From 94bc48dd783989a178ae8cb5956f50d990878a92 Mon Sep 17 00:00:00 2001
From: Weiyi Wang <wwylele@gmail.com>
Date: Fri, 21 Sep 2018 19:53:14 -0400
Subject: common/swap: add swap template for enum

---
 src/common/swap.h | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 52 insertions(+)

(limited to 'src/common')

diff --git a/src/common/swap.h b/src/common/swap.h
index 32af0b6ac..466096f58 100644
--- a/src/common/swap.h
+++ b/src/common/swap.h
@@ -17,6 +17,8 @@
 
 #pragma once
 
+#include <type_traits>
+
 #if defined(_MSC_VER)
 #include <cstdlib>
 #elif defined(__linux__)
@@ -605,6 +607,44 @@ struct swap_double_t {
     }
 };
 
+template <typename T>
+struct swap_enum_t {
+    static_assert(std::is_enum_v<T>);
+    using base = std::underlying_type_t<T>;
+
+public:
+    swap_enum_t() = default;
+    swap_enum_t(const T& v) : value(swap(v)) {}
+
+    swap_enum_t& operator=(const T& v) {
+        value = swap(v);
+        return *this;
+    }
+
+    operator T() const {
+        return swap(value);
+    }
+
+    explicit operator base() const {
+        return static_cast<base>(swap(value));
+    }
+
+protected:
+    T value{};
+    // clang-format off
+    using swap_t = std::conditional_t<
+        std::is_same_v<base, u16>, swap_16_t<u16>, std::conditional_t<
+        std::is_same_v<base, s16>, swap_16_t<s16>, std::conditional_t<
+        std::is_same_v<base, u32>, swap_32_t<u32>, std::conditional_t<
+        std::is_same_v<base, s32>, swap_32_t<s32>, std::conditional_t<
+        std::is_same_v<base, u64>, swap_64_t<u64>, std::conditional_t<
+        std::is_same_v<base, s64>, swap_64_t<s64>, void>>>>>>;
+    // clang-format on
+    static T swap(T x) {
+        return static_cast<T>(swap_t::swap(static_cast<base>(x)));
+    }
+};
+
 #if COMMON_LITTLE_ENDIAN
 using u16_le = u16;
 using u32_le = u32;
@@ -614,6 +654,9 @@ using s16_le = s16;
 using s32_le = s32;
 using s64_le = s64;
 
+template <typename T>
+using enum_le = std::enable_if_t<std::is_enum_v<T>, T>;
+
 using float_le = float;
 using double_le = double;
 
@@ -626,6 +669,9 @@ using s32_be = swap_struct_t<s32, swap_32_t<s32>>;
 using u16_be = swap_struct_t<u16, swap_16_t<u16>>;
 using s16_be = swap_struct_t<s16, swap_16_t<s16>>;
 
+template <typename T>
+using enum_be = swap_enum_t<T>;
+
 using float_be = swap_struct_t<float, swap_float_t<float>>;
 using double_be = swap_struct_t<double, swap_double_t<double>>;
 #else
@@ -639,6 +685,9 @@ using s32_le = swap_struct_t<s32, swap_32_t<s32>>;
 using u16_le = swap_struct_t<u16, swap_16_t<u16>>;
 using s16_le = swap_struct_t<s16, swap_16_t<s16>>;
 
+template <typename T>
+using enum_le = swap_enum_t<T>;
+
 using float_le = swap_struct_t<float, swap_float_t<float>>;
 using double_le = swap_struct_t<double, swap_double_t<double>>;
 
@@ -650,6 +699,9 @@ using s16_be = s16;
 using s32_be = s32;
 using s64_be = s64;
 
+template <typename T>
+using enum_be = std::enable_if_t<std::is_enum_v<T>, T>;
+
 using float_be = float;
 using double_be = double;
 
-- 
cgit v1.2.3


From 6734c6497653b93d8313ecc30e4eae5348dca2c0 Mon Sep 17 00:00:00 2001
From: Weiyi Wang <wwylele@gmail.com>
Date: Fri, 25 Jan 2019 12:09:12 -0500
Subject: common/swap: use template and tag for LE/BE specification

The tag can be useful for other type-generic templates like BitFields to forward the endianness specification
---
 src/common/swap.h | 130 ++++++++++++++++++++++++++++++++++++++----------------
 1 file changed, 91 insertions(+), 39 deletions(-)

(limited to 'src/common')

diff --git a/src/common/swap.h b/src/common/swap.h
index 466096f58..97aacb4dc 100644
--- a/src/common/swap.h
+++ b/src/common/swap.h
@@ -645,64 +645,116 @@ protected:
     }
 };
 
-#if COMMON_LITTLE_ENDIAN
-using u16_le = u16;
-using u32_le = u32;
-using u64_le = u64;
+struct SwapTag {}; // Use the different endianness from the system
+struct KeepTag {}; // Use the same endianness as the system
+
+template <typename T, typename Tag>
+struct AddEndian;
 
-using s16_le = s16;
-using s32_le = s32;
-using s64_le = s64;
+// KeepTag specializations
 
 template <typename T>
-using enum_le = std::enable_if_t<std::is_enum_v<T>, T>;
+struct AddEndian<T, KeepTag> {
+    using type = T;
+};
+
+// SwapTag specializations
 
-using float_le = float;
-using double_le = double;
+template <>
+struct AddEndian<u8, SwapTag> {
+    using type = u8;
+};
 
-using u64_be = swap_struct_t<u64, swap_64_t<u64>>;
-using s64_be = swap_struct_t<s64, swap_64_t<s64>>;
+template <>
+struct AddEndian<u16, SwapTag> {
+    using type = swap_struct_t<u16, swap_16_t<u16>>;
+};
 
-using u32_be = swap_struct_t<u32, swap_32_t<u32>>;
-using s32_be = swap_struct_t<s32, swap_32_t<s32>>;
+template <>
+struct AddEndian<u32, SwapTag> {
+    using type = swap_struct_t<u32, swap_32_t<u32>>;
+};
 
-using u16_be = swap_struct_t<u16, swap_16_t<u16>>;
-using s16_be = swap_struct_t<s16, swap_16_t<s16>>;
+template <>
+struct AddEndian<u64, SwapTag> {
+    using type = swap_struct_t<u64, swap_64_t<u64>>;
+};
+
+template <>
+struct AddEndian<s8, SwapTag> {
+    using type = s8;
+};
+
+template <>
+struct AddEndian<s16, SwapTag> {
+    using type = swap_struct_t<s16, swap_16_t<s16>>;
+};
+
+template <>
+struct AddEndian<s32, SwapTag> {
+    using type = swap_struct_t<s32, swap_32_t<s32>>;
+};
+
+template <>
+struct AddEndian<s64, SwapTag> {
+    using type = swap_struct_t<s64, swap_64_t<s64>>;
+};
+
+template <>
+struct AddEndian<float, SwapTag> {
+    using type = swap_struct_t<float, swap_float_t<float>>;
+};
+
+template <>
+struct AddEndian<double, SwapTag> {
+    using type = swap_struct_t<double, swap_double_t<double>>;
+};
 
 template <typename T>
-using enum_be = swap_enum_t<T>;
+struct AddEndian<T, SwapTag> {
+    static_assert(std::is_enum_v<T>);
+    using type = swap_enum_t<T>;
+};
+
+// Alias LETag/BETag as KeepTag/SwapTag depending on the system
+#if COMMON_LITTLE_ENDIAN
+
+using LETag = KeepTag;
+using BETag = SwapTag;
 
-using float_be = swap_struct_t<float, swap_float_t<float>>;
-using double_be = swap_struct_t<double, swap_double_t<double>>;
 #else
 
-using u64_le = swap_struct_t<u64, swap_64_t<u64>>;
-using s64_le = swap_struct_t<s64, swap_64_t<s64>>;
+using BETag = KeepTag;
+using LETag = SwapTag;
 
-using u32_le = swap_struct_t<u32, swap_32_t<u32>>;
-using s32_le = swap_struct_t<s32, swap_32_t<s32>>;
+#endif
 
-using u16_le = swap_struct_t<u16, swap_16_t<u16>>;
-using s16_le = swap_struct_t<s16, swap_16_t<s16>>;
+// Aliases for LE types
+using u16_le = AddEndian<u16, LETag>::type;
+using u32_le = AddEndian<u32, LETag>::type;
+using u64_le = AddEndian<u64, LETag>::type;
+
+using s16_le = AddEndian<s16, LETag>::type;
+using s32_le = AddEndian<s32, LETag>::type;
+using s64_le = AddEndian<s64, LETag>::type;
 
 template <typename T>
-using enum_le = swap_enum_t<T>;
+using enum_le = std::enable_if_t<std::is_enum_v<T>, typename AddEndian<T, LETag>::type>;
 
-using float_le = swap_struct_t<float, swap_float_t<float>>;
-using double_le = swap_struct_t<double, swap_double_t<double>>;
+using float_le = AddEndian<float, LETag>::type;
+using double_le = AddEndian<double, LETag>::type;
 
-using u16_be = u16;
-using u32_be = u32;
-using u64_be = u64;
+// Aliases for BE types
+using u16_be = AddEndian<u16, BETag>::type;
+using u32_be = AddEndian<u32, BETag>::type;
+using u64_be = AddEndian<u64, BETag>::type;
 
-using s16_be = s16;
-using s32_be = s32;
-using s64_be = s64;
+using s16_be = AddEndian<s16, BETag>::type;
+using s32_be = AddEndian<s32, BETag>::type;
+using s64_be = AddEndian<s64, BETag>::type;
 
 template <typename T>
-using enum_be = std::enable_if_t<std::is_enum_v<T>, T>;
-
-using float_be = float;
-using double_be = double;
+using enum_be = std::enable_if_t<std::is_enum_v<T>, typename AddEndian<T, BETag>::type>;
 
-#endif
+using float_be = AddEndian<float, BETag>::type;
+using double_be = AddEndian<double, BETag>::type;
-- 
cgit v1.2.3


From 71530781f33423fc48c9bf43702f1291a38a259d Mon Sep 17 00:00:00 2001
From: Weiyi Wang <wwylele@gmail.com>
Date: Fri, 25 Jan 2019 12:16:00 -0500
Subject: common/swap: remove default value for swap type internal storage

This is compromise for swap type being used in union. A union has deleted default constructor if it has at least one variant member with non-trivial default constructor, and no variant member of T has a default member initializer. In the use case of Bitfield, all variant members will be the swap type on endianness mismatch, which would all have non-trivial default constructor if default value is specified, and non of them can have member initializer
---
 src/common/swap.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'src/common')

diff --git a/src/common/swap.h b/src/common/swap.h
index 97aacb4dc..4b82865fe 100644
--- a/src/common/swap.h
+++ b/src/common/swap.h
@@ -172,7 +172,7 @@ struct swap_struct_t {
     using swapped_t = swap_struct_t;
 
 protected:
-    T value = T();
+    T value;
 
     static T swap(T v) {
         return F::swap(v);
-- 
cgit v1.2.3


From 6b81ceb060a0e985380bc33d2f51dcc76aad3eb3 Mon Sep 17 00:00:00 2001
From: Weiyi Wang <wwylele@gmail.com>
Date: Fri, 25 Jan 2019 12:16:23 -0500
Subject: common/bitfield: make it endianness-aware

---
 src/common/bit_field.h         | 12 ++++--
 src/tests/CMakeLists.txt       |  1 +
 src/tests/common/bit_field.cpp | 90 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 100 insertions(+), 3 deletions(-)
 create mode 100644 src/tests/common/bit_field.cpp

(limited to 'src/common')

diff --git a/src/common/bit_field.h b/src/common/bit_field.h
index 21e07925d..bd9e21e1e 100644
--- a/src/common/bit_field.h
+++ b/src/common/bit_field.h
@@ -34,6 +34,7 @@
 #include <limits>
 #include <type_traits>
 #include "common/common_funcs.h"
+#include "common/swap.h"
 
 /*
  * Abstract bitfield class
@@ -108,7 +109,7 @@
  * symptoms.
  */
 #pragma pack(1)
-template <std::size_t Position, std::size_t Bits, typename T>
+template <std::size_t Position, std::size_t Bits, typename T, typename EndianTag = LETag>
 struct BitField {
 private:
     // We hide the copy assigment operator here, because the default copy
@@ -127,6 +128,8 @@ private:
     // We store the value as the unsigned type to avoid undefined behaviour on value shifting
     using StorageType = std::make_unsigned_t<UnderlyingType>;
 
+    using StorageTypeWithEndian = typename AddEndian<StorageType, EndianTag>::type;
+
 public:
     /// Constants to allow limited introspection of fields if needed
     static constexpr std::size_t position = Position;
@@ -172,7 +175,7 @@ public:
     }
 
     constexpr FORCE_INLINE void Assign(const T& value) {
-        storage = (storage & ~mask) | FormatValue(value);
+        storage = (static_cast<StorageType>(storage) & ~mask) | FormatValue(value);
     }
 
     constexpr T Value() const {
@@ -184,7 +187,7 @@ public:
     }
 
 private:
-    StorageType storage;
+    StorageTypeWithEndian storage;
 
     static_assert(bits + position <= 8 * sizeof(T), "Bitfield out of range");
 
@@ -195,3 +198,6 @@ private:
     static_assert(std::is_trivially_copyable_v<T>, "T must be trivially copyable in a BitField");
 };
 #pragma pack()
+
+template <std::size_t Position, std::size_t Bits, typename T>
+using BitFieldBE = BitField<Position, Bits, T, BETag>;
diff --git a/src/tests/CMakeLists.txt b/src/tests/CMakeLists.txt
index 37f09ce5f..d0284bdf4 100644
--- a/src/tests/CMakeLists.txt
+++ b/src/tests/CMakeLists.txt
@@ -1,4 +1,5 @@
 add_executable(tests
+    common/bit_field.cpp
     common/param_package.cpp
     common/ring_buffer.cpp
     core/arm/arm_test_common.cpp
diff --git a/src/tests/common/bit_field.cpp b/src/tests/common/bit_field.cpp
new file mode 100644
index 000000000..8ca1889f9
--- /dev/null
+++ b/src/tests/common/bit_field.cpp
@@ -0,0 +1,90 @@
+// Copyright 2019 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <array>
+#include <cstring>
+#include <type_traits>
+#include <catch2/catch.hpp>
+#include "common/bit_field.h"
+
+TEST_CASE("BitField", "[common]") {
+    enum class TestEnum : u32 {
+        A = 0b10111101,
+        B = 0b10101110,
+        C = 0b00001111,
+    };
+
+    union LEBitField {
+        u32_le raw;
+        BitField<0, 6, u32> a;
+        BitField<6, 4, s32> b;
+        BitField<10, 8, TestEnum> c;
+        BitField<18, 14, u32> d;
+    } le_bitfield;
+
+    union BEBitField {
+        u32_be raw;
+        BitFieldBE<0, 6, u32> a;
+        BitFieldBE<6, 4, s32> b;
+        BitFieldBE<10, 8, TestEnum> c;
+        BitFieldBE<18, 14, u32> d;
+    } be_bitfield;
+
+    static_assert(sizeof(LEBitField) == sizeof(u32));
+    static_assert(sizeof(BEBitField) == sizeof(u32));
+    static_assert(std::is_trivially_copyable_v<LEBitField>);
+    static_assert(std::is_trivially_copyable_v<BEBitField>);
+
+    std::array<u8, 4> raw{{
+        0b01101100,
+        0b11110110,
+        0b10111010,
+        0b11101100,
+    }};
+
+    std::memcpy(&le_bitfield, &raw, sizeof(raw));
+    std::memcpy(&be_bitfield, &raw, sizeof(raw));
+
+    // bit fields: 11101100101110'10111101'1001'101100
+    REQUIRE(le_bitfield.raw == 0b11101100'10111010'11110110'01101100);
+    REQUIRE(le_bitfield.a == 0b101100);
+    REQUIRE(le_bitfield.b == -7); // 1001 as two's complement
+    REQUIRE(le_bitfield.c == TestEnum::A);
+    REQUIRE(le_bitfield.d == 0b11101100101110);
+
+    le_bitfield.a.Assign(0b000111);
+    le_bitfield.b.Assign(-1);
+    le_bitfield.c.Assign(TestEnum::C);
+    le_bitfield.d.Assign(0b01010101010101);
+    std::memcpy(&raw, &le_bitfield, sizeof(raw));
+    // bit fields: 01010101010101'00001111'1111'000111
+    REQUIRE(le_bitfield.raw == 0b01010101'01010100'00111111'11000111);
+    REQUIRE(raw == std::array<u8, 4>{{
+                       0b11000111,
+                       0b00111111,
+                       0b01010100,
+                       0b01010101,
+                   }});
+
+    // bit fields: 01101100111101'10101110'1011'101100
+    REQUIRE(be_bitfield.raw == 0b01101100'11110110'10111010'11101100);
+    REQUIRE(be_bitfield.a == 0b101100);
+    REQUIRE(be_bitfield.b == -5); // 1011 as two's complement
+    REQUIRE(be_bitfield.c == TestEnum::B);
+    REQUIRE(be_bitfield.d == 0b01101100111101);
+
+    be_bitfield.a.Assign(0b000111);
+    be_bitfield.b.Assign(-1);
+    be_bitfield.c.Assign(TestEnum::C);
+    be_bitfield.d.Assign(0b01010101010101);
+    std::memcpy(&raw, &be_bitfield, sizeof(raw));
+    // bit fields: 01010101010101'00001111'1111'000111
+    REQUIRE(be_bitfield.raw == 0b01010101'01010100'00111111'11000111);
+    REQUIRE(raw == std::array<u8, 4>{{
+                       0b01010101,
+                       0b01010100,
+                       0b00111111,
+                       0b11000111,
+                   }});
+}
-- 
cgit v1.2.3


From efd83570bdb70597b3e06eeb3bced5486ac85eab Mon Sep 17 00:00:00 2001
From: fearlessTobi <thm.frey@gmail.com>
Date: Wed, 5 Sep 2018 02:24:44 +0200
Subject: Make bitfield assignment operator public

This change needs to be made to get the code compiling again. It was suggested after a conversation with Lioncash.

The conversation can be seen here: https://user-images.githubusercontent.com/20753089/45064197-b6107800-b0b2-11e8-9db8-f696299fb86a.PNG
---
 src/common/bit_field.h | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

(limited to 'src/common')

diff --git a/src/common/bit_field.h b/src/common/bit_field.h
index bd9e21e1e..639efe22d 100644
--- a/src/common/bit_field.h
+++ b/src/common/bit_field.h
@@ -112,12 +112,6 @@
 template <std::size_t Position, std::size_t Bits, typename T, typename EndianTag = LETag>
 struct BitField {
 private:
-    // We hide the copy assigment operator here, because the default copy
-    // assignment would copy the full storage value, rather than just the bits
-    // relevant to this particular bit field.
-    // We don't delete it because we want BitField to be trivially copyable.
-    constexpr BitField& operator=(const BitField&) = default;
-
     // UnderlyingType is T for non-enum types and the underlying type of T if
     // T is an enumeration. Note that T is wrapped within an enable_if in the
     // former case to workaround compile errors which arise when using
@@ -131,6 +125,8 @@ private:
     using StorageTypeWithEndian = typename AddEndian<StorageType, EndianTag>::type;
 
 public:
+    BitField& operator=(const BitField&) = default;
+
     /// Constants to allow limited introspection of fields if needed
     static constexpr std::size_t position = Position;
     static constexpr std::size_t bits = Bits;
-- 
cgit v1.2.3