AK: Resolve clang-tidy readability-bool-conversion warnings

... In files included by Kernel/Process.cpp and Kernel/Thread.cpp

AK/Bitmap.h

@@ -91,7 +91,7 @@ public:
 
         if (previous_data != nullptr) {
             __builtin_memcpy(m_data, previous_data, previous_size_bytes);
-            if (previous_size % 8)
+            if ((previous_size % 8) != 0)
                 set_range(previous_size, 8 - previous_size % 8, default_value);
             kfree_sized(previous_data, previous_size_bytes);
         }

AK/BitmapView.h

@@ -86,7 +86,7 @@ public:
         return count;
     }
 
-    [[nodiscard]] bool is_null() const { return !m_data; }
+    [[nodiscard]] bool is_null() const { return m_data == nullptr; }
 
     [[nodiscard]] const u8* data() const { return m_data; }
 
@@ -279,7 +279,7 @@ public:
             size_t trailing_bits = size() % 32;
             for (size_t i = 0; i < trailing_bits; ++i) {
                 if (!get(first_trailing_bit + i)) {
-                    if (!free_chunks)
+                    if (free_chunks == 0)
                         *start_of_free_chunks = first_trailing_bit + i;
                     if (++free_chunks >= min_length)
                         return min(free_chunks, max_length);
@@ -313,7 +313,7 @@ public:
         }
 
         found_range_size = max_region_size;
-        if (max_region_size) {
+        if (max_region_size != 0) {
             return max_region_start;
         }
         return {};

AK/ByteBuffer.h

@@ -118,7 +118,7 @@ public:
         return data()[i];
     }
 
-    [[nodiscard]] bool is_empty() const { return !m_size; }
+    [[nodiscard]] bool is_empty() const { return m_size == 0; }
     [[nodiscard]] size_t size() const { return m_size; }
 
     [[nodiscard]] u8* data() { return m_inline ? m_inline_buffer : m_outline_buffer; }

AK/CircularQueue.h

@@ -33,7 +33,7 @@ public:
         m_size = 0;
     }
 
-    bool is_empty() const { return !m_size; }
+    bool is_empty() const { return m_size == 0; }
     size_t size() const { return m_size; }
 
     size_t capacity() const { return Capacity; }

AK/HashTable.h

@@ -181,7 +181,7 @@ public:
             swap(a.m_collection_data, b.m_collection_data);
     }
 
-    [[nodiscard]] bool is_empty() const { return !m_size; }
+    [[nodiscard]] bool is_empty() const { return m_size == 0; }
     [[nodiscard]] size_t size() const { return m_size; }
     [[nodiscard]] size_t capacity() const { return m_capacity; }
 

AK/StringImpl.h

@@ -60,7 +60,7 @@ public:
     {
         if (length() != other.length())
             return false;
-        return !__builtin_memcmp(characters(), other.characters(), length());
+        return __builtin_memcmp(characters(), other.characters(), length()) == 0;
     }
 
     unsigned hash() const

AK/StringView.h

@@ -52,7 +52,7 @@ public:
     explicit StringView(String&&) = delete;
     explicit StringView(FlyString&&) = delete;
 
-    [[nodiscard]] constexpr bool is_null() const { return !m_characters; }
+    [[nodiscard]] constexpr bool is_null() const { return m_characters == nullptr; }
     [[nodiscard]] constexpr bool is_empty() const { return m_length == 0; }
 
     [[nodiscard]] constexpr char const* characters_without_null_termination() const { return m_characters; }
@@ -151,18 +151,18 @@ public:
     constexpr bool operator==(const char* cstring) const
     {
         if (is_null())
-            return !cstring;
+            return cstring == nullptr;
         if (!cstring)
             return false;
         // NOTE: `m_characters` is not guaranteed to be null-terminated, but `cstring` is.
         const char* cp = cstring;
         for (size_t i = 0; i < m_length; ++i) {
-            if (!*cp)
+            if (*cp == '\0')
                 return false;
             if (m_characters[i] != *(cp++))
                 return false;
         }
-        return !*cp;
+        return *cp == '\0';
     }
 
     constexpr bool operator!=(const char* cstring) const
@@ -180,7 +180,7 @@ public:
             return false;
         if (length() != other.length())
             return false;
-        return !__builtin_memcmp(m_characters, other.m_characters, m_length);
+        return __builtin_memcmp(m_characters, other.m_characters, m_length) == 0;
     }
 
     constexpr bool operator!=(StringView other) const

AK/Time.h

@@ -50,7 +50,7 @@ inline bool is_leap_year(int year)
 
 inline int days_in_year(int year)
 {
-    return 365 + is_leap_year(year);
+    return 365 + (is_leap_year(year) ? 1 : 0);
 }
 
 inline int years_to_days_since_epoch(int year)
@@ -163,7 +163,7 @@ public:
     // Rounds towards -inf (it was the easiest to implement).
     [[nodiscard]] timeval to_timeval() const;
 
-    [[nodiscard]] bool is_zero() const { return !m_seconds && !m_nanoseconds; }
+    [[nodiscard]] bool is_zero() const { return (m_seconds == 0) && (m_nanoseconds == 0); }
     [[nodiscard]] bool is_negative() const { return m_seconds < 0; }
 
     bool operator==(const Time& other) const { return this->m_seconds == other.m_seconds && this->m_nanoseconds == other.m_nanoseconds; }

AK/TypedTransfer.h

@@ -15,7 +15,7 @@ class TypedTransfer {
 public:
     static void move(T* destination, T* source, size_t count)
     {
-        if (!count)
+        if (count == 0)
             return;
 
         if constexpr (Traits<T>::is_trivial()) {
@@ -29,13 +29,11 @@ public:
             else
                 new (&destination[count - i - 1]) T(std::move(source[count - i - 1]));
         }
-
-        return;
     }
 
     static size_t copy(T* destination, const T* source, size_t count)
     {
-        if (!count)
+        if (count == 0)
             return 0;
 
         if constexpr (Traits<T>::is_trivial()) {
@@ -55,7 +53,7 @@ public:
 
     static bool compare(const T* a, const T* b, size_t count)
     {
-        if (!count)
+        if (count == 0)
             return true;
 
         if constexpr (Traits<T>::is_trivial())

AK/Userspace.h

@@ -20,7 +20,6 @@ class Userspace {
 public:
     Userspace() = default;
 
-    operator bool() const { return m_ptr; }
     operator FlatPtr() const { return (FlatPtr)m_ptr; }
 
     // Disable default implementations that would use surprising integer promotion.
@@ -36,6 +35,8 @@ public:
     {
     }
 
+    explicit operator bool() const { return m_ptr != 0; }
+
     FlatPtr ptr() const { return m_ptr; }
     T unsafe_userspace_ptr() const { return (T)m_ptr; }
 #else
@@ -44,6 +45,8 @@ public:
     {
     }
 
+    explicit operator bool() const { return m_ptr != nullptr; }
+
     T ptr() const { return m_ptr; }
 #endif
 

AK/Vector.h

@@ -520,7 +520,7 @@ public:
 
     ErrorOr<void> try_append(StorageType const* values, size_t count)
     {
-        if (!count)
+        if (count == 0)
             return {};
         TRY(try_grow_capacity(size() + count));
         TypedTransfer<StorageType>::copy(slot(m_size), values, count);
@@ -569,7 +569,7 @@ public:
 
     ErrorOr<void> try_prepend(StorageType const* values, size_t count)
     {
-        if (!count)
+        if (count == 0)
             return {};
         TRY(try_grow_capacity(size() + count));
         TypedTransfer<StorageType>::move(slot(count), slot(0), m_size);
@@ -645,7 +645,7 @@ public:
         if (new_size == size())
             return;
 
-        if (!new_size) {
+        if (new_size == 0) {
             if (keep_capacity)
                 clear_with_capacity();
             else

AK/Weakable.h

@@ -66,7 +66,7 @@ public:
 
     bool is_null() const
     {
-        return !unsafe_ptr<void>();
+        return unsafe_ptr<void>() == nullptr;
     }
 
     void revoke()