Factor out the code to pretty-print diagnostics.

artiq/coredevice/core.py

@@ -1,4 +1,4 @@
-import sys
+import os
 
 from pythonparser import diagnostic
 
@@ -14,7 +14,19 @@ from artiq.coredevice import exceptions
 
 
 class CompileError(Exception):
-    pass
+    def __init__(self, diagnostic):
+        self.diagnostic = diagnostic
+
+    def render_string(self, colored=False):
+        def shorten_path(path):
+            return path.replace(os.path.normpath(os.path.join(__file__, "..", "..")), "<artiq>")
+        lines = [shorten_path(path) for path in self.diagnostic.render(colored=colored)]
+        return "\n".join(lines)
+
+    def __str__(self):
+        # Prepend a newline so that the message shows up on after
+        # exception class name printed by Python.
+        return "\n" + self.render_string(colored=True)
 
 
 @syscall
@@ -48,7 +60,7 @@ class Core:
             return stitcher.object_map, stripped_library, \
                    lambda addresses: target.symbolize(library, addresses)
         except diagnostic.Error as error:
-            raise CompileError() from error
+            raise CompileError(error.diagnostic) from error
 
     def run(self, function, args, kwargs):
         object_map, kernel_library, symbolizer = self.compile(function, args, kwargs)

artiq/frontend/artiq_compile.py

@@ -1,10 +1,10 @@
 #!/usr/bin/env python3
 
-import logging
+import sys, logging, argparse
-import argparse
 
 from artiq.protocols.file_db import FlatFileDB
 from artiq.master.worker_db import DeviceManager
+from artiq.coredevice.core import CompileError
 from artiq.tools import *
 
 
@@ -53,6 +53,9 @@ def main():
         object_map, kernel_library, symbolizer = \
             core.compile(exp.run, [exp_inst], {},
                          with_attr_writeback=False)
+    except CompileError as error:
+        print(error.render_string(colored=True), file=sys.stderr)
+        return
     finally:
         dmgr.close_devices()
 

artiq/frontend/artiq_run.py

@@ -124,10 +124,8 @@ def run(with_file=False):
         exp_inst.run()
         exp_inst.analyze()
     except CompileError as error:
-        message = "\n".join(error.__cause__.diagnostic.render(colored=True))
+        print(error.render_string(colored=True), file=sys.stderr)
-        message = message.replace(os.path.normpath(os.path.join(os.path.dirname(__file__), "..")),
+        return
-                                  "<artiq>")
-        print(message, file=sys.stderr)
     finally:
         dmgr.close_devices()
 

artiq/test/hardware_testbench.py

@@ -1,9 +1,7 @@
-import os
+import os, sys, unittest, logging
-import sys
-import unittest
-import logging
 
 from artiq.language import *
+from artiq.coredevice.core import CompileError
 from artiq.protocols.file_db import FlatFileDB
 from artiq.master.worker_db import DeviceManager, ResultDB
 from artiq.frontend.artiq_run import DummyScheduler
@@ -58,5 +56,8 @@ class ExperimentCase(unittest.TestCase):
             exp.run()
             exp.analyze()
             return exp
+        except CompileError as error:
+            # Reduce amount of text on terminal.
+            raise error from None
         finally:
             self.dmgr.close_devices()