#1018 Program fails until a $write debug statement is added

[Evan Lavelle]

git, v10-branch

Sorry, not much to go on here. The attached program (iverilog test.v) should create an output file which has a length of 192 bytes. It's compiler-generated, and worked on v0.9 and early versions of 0.10, and various other compilers. It now only produces 112 bytes before terminating (there should be 20 calls to $fwrite; the last 8 calls to $fwrite are either not happening, or the program terminates early).

I've added a debug call to $write on line 349. This just writes text to the console. When the debug call is commented out, the program fails, producing 112 bytes in 'stream21.op2'. When you enable the call, the program passes, producing 192 bytes in 'stream21.op2'. No idea why.

[Cary R.]

I cannot reproduce the problem using the latest version of 10 or devel I get the expected results with the $write line commented out. It looks like you are using the latest 10 version so this discrepency is odd.

[Martin Whitaker]

I can't reproduce the failure either. Evan, could you try commenting out the four disable statements (which I believe are redundant) to see if that makes the test pass. If so, it is likely this is the same problem as bug #1016 (which I still haven't been able to pin down).

[Martin Whitaker]

I believe this is the same root cause as bugs 1017 and 1016 (a use after free bug), but as I was unable to reproduce it (no doubt due to the random nature of such bugs), I can't confirm this. Please test the head of the v10 branch, and close this bug if you believe it is fixed.

[Martin Whitaker]

No response, so closing as fixed. Please reopen if you still see this bug.

[Evan Lavelle]

Sorry about that - only just managed to get back on to this after 7 months! I did a git pull and re-ran the regressions just before your mail, and can confirm that all the failures that I had in July are now gone. So, presumably #1016 and #1017 fixed everything. Great work - thanks very much.