From fb7a94c9594d0891d30594edaf9fdc04736aee50 Mon Sep 17 00:00:00 2001
From: asynts <asynts@gmail.com>
Date: Wed, 30 Sep 2020 14:38:47 +0200
Subject: [PATCH] AK: Add formatter for pointer types.

---
 AK/Format.cpp           | 18 +++++++++++++++++-
 AK/Format.h             |  9 +++++++++
 AK/Tests/TestFormat.cpp | 15 +++++++++++++++
 3 files changed, 41 insertions(+), 1 deletion(-)

diff --git a/AK/Format.cpp b/AK/Format.cpp
index d31a3c7790..e9211cc570 100644
--- a/AK/Format.cpp
+++ b/AK/Format.cpp
@@ -367,6 +367,22 @@ void Formatter<T, typename EnableIf<IsIntegral<T>::value>::Type>::format(StringB
     if (m_precision != value_not_set)
         ASSERT_NOT_REACHED();
 
+    if (m_mode == Mode::Pointer) {
+        if (m_sign != Sign::Default)
+            ASSERT_NOT_REACHED();
+        if (m_align != Align::Default)
+            ASSERT_NOT_REACHED();
+        if (m_alternative_form)
+            ASSERT_NOT_REACHED();
+        if (m_width != value_not_set)
+            ASSERT_NOT_REACHED();
+
+        m_mode = Mode::Hexadecimal;
+        m_alternative_form = true;
+        m_width = 2 * sizeof(void*) + 2;
+        m_zero_pad = true;
+    }
+
     u8 base = 0;
     bool upper_case = false;
     if (m_mode == Mode::Binary) {
@@ -389,7 +405,7 @@ void Formatter<T, typename EnableIf<IsIntegral<T>::value>::Type>::format(StringB
         ASSERT_NOT_REACHED();
     }
 
-    auto width = decode_value(m_width, context);
+    const auto width = decode_value(m_width, context);
 
     const auto put_padding = [&](size_t amount, char fill) {
         for (size_t i = 0; i < amount; ++i)
diff --git a/AK/Format.h b/AK/Format.h
index 5389565865..cf20ae942c 100644
--- a/AK/Format.h
+++ b/AK/Format.h
@@ -198,6 +198,15 @@ struct Formatter<T, typename EnableIf<IsIntegral<T>::value>::Type> : StandardFor
     void format(StringBuilder&, T value, FormatterContext&);
 };
 
+template<typename T>
+struct Formatter<T*> : StandardFormatter {
+    void format(StringBuilder& builder, T* value, FormatterContext& context)
+    {
+        Formatter<FlatPtr> formatter { *this };
+        formatter.format(builder, reinterpret_cast<FlatPtr>(value), context);
+    }
+};
+
 template<>
 struct Formatter<bool> : StandardFormatter {
     void format(StringBuilder&, bool value, FormatterContext&);
diff --git a/AK/Tests/TestFormat.cpp b/AK/Tests/TestFormat.cpp
index fe8c6032e0..2441303e6d 100644
--- a/AK/Tests/TestFormat.cpp
+++ b/AK/Tests/TestFormat.cpp
@@ -147,4 +147,19 @@ TEST_CASE(boolean_values)
     EXPECT_EQ(String::formatted("{:#08x}", true), "0x000001");
 }
 
+TEST_CASE(pointers)
+{
+    void* ptr = reinterpret_cast<void*>(0x4000);
+
+    if (sizeof(void*) == 4) {
+        EXPECT_EQ(String::formatted("{:p}", 32), "0x00000020");
+        EXPECT_EQ(String::formatted("{:p}", ptr), "0x00004000");
+    } else if (sizeof(void*) == 8) {
+        EXPECT_EQ(String::formatted("{:p}", 32), "0x0000000000000020");
+        EXPECT_EQ(String::formatted("{:p}", ptr), "0x0000000000004000");
+    } else {
+        ASSERT_NOT_REACHED();
+    }
+}
+
 TEST_MAIN(Format)