How to turn up the warning levels in Keil uVision (ARM LPC40xx)

Ok, this can't be this hard! Please show me the error of my ways. 

I am using Keil uVision, building for LPX40xx processors, and I want to crank the warning levels up (more strict). I'm used to using --pedantic with gcc and would like to be able to enable the same sort of syntax checking in my Keil project. 

I see where I can add command line armcc options under "Misc Controls" within the "Options For Target / C/C+" tab, so based on this: 

https://developer.arm.com/docs/100748/latest/using-common-compiler-options/controlling-diagnostic-messages

I've tried adding -Wpedantic, and I get: Fatal error: C3900U: Unrecognized option '-pedantic'.

I would also be fine with doing this on a file-by-file basis, by adding #pragma diag_warning statements to my source files, as hinted at here:

infocenter.arm.com/.../index.jsp

but I can't find a list of tags.

Any help would be gratefully appreciated.