Want to help DMD bugfixing? Write a simple utility.

[Don]

Jonathan M Davis wrote:
> On Saturday 19 March 2011 17:11:56 Don wrote:
>> Here's the task:
>> Given a .d source file, strip out all of the unittest {} blocks,
>> including everything inside them.
>> Strip out all comments as well.
>> Print out the resulting file.
>>
>> Motivation: Bug reports frequently come with very large test cases.
>> Even ones which look small often import from Phobos.
>> Reducing the test case is the first step in fixing the bug, and it's
>> frequently ~30% of the total time required. Stripping out the unit tests
>> is the most time-consuming and error-prone part of reducing the test case.
>>
>> This should be a good task if you're relatively new to D but would like
>> to do something really useful.
> 
> Unfortunately, to do that 100% correctly, you need to actually have a working D 
> lexer (and possibly parser). You might be able to get something close enough to 
> work in most cases, but it doesn't take all that much to throw off a basic 
> implementation of this sort of thing if you don't lex/parse it with something 
> which properly understands D.
> 
> - Jonathan M Davis

I didn't say it needs 100% accuracy. You can assume, for example, that 
"unittest" always occurs at the start of a line. The only other things 
you need to lex are {}, string literals, and comments.

BTW, the immediate motivation for this is std.datetime in Phobos. The 
sheer number of unittests in there is an absolute catastrophe for 
tracking down bugs. It makes a tool like this MANDATORY.