Improve readability of code that uses the Qt signed size typev5.10.0-rc2

During the container BoF session at the Qt Contributor Summit 2017 the
name of the signed size type became a subject of discussion in the
context of readability of code using this type and the intention of
using it for all length, size and count properties throughout the entire
framework in future versions of Qt.

This change proposes qsizetype as new name for qssize_t to emphasize the
readability of code over POSIX compatibility, the former being
potentially more relevant than the latter to the majority of users of
Qt.

Change-Id: Idb99cb4a8782703c054fa463a9e5af23a918e7f3
Reviewed-by: Samuel Gaist <samuel.gaist@edeltech.ch>
Reviewed-by: David Faure <david.faure@kdab.com>

1 files changed, 20 insertions, 20 deletions

diff --git a/src/corelib/global/qrandom.cpp b/src/corelib/global/qrandom.cpp
index 72ac8d332b..6769190335 100644
--- a/src/corelib/global/qrandom.cpp
+++ b/src/corelib/global/qrandom.cpp
@@ -93,7 +93,7 @@ DECLSPEC_IMPORT BOOLEAN WINAPI SystemFunction036(PVOID RandomBuffer, ULONG Rando
 QT_BEGIN_NAMESPACE
 
 #if defined(Q_PROCESSOR_X86) && QT_COMPILER_SUPPORTS_HERE(RDRND)
-static qssize_t qt_random_cpu(void *buffer, qssize_t count) Q_DECL_NOTHROW;
+static qsizetype qt_random_cpu(void *buffer, qsizetype count) Q_DECL_NOTHROW;
 
 #  ifdef Q_PROCESSOR_X86_64
 #    define _rdrandXX_step _rdrand64_step
@@ -101,7 +101,7 @@ static qssize_t qt_random_cpu(void *buffer, qssize_t count) Q_DECL_NOTHROW;
 #    define _rdrandXX_step _rdrand32_step
 #  endif
 
-static QT_FUNCTION_TARGET(RDRND) qssize_t qt_random_cpu(void *buffer, qssize_t count) Q_DECL_NOTHROW
+static QT_FUNCTION_TARGET(RDRND) qsizetype qt_random_cpu(void *buffer, qsizetype count) Q_DECL_NOTHROW
 {
     unsigned *ptr = reinterpret_cast<unsigned *>(buffer);
     unsigned *end = ptr + count;
@@ -122,7 +122,7 @@ out:
     return ptr - reinterpret_cast<unsigned *>(buffer);
 }
 #else
-static qssize_t qt_random_cpu(void *, qssize_t)
+static qsizetype qt_random_cpu(void *, qsizetype)
 {
     return 0;
 }
@@ -136,10 +136,10 @@ enum {
 struct QRandomGenerator::SystemGenerator
 {
 #if QT_CONFIG(getentropy)
-    static qssize_t fillBuffer(void *buffer, qssize_t count) Q_DECL_NOTHROW
+    static qsizetype fillBuffer(void *buffer, qsizetype count) Q_DECL_NOTHROW
     {
         // getentropy can read at most 256 bytes, so break the reading
-        qssize_t read = 0;
+        qsizetype read = 0;
         while (count - read > 256) {
             // getentropy can't fail under normal circumstances
             int ret = getentropy(reinterpret_cast<uchar *>(buffer) + read, 256);
@@ -195,24 +195,24 @@ struct QRandomGenerator::SystemGenerator
 
     Q_DECL_CONSTEXPR SystemGenerator() : fdp1 Q_BASIC_ATOMIC_INITIALIZER(0) {}
 
-    qssize_t fillBuffer(void *buffer, qssize_t count)
+    qsizetype fillBuffer(void *buffer, qsizetype count)
     {
         int fd = openDevice();
         if (Q_UNLIKELY(fd < 0))
             return 0;
 
         qint64 n = qt_safe_read(fd, buffer, count);
-        return qMax<qssize_t>(n, 0);        // ignore any errors
+        return qMax<qsizetype>(n, 0);        // ignore any errors
     }
 
 #elif defined(Q_OS_WIN) && !defined(Q_OS_WINRT)
-    qssize_t fillBuffer(void *buffer, qssize_t count) Q_DECL_NOTHROW
+    qsizetype fillBuffer(void *buffer, qsizetype count) Q_DECL_NOTHROW
     {
         auto RtlGenRandom = SystemFunction036;
         return RtlGenRandom(buffer, ULONG(count)) ? count: 0;
     }
 #elif defined(Q_OS_WINRT)
-    qssize_t fillBuffer(void *, qssize_t) Q_DECL_NOTHROW
+    qsizetype fillBuffer(void *, qsizetype) Q_DECL_NOTHROW
     {
         // always use the fallback
         return 0;
@@ -243,7 +243,7 @@ struct QRandomGenerator::SystemGenerator
 
 #if defined(Q_OS_WIN)
 static void fallback_update_seed(unsigned) {}
-static void fallback_fill(quint32 *ptr, qssize_t left) Q_DECL_NOTHROW
+static void fallback_fill(quint32 *ptr, qsizetype left) Q_DECL_NOTHROW
 {
     // on Windows, rand_s is a high-quality random number generator
     // and it requires no seeding
@@ -255,14 +255,14 @@ static void fallback_fill(quint32 *ptr, qssize_t left) Q_DECL_NOTHROW
 }
 #elif QT_CONFIG(getentropy)
 static void fallback_update_seed(unsigned) {}
-static void fallback_fill(quint32 *, qssize_t) Q_DECL_NOTHROW
+static void fallback_fill(quint32 *, qsizetype) Q_DECL_NOTHROW
 {
     // no fallback necessary, getentropy cannot fail under normal circumstances
     Q_UNREACHABLE();
 }
 #elif defined(Q_OS_BSD4)
 static void fallback_update_seed(unsigned) {}
-static void fallback_fill(quint32 *ptr, qssize_t left) Q_DECL_NOTHROW
+static void fallback_fill(quint32 *ptr, qsizetype left) Q_DECL_NOTHROW
 {
     // BSDs have arc4random(4) and these work even in chroot(2)
     arc4random_buf(ptr, left * sizeof(*ptr));
@@ -281,7 +281,7 @@ Q_NEVER_INLINE
 #ifdef Q_CC_GNU
 __attribute__((cold))   // this function is pretty big, so optimize for size
 #endif
-static void fallback_fill(quint32 *ptr, qssize_t left) Q_DECL_NOTHROW
+static void fallback_fill(quint32 *ptr, qsizetype left) Q_DECL_NOTHROW
 {
     quint32 scratch[12];    // see element count below
     quint32 *end = scratch;
@@ -358,7 +358,7 @@ Q_NEVER_INLINE void QRandomGenerator::SystemGenerator::generate(quint32 *begin,
     Q_DECL_NOEXCEPT_EXPR(FillBufferNoexcept)
 {
     quint32 *buffer = begin;
-    qssize_t count = end - begin;
+    qsizetype count = end - begin;
 
     if (Q_UNLIKELY(uint(qt_randomdevice_control) & SetRandomData)) {
         uint value = uint(qt_randomdevice_control) & RandomDataMask;
@@ -366,14 +366,14 @@ Q_NEVER_INLINE void QRandomGenerator::SystemGenerator::generate(quint32 *begin,
         return;
     }
 
-    qssize_t filled = 0;
+    qsizetype filled = 0;
     if (qt_has_hwrng() && (uint(qt_randomdevice_control) & SkipHWRNG) == 0)
         filled += qt_random_cpu(buffer, count);
 
     if (filled != count && (uint(qt_randomdevice_control) & SkipSystemRNG) == 0) {
-        qssize_t bytesFilled =
-                fillBuffer(buffer + filled, (count - filled) * qssize_t(sizeof(*buffer)));
-        filled += bytesFilled / qssize_t(sizeof(*buffer));
+        qsizetype bytesFilled =
+                fillBuffer(buffer + filled, (count - filled) * qsizetype(sizeof(*buffer)));
+        filled += bytesFilled / qsizetype(sizeof(*buffer));
     }
     if (filled)
         fallback_update_seed(*buffer);
@@ -677,7 +677,7 @@ inline QRandomGenerator::SystemGenerator &QRandomGenerator::SystemGenerator::sel
  */
 
 /*!
-    \fn QRandomGenerator::QRandomGenerator(const quint32 *seedBuffer, qssize_t len)
+    \fn QRandomGenerator::QRandomGenerator(const quint32 *seedBuffer, qsizetype len)
     \overload
 
     Initializes this QRandomGenerator object with \a len values found in
@@ -853,7 +853,7 @@ inline QRandomGenerator::SystemGenerator &QRandomGenerator::SystemGenerator::sel
  */
 
 /*!
-    \fn void QRandomGenerator::fillRange(UInt *buffer, qssize_t count)
+    \fn void QRandomGenerator::fillRange(UInt *buffer, qsizetype count)
 
     Generates \a count 32- or 64-bit quantities (depending on the type \c UInt)
     and stores them in the buffer pointed by \a buffer. This is the most