From 4d83e142b68d1279050e464c7c106be8afa27e32 Mon Sep 17 00:00:00 2001
From: Billy Laws <blaws05@gmail.com>
Date: Sat, 16 Sep 2023 00:03:00 +0100
Subject: [PATCH] crt: Add initial ARM64EC build system support

This introduces basic ARM64EC build support by reusing a modified ARM64
configuration. In the future, the goal is to include both native and
ARM64EC object files in aarch64 archives.

This setup is still subject to change.

Signed-off-by: Jacek Caban <jacek@codeweavers.com>
---
 mingw-w64-crt/Makefile.am  |  6 +++++-
 mingw-w64-crt/configure.ac | 10 ++++++++--
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/mingw-w64-crt/Makefile.am b/mingw-w64-crt/Makefile.am
index 4f0119be8..291d24b24 100644
--- a/mingw-w64-crt/Makefile.am
+++ b/mingw-w64-crt/Makefile.am
@@ -28,7 +28,11 @@ CPPFLAGS32=-m32 -masm=att
 CPPFLAGS64=-m64 -masm=att
 AM_DLLTOOLFLAGS=-k --as=$(AS) --output-lib $@
 DLLTOOLFLAGSARM32=-m arm
-DLLTOOLFLAGSARM64=-m arm64
+if ARM64EC
+    DLLTOOLFLAGSARM64=-m arm64ec
+else
+    DLLTOOLFLAGSARM64=-m arm64
+endif
 DLLTOOLFLAGS32=--as-flags=--32 -m i386
 DLLTOOLFLAGS64=--as-flags=--64 -m i386:x86-64
 DTDEFARM32=$(DLLTOOL) $(DLLTOOLFLAGSARM32) $(AM_DLLTOOLFLAGS) --input-def
diff --git a/mingw-w64-crt/configure.ac b/mingw-w64-crt/configure.ac
index f4f8d954d..ee0e0e9b0 100644
--- a/mingw-w64-crt/configure.ac
+++ b/mingw-w64-crt/configure.ac
@@ -156,7 +156,7 @@ AC_ARG_ENABLE([libarm64],
     [Build the WinARM64 libraries])],
   [],
   [AS_CASE([$host_cpu],
-    [aarch64*],[enable_libarm64=yes],
+    [aarch64* | arm64*],[enable_libarm64=yes],
     [*],[enable_libarm64=no])
   ])
 AC_MSG_RESULT([$enable_libarm64])
@@ -181,7 +181,7 @@ AS_CASE([$host_cpu],
     libx8632suffx=lib
     libarm64suffx=libarm64
     libarm32suffx=libarm32],
-  [aarch64*],[
+  [aarch64* | arm64*],[
     libx8664suffx=libx8664
     libx8632suffx=libx8632
     libarm64suffx=lib
@@ -210,6 +210,8 @@ AC_SUBST([LIBX8632SUFFIXDIR],[$libx8632suffx])
 AC_SUBST([LIBARM64SUFFIXDIR],[$libarm64suffx])
 AC_SUBST([LIBARM32SUFFIXDIR],[$libarm32suffx])
 
+AM_CONDITIONAL([ARM64EC],[test $host_cpu = arm64ec])
+
 # Checks for features.
 
 AC_MSG_CHECKING([whether to enable globbing])
@@ -377,6 +379,10 @@ AC_MSG_CHECKING([whether the linker provides __ImageBase symbol])
 
 cat <<_ACEOF >conftest.$ac_ext
 extern unsigned char __ImageBase[[]];
+
+// Define a dummy call helper to satisfy the linker on ARM64EC
+void *__os_arm64x_dispatch_ret = 0;
+
 void __main(void) {
 }
 int main(void) {