[libcamera-devel] [PATCH v5 2/9] libcamera: yaml_parser: Replace ok flag to get() with std::optional
Laurent Pinchart
laurent.pinchart at ideasonboard.com
Wed Aug 3 00:01:34 CEST 2022
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 ?
> ../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;
> > }
--
Regards,
Laurent Pinchart
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