Merge pull request #6233 from flox/nix-repl-flakes

Nix repl flakes
This commit is contained in:
Théophane Hufschmitt 2022-06-29 17:59:22 +02:00 committed by GitHub
commit 4c8210095e
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GPG key ID: 4AEE18F83AFDEB23
9 changed files with 178 additions and 38 deletions

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@ -2,3 +2,10 @@
* Nix can now be built with LTO by passing `--enable-lto` to `configure`.
LTO is currently only supported when building with GCC.
* `nix repl` now takes installables on the command line, unifying the usage
with other commands that use `--file` and `--expr`. Primary breaking change
is for the common usage of `nix repl '<nixpkgs>'` which can be recovered with
`nix repl --file '<nixpkgs>'` or `nix repl --expr 'import <nixpkgs>{}'`
This is currently guarded by the 'repl-flake' experimental feature

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@ -116,12 +116,13 @@ struct InstallablesCommand : virtual Args, SourceExprCommand
InstallablesCommand();
void prepare() override;
Installables load();
virtual bool useDefaultInstallables() { return true; }
std::optional<FlakeRef> getFlakeRefForCompletion() override;
private:
protected:
std::vector<std::string> _installables;
};

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@ -1036,11 +1036,16 @@ InstallablesCommand::InstallablesCommand()
void InstallablesCommand::prepare()
{
installables = load();
}
Installables InstallablesCommand::load() {
Installables installables;
if (_installables.empty() && useDefaultInstallables())
// FIXME: commands like "nix profile install" should not have a
// default, probably.
_installables.push_back(".");
installables = parseInstallables(getStore(), _installables);
return parseInstallables(getStore(), _installables);
}
std::optional<FlakeRef> InstallablesCommand::getFlakeRefForCompletion()

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@ -132,6 +132,8 @@ struct Installable
const std::vector<std::shared_ptr<Installable>> & installables);
};
typedef std::vector<std::shared_ptr<Installable>> Installables;
struct InstallableValue : Installable
{
ref<EvalState> state;

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@ -22,6 +22,7 @@ extern "C" {
#include "ansicolor.hh"
#include "shared.hh"
#include "eval.hh"
#include "eval-cache.hh"
#include "eval-inline.hh"
#include "attr-path.hh"
#include "store-api.hh"
@ -54,6 +55,8 @@ struct NixRepl
size_t debugTraceIndex;
Strings loadedFiles;
typedef std::vector<std::pair<Value*,std::string>> AnnotatedValues;
std::function<AnnotatedValues()> getValues;
const static int envSize = 32768;
std::shared_ptr<StaticEnv> staticEnv;
@ -63,13 +66,15 @@ struct NixRepl
const Path historyFile;
NixRepl(ref<EvalState> state);
NixRepl(const Strings & searchPath, nix::ref<Store> store,ref<EvalState> state,
std::function<AnnotatedValues()> getValues);
~NixRepl();
void mainLoop(const std::vector<std::string> & files);
void mainLoop();
StringSet completePrefix(const std::string & prefix);
bool getLine(std::string & input, const std::string & prompt);
StorePath getDerivationPath(Value & v);
bool processLine(std::string line);
void loadFile(const Path & path);
void loadFlake(const std::string & flakeRef);
void initEnv();
@ -96,9 +101,11 @@ std::string removeWhitespace(std::string s)
}
NixRepl::NixRepl(ref<EvalState> state)
NixRepl::NixRepl(const Strings & searchPath, nix::ref<Store> store, ref<EvalState> state,
std::function<NixRepl::AnnotatedValues()> getValues)
: state(state)
, debugTraceIndex(0)
, getValues(getValues)
, staticEnv(new StaticEnv(false, state->staticBaseEnv.get()))
, historyFile(getDataDir() + "/nix/repl-history")
{
@ -225,18 +232,12 @@ static std::ostream & showDebugTrace(std::ostream & out, const PosTable & positi
return out;
}
void NixRepl::mainLoop(const std::vector<std::string> & files)
void NixRepl::mainLoop()
{
std::string error = ANSI_RED "error:" ANSI_NORMAL " ";
notice("Welcome to Nix " + nixVersion + ". Type :? for help.\n");
if (!files.empty()) {
for (auto & i : files)
loadedFiles.push_back(i);
}
loadFiles();
if (!loadedFiles.empty()) notice("");
// Allow nix-repl specific settings in .inputrc
rl_readline_name = "nix-repl";
@ -746,7 +747,6 @@ bool NixRepl::processLine(std::string line)
return true;
}
void NixRepl::loadFile(const Path & path)
{
loadedFiles.remove(path);
@ -806,13 +806,15 @@ void NixRepl::loadFiles()
Strings old = loadedFiles;
loadedFiles.clear();
bool first = true;
for (auto & i : old) {
if (!first) notice("");
first = false;
notice("Loading '%1%'...", i);
loadFile(i);
}
for (auto & [i, what] : getValues()) {
notice("Loading installable '%1%'...", what);
addAttrsToScope(*i);
}
}
@ -1012,7 +1014,17 @@ void runRepl(
ref<EvalState>evalState,
const ValMap & extraEnv)
{
auto repl = std::make_unique<NixRepl>(evalState);
auto getValues = [&]()->NixRepl::AnnotatedValues{
NixRepl::AnnotatedValues values;
return values;
};
const Strings & searchPath = {};
auto repl = std::make_unique<NixRepl>(
searchPath,
openStore(),
evalState,
getValues
);
repl->initEnv();
@ -1020,20 +1032,35 @@ void runRepl(
for (auto & [name, value] : extraEnv)
repl->addVarToScope(repl->state->symbols.create(name), *value);
repl->mainLoop({});
repl->mainLoop();
}
struct CmdRepl : StoreCommand, MixEvalArgs
struct CmdRepl : InstallablesCommand
{
std::vector<std::string> files;
CmdRepl()
CmdRepl(){
evalSettings.pureEval = false;
}
void prepare()
{
expectArgs({
.label = "files",
.handler = {&files},
.completer = completePath
});
if (!settings.isExperimentalFeatureEnabled(Xp::ReplFlake) && !(file) && this->_installables.size() >= 1) {
warn("future versions of Nix will require using `--file` to load a file");
if (this->_installables.size() > 1)
warn("more than one input file is not currently supported");
auto filePath = this->_installables[0].data();
file = std::optional(filePath);
_installables.front() = _installables.back();
_installables.pop_back();
}
installables = InstallablesCommand::load();
}
std::vector<std::string> files;
Strings getDefaultFlakeAttrPaths() override
{
return {""};
}
virtual bool useDefaultInstallables() override
{
return file.has_value() or expr.has_value();
}
bool forceImpureByDefault() override
@ -1055,12 +1082,37 @@ struct CmdRepl : StoreCommand, MixEvalArgs
void run(ref<Store> store) override
{
auto evalState = make_ref<EvalState>(searchPath, store);
auto repl = std::make_unique<NixRepl>(evalState);
auto state = getEvalState();
auto getValues = [&]()->NixRepl::AnnotatedValues{
auto installables = load();
NixRepl::AnnotatedValues values;
for (auto & installable: installables){
auto what = installable->what();
if (file){
auto [val, pos] = installable->toValue(*state);
auto what = installable->what();
state->forceValue(*val, pos);
auto autoArgs = getAutoArgs(*state);
auto valPost = state->allocValue();
state->autoCallFunction(*autoArgs, *val, *valPost);
state->forceValue(*valPost, pos);
values.push_back( {valPost, what });
} else {
auto [val, pos] = installable->toValue(*state);
values.push_back( {val, what} );
}
}
return values;
};
auto repl = std::make_unique<NixRepl>(
searchPath,
openStore(),
state,
getValues
);
repl->autoArgs = getAutoArgs(*repl->state);
repl->initEnv();
repl->mainLoop(files);
repl->mainLoop();
}
};

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@ -13,6 +13,7 @@ std::map<ExperimentalFeature, std::string> stringifiedXpFeatures = {
{ Xp::RecursiveNix, "recursive-nix" },
{ Xp::NoUrlLiterals, "no-url-literals" },
{ Xp::FetchClosure, "fetch-closure" },
{ Xp::ReplFlake, "repl-flake" },
};
const std::optional<ExperimentalFeature> parseExperimentalFeature(const std::string_view & name)

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@ -22,6 +22,7 @@ enum struct ExperimentalFeature
RecursiveNix,
NoUrlLiterals,
FetchClosure,
ReplFlake,
};
/**

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@ -24,10 +24,34 @@ R""(
* Interact with Nixpkgs in the REPL:
```console
# nix repl '<nixpkgs>'
# nix repl --file example.nix
Loading Installable ''...
Added 3 variables.
Loading '<nixpkgs>'...
Added 12428 variables.
# nix repl --expr '{a={b=3;c=4;};}'
Loading Installable ''...
Added 1 variables.
# nix repl --expr '{a={b=3;c=4;};}' a
Loading Installable ''...
Added 1 variables.
# nix repl --extra_experimental_features 'flakes repl-flake' nixpkgs
Loading Installable 'flake:nixpkgs#'...
Added 5 variables.
nix-repl> legacyPackages.x86_64-linux.emacs.name
"emacs-27.1"
nix-repl> legacyPackages.x86_64-linux.emacs.name
"emacs-27.1"
nix-repl> :q
# nix repl --expr 'import <nixpkgs>{}'
Loading Installable ''...
Added 12439 variables.
nix-repl> emacs.name
"emacs-27.1"

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@ -55,15 +55,17 @@ testRepl
testRepl --store "$TEST_ROOT/store?real=$NIX_STORE_DIR"
testReplResponse () {
local response="$(nix repl <<< "$1")"
echo "$response" | grep -qs "$2" \
local commands="$1"; shift
local expectedResponse="$1"; shift
local response="$(nix repl "$@" <<< "$commands")"
echo "$response" | grep -qs "$expectedResponse" \
|| fail "repl command set:
$1
$commands
does not respond with:
$2
$expectedResponse
but with:
@ -76,3 +78,48 @@ testReplResponse '
:a { a = "2"; }
"result: ${a}"
' "result: 2"
testReplResponse '
drvPath
' '".*-simple.drv"' \
$testDir/simple.nix
testReplResponse '
drvPath
' '".*-simple.drv"' \
--file $testDir/simple.nix --experimental-features 'ca-derivations'
testReplResponse '
drvPath
' '".*-simple.drv"' \
--file $testDir/simple.nix --extra-experimental-features 'repl-flake ca-derivations'
mkdir -p flake && cat <<EOF > flake/flake.nix
{
outputs = { self }: {
foo = 1;
bar.baz = 2;
changingThing = "beforeChange";
};
}
EOF
testReplResponse '
foo + baz
' "3" \
./flake ./flake\#bar --experimental-features 'flakes repl-flake'
# Test the `:reload` mechansim with flakes:
# - Eval `./flake#changingThing`
# - Modify the flake
# - Re-eval it
# - Check that the result has changed
replResult=$( (
echo "changingThing"
sleep 1 # Leave the repl the time to eval 'foo'
sed -i 's/beforeChange/afterChange/' flake/flake.nix
echo ":reload"
echo "changingThing"
) | nix repl ./flake --experimental-features 'flakes repl-flake')
echo "$replResult" | grep -qs beforeChange
echo "$replResult" | grep -qs afterChange