Remove arch_get_caller

Use the gcc builtin instead, which generates more efficient code (it
saves a function call) and means less platform specific code to write
for us.

Change-Id: I1d55b5703027b2ea4ecde2438ea306bd4850eb32
Reviewed-on: https://review.haiku-os.org/c/haiku/+/1859
Reviewed-by: waddlesplash <waddlesplash@gmail.com>

headers/private/libroot/libroot_private.h

@@ -50,7 +50,6 @@ bigtime_t __arch_get_system_time_offset(struct real_time_data *data);
 bigtime_t __get_system_time_offset();
 void __init_pwd_backend(void);
 void __reinit_pwd_backend_after_fork(void);
-void* __arch_get_caller(void);
 int32 __arch_get_stack_trace(addr_t* returnAddresses, int32 maxCount,
 	int32 skipFrames, addr_t stackBase, addr_t stackEnd);
 

src/system/libroot/os/arch/arm/stack_frame.c

@@ -18,10 +18,3 @@ get_stack_frame(void)
 	return NULL;
 }
 
-
-void*
-__arch_get_caller(void)
-{
-	// TODO: Implement!
-	return NULL;
-}

src/system/libroot/os/arch/m68k/stack_frame.c

@@ -15,10 +15,3 @@ get_stack_frame(void)
 	return NULL;
 }
 
-
-void*
-__arch_get_caller(void)
-{
-	// TODO: Implement!
-	return NULL;
-}

src/system/libroot/os/arch/ppc/stack_frame.c

@@ -15,10 +15,3 @@ get_stack_frame(void)
 	return NULL;
 }
 
-
-void*
-__arch_get_caller(void)
-{
-	// TODO: Implement!
-	return NULL;
-}

src/system/libroot/os/arch/riscv64/stack_frame.c

@@ -15,11 +15,3 @@ get_stack_frame(void)
 	return NULL;
 }
 
-
-void*
-__arch_get_caller(void)
-{
-	// TODO: Implement!
-	return NULL;
-}
-

src/system/libroot/os/arch/sparc/stack_frame.c

@@ -15,11 +15,3 @@ get_stack_frame(void)
 	return NULL;
 }
 
-
-void*
-__arch_get_caller(void)
-{
-	// TODO: Implement!
-	return NULL;
-}
-

src/system/libroot/os/arch/x86/get_stack_frame.S

@@ -12,10 +12,3 @@ FUNCTION(get_stack_frame):
 	ret
 FUNCTION_END(get_stack_frame)
 
-
-/* void* __arch_get_caller(void); */
-FUNCTION(__arch_get_caller):
-	mov		4(%ebp), %eax
-	ret
-FUNCTION_END(__arch_get_caller)
-

src/system/libroot/os/arch/x86_64/get_stack_frame.S

@@ -13,10 +13,3 @@ FUNCTION(get_stack_frame):
 	ret
 FUNCTION_END(get_stack_frame)
 
-
-/* void* __arch_get_caller(void); */
-FUNCTION(__arch_get_caller):
-	movq	8(%rbp), %rax
-	ret
-FUNCTION_END(__arch_get_caller)
-

src/system/libroot/posix/dlfcn.c

@@ -40,8 +40,9 @@ dlsym(void *handle, char const *name)
 	status_t status;
 	void* caller = NULL;
 
-	if (handle == RTLD_NEXT)
-		caller = __arch_get_caller();
+	if (handle == RTLD_NEXT) {
+		caller = __builtin_return_address(0);
+	}
 
 	status = __gRuntimeLoader->get_library_symbol(handle, caller, name,
 		&location);

src/system/libroot/stubbed/libroot_stubs.c

@@ -608,7 +608,6 @@ void __acosl() {}
 void __acr() {}
 void __add() {}
 void __allocate_pthread() {}
-void __arch_get_caller() {}
 void __arch_get_stack_trace() {}
 void __arch_get_system_time_offset() {}
 void __arch_init_time() {}

src/system/libroot/stubbed/libroot_stubs_legacy.c

@@ -418,7 +418,6 @@ void __acoshl() {}
 void __acosl() {}
 void __adjust_heap__H3ZPQ217EnvironmentFilter5EntryZlZQ217EnvironmentFilter5Entry_X01X11X11X21_v() {}
 void __allocate_pthread() {}
-void __arch_get_caller() {}
 void __arch_get_stack_trace() {}
 void __arch_get_system_time_offset() {}
 void __arch_init_time() {}