Implement proper exception type hierarchy.

Each built-in exception is now a type, with base type BaseException.
C exceptions are created by passing a pointer to the exception type to
make an instance of.  When raising an exception from the VM, an
instance is created automatically if an exception type is raised (as
opposed to an exception instance).

Exception matching (RT_BINARY_OP_EXCEPTION_MATCH) is now proper.

Handling of parse error changed to match new exceptions.

mp_const_type renamed to mp_type_type for consistency.

1 files changed, 2 insertions, 1 deletions

diff --git a/stm/usb.c b/stm/usb.c
index 0fe56d3212..718d432e61 100644
--- a/stm/usb.c
+++ b/stm/usb.c
@@ -41,7 +41,7 @@ void pyb_usb_dev_init(void) {
     dev_is_enabled = 1;
 
     // create an exception object for interrupting by VCP
-    mp_const_vcp_interrupt = mp_obj_new_exception(qstr_from_str("VCPInterrupt"));
+    mp_const_vcp_interrupt = mp_obj_new_exception_msg(&mp_type_OSError, "VCPInterrupt");
 #endif
 }
 
@@ -66,6 +66,7 @@ void usb_vcp_receive(const char *buf, uint32_t len) {
             // catch special interrupt character
             if (buf[i] == interrupt_char) {
                 // raise exception when interrupts are finished
+                mp_obj_exception_clear_traceback(mp_const_vcp_interrupt);
                 pendsv_nlr_jump(mp_const_vcp_interrupt);
                 interrupt_char = VCP_CHAR_NONE;
                 continue;