[cfe-dev] [llvm-dev] Is there precedent for customizing clang -help output in a toolchain specific way
Snider, Todd via cfe-dev
cfe-dev at lists.llvm.org
Wed Aug 5 08:26:12 PDT 2020
I've been playing around with a couple of approaches to allow a toolchain to take control of the content of the -help output, but I'm not thrilled with the results.
The general approach that I've tried is to have a toolchain-specific version of PrintHelp() create its own OptTable either by filtering the OptTable generated from Options.td or by using a toolchain-specific version of Options.td that contains only the options and HelpText fields that the toolchain wants in the -help output. Each of these approaches has to mess with a generic API in some way (either the OptTable API or the Driver API).
Have you had some success in your attempts to customize Driver::PrintHelp()? I'd be interested to learn what you've tried.
From: llvm-dev [mailto:llvm-dev-bounces at lists.llvm.org] On Behalf Of Andrzej Warzynski via llvm-dev
Sent: Monday, July 27, 2020 3:53 AM
To: llvm-dev at lists.llvm.org; 'cfe-dev at lists.llvm.org'
Subject: [EXTERNAL] Re: [llvm-dev] Is there precedent for customizing clang -help output in a toolchain specific way
We're currently trying to solve a similar problem for Flang . From
what we have seen so far,
* the only instance of DriverOptTable 
* the ID enum from clang/include/clang/Driver/Options.h 
are tightly coupled together and hence it is tricky to pick and choose
what you want.
There's also getIncludeExcludeOptionFlagMasks in
clang/lib/Driver/Driver.cpp , but I'm confused about the meaning of
IncludedFlagsBitmask and ExcludedFlagsBitmask. We did experiment with
that, but that made libclangDriver quite unhappy (things started to
break in an unexpected way).
Perhaps somebody on cfe-dev (CC'ed) would have some hints? In the
meantime we've also been customising Driver::PrintHelp().
On 24/07/2020 20:36, Snider, Todd via llvm-dev wrote:
> Hi All,
> I am looking to customize the -help display for a downstream clang port
> as many options defined in Options.td are not applicable to the
> processor family Iï¿½m targeting and several applicable options do not
> have HelpText.
> Iï¿½ve considered adding a toolchain specific hook in the vicinity of
> Driver::PrintHelp(), but Iï¿½d rather avoid adding a hook if there is a
> better solution that already exists.
> Is there a best practice for enabling a toolchain to control the output
> of the clang ï¿½help option?
> ~ Todd Snider
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org
LLVM Developers mailing list
llvm-dev at lists.llvm.org
More information about the cfe-dev