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try: block without except: or ensure: produces internal compiler error

Details

  • Type: Bug Bug
  • Status: Resolved Resolved
  • Priority: Major Major
  • Resolution: Fixed
  • Affects Version/s: 0.6
  • Fix Version/s: 0.7
  • Component/s: Compiler
  • Labels:
    None
  • Environment:
    Mono 1.1.8 on Linux/x86, Mono 1.1.8 on Mac OS X, .NET 1.1 on Windows XP SP2
  • Number of attachments :
    0

Description

A try block with no following except: or ensure: blocks produces an internal compiler error or runtime crash. Sample code:

try:
print "Foo"

On the .NET 1.1 runtime the low-level ILGenerator throws an exception which is caught and returned as an ICE:
ERROR: Internal compiler error: Incorrect code generation for exception block.

On Mono an assertion failure simply crashes the runtime:

    • ERROR **: file reflection.c: line 835 (method_encode_clauses): assertion failed: (ex_info->handlers)
      aborting...

The case should probably be caught as illegal at a higher level and a descriptive error message returned; or if it's meant to be possible to do this, an empty catch block needs to be implicitly added in the emitted IL.

I've posted a short C# program which triggers the same emitter error on my bug report for the assertion failure on Mono:
http://bugzilla.ximian.com/show_bug.cgi?id=76002

Activity

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Doug H added a comment -

If we have a try block with no except, should it be a syntax error, or should it add an except handler that re-raises, or an except that passes?

except e:
raise

or

except e:
pass //nothing happens if exception occurs

I'm guessing maybe the raise one is best, although technically "pass" means an empty block.

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Doug H added a comment - If we have a try block with no except, should it be a syntax error, or should it add an except handler that re-raises, or an except that passes? except e: raise or except e: pass //nothing happens if exception occurs I'm guessing maybe the raise one is best, although technically "pass" means an empty block.

People

  • Assignee:
    Rodrigo B. de Oliveira
    Reporter:
    Brion Vibber
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Dates

  • Created:
    Updated:
    Resolved: