diff options
25 files changed, 355 insertions, 3 deletions
diff --git a/doc/manual/rl-next/repl-overlays.md b/doc/manual/rl-next/repl-overlays.md new file mode 100644 index 000000000..9f48cf381 --- /dev/null +++ b/doc/manual/rl-next/repl-overlays.md @@ -0,0 +1,36 @@ +--- +synopsis: Add `repl-overlays` option +prs: 10203 +cls: 504 +--- + +A `repl-overlays` option has been added, which specifies files that can overlay +and modify the top-level bindings in `nix repl`. For example, with the +following contents in `~/.config/nix/repl.nix`: + +```nix +info: final: prev: let + optionalAttrs = predicate: attrs: + if predicate + then attrs + else {}; +in + optionalAttrs (prev ? legacyPackages && prev.legacyPackages ? ${info.currentSystem}) + { + pkgs = prev.legacyPackages.${info.currentSystem}; + } +``` + +We can run `nix repl` and use `pkgs` to refer to `legacyPackages.${currentSystem}`: + +```ShellSession +$ nix repl --repl-overlays ~/.config/nix/repl.nix nixpkgs +Lix 2.90.0 +Type :? for help. +Loading installable 'flake:nixpkgs#'... +Added 5 variables. +Loading 'repl-overlays'... +Added 6 variables. +nix-repl> pkgs.bash +«derivation /nix/store/g08b5vkwwh0j8ic9rkmd8mpj878rk62z-bash-5.2p26.drv» +``` diff --git a/src/libcmd/local.mk b/src/libcmd/local.mk index dcd33e84c..5d0e3ed7e 100644 --- a/src/libcmd/local.mk +++ b/src/libcmd/local.mk @@ -13,3 +13,5 @@ libcmd_LDFLAGS = $(EDITLINE_LIBS) $(LOWDOWN_LIBS) $(NIXDOC_LIBS) -pthread libcmd_LIBS = libstore libutil libexpr libmain libfetchers $(eval $(call install-file-in, $(buildprefix)$(d)/nix-cmd.pc, $(libdir)/pkgconfig, 0644)) + +$(d)/repl.cc: $(d)/repl-overlays.nix.gen.hh diff --git a/src/libcmd/meson.build b/src/libcmd/meson.build index 867508926..b057daa37 100644 --- a/src/libcmd/meson.build +++ b/src/libcmd/meson.build @@ -32,8 +32,13 @@ libcmd_headers = files( 'repl.hh', ) +libcmd_generated_headers = [ + gen_header.process('repl-overlays.nix', preserve_path_from: meson.current_source_dir()), +] + libcmd = library( 'nixcmd', + libcmd_generated_headers, libcmd_sources, dependencies : [ liblixutil, diff --git a/src/libcmd/repl-overlays.nix b/src/libcmd/repl-overlays.nix new file mode 100644 index 000000000..33ce49482 --- /dev/null +++ b/src/libcmd/repl-overlays.nix @@ -0,0 +1,8 @@ +info: +initial: +functions: +let final = builtins.foldl' + (prev: function: prev // (function info final prev)) + initial + functions; +in final diff --git a/src/libcmd/repl.cc b/src/libcmd/repl.cc index ee3a6e268..4aa46dbc0 100644 --- a/src/libcmd/repl.cc +++ b/src/libcmd/repl.cc @@ -30,6 +30,7 @@ #include "signals.hh" #include "print.hh" #include "progress-bar.hh" +#include "gc-small-vector.hh" #if HAVE_BOEHMGC #define GC_INCLUDE_NEW @@ -118,6 +119,45 @@ struct NixRepl void evalString(std::string s, Value & v); void loadDebugTraceEnv(DebugTrace & dt); + /** + * Load the `repl-overlays` and add the resulting AttrSet to the top-level + * bindings. + */ + void loadReplOverlays(); + + /** + * Get a list of each of the `repl-overlays` (parsed and evaluated). + */ + Value * replOverlays(); + + /** + * Get the Nix function that composes the `repl-overlays` together. + */ + Value * getReplOverlaysEvalFunction(); + + /** + * Cached return value of `getReplOverlaysEvalFunction`. + * + * Note: This is `shared_ptr` to avoid garbage collection. + */ + std::shared_ptr<Value *> replOverlaysEvalFunction = + std::allocate_shared<Value *>(traceable_allocator<Value *>(), nullptr); + + /** + * Get the `info` AttrSet that's passed as the first argument to each + * of the `repl-overlays`. + */ + Value * replInitInfo(); + + /** + * Get the current top-level bindings as an AttrSet. + */ + Value * bindingsToAttrs(); + /** + * Parse a file, evaluate its result, and force the resulting value. + */ + Value * evalFile(SourcePath & path); + void printValue(std::ostream & str, Value & v, unsigned int maxDepth = std::numeric_limits<unsigned int>::max()) @@ -770,14 +810,114 @@ void NixRepl::loadFiles() loadedFiles.clear(); for (auto & i : old) { - notice("Loading '%1%'...", i); + notice("Loading '%1%'...", Magenta(i)); loadFile(i); } for (auto & [i, what] : getValues()) { - notice("Loading installable '%1%'...", what); + notice("Loading installable '%1%'...", Magenta(what)); addAttrsToScope(*i); } + + loadReplOverlays(); +} + +void NixRepl::loadReplOverlays() +{ + if (!evalSettings.replOverlays) { + return; + } + + notice("Loading '%1%'...", Magenta("repl-overlays")); + auto replInitFilesFunction = getReplOverlaysEvalFunction(); + + Value &newAttrs(*state->allocValue()); + SmallValueVector<3> args = {replInitInfo(), bindingsToAttrs(), replOverlays()}; + state->callFunction( + *replInitFilesFunction, + args.size(), + args.data(), + newAttrs, + replInitFilesFunction->determinePos(noPos) + ); + + addAttrsToScope(newAttrs); +} + +Value * NixRepl::getReplOverlaysEvalFunction() +{ + if (replOverlaysEvalFunction && *replOverlaysEvalFunction) { + return *replOverlaysEvalFunction; + } + + auto evalReplInitFilesPath = CanonPath::root + "repl-overlays.nix"; + *replOverlaysEvalFunction = state->allocValue(); + auto code = + #include "repl-overlays.nix.gen.hh" + ; + auto expr = state->parseExprFromString( + code, + SourcePath(evalReplInitFilesPath), + state->staticBaseEnv + ); + + state->eval(expr, **replOverlaysEvalFunction); + + return *replOverlaysEvalFunction; +} + +Value * NixRepl::replOverlays() +{ + Value * replInits(state->allocValue()); + state->mkList(*replInits, evalSettings.replOverlays.get().size()); + Value ** replInitElems = replInits->listElems(); + + size_t i = 0; + for (auto path : evalSettings.replOverlays.get()) { + debug("Loading '%1%' path '%2%'...", "repl-overlays", path); + SourcePath sourcePath((CanonPath(path))); + auto replInit = evalFile(sourcePath); + + if (!replInit->isLambda()) { + state->error<TypeError>( + "Expected `repl-overlays` to be a lambda but found %1%: %2%", + showType(*replInit), + ValuePrinter(*state, *replInit, errorPrintOptions) + ) + .atPos(replInit->determinePos(noPos)) + .debugThrow(); + } + + if (replInit->lambda.fun->hasFormals() + && !replInit->lambda.fun->formals->ellipsis) { + state->error<TypeError>( + "Expected first argument of %1% to have %2% to allow future versions of Lix to add additional attributes to the argument", + "repl-overlays", + "..." + ) + .atPos(replInit->determinePos(noPos)) + .debugThrow(); + } + + replInitElems[i] = replInit; + i++; + } + + + return replInits; +} + +Value * NixRepl::replInitInfo() +{ + auto builder = state->buildBindings(2); + + Value * currentSystem(state->allocValue()); + currentSystem->mkString(evalSettings.getCurrentSystem()); + builder.insert(state->symbols.create("currentSystem"), currentSystem); + + Value * info(state->allocValue()); + info->mkAttrs(builder.finish()); + return info; } @@ -810,6 +950,18 @@ void NixRepl::addVarToScope(const Symbol name, Value & v) varNames.emplace(state->symbols[name]); } +Value * NixRepl::bindingsToAttrs() +{ + auto builder = state->buildBindings(staticEnv->vars.size()); + for (auto & [symbol, displacement] : staticEnv->vars) { + builder.insert(symbol, env->values[displacement]); + } + + Value * attrs(state->allocValue()); + attrs->mkAttrs(builder.finish()); + return attrs; +} + Expr * NixRepl::parseString(std::string s) { @@ -824,6 +976,15 @@ void NixRepl::evalString(std::string s, Value & v) state->forceValue(v, v.determinePos(noPos)); } +Value * NixRepl::evalFile(SourcePath & path) +{ + auto expr = state->parseExprFromFile(path, staticEnv); + Value * result(state->allocValue()); + expr->eval(*state, *env, *result); + state->forceValue(*result, result->determinePos(noPos)); + return result; +} + std::unique_ptr<AbstractNixRepl> AbstractNixRepl::create( const SearchPath & searchPath, nix::ref<Store> store, ref<EvalState> state, diff --git a/src/libexpr/eval-settings.hh b/src/libexpr/eval-settings.hh index c264b521f..98fe6881e 100644 --- a/src/libexpr/eval-settings.hh +++ b/src/libexpr/eval-settings.hh @@ -125,6 +125,42 @@ struct EvalSettings : Config This is useful for debugging warnings in third-party Nix code. )"}; + + PathsSetting replOverlays{this, Paths(), "repl-overlays", + R"( + A list of files containing Nix expressions that can be used to add + default bindings to [`nix + repl`](@docroot@/command-ref/new-cli/nix3-repl.md) sessions. + + Each file is called with three arguments: + 1. An [attribute set](@docroot@/language/values.html#attribute-set) + containing at least a + [`currentSystem`](@docroot@/language/builtin-constants.md#builtins-currentSystem) + attribute (this is identical to + [`builtins.currentSystem`](@docroot@/language/builtin-constants.md#builtins-currentSystem), + except that it's available in + [`pure-eval`](@docroot@/command-ref/conf-file.html#conf-pure-eval) + mode). + 2. The top-level bindings produced by the previous `repl-overlays` + value (or the default top-level bindings). + 3. The final top-level bindings produced by calling all + `repl-overlays`. + + For example, the following file would alias `pkgs` to + `legacyPackages.${info.currentSystem}` (if that attribute is defined): + + ```nix + info: final: prev: + if prev ? legacyPackages + && prev.legacyPackages ? ${info.currentSystem} + then + { + pkgs = prev.legacyPackages.${info.currentSystem}; + } + else + { } + ``` + )"}; }; extern EvalSettings evalSettings; diff --git a/tests/functional/repl_characterization/data/extra_data/repl-overlay-fail.nix b/tests/functional/repl_characterization/data/extra_data/repl-overlay-fail.nix new file mode 100644 index 000000000..426127916 --- /dev/null +++ b/tests/functional/repl_characterization/data/extra_data/repl-overlay-fail.nix @@ -0,0 +1 @@ +info: final: prev: builtins.abort "uh oh!" diff --git a/tests/functional/repl_characterization/data/extra_data/repl-overlay-no-dotdotdot.nix b/tests/functional/repl_characterization/data/extra_data/repl-overlay-no-dotdotdot.nix new file mode 100644 index 000000000..e242d644d --- /dev/null +++ b/tests/functional/repl_characterization/data/extra_data/repl-overlay-no-dotdotdot.nix @@ -0,0 +1,6 @@ +let + puppy = "doggy"; +in + {currentSystem}: final: prev: { + inherit puppy; + } diff --git a/tests/functional/repl_characterization/data/extra_data/repl-overlay-no-formals.nix b/tests/functional/repl_characterization/data/extra_data/repl-overlay-no-formals.nix new file mode 100644 index 000000000..cf31550c0 --- /dev/null +++ b/tests/functional/repl_characterization/data/extra_data/repl-overlay-no-formals.nix @@ -0,0 +1 @@ +info: final: prev: {} diff --git a/tests/functional/repl_characterization/data/extra_data/repl-overlay-packages-is-pkgs.nix b/tests/functional/repl_characterization/data/extra_data/repl-overlay-packages-is-pkgs.nix new file mode 100644 index 000000000..57895a97f --- /dev/null +++ b/tests/functional/repl_characterization/data/extra_data/repl-overlay-packages-is-pkgs.nix @@ -0,0 +1,4 @@ +info: final: prev: +{ + pkgs = final.packages.x86_64-linux; +} diff --git a/tests/functional/repl_characterization/data/extra_data/repl-overlays-compose-1.nix b/tests/functional/repl_characterization/data/extra_data/repl-overlays-compose-1.nix new file mode 100644 index 000000000..055e9ea0f --- /dev/null +++ b/tests/functional/repl_characterization/data/extra_data/repl-overlays-compose-1.nix @@ -0,0 +1,7 @@ +info: final: prev: +{ + var = prev.var + "b"; + + # We can access the final value of `var` here even though it isn't defined yet: + varUsingFinal = "final value is: " + final.newVar; +} diff --git a/tests/functional/repl_characterization/data/extra_data/repl-overlays-compose-2.nix b/tests/functional/repl_characterization/data/extra_data/repl-overlays-compose-2.nix new file mode 100644 index 000000000..e88407311 --- /dev/null +++ b/tests/functional/repl_characterization/data/extra_data/repl-overlays-compose-2.nix @@ -0,0 +1,6 @@ +info: final: prev: +{ + var = prev.var + "c"; + + newVar = "puppy"; +} diff --git a/tests/functional/repl_characterization/data/repl_overlays.nix b/tests/functional/repl_characterization/data/repl_overlays.nix new file mode 100644 index 000000000..09f115f03 --- /dev/null +++ b/tests/functional/repl_characterization/data/repl_overlays.nix @@ -0,0 +1,3 @@ +{ + packages.x86_64-linux.default = "my package"; +} diff --git a/tests/functional/repl_characterization/data/repl_overlays.test b/tests/functional/repl_characterization/data/repl_overlays.test new file mode 100644 index 000000000..56f1392e1 --- /dev/null +++ b/tests/functional/repl_characterization/data/repl_overlays.test @@ -0,0 +1,5 @@ +Check basic `repl-overlays` functionality. +@args --repl-overlays +@args ${PWD}/extra_data/repl-overlay-packages-is-pkgs.nix + nix-repl> pkgs + { default = "my package"; } diff --git a/tests/functional/repl_characterization/data/repl_overlays_compose.nix b/tests/functional/repl_characterization/data/repl_overlays_compose.nix new file mode 100644 index 000000000..aa6596dc7 --- /dev/null +++ b/tests/functional/repl_characterization/data/repl_overlays_compose.nix @@ -0,0 +1,3 @@ +{ + var = "a"; +} diff --git a/tests/functional/repl_characterization/data/repl_overlays_compose.test b/tests/functional/repl_characterization/data/repl_overlays_compose.test new file mode 100644 index 000000000..b674a55be --- /dev/null +++ b/tests/functional/repl_characterization/data/repl_overlays_compose.test @@ -0,0 +1,7 @@ +Check that multiple `repl-overlays` can compose together +@args --repl-overlays +@args "${PWD}/extra_data/repl-overlays-compose-1.nix ${PWD}/extra_data/repl-overlays-compose-2.nix" + nix-repl> var + "abc" + nix-repl> varUsingFinal + "final value is: puppy" diff --git a/tests/functional/repl_characterization/data/repl_overlays_destructure_without_dotdotdot_errors.test b/tests/functional/repl_characterization/data/repl_overlays_destructure_without_dotdotdot_errors.test new file mode 100644 index 000000000..daf1f27bd --- /dev/null +++ b/tests/functional/repl_characterization/data/repl_overlays_destructure_without_dotdotdot_errors.test @@ -0,0 +1,10 @@ +`repl-overlays` that try to parse out the `info` argument without a `...` error. +@args --repl-overlays +@args ${PWD}/extra_data/repl-overlay-no-dotdotdot.nix +@should-start false + error: Expected first argument of repl-overlays to have ... to allow future versions of Lix to add additional attributes to the argument + at $TEST_DATA/extra_data/repl-overlay-no-dotdotdot.nix:4:3: + 3| in + 4| {currentSystem}: final: prev: { + | ^ + 5| inherit puppy;\n diff --git a/tests/functional/repl_characterization/data/repl_overlays_destructure_without_formals_ok.test b/tests/functional/repl_characterization/data/repl_overlays_destructure_without_formals_ok.test new file mode 100644 index 000000000..3aa89e434 --- /dev/null +++ b/tests/functional/repl_characterization/data/repl_overlays_destructure_without_formals_ok.test @@ -0,0 +1,5 @@ +`repl-overlays` that don't destructure the `info` argument are OK. +@args --repl-overlays +@args ${PWD}/extra_data/repl-overlay-no-formals.nix + nix-repl> 1 + 1 diff --git a/tests/functional/repl_characterization/data/repl_overlays_error.test b/tests/functional/repl_characterization/data/repl_overlays_error.test new file mode 100644 index 000000000..2d8702df1 --- /dev/null +++ b/tests/functional/repl_characterization/data/repl_overlays_error.test @@ -0,0 +1,22 @@ +`repl-overlays` that fail to evaluate should error. +@args --repl-overlays +@args ${PWD}/extra_data/repl-overlay-fail.nix +@should-start false + error: + … while calling the 'foldl'' builtin + at «string»:5:13: + 4| functions: + 5| let final = builtins.foldl' + | ^ + 6| (prev: function: prev // (function info final prev)) + + … in the right operand of the update (//) operator + at «string»:6:37: + 5| let final = builtins.foldl' + 6| (prev: function: prev // (function info final prev)) + | ^ + 7| initial + + (stack trace truncated; use '--show-trace' to show the full trace) + + error: evaluation aborted with the following error message: 'uh oh!' diff --git a/tests/functional/repl_characterization/extra_data/repl-overlay-fail.nix b/tests/functional/repl_characterization/extra_data/repl-overlay-fail.nix new file mode 100644 index 000000000..426127916 --- /dev/null +++ b/tests/functional/repl_characterization/extra_data/repl-overlay-fail.nix @@ -0,0 +1 @@ +info: final: prev: builtins.abort "uh oh!" diff --git a/tests/functional/repl_characterization/extra_data/repl-overlay-no-dotdotdot.nix b/tests/functional/repl_characterization/extra_data/repl-overlay-no-dotdotdot.nix new file mode 100644 index 000000000..1cced3324 --- /dev/null +++ b/tests/functional/repl_characterization/extra_data/repl-overlay-no-dotdotdot.nix @@ -0,0 +1 @@ +{currentSystem}: final: prev: {} diff --git a/tests/functional/repl_characterization/extra_data/repl-overlay-packages-is-pkgs.nix b/tests/functional/repl_characterization/extra_data/repl-overlay-packages-is-pkgs.nix new file mode 100644 index 000000000..57895a97f --- /dev/null +++ b/tests/functional/repl_characterization/extra_data/repl-overlay-packages-is-pkgs.nix @@ -0,0 +1,4 @@ +info: final: prev: +{ + pkgs = final.packages.x86_64-linux; +} diff --git a/tests/functional/repl_characterization/extra_data/repl-overlays-compose-1.nix b/tests/functional/repl_characterization/extra_data/repl-overlays-compose-1.nix new file mode 100644 index 000000000..055e9ea0f --- /dev/null +++ b/tests/functional/repl_characterization/extra_data/repl-overlays-compose-1.nix @@ -0,0 +1,7 @@ +info: final: prev: +{ + var = prev.var + "b"; + + # We can access the final value of `var` here even though it isn't defined yet: + varUsingFinal = "final value is: " + final.newVar; +} diff --git a/tests/functional/repl_characterization/extra_data/repl-overlays-compose-2.nix b/tests/functional/repl_characterization/extra_data/repl-overlays-compose-2.nix new file mode 100644 index 000000000..e88407311 --- /dev/null +++ b/tests/functional/repl_characterization/extra_data/repl-overlays-compose-2.nix @@ -0,0 +1,6 @@ +info: final: prev: +{ + var = prev.var + "c"; + + newVar = "puppy"; +} diff --git a/tests/functional/repl_characterization/repl_characterization.cc b/tests/functional/repl_characterization/repl_characterization.cc index eb90f349d..f84bbdaae 100644 --- a/tests/functional/repl_characterization/repl_characterization.cc +++ b/tests/functional/repl_characterization/repl_characterization.cc @@ -179,7 +179,12 @@ REPL_TEST(no_nested_debuggers); REPL_TEST(regression_9917); REPL_TEST(regression_9918); REPL_TEST(regression_l145); -REPL_TEST(stack_vars); +REPL_TEST(repl_overlays); +REPL_TEST(repl_overlays_compose); +REPL_TEST(repl_overlays_destructure_without_dotdotdot_errors); +REPL_TEST(repl_overlays_destructure_without_formals_ok); +REPL_TEST(repl_overlays_error); REPL_TEST(repl_printing); +REPL_TEST(stack_vars); }; // namespace nix |