From 12fffb0724998ce194af47186bf52b80ee0f3a0d Mon Sep 17 00:00:00 2001
From: Mis012 <Michael.Srba@seznam.cz>
Date: Thu, 24 Nov 2022 18:42:18 +0100
Subject: [PATCH] src/libandroid/looper.c: fix for aarch64 (TODO: just
 implement these as extern C straight in libutils?)

---
 src/libandroid/looper.c | 52 +++++++++++++++++++++++++++++++----------
 1 file changed, 40 insertions(+), 12 deletions(-)

diff --git a/src/libandroid/looper.c b/src/libandroid/looper.c
index 8fc1c590..7855f69f 100644
--- a/src/libandroid/looper.c
+++ b/src/libandroid/looper.c
@@ -4,22 +4,50 @@
 typedef void ALooper;
 typedef int (*Looper_callbackFunc)(int fd, int events, void* data);
 
-void _ZN7android6Looper12getForThreadEv(void **ret); // no clue why itanium ABI does this with return values
-ALooper * ALooper_forThread()
-{
-	void *ret;
-	_ZN7android6Looper12getForThreadEv(&ret);
-	return ret;
+/* macros for creating wrappers for methods which use C++ itanium ABI */
+
+#ifdef __aarch64__
+
+#define ITANIUM_OBJ_RET_WRAPPER_DEC(ret_type, wrapper_name, mangled_name, ...) \
+void mangled_name(__VA_ARGS__); /* r8 used instead of implicit parameter, fun innit */\
+ret_type * wrapper_name(__VA_ARGS__)
+
+#define ITANIUM_OBJ_RET_WRAPPER_BODY(ret_type, wrapper_name, mangled_name, ...) \
+{ \
+	ret_type *ret; \
+	register ret_type **addr_of_ret asm("r8"); /* arm wants to be special :( */\
+	__asm__ ("" : : "" (addr_of_ret)); /* apparently __attribute__((used)) is not a thing */\
+	addr_of_ret = &ret; \
+	mangled_name(__VA_ARGS__); \
+	return ret; \
 }
 
-void _ZN7android6Looper7prepareEi(void **ret, int opts); // no clue why itanium ABI does this with return values
-ALooper * ALooper_prepare(int opts)
-{
-	void *ret;
-	_ZN7android6Looper7prepareEi(&ret, opts);
-	return ret;
+#else
+
+#define ITANIUM_OBJ_RET_WRAPPER_DEC(ret_type, wrapper_name, mangled_name, ...) \
+void mangled_name(ret_type **ret, ##__VA_ARGS__); /* implicit first parameter used for return value */\
+ret_type * wrapper_name(__VA_ARGS__)
+
+#define ITANIUM_OBJ_RET_WRAPPER_BODY(ret_type, wrapper_name, mangled_name, ...) \
+{ \
+	ret_type *ret; \
+	mangled_name(&ret, ##__VA_ARGS__); \
+	return ret; \
 }
 
+#endif
+
+#define ITANIUM_OBJ_RET_WRAPPER_NOARGS(ret_type, wrapper_name, mangled_name) \
+ITANIUM_OBJ_RET_WRAPPER_DEC(ret_type, wrapper_name, mangled_name) \
+ITANIUM_OBJ_RET_WRAPPER_BODY(ret_type, wrapper_name, mangled_name)
+
+// ALooper * ALooper_forThread()
+ITANIUM_OBJ_RET_WRAPPER_NOARGS(ALooper, ALooper_forThread, _ZN7android6Looper12getForThreadEv)
+
+// ALooper * ALooper_prepare(int opts)
+ITANIUM_OBJ_RET_WRAPPER_DEC(ALooper, ALooper_prepare, _ZN7android6Looper7prepareEi, int opts)
+ITANIUM_OBJ_RET_WRAPPER_BODY(ALooper, ALooper_prepare, _ZN7android6Looper7prepareEi, opts)
+
 int _ZN7android6Looper7pollAllEiPiS1_PPv(void *this, int timeoutMillis, int* outFd, int* outEvents, void** outData);
 int ALooper_pollAll(int timeoutMillis, int* outFd, int* outEvents, void** outData)
 {