Sane handling of %x and %X for pointers in Format

3 files changed, 38 insertions, 5 deletions

diff --git a/library/cpp/yt/string/format-inl.h b/library/cpp/yt/string/format-inl.h
index c437d7ab34..a6a15485eb 100644
--- a/library/cpp/yt/string/format-inl.h
+++ b/library/cpp/yt/string/format-inl.h
@@ -462,6 +462,11 @@ void FormatIntValue(
     TStringBuf format,
     TStringBuf genericSpec);
 
+void FormatPointerValue(
+    TStringBuilderBase* builder,
+    const void* value,
+    TStringBuf format);
+
 } // namespace NDetail
 
 #define XX(valueType, castType, genericSpec) \
@@ -501,7 +506,7 @@ XX(float,               float,    TStringBuf("f"))
 template <class T>
 void FormatValue(TStringBuilderBase* builder, T* value, TStringBuf format)
 {
-    NYT::NDetail::FormatValueViaSprintf(builder, static_cast<const void*>(value), format, TStringBuf("p"));
+    NYT::NDetail::FormatPointerValue(builder, static_cast<const void*>(value), format);
 }
 
 // TDuration (specialize for performance reasons)
diff --git a/library/cpp/yt/string/format.cpp b/library/cpp/yt/string/format.cpp
index 6c824e8ba3..47b0c1d712 100644
--- a/library/cpp/yt/string/format.cpp
+++ b/library/cpp/yt/string/format.cpp
@@ -30,7 +30,8 @@ void FormatValueViaSprintf(
     char formatBuf[MaxFormatSize];
     YT_VERIFY(format.length() >= 1 && format.length() <= MaxFormatSize - 2); // one for %, one for \0
     formatBuf[0] = '%';
-    if (format[format.length() - 1] == GenericSpecSymbol) {
+
+    if (format.back() == GenericSpecSymbol) {
         char* formatEnd = copyFormat(formatBuf + 1, format.begin(), format.length() - 1);
         ::memcpy(formatEnd, genericSpec.begin(), genericSpec.length());
         formatEnd[genericSpec.length()] = '\0';
@@ -105,6 +106,22 @@ XX(ui64)
 
 #undef XX
 
+void FormatPointerValue(
+    TStringBuilderBase* builder,
+    const void* value,
+    TStringBuf format)
+{
+    static_assert(sizeof(value) == sizeof(ui64));
+    if (format == TStringBuf("p") || format == TStringBuf("v")) {
+        builder->AppendString(TStringBuf("0x"));
+        FormatValue(builder, reinterpret_cast<ui64>(value), TStringBuf("x"));
+    } else if (format == TStringBuf("x") || format == TStringBuf("X")) {
+        FormatValue(builder, reinterpret_cast<ui64>(value), format);
+    } else {
+        builder->AppendString("<invalid pointer format>");
+    }
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 
 } // namespace NYT::NDetail
diff --git a/library/cpp/yt/string/unittests/format_ut.cpp b/library/cpp/yt/string/unittests/format_ut.cpp
index 20ec6392b5..47bb4602e3 100644
--- a/library/cpp/yt/string/unittests/format_ut.cpp
+++ b/library/cpp/yt/string/unittests/format_ut.cpp
@@ -160,9 +160,20 @@ TEST(TFormatTest, Nullable)
 
 TEST(TFormatTest, Pointers)
 {
-    // No idea if pointer format is standardized, check against Sprintf.
-    auto p = reinterpret_cast<void*>(123);
-    EXPECT_EQ(Sprintf("%p", reinterpret_cast<void*>(123)), Format("%p", p));
+    {
+        auto ptr = reinterpret_cast<void*>(0x12345678);
+        EXPECT_EQ("0x12345678", Format("%p", ptr));
+        EXPECT_EQ("0x12345678", Format("%v", ptr));
+        EXPECT_EQ("12345678", Format("%x", ptr));
+        EXPECT_EQ("12345678", Format("%X", ptr));
+    }
+    {
+        auto ptr = reinterpret_cast<void*>(0x12345678abcdefab);
+        EXPECT_EQ("0x12345678abcdefab", Format("%p", ptr));
+        EXPECT_EQ("0x12345678abcdefab", Format("%v", ptr));
+        EXPECT_EQ("12345678abcdefab", Format("%x", ptr));
+        EXPECT_EQ("12345678ABCDEFAB", Format("%X", ptr));
+    }
 }
 
 ////////////////////////////////////////////////////////////////////////////////