klayout fails to detect format of defok file written by OpenRoad

[stefanottili]

klayout's automatic format detection fails on .defok file written by OpenROAD.
It does detect the format for the input file. The first 261 lines of both files are identical.
https://github.com/The-OpenROAD-Project/OpenROAD/tree/master/src/tap/test

klayout OpenROAD/src/tap/test/gf180/aes.def
klayout OpenROAD/src/tap/test/aes_gf180.defok
ERROR: Stream has unknown format: OpenROAD/src/tap/test/aes_gf180.defok

diff OpenROAD/src/tap/test/gf180/aes.def OpenROAD/src/tap/test/aes_gf180.defok | more
261c261,4403
< COMPONENTS 15174 ;
---
> COMPONENTS 19316 ;

VERSION 5.8 ;
DIVIDERCHAR "/" ;
BUSBITCHARS "[]" ;
DESIGN aes_cipher_top ;
UNITS DISTANCE MICRONS 2000 ;
DIEAREA ( 0 0 ) ( 2479910 2479910 ) ;
ROW ROW_0 GF018hv5v_green_sc9 4480 10080 N DO 2206 BY 1 STEP 1120 0 ;
ROW ROW_1 GF018hv5v_green_sc9 4480 20160 FS DO 2206 BY 1 STEP 1120 0 ;
...

[stefanottili]

I was wrongly under the impression that the reader would look at the contents of the file.
I vaguely remember a bug report for cif having more then 64k of comment and failing because of it.

Please add .defok (and .lefok) to the list of suffixes.

69 static const char *suffixes[] = { ".def", ".DEF", ".def.gz", ".DEF.gz" };

[stefanottili]

ERROR: Stream has unknown format:
This error message doesn’t give a hint that the issue is an unknown file extension.

[klayoutmatthias]

Okay ... so is ".defok" or ".lefok" some commonly used extension?

I mean, basically the file has a certain look, but I'm not sure what a minimal DEF would look like.

First line being VERSION.*; is probably not a good indication, isn't it?

Brute force approach would by trying all readers and see which one didn't throw an error, but I recall that CIF is so flexible, it almost accepts everything.

Matthias

[stefanottili]

As usual, it might be good to make lef/def extensions configurable.

OpenROAD uses defok, defok1, defok2, lefok as output and in a previous life I've seen lef_5.7 and lef_5.8.
Also .tlef seems to be used occasionally.

[klayoutmatthias]

How about having an option to override the file format, like

file.defok[def]

?

I recently had a complaint that someone for some reason neeed to write the output file of strmxor to OASIS, but had to call the file ".gds" (mad flow). I did not have an option to offer for setting the format, apart from naming the file ".oas" and then renaming it.

With the optional file type specification I could give them

strmxor a.gds b.gds xor.gds[oas]

... if they really have to.

A similar thing is already in place for scripts - you can force a script to be run as DRC script using

klayout -b -r script.txt[drc]

Matthias

[stefanottili]

I always argued for "respect the extension" and would have preferred for OR to use .ok.def instead of .defok ...
But since that can't be changed, there has to "a" way to be able to specify which format the user wants to read.
And since people use the file bowser to select files based on extensions, one should just be able to specify which one one wants.

I would draw a line in the sand on the "xor.gds[oas]" request and just refuse to write the "wrong" format.