4 files changed, 6 insertions, 14 deletions
diff --git a/src/corelib/global/qcompilerdetection.h b/src/corelib/global/qcompilerdetection.h
index b173dcf522..ad3d2be69b 100644
--- a/src/corelib/global/qcompilerdetection.h
+++ b/src/corelib/global/qcompilerdetection.h
@@ -91,7 +91,6 @@
 #  define Q_OUTOFLINE_TEMPLATE inline
 #  define Q_COMPILER_MANGLES_RETURN_TYPE
 #  define Q_FUNC_INFO __FUNCSIG__
-#  define Q_DECL_ALIGN(n) __declspec(align(n))
 #  define Q_ASSUME_IMPL(expr) __assume(expr)
 #  define Q_UNREACHABLE_IMPL() __assume(0)
 #  define Q_NORETURN __declspec(noreturn)
@@ -223,7 +222,6 @@
 #  define Q_FUNC_INFO       __PRETTY_FUNCTION__
 #  define Q_TYPEOF(expr)    __typeof__(expr)
 #  define Q_DECL_DEPRECATED __attribute__ ((__deprecated__))
-#  define Q_DECL_ALIGN(n)   __attribute__((__aligned__(n)))
 #  define Q_DECL_UNUSED     __attribute__((__unused__))
 #  define Q_LIKELY(expr)    __builtin_expect(!!(expr), true)
 #  define Q_UNLIKELY(expr)  __builtin_expect(!!(expr), false)
@@ -271,7 +269,6 @@
 #    error "Compiler not supported"
 #  elif __xlC__ >= 0x0600
 #    define Q_TYPEOF(expr)      __typeof__(expr)
-#    define Q_DECL_ALIGN(n)     __attribute__((__aligned__(n)))
 #    define Q_PACKED            __attribute__((__packed__))
 #  endif
 
@@ -447,7 +444,6 @@
    /* see http://developers.sun.com/sunstudio/support/Ccompare.html */
 #    if __SUNPRO_CC >= 0x590
 #      define Q_TYPEOF(expr)    __typeof__(expr)
-#      define Q_DECL_ALIGN(n)   __attribute__((__aligned__(n)))
 #    endif
 #    if __SUNPRO_CC >= 0x550
 #      define Q_DECL_EXPORT     __global
@@ -484,9 +480,6 @@
 #      define Q_DECL_EXPORT     __declspec(dllexport)
 #      define Q_DECL_IMPORT     __declspec(dllimport)
 #    endif
-#    if __HP_aCC-0 >= 061200
-#      define Q_DECL_ALIGN(n) __attribute__((aligned(n)))
-#    endif
 #    if __HP_aCC-0 >= 062000
 #      define Q_DECL_EXPORT     __attribute__((visibility("default")))
 #      define Q_DECL_HIDDEN     __attribute__((visibility("hidden")))
@@ -1127,9 +1120,8 @@
 # define Q_ALIGNOF(x)  alignof(x)
 #endif
 
-#if defined(Q_COMPILER_ALIGNAS)
-#  undef Q_DECL_ALIGN
-#  define Q_DECL_ALIGN(n)   alignas(n)
+#ifndef Q_DECL_ALIGN
+# define Q_DECL_ALIGN(n)   alignas(n)
 #endif
 
 #if QT_HAS_CPP_ATTRIBUTE(nodiscard) && !defined(Q_CC_CLANG)         // P0188R1
diff --git a/src/corelib/global/qendian.cpp b/src/corelib/global/qendian.cpp
index 7fd6e13d3b..c56a7ffbf7 100644
--- a/src/corelib/global/qendian.cpp
+++ b/src/corelib/global/qendian.cpp
@@ -765,7 +765,7 @@ QT_BEGIN_NAMESPACE
 
 #if defined(__SSSE3__)
 using ShuffleMask = uchar[16];
-Q_DECL_ALIGN(16) static const ShuffleMask shuffleMasks[3] = {
+alignas(16) static const ShuffleMask shuffleMasks[3] = {
     // 16-bit
     {1, 0, 3, 2,  5, 4, 7, 6,  9, 8, 11, 10,  13, 12, 15, 14},
     // 32-bit
diff --git a/src/corelib/global/qrandom.cpp b/src/corelib/global/qrandom.cpp
index 3cbd40b772..563e5eb7ed 100644
--- a/src/corelib/global/qrandom.cpp
+++ b/src/corelib/global/qrandom.cpp
@@ -355,7 +355,7 @@ struct QRandomGenerator::SystemAndGlobalGenerators
     //    the state in case another thread tries to lock the mutex. It's not
     //    a common scenario, but since sizeof(QRandomGenerator) >= 2560, the
     //    overhead is actually acceptable.
-    // 2) We use both Q_DECL_ALIGN and std::aligned_storage<..., 64> because
+    // 2) We use both alignas and std::aligned_storage<..., 64> because
     //    some implementations of std::aligned_storage can't align to more
     //    than a primitive type's alignment.
     // 3) We don't store the entire system QRandomGenerator, only the space
@@ -364,7 +364,7 @@ struct QRandomGenerator::SystemAndGlobalGenerators
     QBasicMutex globalPRNGMutex;
     struct ShortenedSystem { uint type; } system_;
     SystemGenerator sys;
-    Q_DECL_ALIGN(64) std::aligned_storage<sizeof(QRandomGenerator64), 64>::type global_;
+    alignas(64) std::aligned_storage<sizeof(QRandomGenerator64), 64>::type global_;
 
 #ifdef Q_COMPILER_CONSTEXPR
     constexpr SystemAndGlobalGenerators()
diff --git a/src/corelib/text/qbytearraymatcher.h b/src/corelib/text/qbytearraymatcher.h
index 0eedfc1d20..7cc5037095 100644
--- a/src/corelib/text/qbytearraymatcher.h
+++ b/src/corelib/text/qbytearraymatcher.h
@@ -85,7 +85,7 @@ private:
 
 class QStaticByteArrayMatcherBase
 {
-    Q_DECL_ALIGN(16)
+    alignas(16)
     struct Skiptable {
         uchar data[256];
     } m_skiptable;