From 2fa32b563f594673afb44eef73cde5a18b34cbff Mon Sep 17 00:00:00 2001 From: sterni Date: Sun, 22 Aug 2021 17:43:21 +0200 Subject: docs(nix/buildLisp): document recent changes to buildLisp Doing this in a separate CL to avoid having to track the intermediate changes no one will ever see in documentation as well which would be unnecessary effort. * Multi-implementation support introduced in cl/3292 and refined in cl/3368 in terms of the user interface. * Implementation specific srcs and deps introduced in cl/3321 * Implementation passthru attrs and rename from .sbcl -> .repl was done in cl/3359 * ECL added in cl/3297, CCL in cl/3350 Change-Id: Ia13f2aea4e7e091c00991fcbfc601de364413979 Reviewed-on: https://cl.tvl.fyi/c/depot/+/3380 Tested-by: BuildkiteCI Reviewed-by: tazjin --- nix/buildLisp/README.md | 129 ++++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 119 insertions(+), 10 deletions(-) (limited to 'nix/buildLisp') diff --git a/nix/buildLisp/README.md b/nix/buildLisp/README.md index 5ee560e056..76fe5ca9e4 100644 --- a/nix/buildLisp/README.md +++ b/nix/buildLisp/README.md @@ -6,18 +6,20 @@ This is a build system for Common Lisp, written in Nix. It aims to offer an alternative to ASDF for users who live in a Nix-based ecosystem. This offers several advantages over ASDF: -* Simpler (logic-less) package definitions +* Simpler (almost logic-less) package definitions * Easy linking of native dependencies (from Nix) * Composability with Nix tooling for other languages * Effective, per-system caching strategies * Easy overriding of dependencies and whatnot +* Convenient support for multiple Common Lisp implementations * ... and more! The project is still in its early stages and some important restrictions should be highlighted: -* Only SBCL is supported (though the plan is to add support for at - least ABCL and Clozure CL, and maybe make it extensible) +* Extending `buildLisp` with support for a custom implementation + currently requires some knowledge of internals and may not be + considered stable yet. * Parallel compilation is not possible: Since buildLisp doesn't encode dependencies between components (i. e. source files) like ASDF, it must compile source files in sequence to avoid errors due to @@ -36,6 +38,7 @@ restrictions should be highlighted: | `deps` | `list` | List of dependencies | no | | `native` | `list` | List of native dependencies | no | | `test` | see "Tests" | Specification for test suite | no | + | `implementation` | see "Implementations" | Common Lisp implementation to use | no | The output of invoking this is a directory containing a FASL file that is the concatenated result of all compiled sources. @@ -50,6 +53,7 @@ restrictions should be highlighted: | `native` | `list` | List of native dependencies | no | | `main` | `string` | Entrypoint function | no | | `test` | see "Tests" | Specification for test suite | no | + | `implementation` | see "Implementations" | Common Lisp implementation to use | no | The `main` parameter should be the name of a function and defaults to `${name}:main` (i.e. the *exported* `main` function of the @@ -68,13 +72,6 @@ restrictions should be highlighted: built-in library and returns a "package" that simply requires this library. -* `buildLisp.sbclWith`: Creates an SBCL pre-loaded with various dependencies. - - This function takes a single argument which is a list of Lisp - libraries programs or programs. It creates an SBCL that is - pre-loaded with all of that Lisp code and can be used as the host - for e.g. Sly or SLIME. - ## Tests Both `buildLisp.library` and `buildLisp.program` take an optional argument @@ -91,6 +88,113 @@ the `expression` parameter should be a Lisp expression and will be evaluated after loading all sources and dependencies (including library/program dependencies). It must return a non-`NIL` value if the test suite has passed. +## Development REPLs + +`buildLisp` builds loadable variants of both `program` and `library` derivations +(usually FASL files). Therefore it can provide a convenient way to obtain an +instance of any implementation preloaded with `buildLisp`-derivations. This +is especially useful to use as a host for Sly or SLIME. + +* `buildLisp.sbcl.lispWith`, `buildLisp.ccl.lispWith`, ...: + Creates a wrapper script preloading a Lisp implementation with various dependencies. + + This function takes a single argument which is a list of Lisp + libraries programs or programs. The desired Lisp implementation + will load all given derivations and all their dependencies on + startup. + + The shortcut `buildLisp.sbclWith` for `buildLisp.sbcl.lispWith` is also provided. + +* `repl` passthru attribute: `derivation.repl` is provided as a shortcut + for `buildLisp.${implementationName}.lispWith [ derivation ]`. + `derivation.ccl.repl`, `derivation.sbcl.repl` etc. work as well, of course + (see also "Implementations" section). + +## Implementations + +Both `buildLisp.library` and `buildLisp.program` allow specifying a different +Common Lisp implementation than the default one (which is SBCL). When an +implementation is passed, `buildLisp` makes sure all dependencies are built +with that implementation as well since build artifacts from different +implementation will be incompatible with each other. + +The argument taken by `implementation` is a special attribute set which +describes how to do certain tasks for a given implementation, like building +or loading a library. In case you want to use a custom implementation +description, the precise structure needed is documented in `buildLisp`'s +source code for now. `buildLisp` also exposes the following already +working implementation sets: + +* `buildLisp.sbcl`: [SBCL][sbcl], our default implementation + +* `buildLisp.ccl`: [CCL][ccl], similar to SBCL, but with very good macOS support + +* `buildLisp.ecl`: [ECL][ecl] setup to produce statically linked binaries and + libraries. Note that its runtime library is LGPL, so [extra conditions][lgpl-static] + must be fulfilled when distributing binaries produced this way. + +* Support for ABCL is planned. + +For every of these “known” implementations, `buildLisp` will create a `passthru` +attribute named like the implementation which points to a variant of the derivation +built with said implementation. Say we have a derivation, `myDrv`, built using SBCL: +While `myDrv` and `myDrv.sbcl` are built using SBCL, `myDrv.ecl`, `myDrv.ccl` etc. +build the derivation and all its dependencies using ECL and CCL respectively. + +This is useful to test portability of your derivation, but is also used internally +to speed up the “normalization” of the dependency graph. Thus it is important to +make sure that your custom implementation's name doesn't clash with one of the +“known” ones. + +## Handling Implementation Specifics + +When targeting multiple Common Lisp implementation, it is often necessary to +handle differing interfaces for OS interaction or to make use of special +implementation features. For this reason, `buildLisp` allows specifying +dependencies and source files for specific implementations only. This can +be utilized by having an attribute set in the list for the `deps` or `srcs` +argument: `buildLisp` will pick the value of the attribute named like the +used implementation or `default` and ignore the set completely if both +are missing. + +```nix +{ buildLisp, lispPkgs }: + +buildLisp.library { + name = "mylib"; + + srcs = [ + # These are included always of course + ./package.lisp + ./portable-lib.lisp + + # Choose right impl-* file + { + sbcl = ./impl-sbcl.lisp; + ccl = ./impl-ccl.lisp; + ecl = ./impl-ecl.lisp; + } + + # We can also use this to inject extra files + { ecl = ./extra-ecl-optimizations.lisp; } + ]; + + deps = [ + # Use SBCL's special bundled package, flexi-streams otherwise + { + sbcl = buildLisp.bundled "sb-rotate-byte"; + default = lispPkgs.flexi-streams; + } + ]; +} +``` + +Additionally a `brokenOn` parameter is accepted which takes a list of +implementation names on which the derivation is not expected to work. +This only influences `meta.targets` which is read by depot's CI to +check which variants (see "Implementations") of the derivation to +build, so it may not be useful outside of depot. + ## Example Using buildLisp could look like this: @@ -119,3 +223,8 @@ in buildLisp.program { }; } ``` + +[sbcl]: http://www.sbcl.org/ +[ccl]: https://ccl.clozure.com/ +[ecl]: https://common-lisp.net/project/ecl/ +[lgpl-static]: https://www.gnu.org/licenses/gpl-faq.en.html#LGPLStaticVsDynamic -- cgit 1.4.1