Add basic support for embedded functions with new compiler.

artiq/compiler/__init__.py

@@ -1 +1,2 @@
 from .module import Module, Source
+from .embedding import Stitcher

artiq/compiler/asttyped.py

@@ -93,3 +93,5 @@ class YieldFromT(ast.YieldFrom, commontyped):
 # Novel typed nodes
 class CoerceT(ast.expr, commontyped):
     _fields = ('value',) # other_value deliberately not in _fields
+class QuoteT(ast.expr, commontyped):
+    _fields = ('value',)

artiq/compiler/embedding.py

@@ -0,0 +1,157 @@
+"""
+The :class:`Stitcher` class allows to transparently combine compiled
+Python code and Python code executed on the host system: it resolves
+the references to the host objects and translates the functions
+annotated as ``@kernel`` when they are referenced.
+"""
+
+import inspect
+from pythonparser import ast, source, diagnostic, parse_buffer
+from . import types, builtins, asttyped, prelude
+from .transforms import ASTTypedRewriter, Inferencer
+
+
+class ASTSynthesizer:
+    def __init__(self):
+        self.source = ""
+        self.source_buffer = source.Buffer(self.source, "<synthesized>")
+
+    def finalize(self):
+        self.source_buffer.source = self.source
+        return self.source_buffer
+
+    def _add(self, fragment):
+        range_from   = len(self.source)
+        self.source += fragment
+        range_to     = len(self.source)
+        return source.Range(self.source_buffer, range_from, range_to)
+
+    def quote(self, value):
+        """Construct an AST fragment equal to `value`."""
+        if value in (None, True, False):
+            if node.value is True or node.value is False:
+                typ = builtins.TBool()
+            elif node.value is None:
+                typ = builtins.TNone()
+            return asttyped.NameConstantT(value=value, type=typ,
+                                          loc=self._add(repr(value)))
+        elif isinstance(value, (int, float)):
+            if isinstance(value, int):
+                typ = builtins.TInt()
+            elif isinstance(value, float):
+                typ = builtins.TFloat()
+            return asttyped.NumT(n=value, ctx=None, type=typ,
+                                 loc=self._add(repr(value)))
+        elif isinstance(value, list):
+            begin_loc = self._add("[")
+            elts = []
+            for index, elt in value:
+                elts.append(self.quote(elt))
+                if index < len(value) - 1:
+                    self._add(", ")
+            end_loc   = self._add("]")
+            return asttyped.ListT(elts=elts, ctx=None, type=types.TVar(),
+                                  begin_loc=begin_loc, end_loc=end_loc,
+                                  loc=begin_loc.join(end_loc))
+        else:
+            raise "no"
+            # return asttyped.QuoteT(value=value, type=types.TVar())
+
+    def call(self, function_node, args, kwargs):
+        """
+        Construct an AST fragment calling a function specified by
+        an AST node `function_node`, with given arguments.
+        """
+        arg_nodes   = []
+        kwarg_nodes = []
+        kwarg_locs  = []
+
+        name_loc       = self._add(function_node.name)
+        begin_loc      = self._add("(")
+        for index, arg in enumerate(args):
+            arg_nodes.append(self.quote(arg))
+            if index < len(args) - 1:
+                         self._add(", ")
+        if any(args) and any(kwargs):
+                         self._add(", ")
+        for index, kw in enumerate(kwargs):
+            arg_loc    = self._add(kw)
+            equals_loc = self._add("=")
+            kwarg_locs.append((arg_loc, equals_loc))
+            kwarg_nodes.append(self.quote(kwargs[kw]))
+            if index < len(kwargs) - 1:
+                         self._add(", ")
+        end_loc        = self._add(")")
+
+        return asttyped.CallT(
+            func=asttyped.NameT(id=function_node.name, ctx=None,
+                                type=function_node.signature_type,
+                                loc=name_loc),
+            args=arg_nodes,
+            keywords=[ast.keyword(arg=kw, value=value,
+                                  arg_loc=arg_loc, equals_loc=equals_loc,
+                                  loc=arg_loc.join(value.loc))
+                      for kw, value, (arg_loc, equals_loc)
+                       in zip(kwargs, kwarg_nodes, kwarg_locs)],
+            starargs=None, kwargs=None,
+            type=types.TVar(),
+            begin_loc=begin_loc, end_loc=end_loc, star_loc=None, dstar_loc=None,
+            loc=name_loc.join(end_loc))
+
+class StitchingASTTypedRewriter(ASTTypedRewriter):
+    pass
+
+class Stitcher:
+    def __init__(self, engine=None):
+        if engine is None:
+            self.engine = diagnostic.Engine(all_errors_are_fatal=True)
+        else:
+            self.engine = engine
+
+        self.asttyped_rewriter = StitchingASTTypedRewriter(
+            engine=self.engine, globals=prelude.globals())
+        self.inferencer = Inferencer(engine=self.engine)
+
+        self.name = "stitched"
+        self.typedtree = None
+        self.globals = self.asttyped_rewriter.globals
+
+        self.rpc_map = {}
+
+    def _iterate(self):
+        # Iterate inference to fixed point.
+        self.inference_finished = False
+        while not self.inference_finished:
+            self.inference_finished = True
+            self.inferencer.visit(self.typedtree)
+
+    def _parse_embedded_function(self, function):
+        if not hasattr(function, "artiq_embedded"):
+            raise ValueError("{} is not an embedded function".format(repr(function)))
+
+        # Extract function source.
+        embedded_function = function.artiq_embedded.function
+        source_code = inspect.getsource(embedded_function)
+        filename = embedded_function.__code__.co_filename
+        first_line = embedded_function.__code__.co_firstlineno
+
+        # Parse.
+        source_buffer = source.Buffer(source_code, filename, first_line)
+        parsetree, comments = parse_buffer(source_buffer, engine=self.engine)
+
+        # Rewrite into typed form.
+        typedtree = self.asttyped_rewriter.visit(parsetree)
+
+        return typedtree, typedtree.body[0]
+
+    def stitch_call(self, function, args, kwargs):
+        self.typedtree, function_node = self._parse_embedded_function(function)
+
+        # We synthesize fake source code for the initial call so that
+        # diagnostics would have something meaningful to display to the user.
+        synthesizer = ASTSynthesizer()
+        call_node = synthesizer.call(function_node, args, kwargs)
+        synthesizer.finalize()
+        self.typedtree.body.append(call_node)
+
+        self._iterate()

artiq/compiler/transforms/asttyped_rewriter.py

@@ -190,10 +190,15 @@ class ASTTypedRewriter(algorithm.Transformer):
         self.globals = None
         self.env_stack = [globals]
 
-    def _find_name(self, name, loc):
+    def _try_find_name(self, name):
         for typing_env in reversed(self.env_stack):
             if name in typing_env:
                 return typing_env[name]
+
+    def _find_name(self, name, loc):
+        typ = self._try_find_name(name)
+        if typ is not None:
+            return typ
         diag = diagnostic.Diagnostic("fatal",
             "name '{name}' is not bound to anything", {"name":name}, loc)
         self.engine.process(diag)

artiq/coredevice/comm_generic.py

@@ -3,9 +3,7 @@ import logging
 from enum import Enum
 from fractions import Fraction
 
-from artiq.coredevice import runtime_exceptions
 from artiq.language import core as core_language
-from artiq.coredevice.rpc_wrapper import RPCWrapper
 
 
 logger = logging.getLogger(__name__)
@@ -198,35 +196,28 @@ class CommGeneric:
             else:
                 r.append(self._receive_rpc_value(type_tag))
 
-    def _serve_rpc(self, rpc_wrapper, rpc_map, user_exception_map):
+    def _serve_rpc(self, rpc_map):
         rpc_num = struct.unpack(">l", self.read(4))[0]
         args = self._receive_rpc_values()
         logger.debug("rpc service: %d %r", rpc_num, args)
-        eid, r = rpc_wrapper.run_rpc(
+        eid, r = rpc_wrapper.run_rpc(rpc_map[rpc_num], args)
-            user_exception_map, rpc_map[rpc_num], args)
         self._write_header(9+2*4, _H2DMsgType.RPC_REPLY)
         self.write(struct.pack(">ll", eid, r))
         logger.debug("rpc service: %d %r == %r (eid %d)", rpc_num, args,
                      r, eid)
 
-    def _serve_exception(self, rpc_wrapper, user_exception_map):
+    def _serve_exception(self):
         eid, p0, p1, p2 = struct.unpack(">lqqq", self.read(4+3*8))
         rpc_wrapper.filter_rpc_exception(eid)
-        if eid < core_language.first_user_eid:
+        raise exception(self.core, p0, p1, p2)
-            exception = runtime_exceptions.exception_map[eid]
-            raise exception(self.core, p0, p1, p2)
-        else:
-            exception = user_exception_map[eid]
-            raise exception
 
-    def serve(self, rpc_map, user_exception_map):
+    def serve(self, rpc_map):
-        rpc_wrapper = RPCWrapper()
         while True:
             _, ty = self._read_header()
             if ty == _D2HMsgType.RPC_REQUEST:
-                self._serve_rpc(rpc_wrapper, rpc_map, user_exception_map)
+                self._serve_rpc(rpc_map)
             elif ty == _D2HMsgType.KERNEL_EXCEPTION:
-                self._serve_exception(rpc_wrapper, user_exception_map)
+                self._serve_exception()
             elif ty == _D2HMsgType.KERNEL_FINISHED:
                 return
             else:

artiq/coredevice/core.py

@@ -1,50 +1,20 @@
-import os
+import os, sys, tempfile
+
+from pythonparser import diagnostic
 
 from artiq.language.core import *
 from artiq.language.units import ns
 
-from artiq.transforms.inline import inline
+from artiq.compiler import Stitcher, Module
-from artiq.transforms.quantize_time import quantize_time
+from artiq.compiler.targets import OR1KTarget
-from artiq.transforms.remove_inter_assigns import remove_inter_assigns
-from artiq.transforms.fold_constants import fold_constants
-from artiq.transforms.remove_dead_code import remove_dead_code
-from artiq.transforms.unroll_loops import unroll_loops
-from artiq.transforms.interleave import interleave
-from artiq.transforms.lower_time import lower_time
-from artiq.transforms.unparse import unparse
 
-from artiq.coredevice.runtime import Runtime
+# Import for side effects (creating the exception classes).
-
+from artiq.coredevice import exceptions
-from artiq.py2llvm import get_runtime_binary
 
 
-def _announce_unparse(label, node):
+class CompileError(Exception):
-    print("*** Unparsing: "+label)
-    print(unparse(node))
-
-
-def _make_debug_unparse(final):
-    try:
-        env = os.environ["ARTIQ_UNPARSE"]
-    except KeyError:
-        env = ""
-    selected_labels = set(env.split())
-    if "all" in selected_labels:
-        return _announce_unparse
-    else:
-        if "final" in selected_labels:
-            selected_labels.add(final)
-
-        def _filtered_unparse(label, node):
-            if label in selected_labels:
-                _announce_unparse(label, node)
-        return _filtered_unparse
-
-
-def _no_debug_unparse(label, node):
     pass
 
-
 class Core:
     def __init__(self, dmgr, ref_period=8*ns, external_clock=False):
         self.comm = dmgr.get("comm")
@@ -54,69 +24,40 @@ class Core:
         self.first_run = True
         self.core = self
         self.comm.core = self
-        self.runtime = Runtime()
 
-    def transform_stack(self, func_def, rpc_map, exception_map,
+    def compile(self, function, args, kwargs, with_attr_writeback=True):
-                        debug_unparse=_no_debug_unparse):
+        try:
-        remove_inter_assigns(func_def)
+            engine = diagnostic.Engine(all_errors_are_fatal=True)
-        debug_unparse("remove_inter_assigns_1", func_def)
 
-        quantize_time(func_def, self.ref_period)
+            stitcher = Stitcher(engine=engine)
-        debug_unparse("quantize_time", func_def)
+            stitcher.stitch_call(function, args, kwargs)
 
-        fold_constants(func_def)
+            module  = Module(stitcher)
-        debug_unparse("fold_constants_1", func_def)
+            library = OR1KTarget().compile_and_link([module])
 
-        unroll_loops(func_def, 500)
+            return library, stitcher.rpc_map
-        debug_unparse("unroll_loops", func_def)
+        except diagnostic.Error as error:
+            print("\n".join(error.diagnostic.render(colored=True)), file=sys.stderr)
+            raise CompileError() from error
 
-        interleave(func_def)
+    def run(self, function, args, kwargs):
-        debug_unparse("interleave", func_def)
-
-        lower_time(func_def)
-        debug_unparse("lower_time", func_def)
-
-        remove_inter_assigns(func_def)
-        debug_unparse("remove_inter_assigns_2", func_def)
-
-        fold_constants(func_def)
-        debug_unparse("fold_constants_2", func_def)
-
-        remove_dead_code(func_def)
-        debug_unparse("remove_dead_code_1", func_def)
-
-        remove_inter_assigns(func_def)
-        debug_unparse("remove_inter_assigns_3", func_def)
-
-        fold_constants(func_def)
-        debug_unparse("fold_constants_3", func_def)
-
-        remove_dead_code(func_def)
-        debug_unparse("remove_dead_code_2", func_def)
-
-    def compile(self, k_function, k_args, k_kwargs, with_attr_writeback=True):
-        debug_unparse = _make_debug_unparse("remove_dead_code_2")
-
-        func_def, rpc_map, exception_map = inline(
-            self, k_function, k_args, k_kwargs, with_attr_writeback)
-        debug_unparse("inline", func_def)
-        self.transform_stack(func_def, rpc_map, exception_map, debug_unparse)
-
-        binary = get_runtime_binary(self.runtime, func_def)
-
-        return binary, rpc_map, exception_map
-
-    def run(self, k_function, k_args, k_kwargs):
         if self.first_run:
             self.comm.check_ident()
             self.comm.switch_clock(self.external_clock)
+            self.first_run = False
 
-        binary, rpc_map, exception_map = self.compile(
+        kernel_library, rpc_map = self.compile(function, args, kwargs)
-            k_function, k_args, k_kwargs)
+
-        self.comm.load(binary)
+        try:
-        self.comm.run(k_function.__name__)
+            self.comm.load(kernel_library)
-        self.comm.serve(rpc_map, exception_map)
+        except Exception as error:
-        self.first_run = False
+            shlib_temp = tempfile.NamedTemporaryFile(suffix=".so", delete=False)
+            shlib_temp.write(kernel_library)
+            shlib_temp.close()
+            raise RuntimeError("shared library dumped to {}".format(shlib_temp.name)) from error
+
+        self.comm.run()
+        self.comm.serve(rpc_map)
 
     @kernel
     def get_rtio_counter_mu(self):

artiq/coredevice/exceptions.py

@@ -0,0 +1,33 @@
+from artiq.language.core import ARTIQException
+
+
+class InternalError(ARTIQException):
+    """Raised when the runtime encounters an internal error condition."""
+
+class RTIOUnderflow(ARTIQException):
+    """Raised when the CPU fails to submit a RTIO event early enough
+    (with respect to the event's timestamp).
+
+    The offending event is discarded and the RTIO core keeps operating.
+    """
+
+class RTIOSequenceError(ARTIQException):
+    """Raised when an event is submitted on a given channel with a timestamp
+    not larger than the previous one.
+
+    The offending event is discarded and the RTIO core keeps operating.
+    """
+
+class RTIOOverflow(ARTIQException):
+    """Raised when at least one event could not be registered into the RTIO
+    input FIFO because it was full (CPU not reading fast enough).
+
+    This does not interrupt operations further than cancelling the current
+    read attempt and discarding some events. Reading can be reattempted after
+    the exception is caught, and events will be partially retrieved.
+    """
+
+class DDSBatchError(ARTIQException):
+    """Raised when attempting to start a DDS batch while already in a batch,
+    or when too many commands are batched.
+    """

artiq/coredevice/rpc_wrapper.py

@@ -1,40 +0,0 @@
-from artiq.coredevice.runtime_exceptions import exception_map, _RPCException
-
-
-def _lookup_exception(d, e):
-    for eid, exception in d.items():
-        if isinstance(e, exception):
-            return eid
-    return 0
-
-
-class RPCWrapper:
-    def __init__(self):
-        self.last_exception = None
-
-    def run_rpc(self, user_exception_map, fn, args):
-        eid = 0
-        r = None
-
-        try:
-            r = fn(*args)
-        except Exception as e:
-            eid = _lookup_exception(user_exception_map, e)
-            if not eid:
-                eid = _lookup_exception(exception_map, e)
-            if eid:
-                self.last_exception = None
-            else:
-                self.last_exception = e
-                eid = _RPCException.eid
-
-        if r is None:
-            r = 0
-        else:
-            r = int(r)
-
-        return eid, r
-
-    def filter_rpc_exception(self, eid):
-        if eid == _RPCException.eid:
-            raise self.last_exception

artiq/coredevice/runtime.py

@@ -3,14 +3,8 @@ import os
 import llvmlite_or1k.ir as ll
 import llvmlite_or1k.binding as llvm
 
-from artiq.py2llvm import base_types, fractions, lists
 from artiq.language import units
 
-
-llvm.initialize()
-llvm.initialize_all_targets()
-llvm.initialize_all_asmprinters()
-
 _syscalls = {
     "now_init": "n:I",
     "now_save": "I:n",
@@ -97,27 +91,6 @@ class LinkInterface:
             self.syscalls[func_name] = ll.Function(
                 llvm_module, func_type, "__syscall_" + func_name)
 
-        # exception handling
-        func_type = ll.FunctionType(ll.IntType(32),
-                                    [ll.PointerType(ll.IntType(8))])
-        self.eh_setjmp = ll.Function(llvm_module, func_type,
-                                     "__eh_setjmp")
-        self.eh_setjmp.attributes.add("nounwind")
-        self.eh_setjmp.attributes.add("returns_twice")
-
-        func_type = ll.FunctionType(ll.PointerType(ll.IntType(8)), [])
-        self.eh_push = ll.Function(llvm_module, func_type, "__eh_push")
-
-        func_type = ll.FunctionType(ll.VoidType(), [ll.IntType(32)])
-        self.eh_pop = ll.Function(llvm_module, func_type, "__eh_pop")
-
-        func_type = ll.FunctionType(ll.IntType(32), [])
-        self.eh_getid = ll.Function(llvm_module, func_type, "__eh_getid")
-
-        func_type = ll.FunctionType(ll.VoidType(), [ll.IntType(32)])
-        self.eh_raise = ll.Function(llvm_module, func_type, "__eh_raise")
-        self.eh_raise.attributes.add("noreturn")
-
     def _build_rpc(self, args, builder):
         r = base_types.VInt()
         if builder is not None:
@@ -159,54 +132,3 @@ class LinkInterface:
             return self._build_rpc(args, builder)
         else:
             return self._build_regular_syscall(syscall_name, args, builder)
-
-    def build_catch(self, builder):
-        jmpbuf = builder.call(self.eh_push, [])
-        exception_occured = builder.call(self.eh_setjmp, [jmpbuf])
-        return builder.icmp_signed("!=",
-                                   exception_occured,
-                                   ll.Constant(ll.IntType(32), 0))
-
-    def build_pop(self, builder, levels):
-        builder.call(self.eh_pop, [ll.Constant(ll.IntType(32), levels)])
-
-    def build_getid(self, builder):
-        return builder.call(self.eh_getid, [])
-
-    def build_raise(self, builder, eid):
-        builder.call(self.eh_raise, [eid])
-
-
-def _debug_dump_obj(obj):
-    try:
-        env = os.environ["ARTIQ_DUMP_OBJECT"]
-    except KeyError:
-        return
-
-    for i in range(1000):
-        filename = "{}_{:03d}.elf".format(env, i)
-        try:
-            f = open(filename, "xb")
-        except FileExistsError:
-            pass
-        else:
-            f.write(obj)
-            f.close()
-            return
-    raise IOError
-
-
-class Runtime(LinkInterface):
-    def __init__(self):
-        self.cpu_type = "or1k"
-        # allow 1ms for all initial DDS programming
-        self.warmup_time = 1*units.ms
-
-    def emit_object(self):
-        tm = llvm.Target.from_triple(self.cpu_type).create_target_machine()
-        obj = tm.emit_object(self.module.llvm_module_ref)
-        _debug_dump_obj(obj)
-        return obj
-
-    def __repr__(self):
-        return "<Runtime {}>".format(self.cpu_type)

artiq/coredevice/runtime_exceptions.py

@@ -1,69 +0,0 @@
-import inspect
-
-from artiq.language.core import RuntimeException
-
-
-# Must be kept in sync with soc/runtime/exceptions.h
-
-class InternalError(RuntimeException):
-    """Raised when the runtime encounters an internal error condition."""
-    eid = 1
-
-
-class _RPCException(RuntimeException):
-    eid = 2
-
-
-class RTIOUnderflow(RuntimeException):
-    """Raised when the CPU fails to submit a RTIO event early enough
-    (with respect to the event's timestamp).
-
-    The offending event is discarded and the RTIO core keeps operating.
-    """
-    eid = 3
-
-    def __str__(self):
-        return "at {} on channel {}, violation {}".format(
-            self.p0*self.core.ref_period,
-            self.p1,
-            (self.p2 - self.p0)*self.core.ref_period)
-
-
-class RTIOSequenceError(RuntimeException):
-    """Raised when an event is submitted on a given channel with a timestamp
-    not larger than the previous one.
-
-    The offending event is discarded and the RTIO core keeps operating.
-    """
-    eid = 4
-
-    def __str__(self):
-        return "at {} on channel {}".format(self.p0*self.core.ref_period,
-                                            self.p1)
-
-
-class RTIOOverflow(RuntimeException):
-    """Raised when at least one event could not be registered into the RTIO
-    input FIFO because it was full (CPU not reading fast enough).
-
-    This does not interrupt operations further than cancelling the current
-    read attempt and discarding some events. Reading can be reattempted after
-    the exception is caught, and events will be partially retrieved.
-    """
-    eid = 5
-
-    def __str__(self):
-        return "on channel {}".format(self.p0)
-
-
-class DDSBatchError(RuntimeException):
-    """Raised when attempting to start a DDS batch while already in a batch,
-    or when too many commands are batched.
-    """
-    eid = 6
-
-
-exception_map = {e.eid: e for e in globals().values()
-                 if inspect.isclass(e)
-                 and issubclass(e, RuntimeException)
-                 and hasattr(e, "eid")}

artiq/language/core.py

@@ -8,7 +8,7 @@ from functools import wraps
 
 __all__ = ["int64", "round64", "kernel", "portable",
            "set_time_manager", "set_syscall_manager", "set_watchdog_factory",
-           "RuntimeException", "EncodedException"]
+           "ARTIQException"]
 
 # global namespace for kernels
 kernel_globals = ("sequential", "parallel",
@@ -77,7 +77,7 @@ def round64(x):
     return int64(round(x))
 
 
-_KernelFunctionInfo = namedtuple("_KernelFunctionInfo", "core_name k_function")
+_ARTIQEmbeddedInfo = namedtuple("_ARTIQEmbeddedInfo", "core_name function")
 
 
 def kernel(arg):
@@ -100,25 +100,19 @@ def kernel(arg):
     specifies the name of the attribute to use as core device driver.
     """
     if isinstance(arg, str):
-        def real_decorator(k_function):
+        def inner_decorator(function):
-            @wraps(k_function)
+            @wraps(function)
-            def run_on_core(exp, *k_args, **k_kwargs):
+            def run_on_core(self, *k_args, **k_kwargs):
-                return getattr(exp, arg).run(k_function,
+                return getattr(self, arg).run(function, ((self,) + k_args), k_kwargs)
-                                             ((exp,) + k_args), k_kwargs)
+            run_on_core.artiq_embedded = _ARTIQEmbeddedInfo(
-            run_on_core.k_function_info = _KernelFunctionInfo(
+                core_name=arg, function=function)
-                core_name=arg, k_function=k_function)
             return run_on_core
-        return real_decorator
+        return inner_decorator
     else:
-        @wraps(arg)
+        return kernel("core")(arg)
-        def run_on_core(exp, *k_args, **k_kwargs):
-            return exp.core.run(arg, ((exp,) + k_args), k_kwargs)
-        run_on_core.k_function_info = _KernelFunctionInfo(
-            core_name="core", k_function=arg)
-        return run_on_core
 
 
-def portable(f):
+def portable(function):
     """This decorator marks a function for execution on the same device as its
     caller.
 
@@ -127,8 +121,8 @@ def portable(f):
     core device). A decorated function called from a kernel will be executed
     on the core device (no RPC).
     """
-    f.k_function_info = _KernelFunctionInfo(core_name="", k_function=f)
+    function.artiq_embedded = _ARTIQEmbeddedInfo(core_name="", function=function)
-    return f
+    return function
 
 
 class _DummyTimeManager:
@@ -280,32 +274,34 @@ def watchdog(timeout):
     return _watchdog_factory(timeout)
 
 
-_encoded_exceptions = dict()
+class ARTIQException(Exception):
+    """Base class for exceptions raised or passed through the core device."""
 
+    # Try and create an instance of the specific class, if one exists.
+    def __new__(cls, name, message, params):
+        def find_subclass(cls):
+            if cls.__name__ == name:
+                return cls
+            else:
+                for subclass in cls.__subclasses__():
+                    cls = find_subclass(subclass)
+                    if cls is not None:
+                        return cls
 
-def EncodedException(eid):
+        more_specific_cls = find_subclass(cls)
-    """Represents exceptions on the core device, which are identified
+        if more_specific_cls is None:
-    by a single number."""
+            more_specific_cls = cls
-    try:
-        return _encoded_exceptions[eid]
-    except KeyError:
-        class EncodedException(Exception):
-            def __init__(self):
-                Exception.__init__(self, eid)
-        _encoded_exceptions[eid] = EncodedException
-        return EncodedException
 
+        exn = Exception.__new__(more_specific_cls)
+        exn.__init__(name, message, params)
+        return exn
 
-class RuntimeException(Exception):
+    def __init__(self, name, message, params):
-    """Base class for all exceptions used by the device runtime.
+        Exception.__init__(self, name, message, *params)
-    Those exceptions are defined in ``artiq.coredevice.runtime_exceptions``.
+        self.name, self.message, self.params = name, message, params
-    """
-    def __init__(self, core, p0, p1, p2):
-        Exception.__init__(self)
-        self.core = core
-        self.p0 = p0
-        self.p1 = p1
-        self.p2 = p2
 
-
+    def __str__(self):
-first_user_eid = 1024
+        if type(self).__name__ == self.name:
+            return self.message.format(*self.params)
+        else:
+            return "({}) {}".format(self.name, self.message.format(*self.params))