get(const bool &defaultValue, bool *ok) const
>>> +std::optional<bool> YamlObject::get() const
>>> {
>>> - setOk(ok, false);
>>> -
>>> if (type_ != Type::Value)
>>> - return defaultValue;
>>> + return {};
>>>
>>> - if (value_ == "true") {
>>> - setOk(ok, true);
>>> + if (value_ == "true")
>>> return true;
>>> - } else if (value_ == "false") {
>>> - setOk(ok, true);
>>> + else if (value_ == "false")
>>> return false;
>>> - }
>>>
>>> - return defaultValue;
>>> + return {};
>>> }
>>>
>>> template<>
>>> -int16_t YamlObject::get(const int16_t &defaultValue, bool *ok) const
>>> +std::optional<int16_t> YamlObject::get() const
>>> {
>>> - setOk(ok, false);
>>> -
>>> if (type_ != Type::Value)
>>> - return defaultValue;
>>> + return {};
>>>
>>> if (value_ == "")
>>> - return defaultValue;
>>> + return {};
>>>
>>> char *end;
>>>
>>> @@ -157,22 +149,19 @@ int16_t YamlObject::get(const int16_t &defaultValue, bool *ok) const
>>> if ('\0' != *end || errno == ERANGE ||
>>> value < std::numeric_limits<int16_t>::min() ||
>>> value > std::numeric_limits<int16_t>::max())
>>> - return defaultValue;
>>> + return {};
>>>
>>> - setOk(ok, true);
>>> return value;
>>> }
>>>
>>> template<>
>>> -uint16_t YamlObject::get(const uint16_t &defaultValue, bool *ok) const
>>> +std::optional<uint16_t> YamlObject::get() const
>>> {
>>> - setOk(ok, false);
>>> -
>>> if (type_ != Type::Value)
>>> - return defaultValue;
>>> + return {};
>>>
>>> if (value_ == "")
>>> - return defaultValue;
>>> + return {};
>>>
>>> /*
>>> * libyaml parses all scalar values as strings. When a string has
>>> @@ -183,7 +172,7 @@ uint16_t YamlObject::get(const uint16_t &defaultValue, bool *ok) const
>>> */
>>> std::size_t found = value_.find_first_not_of(" \t");
>>> if (found != std::string::npos && value_[found] == '-')
>>> - return defaultValue;
>>> + return {};
>>>
>>> char *end;
>>>
>>> @@ -193,22 +182,19 @@ uint16_t YamlObject::get(const uint16_t &defaultValue, bool *ok) const
>>> if ('\0' != *end || errno == ERANGE ||
>>> value < std::numeric_limits<uint16_t>::min() ||
>>> value > std::numeric_limits<uint16_t>::max())
>>> - return defaultValue;
>>> + return {};
>>>
>>> - setOk(ok, true);
>>> return value;
>>> }
>>>
>>> template<>
>>> -int32_t YamlObject::get(const int32_t &defaultValue, bool *ok) const
>>> +std::optional<int32_t> YamlObject::get() const
>>> {
>>> - setOk(ok, false);
>>> -
>>> if (type_ != Type::Value)
>>> - return defaultValue;
>>> + return {};
>>>
>>> if (value_ == "")
>>> - return defaultValue;
>>> + return {};
>>>
>>> char *end;
>>>
>>> @@ -218,22 +204,19 @@ int32_t YamlObject::get(const int32_t &defaultValue, bool *ok) const
>>> if ('\0' != *end || errno == ERANGE ||
>>> value < std::numeric_limits<int32_t>::min() ||
>>> value > std::numeric_limits<int32_t>::max())
>>> - return defaultValue;
>>> + return {};
>>>
>>> - setOk(ok, true);
>>> return value;
>>> }
>>>
>>> template<>
>>> -uint32_t YamlObject::get(const uint32_t &defaultValue, bool *ok) const
>>> +std::optional<uint32_t> YamlObject::get() const
>>> {
>>> - setOk(ok, false);
>>> -
>>> if (type_ != Type::Value)
>>> - return defaultValue;
>>> + return {};
>>>
>>> if (value_ == "")
>>> - return defaultValue;
>>> + return {};
>>>
>>> /*
>>> * libyaml parses all scalar values as strings. When a string has
>>> @@ -244,7 +227,7 @@ uint32_t YamlObject::get(const uint32_t &defaultValue, bool *ok) const
>>> */
>>> std::size_t found = value_.find_first_not_of(" \t");
>>> if (found != std::string::npos && value_[found] == '-')
>>> - return defaultValue;
>>> + return {};
>>>
>>> char *end;
>>>
>>> @@ -254,22 +237,19 @@ uint32_t YamlObject::get(const uint32_t &defaultValue, bool *ok) const
>>> if ('\0' != *end || errno == ERANGE ||
>>> value < std::numeric_limits<uint32_t>::min() ||
>>> value > std::numeric_limits<uint32_t>::max())
>>> - return defaultValue;
>>> + return {};
>>>
>>> - setOk(ok, true);
>>> return value;
>>> }
>>>
>>> template<>
>>> -double YamlObject::get(const double &defaultValue, bool *ok) const
>>> +std::optional<double> YamlObject::get() const
>>> {
>>> - setOk(ok, false);
>>> -
>>> if (type_ != Type::Value)
>>> - return defaultValue;
>>> + return {};
>>>
>>> if (value_ == "")
>>> - return defaultValue;
>>> + return {};
>>>
>>> char *end;
>>>
>>> @@ -277,50 +257,38 @@ double YamlObject::get(const double &defaultValue, bool *ok) const
>>> double value = std::strtod(value_.c_str(), &end);
>>>
>>> if ('\0' != *end || errno == ERANGE)
>>> - return defaultValue;
>>> + return {};
>>>
>>> - setOk(ok, true);
>>> return value;
>>> }
>>>
>>> template<>
>>> -std::string YamlObject::get(const std::string &defaultValue, bool *ok) const
>>> +std::optional<std::string> YamlObject::get() const
>>> {
>>> - setOk(ok, false);
>>> -
>>> if (type_ != Type::Value)
>>> - return defaultValue;
>>> + return {};
>>>
>>> - setOk(ok, true);
>>> return value_;
>>> }
>>>
>>> template<>
>>> -Size YamlObject::get(const Size &defaultValue, bool *ok) const
>>> +std::optional<Size> YamlObject::get() const
>>> {
>>> - setOk(ok, false);
>>> -
>>> if (type_ != Type::List)
>>> - return defaultValue;
>>> + return {};
>>>
>>> if (list_.size() != 2)
>>> - return defaultValue;
>>> + return {};
>>>
>>> - /*
>>> - * Add a local variable to validate each dimension in case
>>> - * that ok == nullptr.
>>> - */
>>> - bool valid;
>>> - uint32_t width = list_[0]->get<uint32_t>(0, &valid);
>>> - if (!valid)
>>> - return defaultValue;
>>> + auto width = list_[0]->get<uint32_t>();
>>> + if (!width)
>>> + return {};
>>>
>>> - uint32_t height = list_[1]->get<uint32_t>(0, &valid);
>>> - if (!valid)
>>> - return defaultValue;
>>> + auto height = list_[1]->get<uint32_t>();
>>> + if (!height)
>>> + return {};
>>>
>>> - setOk(ok, true);
>>> - return Size(width, height);
>>> + return Size(*width, *height);
>>> }
>>>
>>> #endif /* __DOXYGEN__ */
>>> diff --git a/test/yaml-parser.cpp b/test/yaml-parser.cpp
>>> index 38f848232fa6..ebb654f2ef9c 100644
>>> --- a/test/yaml-parser.cpp
>>> +++ b/test/yaml-parser.cpp
>>> @@ -148,7 +148,6 @@ protected:
>>> }
>>>
>>> /* Test string object */
>>> - bool ok;
>>> auto &strObj = (*root)["string"];
>>>
>>> if (strObj.isDictionary()) {
>>> @@ -161,27 +160,27 @@ protected:
>>> return TestFail;
>>> }
>>>
>>> - if (strObj.get<string>("", &ok) != "libcamera" || !ok) {
>>> + if (strObj.get<string>().value_or("") != "libcamera") {
>>> cerr << "String object parse as wrong content" << std::endl;
>>> return TestFail;
>>> }
>>>
>>> - if (strObj.get<int32_t>(-1, &ok) != -1 || ok) {
>>> + if (strObj.get<int32_t>()) {
>>> cerr << "String object parse as integer" << std::endl;
>>> return TestFail;
>>> }
>>>
>>> - if (strObj.get<uint32_t>(1, &ok) != 1 || ok) {
>>> + if (strObj.get<uint32_t>()) {
>>> cerr << "String object parse as unsigned integer" << std::endl;
>>> return TestFail;
>>> }
>>>
>>> - if (strObj.get<double>(1.0, &ok) != 1.0 || ok) {
>>> + if (strObj.get<double>()) {
>>> cerr << "String object parse as double" << std::endl;
>>> return TestFail;
>>> }
>>>
>>> - if (strObj.get<Size>(Size(0, 0), &ok) != Size(0, 0) || ok) {
>>> + if (strObj.get<Size>()) {
>>> cerr << "String object parse as Size" << std::endl;
>>> return TestFail;
>>> }
>>> @@ -199,27 +198,27 @@ protected:
>>> return TestFail;
>>> }
>>>
>>> - if (int32Obj.get<int32_t>(-100, &ok) != -100 || !ok) {
>>> + if (int32Obj.get<int32_t>().value_or(0) != -100) {
>>> cerr << "Integer object parse as wrong value" << std::endl;
>>> return TestFail;
>>> }
>>>
>>> - if (int32Obj.get<string>("", &ok) != "-100" || !ok) {
>>> + if (int32Obj.get<string>().value_or("") != "-100") {
>>> cerr << "Integer object fail to parse as string" << std::endl;
>>> return TestFail;
>>> }
>>>
>>> - if (int32Obj.get<double>(1.0, &ok) != -100.0 || !ok) {
>>> + if (int32Obj.get<double>().value_or(0.0) != -100.0) {
>>> cerr << "Integer object fail to parse as double" << std::endl;
>>> return TestFail;
>>> }
>>>
>>> - if (int32Obj.get<uint32_t>(1, &ok) != 1 || ok) {
>>> + if (int32Obj.get<uint32_t>()) {
>>> cerr << "Negative integer object parse as unsigned integer" << std::endl;
>>> return TestFail;
>>> }
>>>
>>> - if (int32Obj.get<Size>(Size(0, 0), &ok) != Size(0, 0) || ok) {
>>> + if (int32Obj.get<Size>()) {
>>> cerr << "Integer object parse as Size" << std::endl;
>>> return TestFail;
>>> }
>>> @@ -237,27 +236,27 @@ protected:
>>> return TestFail;
>>> }
>>>
>>> - if (uint32Obj.get<int32_t>(-1, &ok) != 100 || !ok) {
>>> + if (uint32Obj.get<int32_t>().value_or(0) != 100) {
>>> cerr << "Unsigned integer object fail to parse as integer" << std::endl;
>>> return TestFail;
>>> }
>>>
>>> - if (uint32Obj.get<string>("", &ok) != "100" || !ok) {
>>> + if (uint32Obj.get<string>().value_or("") != "100") {
>>> cerr << "Unsigned integer object fail to parse as string" << std::endl;
>>> return TestFail;
>>> }
>>>
>>> - if (uint32Obj.get<double>(1.0, &ok) != 100.0 || !ok) {
>>> + if (uint32Obj.get<double>().value_or(0.0) != 100.0) {
>>> cerr << "Unsigned integer object fail to parse as double" << std::endl;
>>> return TestFail;
>>> }
>>>
>>> - if (uint32Obj.get<uint32_t>(100, &ok) != 100 || !ok) {
>>> + if (uint32Obj.get<uint32_t>().value_or(0) != 100) {
>>> cerr << "Unsigned integer object parsed as wrong value" << std::endl;
>>> return TestFail;
>>> }
>>>
>>> - if (uint32Obj.get<Size>(Size(0, 0), &ok) != Size(0, 0) || ok) {
>>> + if (uint32Obj.get<Size>()) {
>>> cerr << "Unsigned integer object parsed as Size" << std::endl;
>>> return TestFail;
>>> }
>>> @@ -275,27 +274,27 @@ protected:
>>> return TestFail;
>>> }
>>>
>>> - if (doubleObj.get<string>("", &ok) != "3.14159" || !ok) {
>>> + if (doubleObj.get<string>().value_or("") != "3.14159") {
>>> cerr << "Double object fail to parse as string" << std::endl;
>>> return TestFail;
>>> }
>>>
>>> - if (doubleObj.get<double>(1.0, &ok) != 3.14159 || !ok) {
>>> + if (doubleObj.get<double>().value_or(0.0) != 3.14159) {
>>> cerr << "Double object parse as wrong value" << std::endl;
>>> return TestFail;
>>> }
>>>
>>> - if (doubleObj.get<int32_t>(-1, &ok) != -1 || ok) {
>>> + if (doubleObj.get<int32_t>()) {
>>> cerr << "Double object parse as integer" << std::endl;
>>> return TestFail;
>>> }
>>>
>>> - if (doubleObj.get<uint32_t>(1, &ok) != 1 || ok) {
>>> + if (doubleObj.get<uint32_t>()) {
>>> cerr << "Double object parse as unsigned integer" << std::endl;
>>> return TestFail;
>>> }
>>>
>>> - if (doubleObj.get<Size>(Size(0, 0), &ok) != Size(0, 0) || ok) {
>>> + if (doubleObj.get<Size>()) {
>>> cerr << "Double object parse as Size" << std::endl;
>>> return TestFail;
>>> }
>>> @@ -313,27 +312,27 @@ protected:
>>> return TestFail;
>>> }
>>>
>>> - if (sizeObj.get<string>("", &ok) != "" || ok) {
>>> + if (sizeObj.get<string>()) {
>>> cerr << "Size object parse as string" << std::endl;
>>> return TestFail;
>>> }
>>>
>>> - if (sizeObj.get<double>(1.0, &ok) != 1.0 || ok) {
>>> + if (sizeObj.get<double>()) {
>>> cerr << "Size object parse as double" << std::endl;
>>> return TestFail;
>>> }
>>>
>>> - if (sizeObj.get<int32_t>(-1, &ok) != -1 || ok) {
>>> + if (sizeObj.get<int32_t>()) {
>>> cerr << "Size object parse as integer" << std::endl;
>>> return TestFail;
>>> }
>>>
>>> - if (sizeObj.get<uint32_t>(1, &ok) != 1 || ok) {
>>> + if (sizeObj.get<uint32_t>()) {
>>> cerr << "Size object parse as unsigned integer" << std::endl;
>>> return TestFail;
>>> }
>>>
>>> - if (sizeObj.get<Size>(Size(0, 0), &ok) != Size(1920, 1080) || !ok) {
>>> + if (sizeObj.get<Size>().value_or(Size(0, 0)) != Size(1920, 1080)) {
>>> cerr << "Size object parse as wrong value" << std::endl;
>>> return TestFail;
>>> }
>>> @@ -351,27 +350,27 @@ protected:
>>> return TestFail;
>>> }
>>>
>>> - if (listObj.get<string>("", &ok) != "" || ok) {
>>> + if (listObj.get<string>()) {
>>> cerr << "List object parse as string" << std::endl;
>>> return TestFail;
>>> }
>>>
>>> - if (listObj.get<double>(1.0, &ok) != 1.0 || ok) {
>>> + if (listObj.get<double>()) {
>>> cerr << "List object parse as double" << std::endl;
>>> return TestFail;
>>> }
>>>
>>> - if (listObj.get<int32_t>(-1, &ok) != -1 || ok) {
>>> + if (listObj.get<int32_t>()) {
>>> cerr << "List object parse as integer" << std::endl;
>>> return TestFail;
>>> }
>>>
>>> - if (listObj.get<uint32_t>(1, &ok) != 1 || ok) {
>>> + if (listObj.get<uint32_t>()) {
>>> cerr << "List object parse as unsigne integer" << std::endl;
>>> return TestFail;
>>> }
>>>
>>> - if (listObj.get<Size>(Size(0, 0), &ok) != Size(0, 0) || ok) {
>>> + if (listObj.get<Size>()) {
>>> cerr << "String list object parse as Size" << std::endl;
>>> return TestFail;
>>> }
>>> @@ -424,27 +423,27 @@ protected:
>>> return TestFail;
>>> }
>>>
>>> - if (dictObj.get<string>("", &ok) != "" || ok) {
>>> + if (dictObj.get<string>()) {
>>> cerr << "Dictionary object parse as string" << std::endl;
>>> return TestFail;
>>> }
>>>
>>> - if (dictObj.get<double>(1.0, &ok) != 1.0 || ok) {
>>> + if (dictObj.get<double>()) {
>>> cerr << "Dictionary object parse as double" << std::endl;
>>> return TestFail;
>>> }
>>>
>>> - if (dictObj.get<int32_t>(-1, &ok) != -1 || ok) {
>>> + if (dictObj.get<int32_t>()) {
>>> cerr << "Dictionary object parse as integer" << std::endl;
>>> return TestFail;
>>> }
>>>
>>> - if (dictObj.get<uint32_t>(1, &ok) != 1 || ok) {
>>> + if (dictObj.get<uint32_t>()) {
>>> cerr << "Dictionary object parse as unsigned integer" << std::endl;
>>> return TestFail;
>>> }
>>>
>>> - if (dictObj.get<Size>(Size(0, 0), &ok) != Size(0, 0) || ok) {
>>> + if (dictObj.get<Size>()) {
>>> cerr << "Dictionary object parse as Size" << std::endl;
>>> return TestFail;
>>> }
>
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