From 25caa49adc95585872cbaf5649c7a8f5c95dcd91 Mon Sep 17 00:00:00 2001
From: Harishmcw <harish.rajaselvan@multicorewareinc.com>
Date: Fri, 17 Oct 2025 18:03:44 +0530
Subject:[PATCH v2] Fix .def file generation for ARM64EC builds on Windows

When building DLLs on ARM64EC, the default use of `dumpbin -linkermember:1`
fails because ARM64EC static libraries use a different linker member format.
Use `-linkermember:32` for ARM64EC to correctly extract symbols.

Additionally, MSVC inserts $exit_thunk and $entry_thunk symbols for ARM64EC
to handle x64 ↔ ARM64 transitions. These are internal thunks and must not be
exported. Filter them out when generating the .def file to avoid unresolved
symbols or invalid exports.

This ensures correct symbol extraction and stable DLL generation on ARM64EC
targets, while keeping behavior unchanged for other Windows architectures.

Signed-off-by: Harishmcw <harish.rajaselvan@multicorewareinc.com>
---
 compat/windows/makedef | 23 +++++++++++++++++++----
 configure              |  4 ++--
 2 files changed, 21 insertions(+), 6 deletions(-)

diff --git a/compat/windows/makedef b/compat/windows/makedef
index add8222d13..261e7d463f 100755
--- a/compat/windows/makedef
+++ b/compat/windows/makedef
@@ -48,7 +48,13 @@ trap 'rm -f -- $libname' EXIT
 if [ -n "$AR" ]; then
     $AR rcs ${libname} $@ >/dev/null
 else
-    lib.exe -out:${libname} $@ >/dev/null
+    machine_flag=""
+    case "$LDFLAGS" in
+    *"/machine:arm64ec"*)
+        machine_flag="-machine:arm64ec"
+        ;;
+    esac
+    lib.exe ${machine_flag} -out:${libname} $@ >/dev/null
 fi
 if [ $? != 0 ]; then
     echo "Could not create temporary library." >&2
@@ -108,10 +114,19 @@ if [ -n "$NM" ]; then
               cut -d' ' -f3 |
               sed -e "s/^${prefix}//")
 else
-    dump=$(dumpbin.exe -linkermember:1 ${libname} |
-              sed -e '/public symbols/,$!d' -e '/^ \{1,\}Summary/,$d' -e "s/ \{1,\}${prefix}/ /" -e 's/ \{1,\}/ /g' |
+    member=1
+    case "$LDFLAGS" in
+    *"/machine:arm64ec"*)
+        member=32
+        ;;
+    esac
+    dump=$(dumpbin.exe -linkermember:${member} ${libname} |
+              sed -e '/public symbols/,$!d' -e '/^ \{1,\}Summary/,$d' -e 's/^[[:space:]]*[0-9A-Fa-f]* //' -e "s/^${prefix}//" -e 's/^#//' |
               tail -n +2 |
-              cut -d' ' -f3)
+              cut -d' ' -f3 |
+              grep -v '\$exit_thunk$' |
+              grep -v '\$entry_thunk' |
+              grep -v '\$exit_thunk')
 fi
 
 rm ${libname}
diff --git a/configure b/configure
index 7828381b5d..fbf5ab38a4 100755
--- a/configure
+++ b/configure
@@ -6040,7 +6040,7 @@ case $target_os in
         SLIB_INSTALL_LINKS=
         SLIB_INSTALL_EXTRA_SHLIB='$(SLIBNAME:$(SLIBSUF)=.lib)'
         SLIB_INSTALL_EXTRA_LIB='lib$(SLIBNAME:$(SLIBSUF)=.dll.a) $(SLIBNAME_WITH_MAJOR:$(SLIBSUF)=.def)'
-        SLIB_CREATE_DEF_CMD='EXTERN_PREFIX="$(EXTERN_PREFIX)" AR="$(AR_CMD)" NM="$(NM_CMD)" $(SRC_PATH)/compat/windows/makedef $(SUBDIR)lib$(NAME).ver $(OBJS) > $$(@:$(SLIBSUF)=.def)'
+        SLIB_CREATE_DEF_CMD='LDFLAGS="$(LDFLAGS)" EXTERN_PREFIX="$(EXTERN_PREFIX)" AR="$(AR_CMD)" NM="$(NM_CMD)" $(SRC_PATH)/compat/windows/makedef $(SUBDIR)lib$(NAME).ver $(OBJS) > $$(@:$(SLIBSUF)=.def)'
         SHFLAGS='-shared -Wl,--out-implib,$(SUBDIR)lib$(SLIBNAME:$(SLIBSUF)=.dll.a) -Wl,--disable-auto-image-base $$(@:$(SLIBSUF)=.def)'
         enabled x86_64 && objformat="win64" || objformat="win32"
         dlltool="${cross_prefix}dlltool"
@@ -6078,7 +6078,7 @@ case $target_os in
         SLIBSUF=".dll"
         SLIBNAME_WITH_VERSION='$(SLIBPREF)$(FULLNAME)-$(LIBVERSION)$(SLIBSUF)'
         SLIBNAME_WITH_MAJOR='$(SLIBPREF)$(FULLNAME)-$(LIBMAJOR)$(SLIBSUF)'
-        SLIB_CREATE_DEF_CMD='EXTERN_PREFIX="$(EXTERN_PREFIX)" $(SRC_PATH)/compat/windows/makedef $(SUBDIR)lib$(NAME).ver $(OBJS) > $$(@:$(SLIBSUF)=.def)'
+        SLIB_CREATE_DEF_CMD='LDFLAGS="$(LDFLAGS)" EXTERN_PREFIX="$(EXTERN_PREFIX)" $(SRC_PATH)/compat/windows/makedef $(SUBDIR)lib$(NAME).ver $(OBJS) > $$(@:$(SLIBSUF)=.def)'
         SLIB_INSTALL_NAME='$(SLIBNAME_WITH_MAJOR)'
         SLIB_INSTALL_LINKS=
         SLIB_INSTALL_EXTRA_SHLIB='$(SLIBNAME:$(SLIBSUF)=.lib)'
-- 
2.50.1.windows.1