py/objexcept.c - lite/micropython - Linaro Git Browser

 /*
  * This file is part of the Micro Python project, http://micropython.org/
  *
  * The MIT License (MIT)
  *
  * Copyright (c) 2013, 2014 Damien P. George
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */

 #include <string.h>
 #include <stdarg.h>
 #include <assert.h>

 #include "mpconfig.h"
 #include "nlr.h"
 #include "misc.h"
 #include "qstr.h"
 #include "obj.h"
 #include "objtuple.h"
 #include "objtype.h"
 #include "runtime.h"
 #include "runtime0.h"
 #include "gc.h"

 typedef struct _mp_obj_exception_t {
     mp_obj_base_t base;
     mp_obj_t traceback; // a list object, holding (file,line,block) as numbers (not Python objects); a hack for now
     mp_obj_tuple_t *args;
 } mp_obj_exception_t;

 // Instance of MemoryError exception - needed by mp_malloc_fail
 const mp_obj_exception_t mp_const_MemoryError_obj = {{&mp_type_MemoryError}, MP_OBJ_NULL, mp_const_empty_tuple};

 // Local non-heap memory for allocating an exception when we run out of RAM
 STATIC mp_obj_exception_t mp_emergency_exception_obj;

 // Instance of GeneratorExit exception - needed by generator.close()
 // This would belong to objgenerator.c, but to keep mp_obj_exception_t
 // definition module-private so far, have it here.
 const mp_obj_exception_t mp_const_GeneratorExit_obj = {{&mp_type_GeneratorExit}, MP_OBJ_NULL, mp_const_empty_tuple};

 STATIC void mp_obj_exception_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t o_in, mp_print_kind_t kind) {
     mp_obj_exception_t *o = o_in;
     mp_print_kind_t k = kind & ~PRINT_EXC_SUBCLASS;
     bool is_subclass = kind & PRINT_EXC_SUBCLASS;
     if (!is_subclass && (k == PRINT_REPR || k == PRINT_EXC)) {
         print(env, "%s", qstr_str(o->base.type->name));
     }

     if (k == PRINT_EXC) {
         print(env, ": ");
     }

     if (k == PRINT_STR || k == PRINT_EXC) {
         if (o->args == NULL || o->args->len == 0) {
             print(env, "");
             return;
         } else if (o->args->len == 1) {
             mp_obj_print_helper(print, env, o->args->items[0], PRINT_STR);
             return;
         }
     }
     mp_obj_tuple_print(print, env, o->args, kind);
 }

 mp_obj_t mp_obj_exception_make_new(mp_obj_t type_in, uint n_args, uint n_kw, const mp_obj_t *args) {
     mp_obj_type_t *type = type_in;

     if (n_kw != 0) {
         nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_TypeError, "%s does not take keyword arguments", mp_obj_get_type_str(type_in)));
     }

     mp_obj_exception_t *o = m_new_obj_var_maybe(mp_obj_exception_t, mp_obj_t, 0);
     if (o == NULL) {
         // Couldn't allocate heap memory; use local data instead.
         o = &mp_emergency_exception_obj;
         // We can't store any args.
         n_args = 0;
         o->args = mp_const_empty_tuple;
     } else {
         o->args = mp_obj_new_tuple(n_args, args);
     }
     o->base.type = type;
     o->traceback = MP_OBJ_NULL;
     return o;
 }

 // Get exception "value" - that is, first argument, or None
 mp_obj_t mp_obj_exception_get_value(mp_obj_t self_in) {
     mp_obj_exception_t *self = self_in;
     if (self->args->len == 0) {
         return mp_const_none;
     } else {
         return self->args->items[0];
     }
 }

 STATIC void exception_load_attr(mp_obj_t self_in, qstr attr, mp_obj_t *dest) {
     mp_obj_exception_t *self = self_in;
     if (attr == MP_QSTR_args) {
         dest[0] = self->args;
     } else if (self->base.type == &mp_type_StopIteration && attr == MP_QSTR_value) {
         dest[0] = mp_obj_exception_get_value(self);
     }
 }

 STATIC mp_obj_t exc___init__(uint n_args, const mp_obj_t *args) {
     mp_obj_exception_t *self = args[0];
     mp_obj_t argst = mp_obj_new_tuple(n_args - 1, args + 1);
     self->args = argst;
     return mp_const_none;
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(exc___init___obj, 1, MP_OBJ_FUN_ARGS_MAX, exc___init__);

 STATIC const mp_map_elem_t exc_locals_dict_table[] = {
     { MP_OBJ_NEW_QSTR(MP_QSTR___init__), (mp_obj_t)&exc___init___obj },
 };

 STATIC MP_DEFINE_CONST_DICT(exc_locals_dict, exc_locals_dict_table);

 const mp_obj_type_t mp_type_BaseException = {
     { &mp_type_type },
     .name = MP_QSTR_BaseException,
     .print = mp_obj_exception_print,
     .make_new = mp_obj_exception_make_new,
     .load_attr = exception_load_attr,
     .locals_dict = (mp_obj_t)&exc_locals_dict,
 };

 #define MP_DEFINE_EXCEPTION_BASE(base_name) \
 STATIC const mp_obj_tuple_t mp_type_ ## base_name ## _base_tuple = {{&mp_type_tuple}, 1, {(mp_obj_t)&mp_type_ ## base_name}};\

 #define MP_DEFINE_EXCEPTION(exc_name, base_name) \
 const mp_obj_type_t mp_type_ ## exc_name = { \
     { &mp_type_type }, \
     .name = MP_QSTR_ ## exc_name, \
     .print = mp_obj_exception_print, \
     .make_new = mp_obj_exception_make_new, \
     .load_attr = exception_load_attr, \
     .bases_tuple = (mp_obj_t)&mp_type_ ## base_name ## _base_tuple, \
 };

 // List of all exceptions, arranged as in the table at:
 // http://docs.python.org/3/library/exceptions.html
 MP_DEFINE_EXCEPTION_BASE(BaseException)
 MP_DEFINE_EXCEPTION(SystemExit, BaseException)
 //MP_DEFINE_EXCEPTION(KeyboardInterrupt, BaseException)
 MP_DEFINE_EXCEPTION(GeneratorExit, BaseException)
 MP_DEFINE_EXCEPTION(Exception, BaseException)
   MP_DEFINE_EXCEPTION_BASE(Exception)
   MP_DEFINE_EXCEPTION(StopIteration, Exception)
   MP_DEFINE_EXCEPTION(ArithmeticError, Exception)
     MP_DEFINE_EXCEPTION_BASE(ArithmeticError)
     //MP_DEFINE_EXCEPTION(FloatingPointError, ArithmeticError)
     MP_DEFINE_EXCEPTION(OverflowError, ArithmeticError)
     MP_DEFINE_EXCEPTION(ZeroDivisionError, ArithmeticError)
   MP_DEFINE_EXCEPTION(AssertionError, Exception)
   MP_DEFINE_EXCEPTION(AttributeError, Exception)
   //MP_DEFINE_EXCEPTION(BufferError, Exception)
   //MP_DEFINE_EXCEPTION(EnvironmentError, Exception)
   MP_DEFINE_EXCEPTION(EOFError, Exception)
   MP_DEFINE_EXCEPTION(ImportError, Exception)
   MP_DEFINE_EXCEPTION(IOError, Exception)
   MP_DEFINE_EXCEPTION(LookupError, Exception)
     MP_DEFINE_EXCEPTION_BASE(LookupError)
     MP_DEFINE_EXCEPTION(IndexError, LookupError)
     MP_DEFINE_EXCEPTION(KeyError, LookupError)
   MP_DEFINE_EXCEPTION(MemoryError, Exception)
   MP_DEFINE_EXCEPTION(NameError, Exception)
     /*
     MP_DEFINE_EXCEPTION_BASE(NameError)
     MP_DEFINE_EXCEPTION(UnboundLocalError, NameError)
     */
   MP_DEFINE_EXCEPTION(OSError, Exception)
     /*
     MP_DEFINE_EXCEPTION_BASE(OSError)
     MP_DEFINE_EXCEPTION(BlockingIOError, OSError)
     MP_DEFINE_EXCEPTION(ChildProcessError, OSError)
     MP_DEFINE_EXCEPTION(ConnectionError, OSError)
       MP_DEFINE_EXCEPTION(BrokenPipeError, ConnectionError)
       MP_DEFINE_EXCEPTION(ConnectionAbortedError, ConnectionError)
       MP_DEFINE_EXCEPTION(ConnectionRefusedError, ConnectionError)
       MP_DEFINE_EXCEPTION(ConnectionResetError, ConnectionError)
     MP_DEFINE_EXCEPTION(InterruptedError, OSError)
     MP_DEFINE_EXCEPTION(IsADirectoryError, OSError)
     MP_DEFINE_EXCEPTION(NotADirectoryError, OSError)
     MP_DEFINE_EXCEPTION(PermissionError, OSError)
     MP_DEFINE_EXCEPTION(ProcessLookupError, OSError)
     MP_DEFINE_EXCEPTION(TimeoutError, OSError)
     MP_DEFINE_EXCEPTION(FileExistsError, OSError)
     MP_DEFINE_EXCEPTION(FileNotFoundError, OSError)
     MP_DEFINE_EXCEPTION(ReferenceError, Exception)
     */
   MP_DEFINE_EXCEPTION(RuntimeError, Exception)
     MP_DEFINE_EXCEPTION_BASE(RuntimeError)
     MP_DEFINE_EXCEPTION(NotImplementedError, RuntimeError)
   MP_DEFINE_EXCEPTION(SyntaxError, Exception)
     MP_DEFINE_EXCEPTION_BASE(SyntaxError)
     MP_DEFINE_EXCEPTION(IndentationError, SyntaxError)
     /*
       MP_DEFINE_EXCEPTION_BASE(IndentationError)
       MP_DEFINE_EXCEPTION(TabError, IndentationError)
       */
   MP_DEFINE_EXCEPTION(SystemError, Exception)
   MP_DEFINE_EXCEPTION(TypeError, Exception)
   MP_DEFINE_EXCEPTION(ValueError, Exception)
     //TODO: Implement UnicodeErrors which take arguments
   /*
   MP_DEFINE_EXCEPTION(Warning, Exception)
     MP_DEFINE_EXCEPTION_BASE(Warning)
     MP_DEFINE_EXCEPTION(DeprecationWarning, Warning)
     MP_DEFINE_EXCEPTION(PendingDeprecationWarning, Warning)
     MP_DEFINE_EXCEPTION(RuntimeWarning, Warning)
     MP_DEFINE_EXCEPTION(SyntaxWarning, Warning)
     MP_DEFINE_EXCEPTION(UserWarning, Warning)
     MP_DEFINE_EXCEPTION(FutureWarning, Warning)
     MP_DEFINE_EXCEPTION(ImportWarning, Warning)
     MP_DEFINE_EXCEPTION(UnicodeWarning, Warning)
     MP_DEFINE_EXCEPTION(BytesWarning, Warning)
     MP_DEFINE_EXCEPTION(ResourceWarning, Warning)
     */

 mp_obj_t mp_obj_new_exception(const mp_obj_type_t *exc_type) {
     return mp_obj_new_exception_args(exc_type, 0, NULL);
 }

 // "Optimized" version for common(?) case of having 1 exception arg
 mp_obj_t mp_obj_new_exception_arg1(const mp_obj_type_t *exc_type, mp_obj_t arg) {
     return mp_obj_new_exception_args(exc_type, 1, &arg);
 }

 mp_obj_t mp_obj_new_exception_args(const mp_obj_type_t *exc_type, uint n_args, const mp_obj_t *args) {
     assert(exc_type->make_new == mp_obj_exception_make_new);
     return exc_type->make_new((mp_obj_t)exc_type, n_args, 0, args);
 }

 mp_obj_t mp_obj_new_exception_msg(const mp_obj_type_t *exc_type, const char *msg) {
     return mp_obj_new_exception_msg_varg(exc_type, msg);
 }

 mp_obj_t mp_obj_new_exception_msg_varg(const mp_obj_type_t *exc_type, const char *fmt, ...) {
     // check that the given type is an exception type
     assert(exc_type->make_new == mp_obj_exception_make_new);

     // make exception object
     mp_obj_exception_t *o = m_new_obj_var_maybe(mp_obj_exception_t, mp_obj_t, 0);
     if (o == NULL) {
         // Couldn't allocate heap memory; use local data instead.
         // Unfortunately, we won't be able to format the string...
         o = &mp_emergency_exception_obj;
         o->base.type = exc_type;
         o->traceback = MP_OBJ_NULL;
         o->args = mp_const_empty_tuple;
     } else {
         o->base.type = exc_type;
         o->traceback = MP_OBJ_NULL;
         o->args = mp_obj_new_tuple(1, NULL);

         if (fmt == NULL) {
             // no message
             assert(0);
         } else {
             // render exception message and store as .args[0]
             // TODO: optimize bufferbloat
             vstr_t *vstr = vstr_new();
             va_list ap;
             va_start(ap, fmt);
             vstr_vprintf(vstr, fmt, ap);
             va_end(ap);
             o->args->items[0] = mp_obj_new_str(vstr->buf, vstr->len, false);
             vstr_free(vstr);
         }
     }

     return o;
 }

 // return true if the given object is an exception type
 bool mp_obj_is_exception_type(mp_obj_t self_in) {
     if (MP_OBJ_IS_TYPE(self_in, &mp_type_type)) {
         // optimisation when self_in is a builtin exception
         mp_obj_type_t *self = self_in;
         if (self->make_new == mp_obj_exception_make_new) {
             return true;
         }
     }
     return mp_obj_is_subclass_fast(self_in, &mp_type_BaseException);
 }

 // return true if the given object is an instance of an exception type
 bool mp_obj_is_exception_instance(mp_obj_t self_in) {
     return mp_obj_is_exception_type(mp_obj_get_type(self_in));
 }

 // return true if exception (type or instance) is a subclass of given
 // exception type.
 bool mp_obj_exception_match(mp_obj_t exc, const mp_obj_type_t *exc_type) {
     // TODO: move implementation from RT_BINARY_OP_EXCEPTION_MATCH here.
     return mp_binary_op(MP_BINARY_OP_EXCEPTION_MATCH, exc, (mp_obj_t)exc_type) == mp_const_true;
 }

 // traceback handling functions

 #define GET_NATIVE_EXCEPTION(self, self_in) \
     /* make sure self_in is an exception instance */ \
     assert(mp_obj_is_exception_instance(self_in)); \
     mp_obj_exception_t *self; \
     if (mp_obj_is_native_exception_instance(self_in)) { \
         self = self_in; \
     } else { \
         self = ((mp_obj_instance_t*)self_in)->subobj[0]; \
     }

 void mp_obj_exception_clear_traceback(mp_obj_t self_in) {
     GET_NATIVE_EXCEPTION(self, self_in);
     // just set the traceback to the null object
     // we don't want to call any memory management functions here
     self->traceback = MP_OBJ_NULL;
 }

 void mp_obj_exception_add_traceback(mp_obj_t self_in, qstr file, mp_uint_t line, qstr block) {
     #if MICROPY_ENABLE_GC
     if (gc_is_locked()) {
         // We can't allocate memory, so don't bother to try
         return;
     }
     #endif

     GET_NATIVE_EXCEPTION(self, self_in);

     // for traceback, we are just using the list object for convenience, it's not really a list of Python objects
     if (self->traceback == MP_OBJ_NULL) {
         self->traceback = mp_obj_new_list(0, NULL);
     }
     mp_obj_list_append(self->traceback, (mp_obj_t)(mp_uint_t)file);
     mp_obj_list_append(self->traceback, (mp_obj_t)(mp_uint_t)line);
     mp_obj_list_append(self->traceback, (mp_obj_t)(mp_uint_t)block);
 }

 void mp_obj_exception_get_traceback(mp_obj_t self_in, mp_uint_t *n, mp_uint_t **values) {
     GET_NATIVE_EXCEPTION(self, self_in);

     if (self->traceback == MP_OBJ_NULL) {
         *n = 0;
         *values = NULL;
     } else {
         uint n2;
         mp_obj_list_get(self->traceback, &n2, (mp_obj_t**)values);
         *n = n2;
     }
 }
	/*
	* This file is part of the Micro Python project, http://micropython.org/
	*
	* The MIT License (MIT)
	*
	* Copyright (c) 2013, 2014 Damien P. George
	*
	* Permission is hereby granted, free of charge, to any person obtaining a copy
	* of this software and associated documentation files (the "Software"), to deal
	* in the Software without restriction, including without limitation the rights
	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	* copies of the Software, and to permit persons to whom the Software is
	* furnished to do so, subject to the following conditions:
	*
	* The above copyright notice and this permission notice shall be included in
	* all copies or substantial portions of the Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	* THE SOFTWARE.
	*/

	#include <string.h>
	#include <stdarg.h>
	#include <assert.h>

	#include "mpconfig.h"
	#include "nlr.h"
	#include "misc.h"
	#include "qstr.h"
	#include "obj.h"
	#include "objtuple.h"
	#include "objtype.h"
	#include "runtime.h"
	#include "runtime0.h"
	#include "gc.h"

	typedef struct _mp_obj_exception_t {
	mp_obj_base_t base;
	mp_obj_t traceback; // a list object, holding (file,line,block) as numbers (not Python objects); a hack for now
	mp_obj_tuple_t *args;
	} mp_obj_exception_t;

	// Instance of MemoryError exception - needed by mp_malloc_fail
	const mp_obj_exception_t mp_const_MemoryError_obj = {{&mp_type_MemoryError}, MP_OBJ_NULL, mp_const_empty_tuple};

	// Local non-heap memory for allocating an exception when we run out of RAM
	STATIC mp_obj_exception_t mp_emergency_exception_obj;

	// Instance of GeneratorExit exception - needed by generator.close()
	// This would belong to objgenerator.c, but to keep mp_obj_exception_t
	// definition module-private so far, have it here.
	const mp_obj_exception_t mp_const_GeneratorExit_obj = {{&mp_type_GeneratorExit}, MP_OBJ_NULL, mp_const_empty_tuple};

	STATIC void mp_obj_exception_print(void (print)(void env, const char fmt, ...), void env, mp_obj_t o_in, mp_print_kind_t kind) {
	mp_obj_exception_t *o = o_in;
	mp_print_kind_t k = kind & ~PRINT_EXC_SUBCLASS;
	bool is_subclass = kind & PRINT_EXC_SUBCLASS;
	if (!is_subclass && (k == PRINT_REPR \|\| k == PRINT_EXC)) {
	print(env, "%s", qstr_str(o->base.type->name));
	}

	if (k == PRINT_EXC) {
	print(env, ": ");
	}

	if (k == PRINT_STR \|\| k == PRINT_EXC) {
	if (o->args == NULL \|\| o->args->len == 0) {
	print(env, "");
	return;
	} else if (o->args->len == 1) {
	mp_obj_print_helper(print, env, o->args->items[0], PRINT_STR);
	return;
	}
	}
	mp_obj_tuple_print(print, env, o->args, kind);
	}

	mp_obj_t mp_obj_exception_make_new(mp_obj_t type_in, uint n_args, uint n_kw, const mp_obj_t *args) {
	mp_obj_type_t *type = type_in;

	if (n_kw != 0) {
	nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_TypeError, "%s does not take keyword arguments", mp_obj_get_type_str(type_in)));
	}

	mp_obj_exception_t *o = m_new_obj_var_maybe(mp_obj_exception_t, mp_obj_t, 0);
	if (o == NULL) {
	// Couldn't allocate heap memory; use local data instead.
	o = &mp_emergency_exception_obj;
	// We can't store any args.
	n_args = 0;
	o->args = mp_const_empty_tuple;
	} else {
	o->args = mp_obj_new_tuple(n_args, args);
	}
	o->base.type = type;
	o->traceback = MP_OBJ_NULL;
	return o;
	}

	// Get exception "value" - that is, first argument, or None
	mp_obj_t mp_obj_exception_get_value(mp_obj_t self_in) {
	mp_obj_exception_t *self = self_in;
	if (self->args->len == 0) {
	return mp_const_none;
	} else {
	return self->args->items[0];
	}
	}

	STATIC void exception_load_attr(mp_obj_t self_in, qstr attr, mp_obj_t *dest) {
	mp_obj_exception_t *self = self_in;
	if (attr == MP_QSTR_args) {
	dest[0] = self->args;
	} else if (self->base.type == &mp_type_StopIteration && attr == MP_QSTR_value) {
	dest[0] = mp_obj_exception_get_value(self);
	}
	}

	STATIC mp_obj_t exc___init__(uint n_args, const mp_obj_t *args) {
	mp_obj_exception_t *self = args[0];
	mp_obj_t argst = mp_obj_new_tuple(n_args - 1, args + 1);
	self->args = argst;
	return mp_const_none;
	}
	STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(exc___init___obj, 1, MP_OBJ_FUN_ARGS_MAX, exc___init__);

	STATIC const mp_map_elem_t exc_locals_dict_table[] = {
	{ MP_OBJ_NEW_QSTR(MP_QSTR___init__), (mp_obj_t)&exc___init___obj },
	};

	STATIC MP_DEFINE_CONST_DICT(exc_locals_dict, exc_locals_dict_table);

	const mp_obj_type_t mp_type_BaseException = {
	{ &mp_type_type },
	.name = MP_QSTR_BaseException,
	.print = mp_obj_exception_print,
	.make_new = mp_obj_exception_make_new,
	.load_attr = exception_load_attr,
	.locals_dict = (mp_obj_t)&exc_locals_dict,
	};

	#define MP_DEFINE_EXCEPTION_BASE(base_name) \
	STATIC const mp_obj_tuple_t mp_type_ ## base_name ## _base_tuple = {{&mp_type_tuple}, 1, {(mp_obj_t)&mp_type_ ## base_name}};\

	#define MP_DEFINE_EXCEPTION(exc_name, base_name) \
	const mp_obj_type_t mp_type_ ## exc_name = { \
	{ &mp_type_type }, \
	.name = MP_QSTR_ ## exc_name, \
	.print = mp_obj_exception_print, \
	.make_new = mp_obj_exception_make_new, \
	.load_attr = exception_load_attr, \
	.bases_tuple = (mp_obj_t)&mp_type_ ## base_name ## _base_tuple, \
	};

	// List of all exceptions, arranged as in the table at:
	// http://docs.python.org/3/library/exceptions.html
	MP_DEFINE_EXCEPTION_BASE(BaseException)
	MP_DEFINE_EXCEPTION(SystemExit, BaseException)
	//MP_DEFINE_EXCEPTION(KeyboardInterrupt, BaseException)
	MP_DEFINE_EXCEPTION(GeneratorExit, BaseException)
	MP_DEFINE_EXCEPTION(Exception, BaseException)
	MP_DEFINE_EXCEPTION_BASE(Exception)
	MP_DEFINE_EXCEPTION(StopIteration, Exception)
	MP_DEFINE_EXCEPTION(ArithmeticError, Exception)
	MP_DEFINE_EXCEPTION_BASE(ArithmeticError)
	//MP_DEFINE_EXCEPTION(FloatingPointError, ArithmeticError)
	MP_DEFINE_EXCEPTION(OverflowError, ArithmeticError)
	MP_DEFINE_EXCEPTION(ZeroDivisionError, ArithmeticError)
	MP_DEFINE_EXCEPTION(AssertionError, Exception)
	MP_DEFINE_EXCEPTION(AttributeError, Exception)
	//MP_DEFINE_EXCEPTION(BufferError, Exception)
	//MP_DEFINE_EXCEPTION(EnvironmentError, Exception)
	MP_DEFINE_EXCEPTION(EOFError, Exception)
	MP_DEFINE_EXCEPTION(ImportError, Exception)
	MP_DEFINE_EXCEPTION(IOError, Exception)
	MP_DEFINE_EXCEPTION(LookupError, Exception)
	MP_DEFINE_EXCEPTION_BASE(LookupError)
	MP_DEFINE_EXCEPTION(IndexError, LookupError)
	MP_DEFINE_EXCEPTION(KeyError, LookupError)
	MP_DEFINE_EXCEPTION(MemoryError, Exception)
	MP_DEFINE_EXCEPTION(NameError, Exception)
	/*
	MP_DEFINE_EXCEPTION_BASE(NameError)
	MP_DEFINE_EXCEPTION(UnboundLocalError, NameError)
	*/
	MP_DEFINE_EXCEPTION(OSError, Exception)
	/*
	MP_DEFINE_EXCEPTION_BASE(OSError)
	MP_DEFINE_EXCEPTION(BlockingIOError, OSError)
	MP_DEFINE_EXCEPTION(ChildProcessError, OSError)
	MP_DEFINE_EXCEPTION(ConnectionError, OSError)
	MP_DEFINE_EXCEPTION(BrokenPipeError, ConnectionError)
	MP_DEFINE_EXCEPTION(ConnectionAbortedError, ConnectionError)
	MP_DEFINE_EXCEPTION(ConnectionRefusedError, ConnectionError)
	MP_DEFINE_EXCEPTION(ConnectionResetError, ConnectionError)
	MP_DEFINE_EXCEPTION(InterruptedError, OSError)
	MP_DEFINE_EXCEPTION(IsADirectoryError, OSError)
	MP_DEFINE_EXCEPTION(NotADirectoryError, OSError)
	MP_DEFINE_EXCEPTION(PermissionError, OSError)
	MP_DEFINE_EXCEPTION(ProcessLookupError, OSError)
	MP_DEFINE_EXCEPTION(TimeoutError, OSError)
	MP_DEFINE_EXCEPTION(FileExistsError, OSError)
	MP_DEFINE_EXCEPTION(FileNotFoundError, OSError)
	MP_DEFINE_EXCEPTION(ReferenceError, Exception)
	*/
	MP_DEFINE_EXCEPTION(RuntimeError, Exception)
	MP_DEFINE_EXCEPTION_BASE(RuntimeError)
	MP_DEFINE_EXCEPTION(NotImplementedError, RuntimeError)
	MP_DEFINE_EXCEPTION(SyntaxError, Exception)
	MP_DEFINE_EXCEPTION_BASE(SyntaxError)
	MP_DEFINE_EXCEPTION(IndentationError, SyntaxError)
	/*
	MP_DEFINE_EXCEPTION_BASE(IndentationError)
	MP_DEFINE_EXCEPTION(TabError, IndentationError)
	*/
	MP_DEFINE_EXCEPTION(SystemError, Exception)
	MP_DEFINE_EXCEPTION(TypeError, Exception)
	MP_DEFINE_EXCEPTION(ValueError, Exception)
	//TODO: Implement UnicodeErrors which take arguments
	/*
	MP_DEFINE_EXCEPTION(Warning, Exception)
	MP_DEFINE_EXCEPTION_BASE(Warning)
	MP_DEFINE_EXCEPTION(DeprecationWarning, Warning)
	MP_DEFINE_EXCEPTION(PendingDeprecationWarning, Warning)
	MP_DEFINE_EXCEPTION(RuntimeWarning, Warning)
	MP_DEFINE_EXCEPTION(SyntaxWarning, Warning)
	MP_DEFINE_EXCEPTION(UserWarning, Warning)
	MP_DEFINE_EXCEPTION(FutureWarning, Warning)
	MP_DEFINE_EXCEPTION(ImportWarning, Warning)
	MP_DEFINE_EXCEPTION(UnicodeWarning, Warning)
	MP_DEFINE_EXCEPTION(BytesWarning, Warning)
	MP_DEFINE_EXCEPTION(ResourceWarning, Warning)
	*/

	mp_obj_t mp_obj_new_exception(const mp_obj_type_t *exc_type) {
	return mp_obj_new_exception_args(exc_type, 0, NULL);
	}

	// "Optimized" version for common(?) case of having 1 exception arg
	mp_obj_t mp_obj_new_exception_arg1(const mp_obj_type_t *exc_type, mp_obj_t arg) {
	return mp_obj_new_exception_args(exc_type, 1, &arg);
	}

	mp_obj_t mp_obj_new_exception_args(const mp_obj_type_t exc_type, uint n_args, const mp_obj_t args) {
	assert(exc_type->make_new == mp_obj_exception_make_new);
	return exc_type->make_new((mp_obj_t)exc_type, n_args, 0, args);
	}

	mp_obj_t mp_obj_new_exception_msg(const mp_obj_type_t exc_type, const char msg) {
	return mp_obj_new_exception_msg_varg(exc_type, msg);
	}

	mp_obj_t mp_obj_new_exception_msg_varg(const mp_obj_type_t exc_type, const char fmt, ...) {
	// check that the given type is an exception type
	assert(exc_type->make_new == mp_obj_exception_make_new);

	// make exception object
	mp_obj_exception_t *o = m_new_obj_var_maybe(mp_obj_exception_t, mp_obj_t, 0);
	if (o == NULL) {
	// Couldn't allocate heap memory; use local data instead.
	// Unfortunately, we won't be able to format the string...
	o = &mp_emergency_exception_obj;
	o->base.type = exc_type;
	o->traceback = MP_OBJ_NULL;
	o->args = mp_const_empty_tuple;
	} else {
	o->base.type = exc_type;
	o->traceback = MP_OBJ_NULL;
	o->args = mp_obj_new_tuple(1, NULL);

	if (fmt == NULL) {
	// no message
	assert(0);
	} else {
	// render exception message and store as .args[0]
	// TODO: optimize bufferbloat
	vstr_t *vstr = vstr_new();
	va_list ap;
	va_start(ap, fmt);
	vstr_vprintf(vstr, fmt, ap);
	va_end(ap);
	o->args->items[0] = mp_obj_new_str(vstr->buf, vstr->len, false);
	vstr_free(vstr);
	}
	}

	return o;
	}

	// return true if the given object is an exception type
	bool mp_obj_is_exception_type(mp_obj_t self_in) {
	if (MP_OBJ_IS_TYPE(self_in, &mp_type_type)) {
	// optimisation when self_in is a builtin exception
	mp_obj_type_t *self = self_in;
	if (self->make_new == mp_obj_exception_make_new) {
	return true;
	}
	}
	return mp_obj_is_subclass_fast(self_in, &mp_type_BaseException);
	}

	// return true if the given object is an instance of an exception type
	bool mp_obj_is_exception_instance(mp_obj_t self_in) {
	return mp_obj_is_exception_type(mp_obj_get_type(self_in));
	}

	// return true if exception (type or instance) is a subclass of given
	// exception type.
	bool mp_obj_exception_match(mp_obj_t exc, const mp_obj_type_t *exc_type) {
	// TODO: move implementation from RT_BINARY_OP_EXCEPTION_MATCH here.
	return mp_binary_op(MP_BINARY_OP_EXCEPTION_MATCH, exc, (mp_obj_t)exc_type) == mp_const_true;
	}

	// traceback handling functions

	#define GET_NATIVE_EXCEPTION(self, self_in) \
	/* make sure self_in is an exception instance */ \
	assert(mp_obj_is_exception_instance(self_in)); \
	mp_obj_exception_t *self; \
	if (mp_obj_is_native_exception_instance(self_in)) { \
	self = self_in; \
	} else { \
	self = ((mp_obj_instance_t*)self_in)->subobj[0]; \
	}

	void mp_obj_exception_clear_traceback(mp_obj_t self_in) {
	GET_NATIVE_EXCEPTION(self, self_in);
	// just set the traceback to the null object
	// we don't want to call any memory management functions here
	self->traceback = MP_OBJ_NULL;
	}

	void mp_obj_exception_add_traceback(mp_obj_t self_in, qstr file, mp_uint_t line, qstr block) {
	#if MICROPY_ENABLE_GC
	if (gc_is_locked()) {
	// We can't allocate memory, so don't bother to try
	return;
	}
	#endif

	GET_NATIVE_EXCEPTION(self, self_in);

	// for traceback, we are just using the list object for convenience, it's not really a list of Python objects
	if (self->traceback == MP_OBJ_NULL) {
	self->traceback = mp_obj_new_list(0, NULL);
	}
	mp_obj_list_append(self->traceback, (mp_obj_t)(mp_uint_t)file);
	mp_obj_list_append(self->traceback, (mp_obj_t)(mp_uint_t)line);
	mp_obj_list_append(self->traceback, (mp_obj_t)(mp_uint_t)block);
	}

	void mp_obj_exception_get_traceback(mp_obj_t self_in, mp_uint_t n, mp_uint_t *values) {
	GET_NATIVE_EXCEPTION(self, self_in);

	if (self->traceback == MP_OBJ_NULL) {
	*n = 0;
	*values = NULL;
	} else {
	uint n2;
	mp_obj_list_get(self->traceback, &n2, (mp_obj_t**)values);
	*n = n2;
	}
	}