I was experimenting with conditions under the `suppressif` statement: ``` suppressif TRUE; - element is not present suppressif FALSE; - element is present ``` From the C language I'm used to the fact that 0 is FALSE, and every other number is TRUE. And at first glance it looks like VFR has the same cast: ``` suppressif 2; - not present suppressif 1; - not present suppressif 0; - present ``` But when I've tried to create more complicated expressions I have found out some strange things: ``` suppressif (1 AND 0); - present suppressif (1 AND 1); - present (???) suppressif (0 OR 0); - present suppressif (1 OR 0); - present (???) suppressif (TRUE OR 0); - present (???) ``` It looks like for correct behaviour explicit cast is needed: ``` suppressif ((BOOLEAN)1 AND (BOOLEAN)1); - not present suppressif ((BOOLEAN)1 OR (BOOLEAN)0); - not present suppressif (TRUE OR (BOOLEAN)0); - not present ```
Can someone explain to me the logic when the cast statement is not present?
But when I've tried to create more complicated expressions I have found out some strange things: ``` suppressif (1 AND 0); - present suppressif (1 AND 1); - present (???) suppressif (0 OR 0); - present suppressif (1 OR 0); - present (???) suppressif (TRUE OR 0); - present (???) ``` It looks like for correct behaviour explicit cast is needed: ``` suppressif ((BOOLEAN)1 AND (BOOLEAN)1); - not present suppressif ((BOOLEAN)1 OR (BOOLEAN)0); - not present suppressif (TRUE OR (BOOLEAN)0); - not present ```
Can someone explain to me the logic when the cast statement is not present?
Hi Konstantin,
I could be wrong, but this is my understading of the situation. The process of building and using HII includes transpiling a file written in VFR into IFR bytecode. This transpilation is custom for edk2 and therefore the transpiler is likely to be more 'quirky' than what you'd expect of your mainstream compiler. Especially for less-utilised syntax structures, where it had far less user testing. I've usually limited myself to well-worn paths when writing up a VFR file for a driver.
