fix(core): emulator: coverage data atexit handler

Partially reverts 5fc3c6e617.

[no changelog]

core/embed/bootloader/emulator.c

@@ -22,6 +22,9 @@ uint8_t *FIRMWARE_START = 0;
 
 void set_core_clock(int) {}
 
+// used in fw emulator to raise python exception on exit
+void __attribute__((noreturn)) main_clean_exit() { exit(3); }
+
 int bootloader_main(void);
 
 // assuming storage is single subarea

core/embed/trezorhal/unix/common.c

@@ -28,6 +28,8 @@
 #include "display.h"
 #include "memzero.h"
 
+void __attribute__((noreturn)) main_clean_exit();
+
 void __attribute__((noreturn)) trezor_shutdown(void) {
   printf("SHUTDOWN\n");
 
@@ -49,7 +51,7 @@ uint32_t hal_ticks_ms() {
 static int SDLCALL emulator_event_filter(void *userdata, SDL_Event *event) {
   switch (event->type) {
     case SDL_QUIT:
-      exit(3);
+      main_clean_exit();
       return 0;
     case SDL_KEYUP:
       if (event->key.repeat) {
@@ -57,7 +59,7 @@ static int SDLCALL emulator_event_filter(void *userdata, SDL_Event *event) {
       }
       switch (event->key.keysym.sym) {
         case SDLK_ESCAPE:
-          exit(3);
+          main_clean_exit();
           return 0;
         case SDLK_p:
           display_save("emu");

core/embed/unix/main.c

@@ -408,6 +408,19 @@ STATIC void set_sys_argv(char *argv[], int argc, int start_arg) {
   }
 }
 
+// Inject SystemExit exception. This is primarily needed by prof.py to run the
+// atexit() handler.
+void __attribute__((noreturn)) main_clean_exit() {
+  const int status = 3;
+  fflush(stdout);
+  fflush(stderr);
+  // sys.exit is disabled, so raise a SystemExit exception directly
+  nlr_raise(mp_obj_new_exception_arg1(&mp_type_SystemExit,
+                                      MP_OBJ_NEW_SMALL_INT(status)));
+  // the above shouldn't return, but make sure we exit just in case
+  exit(status);
+}
+
 #ifdef _WIN32
 #define PATHLIST_SEP_CHAR ';'
 #else
@@ -682,7 +695,9 @@ MP_NOINLINE int main_(int argc, char **argv) {
 #if !MICROPY_VFS
 
 #ifdef TREZOR_EMULATOR_FROZEN
-mp_import_stat_t mp_import_stat(const char *path) { return MP_IMPORT_STAT_NO_EXIST; }
+mp_import_stat_t mp_import_stat(const char *path) {
+  return MP_IMPORT_STAT_NO_EXIST;
+}
 #else
 mp_import_stat_t mp_import_stat(const char *path) {
   struct stat st;