jackoalan added inline comments.
================ Comment at: clang/docs/UsersManual.rst:920 +To generate paths relative to the configuration file, the `<@>` token may be +used. This will expand to the absolute path of the directory containing the ---------------- sepavloff wrote: > Response and configuration files are different things, so the documentation > must more specific what facility is extended. > > According to this implementation the response file treatment is extended. > During development of configuration files couple of attempts were taken to > extend the functionality of response files (see for example > https://reviews.llvm.org/D36045). They were rejected as breaking > compatibility with gcc. It does not mean that such extending is not possible, > but it should be discussed in wider community. There must be serious reason > for such extension and significant use case. > > As for using this feature for configuration files, it does not look as very > helpful. Configuration files are searched for in several places and the first > found file is used. In this case specification of various locations relative > to the config-file does not look neither safe nor natural. Specific use case > also would be helpful to ground the need for such extension. > Specific use case also would be helpful to ground the need for such extension. An embedded architecture's community members may wish to deploy their own portable (non-installed) platform packages, while minimizing the user burden of configuring the build system of their choice to set up all the search paths. Ideally, just the `--config` option should be enough to handle everything necessary for full use of the package. Consider an embedded architecture "foo". It deploys a common directory which contains a shared configuration file and headers: ``` -foo-common -config.cfg -include -foo.h -stdlib.h -string.h -... ``` foo-common/config.cfg: ``` --target=foo -isystem <@>/include ``` foo is implemented by a family of boards. Each board SDK is contained in a directory located next to the common one. Each has their own device libraries and some require special feature and machine flags. Here is the directory layout for a board named "bar": ``` -foo-bar -config.cfg -include -bar.h -lib -libbar.a -libc.a -libm.a -ldscripts -link.ld ``` foo-bar/config.cfg: ``` @../foo-common/config.cfg -mcpu=<foo-variant-used-in-bar> -isystem <@>/include -L <@>/lib -T <@>/ldscripts/link.ld ``` Configuration files are very convenient for setting up compiler options in an accessible way (i.e. not having to depend on hard-coded logic in the driver or cmake/makefiles/etc to set up the environment). However, the inability to express config-relative paths is a major burden for setting up search paths in this use case. Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D115604/new/ https://reviews.llvm.org/D115604 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
