Fix broken mp_stack_check: force mp_stack_ctrl_init() and mp_stack_usage() not to be inlined even with -flto

dhalbert · dhalbert · commit 88b449a8cde0 · 2017-06-04T22:05:55.000-04:00
diff --git a/py/stackctrl.c b/py/stackctrl.c
@@ -31,6 +31,8 @@
 #include "py/stackctrl.h"
 
 void mp_stack_ctrl_init(void) {
+    // Force routine to not be inlined. Better guarantee than MP_NOINLINE for -flto.
+    asm("");
     volatile int stack_dummy;
     MP_STATE_THREAD(stack_top) = (char*)&stack_dummy;
 }
@@ -41,6 +43,8 @@ void mp_stack_set_top(void *top) {
 
 mp_uint_t mp_stack_usage(void) {
     // Assumes descending stack
+    // Force routine to not be inlined. Better guarantee than MP_NOINLINE for -flto.
+    asm("");
     volatile int stack_dummy;
     return MP_STATE_THREAD(stack_top) - (char*)&stack_dummy;
 }
