py/runtime: mp_stack_ctrl_init() should be called immediately on startup.

Calling it from mp_init() is too late for some ports (like Unix), and leads
to incomplete stack frame being captured, with following GC issues. So, now
each port should call mp_stack_ctrl_init() on its own, ASAP after startup,
and taking special precautions so it really was called before stack variables
get allocated (because if such variable with a pointer is missed, it may lead
to over-collecting (typical symptom is segfaulting)).

2 files changed, 2 insertions, 0 deletions

diff --git a/qemu-arm/main.c b/qemu-arm/main.c
index f29547523..b6ff73980 100644
--- a/qemu-arm/main.c
+++ b/qemu-arm/main.c
@@ -32,6 +32,7 @@ void do_str(const char *src, mp_parse_input_kind_t input_kind) {
 }
 
 int main(int argc, char **argv) {
+    mp_stack_ctrl_init();
     mp_stack_set_limit(10240);
     void *heap = malloc(16 * 1024);
     gc_init(heap, (char*)heap + 16 * 1024);
diff --git a/qemu-arm/test_main.c b/qemu-arm/test_main.c
index a98e275ce..44f9cc666 100644
--- a/qemu-arm/test_main.c
+++ b/qemu-arm/test_main.c
@@ -49,6 +49,7 @@ end:
 
 int main() {
     const char a[] = {"sim"};
+    mp_stack_ctrl_init();
     mp_stack_set_limit(10240);
     void *heap = malloc(256 * 1024);
     gc_init(heap, (char*)heap + 256 * 1024);