diff options
Diffstat (limited to 'src/corelib/global/qglobal.cpp')
| -rw-r--r-- | src/corelib/global/qglobal.cpp | 108 |
1 files changed, 97 insertions, 11 deletions
diff --git a/src/corelib/global/qglobal.cpp b/src/corelib/global/qglobal.cpp index c0db2c3db6..a8ed8ca6fd 100644 --- a/src/corelib/global/qglobal.cpp +++ b/src/corelib/global/qglobal.cpp @@ -1147,12 +1147,12 @@ Q_STATIC_ASSERT((std::is_same<qsizetype, qptrdiff>::value)); \sa QT_VERSION_STR, QLibraryInfo::version() */ -const char *qVersion() Q_DECL_NOTHROW +const char *qVersion() noexcept { return QT_VERSION_STR; } -bool qSharedBuild() Q_DECL_NOTHROW +bool qSharedBuild() noexcept { #ifdef QT_SHARED return true; @@ -1898,6 +1898,42 @@ bool qSharedBuild() Q_DECL_NOTHROW */ /*! + \macro Q_PROCESSOR_RISCV + \relates <QtGlobal> + \since 5.13 + + Defined if the application is compiled for RISC-V processors. Qt currently + supports two RISC-V variants: \l Q_PROCESSOR_RISCV_32 and \l + Q_PROCESSOR_RISCV_64. + + \sa QSysInfo::buildCpuArchitecture() +*/ + +/*! + \macro Q_PROCESSOR_RISCV_32 + \relates <QtGlobal> + \since 5.13 + + Defined if the application is compiled for 32-bit RISC-V processors. The \l + Q_PROCESSOR_RISCV macro is also defined when Q_PROCESSOR_RISCV_32 is + defined. + + \sa QSysInfo::buildCpuArchitecture() +*/ + +/*! + \macro Q_PROCESSOR_RISCV_64 + \relates <QtGlobal> + \since 5.13 + + Defined if the application is compiled for 64-bit RISC-V processors. The \l + Q_PROCESSOR_RISCV macro is also defined when Q_PROCESSOR_RISCV_64 is + defined. + + \sa QSysInfo::buildCpuArchitecture() +*/ + +/*! \macro Q_PROCESSOR_S390 \relates <QtGlobal> @@ -2916,6 +2952,7 @@ QString QSysInfo::machineHostName() struct utsname u; if (uname(&u) == 0) return QString::fromLocal8Bit(u.nodename); + return QString(); #else # ifdef Q_OS_WIN // Important: QtNetwork depends on machineHostName() initializing ws2_32.dll @@ -2928,7 +2965,6 @@ QString QSysInfo::machineHostName() hostName[sizeof(hostName) - 1] = '\0'; return QString::fromLocal8Bit(hostName); #endif - return QString(); } #endif // QT_BOOTSTRAPPED @@ -3220,7 +3256,7 @@ QByteArray QSysInfo::bootUniqueId() The Q_CHECK_PTR macro calls this function if an allocation check fails. */ -void qt_check_pointer(const char *n, int l) Q_DECL_NOTHROW +void qt_check_pointer(const char *n, int l) noexcept { // make separate printing calls so that the first one may flush; // the second one could want to allocate memory (fputs prints a @@ -3247,7 +3283,7 @@ void qBadAlloc() Allows you to call std::terminate() without including <exception>. Called internally from QT_TERMINATE_ON_EXCEPTION */ -Q_NORETURN void qTerminate() Q_DECL_NOTHROW +Q_NORETURN void qTerminate() noexcept { std::terminate(); } @@ -3256,7 +3292,7 @@ Q_NORETURN void qTerminate() Q_DECL_NOTHROW /* The Q_ASSERT macro calls this function when the test fails. */ -void qt_assert(const char *assertion, const char *file, int line) Q_DECL_NOTHROW +void qt_assert(const char *assertion, const char *file, int line) noexcept { QMessageLogger(file, line, nullptr).fatal("ASSERT: \"%s\" in file %s, line %d", assertion, file, line); } @@ -3264,7 +3300,7 @@ void qt_assert(const char *assertion, const char *file, int line) Q_DECL_NOTHROW /* The Q_ASSERT_X macro calls this function when the test fails. */ -void qt_assert_x(const char *where, const char *what, const char *file, int line) Q_DECL_NOTHROW +void qt_assert_x(const char *where, const char *what, const char *file, int line) noexcept { QMessageLogger(file, line, nullptr).fatal("ASSERT failure in %s: \"%s\", file %s, line %d", where, what, file, line); } @@ -3471,7 +3507,7 @@ QString qEnvironmentVariable(const char *varName) \sa qgetenv(), qEnvironmentVariable(), qEnvironmentVariableIsSet() */ -bool qEnvironmentVariableIsEmpty(const char *varName) Q_DECL_NOEXCEPT +bool qEnvironmentVariableIsEmpty(const char *varName) noexcept { QMutexLocker locker(&environmentMutex); #ifdef Q_CC_MSVC @@ -3506,7 +3542,7 @@ bool qEnvironmentVariableIsEmpty(const char *varName) Q_DECL_NOEXCEPT \sa qgetenv(), qEnvironmentVariable(), qEnvironmentVariableIsSet() */ -int qEnvironmentVariableIntValue(const char *varName, bool *ok) Q_DECL_NOEXCEPT +int qEnvironmentVariableIntValue(const char *varName, bool *ok) noexcept { static const int NumBinaryDigitsPerOctalDigit = 3; static const int MaxDigitsForOctalInt = @@ -3575,7 +3611,7 @@ int qEnvironmentVariableIntValue(const char *varName, bool *ok) Q_DECL_NOEXCEPT \sa qgetenv(), qEnvironmentVariable(), qEnvironmentVariableIsEmpty() */ -bool qEnvironmentVariableIsSet(const char *varName) Q_DECL_NOEXCEPT +bool qEnvironmentVariableIsSet(const char *varName) noexcept { QMutexLocker locker(&environmentMutex); #ifdef Q_CC_MSVC @@ -3583,7 +3619,7 @@ bool qEnvironmentVariableIsSet(const char *varName) Q_DECL_NOEXCEPT (void)getenv_s(&requiredSize, 0, 0, varName); return requiredSize != 0; #else - return ::getenv(varName) != 0; + return ::getenv(varName) != nullptr; #endif } @@ -3777,6 +3813,56 @@ bool qunsetenv(const char *varName) */ /*! + \fn template <typename T, typename U = T> T qExchange(T &obj, U &&newValue) + \relates <QtGlobal> + \since 5.14 + + Replaces the value of \a obj with \a newValue and returns the old value of \a obj. + + This is Qt's implementation of std::exchange(). It differs from std::exchange() + only in that it is \c constexpr already in C++14, and available on all supported + compilers. + + Here is how to use qExchange() to implement move constructors: + \code + MyClass(MyClass &&other) + : m_pointer{qExchange(other.m_pointer, nullptr)}, + m_int{qExchange(other.m_int, 0)}, + m_vector{std::move(other.m_vector)}, + ... + \endcode + + For members of class type, we can use std::move(), as their move-constructor will + do the right thing. But for scalar types such as raw pointers or integer type, move + is the same as copy, which, particularly for pointers, is not what we expect. So, we + cannot use std::move() for such types, but we can use std::exchange()/qExchange() to + make sure the source object's member is already reset by the time we get to the + initialization of our next data member, which might come in handy if the constructor + exits with an exception. + + Here is how to use qExchange() to write a loop that consumes the collection it + iterates over: + \code + for (auto &e : qExchange(collection, {}) + doSomethingWith(e); + \endcode + + Which is equivalent to the following, much more verbose code: + \code + { + auto tmp = std::move(collection); + collection = {}; // or collection.clear() + for (auto &e : tmp) + doSomethingWith(e); + } // destroys 'tmp' + \endcode + + This is perfectly safe, as the for-loop keeps the result of qExchange() alive for as + long as the loop runs, saving the declaration of a temporary variable. Be aware, though, + that qExchange() returns a non-const object, so Qt containers may detach. +*/ + +/*! \macro QT_TR_NOOP(sourceText) \relates <QtGlobal> |