all: cosmetic cleanups

src/util/cxxlib.h

@@ -1,4 +1,4 @@
-/* cxxlib.h --
+/* cxxlib.h -- C++ support library
 
    This file is part of the UPX executable compressor.
 
@@ -35,7 +35,7 @@ namespace upx {
 // type_traits
 **************************************************************************/
 
-// <type_traits> is_bounded_array: same as C++20 std::is_bounded_array
+// is_bounded_array: identical to C++20 std::is_bounded_array
 template <class T>
 struct is_bounded_array : public std::false_type {};
 template <class T, size_t N>
@@ -43,7 +43,7 @@ struct is_bounded_array<T[N]> : public std::true_type {};
 template <class T>
 inline constexpr bool is_bounded_array_v = is_bounded_array<T>::value;
 
-// <type_traits> util: is_same_all and is_same_any means std::is_same for multiple types
+// is_same_all and is_same_any: std::is_same for multiple types
 template <class T, class... Ts>
 struct is_same_all : public std::conjunction<std::is_same<T, Ts>...> {};
 template <class T, class... Ts>
@@ -125,7 +125,7 @@ struct TriBool final {
         return value == TriBool(other).value;
     }
 
-    // "Third" can mean many things, depending on usage context, so provide some alternative names:
+    // "Third" can mean many things - depending on usage context, so provide some alternate names:
     // constexpr bool isDefault() const noexcept { return isThird(); } // might be misleading
     constexpr bool isIndeterminate() const noexcept { return isThird(); }
     constexpr bool isOther() const noexcept { return isThird(); }

src/util/util.cpp

@@ -388,7 +388,7 @@ void upx_std_stable_sort(void *array, size_t n, upx_compare_func_t compare) {
 #endif
 }
 
-#if UPX_QSORT_IS_STABLE_SORT
+#if UPX_CONFIG_USE_STABLE_SORT
 // instantiate function templates for all element sizes we need
 // efficient, but code size bloat
 template void upx_std_stable_sort<1>(void *, size_t, upx_compare_func_t);

src/util/util.h

@@ -138,13 +138,13 @@ void upx_shellsort_memcpy(void *array, size_t n, size_t element_size, upx_compar
 template <size_t ElementSize>
 void upx_std_stable_sort(void *array, size_t n, upx_compare_func_t compare);
 
-#if 1
+// #define UPX_CONFIG_USE_STABLE_SORT 1
+#if UPX_CONFIG_USE_STABLE_SORT
+// use std::stable_sort(); requires that "element_size" is constexpr!
+#define upx_qsort(a, n, element_size, compare) upx_std_stable_sort<(element_size)>(a, n, compare)
+#else
 // use libc qsort()
 #define upx_qsort qsort
-#else
-// use std::stable_sort()
-#define upx_qsort(a, b, c, d)    upx_std_stable_sort<(c)>(a, b, d)
-#define UPX_QSORT_IS_STABLE_SORT 1
 #endif
 
 /*************************************************************************

src/util/xspan.h

@@ -51,7 +51,7 @@
 #include "xspan_impl.h"
 
 #ifdef XSPAN_NAMESPACE_NAME
-// help constructor to distinguish between number of elements and bytes
+// types to help the constructor to distinguish between number of elements and bytes
 using XSPAN_NAMESPACE_NAME::XSpanCount;
 using XSPAN_NAMESPACE_NAME::XSpanSizeInBytes;
 // actual classes
@@ -59,7 +59,7 @@ using XSPAN_NAMESPACE_NAME::Ptr;
 using XSPAN_NAMESPACE_NAME::PtrOrSpan;
 using XSPAN_NAMESPACE_NAME::PtrOrSpanOrNull;
 using XSPAN_NAMESPACE_NAME::Span;
-// util
+// support functions
 using XSPAN_NAMESPACE_NAME::raw_bytes;       // overloaded for all classes
 using XSPAN_NAMESPACE_NAME::raw_index_bytes; // overloaded for all classes
 #endif

src/util/xspan_impl.h

@@ -204,8 +204,6 @@ struct XSpanInternalDummyArg {
 #define XSpanInternalDummyArgInit (XSPAN_NS(XSpanInternalDummyArg)(0, nullptr))
 #endif
 
-XSPAN_NAMESPACE_END
-
 // poison a pointer: point to a non-null invalid address
 // - resulting pointer should crash on dereference
 // - this should be efficient (so no mmap() guard page etc.)
@@ -216,6 +214,8 @@ static forceinline void *XSPAN_GET_POISON_VOID_PTR() {
     return (void *) 251;
 }
 
+XSPAN_NAMESPACE_END
+
 #ifndef XSPAN_DELETED_FUNCTION
 #define XSPAN_DELETED_FUNCTION = delete
 #endif

src/util/xspan_impl_common.h

@@ -443,7 +443,7 @@ public: // raw access
         return ptr;
     }
 
-    // like C++ std::span
+    // like C++20 std::span
     pointer data() const noexcept { return ptr; }
     pointer data(size_t bytes) const { return raw_bytes(bytes); } // UPX extra
     // size_type size() const { return size_bytes() / sizeof(element_type); } // NOT USED