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.

9 files changed, 20 insertions, 22 deletions

diff --git a/stm/adc.c b/stm/adc.c
index 89f137a08..cd915b172 100644
--- a/stm/adc.c
+++ b/stm/adc.c
@@ -332,7 +332,7 @@ static const mp_method_t adc_all_methods[] = {
 };
 
 static const mp_obj_type_t adc_all_type = {
-    { &mp_const_type },
+    { &mp_type_type },
     .name = MP_QSTR_ADC,
     .print = adc_all_print,
     .methods = adc_all_methods,
@@ -386,7 +386,7 @@ static const mp_method_t adc_methods[] = {
 };
 
 static const mp_obj_type_t adc_type = {
-    { &mp_const_type },
+    { &mp_type_type },
     .name = MP_QSTR_ADC,
     .print = adc_print,
     .methods = adc_methods,
@@ -427,7 +427,7 @@ mp_obj_t pyb_ADC(mp_obj_t pin_name_obj) {
     }
 
     if (i == ADC_NUM_CHANNELS) {
-        nlr_jump(mp_obj_new_exception_msg_varg(MP_QSTR_ValueError, "pin %s does not have ADC capabilities", pin_name));
+        nlr_jump(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "pin %s does not have ADC capabilities", pin_name));
     }
 
     // init ADC just for this channel
@@ -438,7 +438,7 @@ mp_obj_t pyb_ADC(mp_obj_t pin_name_obj) {
     return o;
 
 pin_error:
-    nlr_jump(mp_obj_new_exception_msg_varg(MP_QSTR_ValueError, "pin %s does not exist", pin_name));
+    nlr_jump(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "pin %s does not exist", pin_name));
 }
 
 MP_DEFINE_CONST_FUN_OBJ_1(pyb_ADC_obj, pyb_ADC);
diff --git a/stm/file.c b/stm/file.c
index f50d3771a..283159a69 100644
--- a/stm/file.c
+++ b/stm/file.c
@@ -60,7 +60,7 @@ static const mp_method_t file_methods[] = {
 };
 
 static const mp_obj_type_t file_obj_type = {
-    { &mp_const_type },
+    { &mp_type_type },
     .name = MP_QSTR_File,
     .print = file_obj_print,
     .methods = file_methods,
diff --git a/stm/i2c.c b/stm/i2c.c
index f355878f2..33d9a43f3 100644
--- a/stm/i2c.c
+++ b/stm/i2c.c
@@ -335,7 +335,7 @@ static const mp_method_t i2c_methods[] = {
 };
 
 static const mp_obj_type_t i2c_obj_type = {
-    { &mp_const_type },
+    { &mp_type_type },
     .name = MP_QSTR_I2C,
     .print = i2c_obj_print,
     .methods = i2c_methods,
diff --git a/stm/led.c b/stm/led.c
index 3a7d8a7a7..683e82bc6 100644
--- a/stm/led.c
+++ b/stm/led.c
@@ -148,7 +148,7 @@ static const mp_method_t led_methods[] = {
 };
 
 static const mp_obj_type_t led_obj_type = {
-    { &mp_const_type },
+    { &mp_type_type },
     .name = MP_QSTR_Led,
     .print = led_obj_print,
     .methods = led_methods,
diff --git a/stm/main.c b/stm/main.c
index 3484fd28d..2bf7c1ba3 100644
--- a/stm/main.c
+++ b/stm/main.c
@@ -24,6 +24,7 @@
 #include "lexerfatfs.h"
 #include "parse.h"
 #include "obj.h"
+#include "parsehelper.h"
 #include "compile.h"
 #include "runtime0.h"
 #include "runtime.h"
@@ -404,15 +405,13 @@ void do_repl(void) {
         }
 
         mp_lexer_t *lex = mp_lexer_new_from_str_len(MP_QSTR__lt_stdin_gt_, vstr_str(&line), vstr_len(&line), 0);
-        qstr parse_exc_id;
-        const char *parse_exc_msg;
-        mp_parse_node_t pn = mp_parse(lex, MP_PARSE_SINGLE_INPUT, &parse_exc_id, &parse_exc_msg);
+        mp_parse_error_kind_t parse_error_kind;
+        mp_parse_node_t pn = mp_parse(lex, MP_PARSE_SINGLE_INPUT, &parse_error_kind);
         qstr source_name = mp_lexer_source_name(lex);
 
         if (pn == MP_PARSE_NODE_NULL) {
             // parse error
-            mp_lexer_show_error_pythonic_prefix(lex);
-            printf("%s: %s\n", qstr_str(parse_exc_id), parse_exc_msg);
+            mp_parse_show_exception(lex, parse_error_kind);
             mp_lexer_free(lex);
         } else {
             // parse okay
@@ -456,15 +455,13 @@ bool do_file(const char *filename) {
         return false;
     }
 
-    qstr parse_exc_id;
-    const char *parse_exc_msg;
-    mp_parse_node_t pn = mp_parse(lex, MP_PARSE_FILE_INPUT, &parse_exc_id, &parse_exc_msg);
+    mp_parse_error_kind_t parse_error_kind;
+    mp_parse_node_t pn = mp_parse(lex, MP_PARSE_FILE_INPUT, &parse_error_kind);
     qstr source_name = mp_lexer_source_name(lex);
 
     if (pn == MP_PARSE_NODE_NULL) {
         // parse error
-        mp_lexer_show_error_pythonic_prefix(lex);
-        printf("%s: %s\n", qstr_str(parse_exc_id), parse_exc_msg);
+        mp_parse_show_exception(lex, parse_error_kind);
         mp_lexer_free(lex);
         return false;
     }
@@ -536,7 +533,7 @@ mp_obj_t pyb_gpio(uint n_args, mp_obj_t *args) {
     }
 
 pin_error:
-    nlr_jump(mp_obj_new_exception_msg_varg(MP_QSTR_ValueError, "pin %s does not exist", pin_name));
+    nlr_jump(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "pin %s does not exist", pin_name));
 }
 
 MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(pyb_gpio_obj, 1, 2, pyb_gpio);
diff --git a/stm/sdcard.c b/stm/sdcard.c
index c98bab4d9..0b5fdb2c8 100644
--- a/stm/sdcard.c
+++ b/stm/sdcard.c
@@ -202,7 +202,7 @@ static const mp_method_t sdcard_methods[] = {
 };
 
 static const mp_obj_type_t sdcard_type = {
-    { &mp_const_type },
+    { &mp_type_type },
     .name = MP_QSTR_SDcard,
     .methods = sdcard_methods,
 };
diff --git a/stm/servo.c b/stm/servo.c
index 4b69eefcf..4943a6442 100644
--- a/stm/servo.c
+++ b/stm/servo.c
@@ -144,7 +144,7 @@ static const mp_method_t servo_methods[] = {
 };
 
 static const mp_obj_type_t servo_obj_type = {
-    { &mp_const_type },
+    { &mp_type_type },
     .name = MP_QSTR_Servo,
     .print = servo_obj_print,
     .methods = servo_methods,
diff --git a/stm/usart.c b/stm/usart.c
index e24211a83..6478f0115 100644
--- a/stm/usart.c
+++ b/stm/usart.c
@@ -242,7 +242,7 @@ static const mp_method_t usart_methods[] = {
 };
 
 static const mp_obj_type_t usart_obj_type = {
-    { &mp_const_type },
+    { &mp_type_type },
     .name = MP_QSTR_Usart,
     .print = usart_obj_print,
     .methods = usart_methods,
diff --git a/stm/usb.c b/stm/usb.c
index 0fe56d321..718d432e6 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;