From 03fff3572ff60bc1119ac3dfbb0883247e3a83cf Mon Sep 17 00:00:00 2001
From: Itms <itms@wildfiregames.com>
Date: Mon, 4 Aug 2025 14:39:56 +0200
Subject: [PATCH] Use conforming preprocessor with modern MSVC

https://learn.microsoft.com/en-us/cpp/preprocessor/preprocessor-experimental-overview
---
 build/premake/premake5.lua                    |  5 +++
 libraries/get-windows-libs.bat                |  2 +-
 libraries/source/spidermonkey/build.sh        |  6 ---
 .../patches/FixHeadersForMSVC.diff            | 38 -------------------
 source/lib/sysdep/os/win/wdbg_sym.cpp         |  2 +-
 5 files changed, 7 insertions(+), 46 deletions(-)
 delete mode 100644 libraries/source/spidermonkey/patches/FixHeadersForMSVC.diff

diff --git a/build/premake/premake5.lua b/build/premake/premake5.lua
index b64164ceed..68a775fb08 100644
--- a/build/premake/premake5.lua
+++ b/build/premake/premake5.lua
@@ -296,6 +296,11 @@ function project_set_build_flags()
 		-- Finally since VS2012 it's enabled implicitely when not set.
 		vectorextensions "SSE2"
 
+		-- SpiderMonkey only supports building with MSVC on a best-effort basis,
+		-- and the traditional MSVC preprocessor is incompatible with some headers.
+		-- Use the modern, standard-compliant MSVC preprocessor instead.
+		usestandardpreprocessor "On"
+
 		-- use native wchar_t type (not typedef to unsigned short)
 		nativewchar "on"
 
diff --git a/libraries/get-windows-libs.bat b/libraries/get-windows-libs.bat
index 0be2d94359..91c1b6b930 100644
--- a/libraries/get-windows-libs.bat
+++ b/libraries/get-windows-libs.bat
@@ -4,7 +4,7 @@ cd /D "%~dp0"
 
 rem **SVN revision to checkout for windows-libs or windows-libs-amd64**
 rem **Update this line when you commit an update to windows-libs or windows-libs-amd64**
-set "svnrev=28267"
+set "svnrev=28268"
 
 if "%1" == "--amd64" (
     set "LIBS_PATH=win64"
diff --git a/libraries/source/spidermonkey/build.sh b/libraries/source/spidermonkey/build.sh
index 8b322a7778..6e5dfaf9eb 100755
--- a/libraries/source/spidermonkey/build.sh
+++ b/libraries/source/spidermonkey/build.sh
@@ -205,12 +205,6 @@ if [ "${OS}" = "Windows_NT" ]; then
 		cd "${FOLDER}"/build-release/dist/include
 		rm -f mozzconf.h zconf.h zlib.h
 	)
-
-	# SpiderMonkey can be linked/included in projects built with MSVC, however, since clang is now the only
-	# supported compiler on Windows, the codebase has accumulated some divergences with MSVC.
-	# Upstream tries on a best-effort basis to keep the SM headers MSVC-compatible.
-	patch -d "${FOLDER}"/build-debug/dist/include -p1 <patches/FixHeadersForMSVC.diff
-	patch -d "${FOLDER}"/build-release/dist/include -p1 <patches/FixHeadersForMSVC.diff
 fi
 
 # js-config.h is different for debug and release builds, so we need different include directories for both
diff --git a/libraries/source/spidermonkey/patches/FixHeadersForMSVC.diff b/libraries/source/spidermonkey/patches/FixHeadersForMSVC.diff
deleted file mode 100644
index 9fc59c0d86..0000000000
--- a/libraries/source/spidermonkey/patches/FixHeadersForMSVC.diff
+++ /dev/null
@@ -1,38 +0,0 @@
-diff --git a/jspubtd.h b/jspubtd.h
-index 97de470db..1507b6b6b 100644
---- a/jspubtd.h
-+++ b/jspubtd.h
-@@ -51,6 +51,11 @@ enum JSType {
- enum JSProtoKey {
- #define PROTOKEY_AND_INITIALIZER(name, clasp) JSProto_##name,
-   JS_FOR_EACH_PROTOTYPE(PROTOKEY_AND_INITIALIZER)
-+// Workaround MSVC's __VA_ARGS__ quirk, until bug 1768634 is solved
-+// https://bugzilla.mozilla.org/show_bug.cgi?id=1768634
-+#ifdef _MSC_VER
-+  ,
-+#endif
- #undef PROTOKEY_AND_INITIALIZER
-       JSProto_LIMIT
- };
-
-diff --git a/mozilla/Result.h b/mozilla/Result.h
-index cc4f87826..0e763a300 100644
---- a/mozilla/Result.h
-+++ b/mozilla/Result.h
-@@ -212,10 +212,16 @@ using UnsignedIntType = std::conditional_t<
-  */
- template <typename V, typename E>
- class ResultImplementation<V, E, PackingStrategy::LowBitTagIsError> {
-+// These assertions fail with MSVC 14.1. Similar bugs:
-+// https://bugzilla.mozilla.org/show_bug.cgi?id=1778246
-+// https://bugzilla.mozilla.org/show_bug.cgi?id=1778247
-+// TODO: test with recent MSVC before reporting a bug
-+#ifndef _MSC_VER
-   static_assert(std::is_trivially_copyable_v<V> &&
-                 std::is_trivially_destructible_v<V>);
-   static_assert(std::is_trivially_copyable_v<E> &&
-                 std::is_trivially_destructible_v<E>);
-+#endif
- 
-   static constexpr size_t kRequiredSize = std::max(sizeof(V), sizeof(E));
- 
diff --git a/source/lib/sysdep/os/win/wdbg_sym.cpp b/source/lib/sysdep/os/win/wdbg_sym.cpp
index a80a2e66d4..17c19d69c0 100644
--- a/source/lib/sysdep/os/win/wdbg_sym.cpp
+++ b/source/lib/sysdep/os/win/wdbg_sym.cpp
@@ -1337,7 +1337,7 @@ static bool udt_should_suppress(const wchar_t* type_name)
 	// removed obsolete defs: HEVENT, HFILE, HUMPD
 	if(type_name[0] != 'H')
 		goto not_handle;
-#define SUPPRESS_HANDLE(name) if(!wcscmp(type_name, L#name L"__")) return true;
+#define SUPPRESS_HANDLE(name) if(!wcscmp(type_name, L""#name L"__")) return true;
 	SUPPRESS_HANDLE(HACCEL);
 	SUPPRESS_HANDLE(HBITMAP);
 	SUPPRESS_HANDLE(HBRUSH);