diff --git a/stl/inc/source_location b/stl/inc/source_location
index e4e724d652..31d5fb34cb 100644
--- a/stl/inc/source_location
+++ b/stl/inc/source_location
@@ -20,15 +20,25 @@ _STL_DISABLE_CLANG_WARNINGS
 #pragma push_macro("new")
 #undef new
 
+#ifndef _USE_DETAILED_FUNCTION_NAME_IN_SOURCE_LOCATION
+#ifdef __EDG__ // TRANSITION, DevCom-10199227
+#define _USE_DETAILED_FUNCTION_NAME_IN_SOURCE_LOCATION 0
+#elif defined(__clang__) // TRANSITION, Clang 17 has this builtin
+#define _USE_DETAILED_FUNCTION_NAME_IN_SOURCE_LOCATION __has_builtin(__builtin_FUNCSIG)
+#else // ^^^ Clang / MSVC vvv
+#define _USE_DETAILED_FUNCTION_NAME_IN_SOURCE_LOCATION 1
+#endif // ^^^ MSVC ^^^
+#endif // ^^^ !defined(_USE_DETAILED_FUNCTION_NAME_IN_SOURCE_LOCATION) ^^^
+
 _STD_BEGIN
 _EXPORT_STD struct source_location {
     _NODISCARD static consteval source_location current(const uint_least32_t _Line_ = __builtin_LINE(),
         const uint_least32_t _Column_ = __builtin_COLUMN(), const char* const _File_ = __builtin_FILE(),
-#if defined(__clang__) || defined(__EDG__) // TRANSITION, DevCom-10199227 and LLVM-58951
-        const char* const _Function_ = __builtin_FUNCTION()
-#else // ^^^ workaround / no workaround vvv
+#if _USE_DETAILED_FUNCTION_NAME_IN_SOURCE_LOCATION
         const char* const _Function_ = __builtin_FUNCSIG()
-#endif // TRANSITION, DevCom-10199227 and LLVM-58951
+#else // ^^^ detailed / basic vvv
+        const char* const _Function_ = __builtin_FUNCTION()
+#endif // ^^^ basic ^^^
             ) noexcept {
         source_location _Result{};
         _Result._Line     = _Line_;
diff --git a/tests/std/include/test_header_units_and_modules.hpp b/tests/std/include/test_header_units_and_modules.hpp
index 828a3e9bbc..cdb5ce1446 100644
--- a/tests/std/include/test_header_units_and_modules.hpp
+++ b/tests/std/include/test_header_units_and_modules.hpp
@@ -679,11 +679,21 @@ constexpr bool impl_test_source_location() {
     const auto sl = source_location::current();
     assert(sl.line() == __LINE__ - 1);
     assert(sl.column() == 38);
-#if defined(__clang__) || defined(__EDG__) // TRANSITION, DevCom-10199227 and LLVM-58951
-    assert(sl.function_name() == "impl_test_source_location"sv);
-#else // ^^^ workaround / no workaround vvv
+
+#ifdef __EDG__ // TRANSITION, DevCom-10199227
+#define TEST_DETAILED_FUNCTION_NAME 0
+#elif defined(__clang__) // TRANSITION, Clang 17 has this builtin
+#define TEST_DETAILED_FUNCTION_NAME __has_builtin(__builtin_FUNCSIG)
+#else // ^^^ Clang / MSVC vvv
+#define TEST_DETAILED_FUNCTION_NAME 1
+#endif // ^^^ MSVC ^^^
+
+#if TEST_DETAILED_FUNCTION_NAME
     assert(sl.function_name() == "bool __cdecl impl_test_source_location(void)"sv);
-#endif // TRANSITION, DevCom-10199227 and LLVM-58951
+#else // ^^^ detailed / basic vvv
+    assert(sl.function_name() == "impl_test_source_location"sv);
+#endif // ^^^ basic ^^^
+
     assert(string_view{sl.file_name()}.ends_with("test_header_units_and_modules.hpp"sv));
     return true;
 }
diff --git a/tests/std/tests/P1208R6_source_location/header.h b/tests/std/tests/P1208R6_source_location/header.h
index e9c8b48bbb..3369da4d63 100644
--- a/tests/std/tests/P1208R6_source_location/header.h
+++ b/tests/std/tests/P1208R6_source_location/header.h
@@ -17,10 +17,10 @@ constexpr void header_test() {
 #else // ^^^ EDG / C1XX vvv
     assert(x.column() == 37);
 #endif // ^^^ C1XX ^^^
-#if defined(__clang__) || defined(__EDG__) // TRANSITION, DevCom-10199227 and LLVM-58951
-    assert(x.function_name() == "header_test"sv);
-#else // ^^^ workaround / no workaround vvv
+#if _USE_DETAILED_FUNCTION_NAME_IN_SOURCE_LOCATION
     assert(x.function_name() == "void __cdecl header_test(void)"sv);
-#endif // TRANSITION, DevCom-10199227 and LLVM-58951
+#else // ^^^ detailed / basic vvv
+    assert(x.function_name() == "header_test"sv);
+#endif // ^^^ basic ^^^
     assert(string_view{x.file_name()}.ends_with("header.h"sv));
 }
diff --git a/tests/std/tests/P1208R6_source_location/test.cpp b/tests/std/tests/P1208R6_source_location/test.cpp
index 4640ca5c13..18b8f26f57 100644
--- a/tests/std/tests/P1208R6_source_location/test.cpp
+++ b/tests/std/tests/P1208R6_source_location/test.cpp
@@ -9,6 +9,12 @@
 #include <type_traits>
 using namespace std;
 
+#ifdef _M_IX86
+#define THISCALL_OR_CDECL "__thiscall"
+#else
+#define THISCALL_OR_CDECL "__cdecl"
+#endif
+
 static_assert(is_nothrow_default_constructible_v<source_location>);
 static_assert(is_nothrow_move_constructible_v<source_location>);
 static_assert(is_nothrow_move_assignable_v<source_location>);
@@ -61,11 +67,11 @@ constexpr void local_test() {
 #else // ^^^ EDG / C1XX vvv
     assert(x.column() == 37);
 #endif // ^^^ C1XX ^^^
-#if defined(__clang__) || defined(__EDG__) // TRANSITION, DevCom-10199227 and LLVM-58951
-    assert(x.function_name() == "local_test"sv);
-#else // ^^^ workaround / no workaround vvv
+#if _USE_DETAILED_FUNCTION_NAME_IN_SOURCE_LOCATION
     assert(x.function_name() == "void __cdecl local_test(void)"sv);
-#endif // TRANSITION, DevCom-10199227 and LLVM-58951
+#else // ^^^ detailed / basic vvv
+    assert(x.function_name() == "local_test"sv);
+#endif // ^^^ basic ^^^
     assert(string_view{x.file_name()}.ends_with(test_cpp));
 }
 
@@ -73,11 +79,11 @@ constexpr void argument_test(
     const unsigned int line, const unsigned int column, const source_location x = source_location::current()) {
     assert(x.line() == line);
     assert(x.column() == column);
-#if defined(__clang__) || defined(__EDG__) // TRANSITION, DevCom-10199227 and LLVM-58951
-    assert(x.function_name() == "test"sv);
-#else // ^^^ workaround / no workaround vvv
+#if _USE_DETAILED_FUNCTION_NAME_IN_SOURCE_LOCATION
     assert(x.function_name() == "bool __cdecl test(void)"sv);
-#endif // TRANSITION, DevCom-10199227 and LLVM-58951
+#else // ^^^ detailed / basic vvv
+    assert(x.function_name() == "test"sv);
+#endif // ^^^ basic ^^^
     assert(string_view{x.file_name()}.ends_with(test_cpp));
 }
 
@@ -89,15 +95,18 @@ constexpr void sloc_constructor_test() {
 #else // ^^^ defined(__EDG__) / !defined(__EDG__) vvv
     assert(x.loc.column() == 13);
 #endif // ^^^ !defined(__EDG__) ^^^
-#if defined(__clang__) || defined(__EDG__) // TRANSITION, DevCom-10199227 and LLVM-58951
-    assert(x.loc.function_name() == "sloc_constructor_test"sv);
-#else // ^^^ workaround / no workaround vvv
+#if _USE_DETAILED_FUNCTION_NAME_IN_SOURCE_LOCATION
+#if !defined(__clang__) && !defined(__EDG__) // TRANSITION, VSO-1285783
     if (is_constant_evaluated()) {
-        assert(x.loc.function_name() == "int __cdecl main(void)"sv); // TRANSITION, VSO-1285783
-    } else {
+        assert(x.loc.function_name() == "int __cdecl main(void)"sv);
+    } else
+#endif // ^^^ workaround ^^^
+    {
         assert(x.loc.function_name() == "void __cdecl sloc_constructor_test(void)"sv);
     }
-#endif // TRANSITION, DevCom-10199227 and LLVM-58951
+#else // ^^^ detailed / basic vvv
+    assert(x.loc.function_name() == "sloc_constructor_test"sv);
+#endif // ^^^ basic ^^^
     assert(string_view{x.loc.file_name()}.ends_with(test_cpp));
 }
 
@@ -111,13 +120,11 @@ constexpr void different_constructor_test() {
 #else // ^^^ EDG / C1XX vvv
     assert(x.loc.column() == 5);
 #endif // ^^^ C1XX ^^^
-#if defined(__clang__) || defined(__EDG__) // TRANSITION, DevCom-10199227 and LLVM-58951
+#if _USE_DETAILED_FUNCTION_NAME_IN_SOURCE_LOCATION
+    assert(x.loc.function_name() == THISCALL_OR_CDECL " s::s(int)"sv);
+#else // ^^^ detailed / basic vvv
     assert(x.loc.function_name() == "s"sv);
-#elif defined(_M_IX86) // ^^^ workaround / no workaround vvv
-    assert(x.loc.function_name() == "__thiscall s::s(int)"sv);
-#else // ^^^ _M_IX86 / !_M_IX86 vvv
-    assert(x.loc.function_name() == "__cdecl s::s(int)"sv);
-#endif // TRANSITION, DevCom-10199227 and LLVM-58951
+#endif // ^^^ basic ^^^
     assert(string_view{x.loc.file_name()}.ends_with(test_cpp));
 }
 
@@ -129,15 +136,18 @@ constexpr void sub_member_test() {
 #else // ^^^ defined(__EDG__) / !defined(__EDG__) vvv
     assert(s.x.loc.column() == 14);
 #endif // ^^^ !defined(__EDG__) ^^^
-#if defined(__clang__) || defined(__EDG__) // TRANSITION, DevCom-10199227 and LLVM-58951
-    assert(s.x.loc.function_name() == "sub_member_test"sv);
-#else // ^^^ workaround / no workaround vvv
+#if _USE_DETAILED_FUNCTION_NAME_IN_SOURCE_LOCATION
+#if !defined(__clang__) && !defined(__EDG__) // TRANSITION, VSO-1285783
     if (is_constant_evaluated()) {
-        assert(s.x.loc.function_name() == "int __cdecl main(void)"sv); // TRANSITION, VSO-1285783
-    } else {
+        assert(s.x.loc.function_name() == "int __cdecl main(void)"sv);
+    } else
+#endif // ^^^ workaround ^^^
+    {
         assert(s.x.loc.function_name() == "void __cdecl sub_member_test(void)"sv);
     }
-#endif // TRANSITION, DevCom-10199227 and LLVM-58951
+#else // ^^^ detailed / basic vvv
+    assert(s.x.loc.function_name() == "sub_member_test"sv);
+#endif // ^^^ basic ^^^
     assert(string_view{s.x.loc.file_name()}.ends_with(test_cpp));
 
     const s2 s_i{1};
@@ -149,13 +159,11 @@ constexpr void sub_member_test() {
 #else // ^^^ EDG / C1XX vvv
     assert(s_i.x.loc.column() == 5);
 #endif // ^^^ C1XX ^^^
-#if defined(__clang__) || defined(__EDG__) // TRANSITION, DevCom-10199227 and LLVM-58951
+#if _USE_DETAILED_FUNCTION_NAME_IN_SOURCE_LOCATION
+    assert(s_i.x.loc.function_name() == THISCALL_OR_CDECL " s2::s2(int)"sv);
+#else // ^^^ detailed / basic vvv
     assert(s_i.x.loc.function_name() == "s2"sv);
-#elif defined(_M_IX86) // ^^^ workaround / no workaround vvv
-    assert(s_i.x.loc.function_name() == "__thiscall s2::s2(int)"sv);
-#else // ^^^ _M_IX86 / !_M_IX86 vvv
-    assert(s_i.x.loc.function_name() == "__cdecl s2::s2(int)"sv);
-#endif // TRANSITION, DevCom-10199227 and LLVM-58951
+#endif // ^^^ basic ^^^
     assert(string_view{s_i.x.loc.file_name()}.ends_with(test_cpp));
 }
 
@@ -176,19 +184,20 @@ constexpr void lambda_test() {
     assert(x1.column() == 52);
     assert(x2.column() == 50);
 #endif // ^^^ C1XX ^^^
-#if defined(__clang__) || defined(__EDG__) // TRANSITION, DevCom-10199227 and LLVM-58951
-    assert(x1.function_name() == "lambda_test"sv);
-    assert(x2.function_name() == "operator()"sv);
-#elif defined(_M_IX86) // ^^^ workaround / no workaround vvv
-    assert(x1.function_name() == "void __cdecl lambda_test(void)"sv);
-    assert(
-        string_view{x2.function_name()}.starts_with("struct std::source_location __thiscall lambda_test::<lambda_"sv));
-    assert(string_view{x2.function_name()}.ends_with("::operator ()(void) const"sv));
-#else // ^^^ _M_IX86 / !_M_IX86 vvv
+#if _USE_DETAILED_FUNCTION_NAME_IN_SOURCE_LOCATION
     assert(x1.function_name() == "void __cdecl lambda_test(void)"sv);
-    assert(string_view{x2.function_name()}.starts_with("struct std::source_location __cdecl lambda_test::<lambda_"sv));
-    assert(string_view{x2.function_name()}.ends_with("::operator ()(void) const"sv));
-#endif // TRANSITION, DevCom-10199227 and LLVM-58951
+#else // ^^^ detailed / basic vvv
+    assert(x1.function_name() == "lambda_test"sv);
+#endif // ^^^ basic ^^^
+    const string_view fun2{x2.function_name()};
+#if !_USE_DETAILED_FUNCTION_NAME_IN_SOURCE_LOCATION
+    assert(fun2 == "operator()"sv);
+#elif defined(__clang__) // ^^^ basic / detailed Clang vvv
+    assert(fun2 == "auto " THISCALL_OR_CDECL " lambda_test()::(anonymous class)::operator()(void) const"sv);
+#else // ^^^ detailed Clang / detailed non-Clang vvv
+    assert(fun2.starts_with("struct std::source_location " THISCALL_OR_CDECL " lambda_test::<lambda_"sv));
+    assert(fun2.ends_with("::operator ()(void) const"sv));
+#endif // ^^^ detailed non-Clang ^^^
     assert(string_view{x1.file_name()}.ends_with(test_cpp));
     assert(string_view{x2.file_name()}.ends_with(test_cpp));
 }
@@ -208,21 +217,25 @@ constexpr void function_template_test() {
 #else // ^^^ EDG / C1XX vvv
     assert(x1.column() == 29);
 #endif // ^^^ C1XX ^^^
-#if defined(__clang__) || defined(__EDG__) // TRANSITION, DevCom-10199227 and LLVM-58951
+#if !_USE_DETAILED_FUNCTION_NAME_IN_SOURCE_LOCATION
     assert(x1.function_name() == "function_template"sv);
-#else // ^^^ workaround / no workaround vvv
+#elif defined(__clang__) // ^^^ basic / detailed Clang vvv
+    assert(x1.function_name() == "source_location __cdecl function_template(void) [T = void]"sv);
+#else // ^^^ detailed Clang / detailed non-Clang vvv
     assert(x1.function_name() == "struct std::source_location __cdecl function_template<void>(void)"sv);
-#endif // TRANSITION, DevCom-10199227 and LLVM-58951
+#endif // ^^^ detailed non-Clang ^^^
     assert(string_view{x1.file_name()}.ends_with(test_cpp));
 
     const auto x2 = function_template<int>();
     assert(x1.line() == x2.line());
     assert(x1.column() == x2.column());
-#if defined(__clang__) || defined(__EDG__) // TRANSITION, DevCom-10199227 and LLVM-58951
+#if !_USE_DETAILED_FUNCTION_NAME_IN_SOURCE_LOCATION
     assert(x2.function_name() == "function_template"sv);
-#else // ^^^ workaround / no workaround vvv
+#elif defined(__clang__) // ^^^ basic / detailed Clang vvv
+    assert(x2.function_name() == "source_location __cdecl function_template(void) [T = int]"sv);
+#else // ^^^ detailed Clang / detailed non-Clang vvv
     assert(x2.function_name() == "struct std::source_location __cdecl function_template<int>(void)"sv);
-#endif // TRANSITION, DevCom-10199227 and LLVM-58951
+#endif // ^^^ detailed non-Clang ^^^
     assert(string_view{x1.file_name()} == string_view{x2.file_name()});
 }