Merge remote-tracking branch 'origin/master' into coerce-string

src/libcmd/command.cc

@@ -226,7 +226,7 @@ MixProfile::MixProfile()
 {
     addFlag({
         .longName = "profile",
-        .description = "The profile to update.",
+        .description = "The profile to operate on.",
         .labels = {"path"},
         .handler = {&profile},
         .completer = completePath

src/libcmd/common-eval-args.cc

@@ -32,7 +32,77 @@ MixEvalArgs::MixEvalArgs()
     addFlag({
         .longName = "include",
         .shortName = 'I',
-        .description = "Add *path* to the list of locations used to look up `<...>` file names.",
+        .description = R"(
+  Add *path* to the Nix search path. The Nix search path is
+  initialized from the colon-separated [`NIX_PATH`](./env-common.md#env-NIX_PATH) environment
+  variable, and is used to look up the location of Nix expressions using [paths](../language/values.md#type-path) enclosed in angle
+  brackets (i.e., `<nixpkgs>`).
+
+  For instance, passing
+
+  ```
+  -I /home/eelco/Dev
+  -I /etc/nixos
+  ```
+
+  will cause Nix to look for paths relative to `/home/eelco/Dev` and
+  `/etc/nixos`, in that order. This is equivalent to setting the
+  `NIX_PATH` environment variable to
+
+  ```
+  /home/eelco/Dev:/etc/nixos
+  ```
+
+  It is also possible to match paths against a prefix. For example,
+  passing
+
+  ```
+  -I nixpkgs=/home/eelco/Dev/nixpkgs-branch
+  -I /etc/nixos
+  ```
+
+  will cause Nix to search for `<nixpkgs/path>` in
+  `/home/eelco/Dev/nixpkgs-branch/path` and `/etc/nixos/nixpkgs/path`.
+
+  If a path in the Nix search path starts with `http://` or `https://`,
+  it is interpreted as the URL of a tarball that will be downloaded and
+  unpacked to a temporary location. The tarball must consist of a single
+  top-level directory. For example, passing
+
+  ```
+  -I nixpkgs=https://github.com/NixOS/nixpkgs/archive/master.tar.gz
+  ```
+
+  tells Nix to download and use the current contents of the `master`
+  branch in the `nixpkgs` repository.
+
+  The URLs of the tarballs from the official `nixos.org` channels
+  (see [the manual page for `nix-channel`](../nix-channel.md)) can be
+  abbreviated as `channel:<channel-name>`.  For instance, the
+  following two flags are equivalent:
+
+  ```
+  -I nixpkgs=channel:nixos-21.05
+  -I nixpkgs=https://nixos.org/channels/nixos-21.05/nixexprs.tar.xz
+  ```
+
+  You can also fetch source trees using [flake URLs](./nix3-flake.md#url-like-syntax) and add them to the
+  search path. For instance,
+
+  ```
+  -I nixpkgs=flake:nixpkgs
+  ```
+
+  specifies that the prefix `nixpkgs` shall refer to the source tree
+  downloaded from the `nixpkgs` entry in the flake registry. Similarly,
+
+  ```
+  -I nixpkgs=flake:github:NixOS/nixpkgs/nixos-22.05
+  ```
+
+  makes `<nixpkgs>` refer to a particular branch of the
+  `NixOS/nixpkgs` repository on GitHub.
+  )",
         .category = category,
         .labels = {"path"},
         .handler = {[&](std::string s) { searchPath.push_back(s); }}
@@ -89,14 +159,25 @@ Bindings * MixEvalArgs::getAutoArgs(EvalState & state)
 
 Path lookupFileArg(EvalState & state, std::string_view s)
 {
-    if (isUri(s)) {
-        return state.store->toRealPath(
-            fetchers::downloadTarball(
-                state.store, resolveUri(s), "source", false).first.storePath);
-    } else if (s.size() > 2 && s.at(0) == '<' && s.at(s.size() - 1) == '>') {
+    if (EvalSettings::isPseudoUrl(s)) {
+        auto storePath = fetchers::downloadTarball(
+            state.store, EvalSettings::resolvePseudoUrl(s), "source", false).first.storePath;
+        return state.store->toRealPath(storePath);
+    }
+
+    else if (hasPrefix(s, "flake:")) {
+        settings.requireExperimentalFeature(Xp::Flakes);
+        auto flakeRef = parseFlakeRef(std::string(s.substr(6)), {}, true, false);
+        auto storePath = flakeRef.resolve(state.store).fetchTree(state.store).first.storePath;
+        return state.store->toRealPath(storePath);
+    }
+
+    else if (s.size() > 2 && s.at(0) == '<' && s.at(s.size() - 1) == '>') {
         Path p(s.substr(1, s.size() - 2));
         return state.findFile(p);
-    } else
+    }
+
+    else
         return absPath(std::string(s));
 }
 

src/libcmd/installables.cc

@@ -168,7 +168,7 @@ SourceExprCommand::SourceExprCommand(bool supportReadOnlyMode)
 
     addFlag({
         .longName = "derivation",
-        .description = "Operate on the store derivation rather than its outputs.",
+        .description = "Operate on the [store derivation](../../glossary.md#gloss-store-derivation) rather than its outputs.",
         .category = installablesCategory,
         .handler = {&operateOn, OperateOn::Derivation},
     });
@@ -207,55 +207,59 @@ Strings SourceExprCommand::getDefaultFlakeAttrPathPrefixes()
 
 void SourceExprCommand::completeInstallable(std::string_view prefix)
 {
-    if (file) {
-        completionType = ctAttrs;
+    try {
+        if (file) {
+            completionType = ctAttrs;
 
-        evalSettings.pureEval = false;
-        auto state = getEvalState();
-        Expr *e = state->parseExprFromFile(
-            resolveExprPath(state->checkSourcePath(lookupFileArg(*state, *file)))
-        );
+            evalSettings.pureEval = false;
+            auto state = getEvalState();
+            Expr *e = state->parseExprFromFile(
+                resolveExprPath(state->checkSourcePath(lookupFileArg(*state, *file)))
+                );
 
-        Value root;
-        state->eval(e, root);
+            Value root;
+            state->eval(e, root);
 
-        auto autoArgs = getAutoArgs(*state);
+            auto autoArgs = getAutoArgs(*state);
 
-        std::string prefix_ = std::string(prefix);
-        auto sep = prefix_.rfind('.');
-        std::string searchWord;
-        if (sep != std::string::npos) {
-            searchWord = prefix_.substr(sep + 1, std::string::npos);
-            prefix_ = prefix_.substr(0, sep);
-        } else {
-            searchWord = prefix_;
-            prefix_ = "";
-        }
+            std::string prefix_ = std::string(prefix);
+            auto sep = prefix_.rfind('.');
+            std::string searchWord;
+            if (sep != std::string::npos) {
+                searchWord = prefix_.substr(sep + 1, std::string::npos);
+                prefix_ = prefix_.substr(0, sep);
+            } else {
+                searchWord = prefix_;
+                prefix_ = "";
+            }
 
-        auto [v, pos] = findAlongAttrPath(*state, prefix_, *autoArgs, root);
-        Value &v1(*v);
-        state->forceValue(v1, pos);
-        Value v2;
-        state->autoCallFunction(*autoArgs, v1, v2);
+            auto [v, pos] = findAlongAttrPath(*state, prefix_, *autoArgs, root);
+            Value &v1(*v);
+            state->forceValue(v1, pos);
+            Value v2;
+            state->autoCallFunction(*autoArgs, v1, v2);
 
-        if (v2.type() == nAttrs) {
-            for (auto & i : *v2.attrs) {
-                std::string name = state->symbols[i.name];
-                if (name.find(searchWord) == 0) {
-                    if (prefix_ == "")
-                        completions->add(name);
-                    else
-                        completions->add(prefix_ + "." + name);
+            if (v2.type() == nAttrs) {
+                for (auto & i : *v2.attrs) {
+                    std::string name = state->symbols[i.name];
+                    if (name.find(searchWord) == 0) {
+                        if (prefix_ == "")
+                            completions->add(name);
+                        else
+                            completions->add(prefix_ + "." + name);
+                    }
                 }
             }
+        } else {
+            completeFlakeRefWithFragment(
+                getEvalState(),
+                lockFlags,
+                getDefaultFlakeAttrPathPrefixes(),
+                getDefaultFlakeAttrPaths(),
+                prefix);
         }
-    } else {
-        completeFlakeRefWithFragment(
-            getEvalState(),
-            lockFlags,
-            getDefaultFlakeAttrPathPrefixes(),
-            getDefaultFlakeAttrPaths(),
-            prefix);
+    } catch (EvalError&) {
+        // Don't want eval errors to mess-up with the completion engine, so let's just swallow them
     }
 }
 
@@ -395,44 +399,56 @@ static StorePath getDeriver(
 struct InstallableStorePath : Installable
 {
     ref<Store> store;
-    StorePath storePath;
+    DerivedPath req;
 
     InstallableStorePath(ref<Store> store, StorePath && storePath)
-        : store(store), storePath(std::move(storePath)) { }
+        : store(store),
+          req(storePath.isDerivation()
+              ? (DerivedPath) DerivedPath::Built {
+                  .drvPath = std::move(storePath),
+                  .outputs = {},
+              }
+              : (DerivedPath) DerivedPath::Opaque {
+                  .path = std::move(storePath),
+              })
+    { }
 
-    std::string what() const override { return store->printStorePath(storePath); }
+    InstallableStorePath(ref<Store> store, DerivedPath && req)
+        : store(store), req(std::move(req))
+    { }
+
+    std::string what() const override
+    {
+        return req.to_string(*store);
+    }
 
     DerivedPaths toDerivedPaths() override
     {
-        if (storePath.isDerivation()) {
-            auto drv = store->readDerivation(storePath);
-            return {
-                DerivedPath::Built {
-                    .drvPath = storePath,
-                    .outputs = drv.outputNames(),
-                }
-            };
-        } else {
-            return {
-                DerivedPath::Opaque {
-                    .path = storePath,
-                }
-            };
-        }
+        return { req };
     }
 
     StorePathSet toDrvPaths(ref<Store> store) override
     {
-        if (storePath.isDerivation()) {
-            return {storePath};
-        } else {
-            return {getDeriver(store, *this, storePath)};
-        }
+        return std::visit(overloaded {
+            [&](const DerivedPath::Built & bfd) -> StorePathSet {
+                return { bfd.drvPath };
+            },
+            [&](const DerivedPath::Opaque & bo) -> StorePathSet {
+                return { getDeriver(store, *this, bo.path) };
+            },
+        }, req.raw());
     }
 
     std::optional<StorePath> getStorePath() override
     {
-        return storePath;
+        return std::visit(overloaded {
+            [&](const DerivedPath::Built & bfd) {
+                return bfd.drvPath;
+            },
+            [&](const DerivedPath::Opaque & bo) {
+                return bo.path;
+            },
+        }, req.raw());
     }
 };
 
@@ -777,7 +793,8 @@ std::vector<std::shared_ptr<Installable>> SourceExprCommand::parseInstallables(
         if (file == "-") {
             auto e = state->parseStdin();
             state->eval(e, *vFile);
-        } else if (file)
+        }
+        else if (file)
             state->evalFile(lookupFileArg(*state, *file), *vFile);
         else {
             auto e = state->parseExprFromString(*expr, absPath("."));
@@ -798,7 +815,22 @@ std::vector<std::shared_ptr<Installable>> SourceExprCommand::parseInstallables(
         for (auto & s : ss) {
             std::exception_ptr ex;
 
-            if (s.find('/') != std::string::npos) {
+            auto found = s.rfind('^');
+            if (found != std::string::npos) {
+                try {
+                    result.push_back(std::make_shared<InstallableStorePath>(
+                        store,
+                        DerivedPath::Built::parse(*store, s.substr(0, found), s.substr(found + 1))));
+                    continue;
+                } catch (BadStorePath &) {
+                } catch (...) {
+                    if (!ex)
+                        ex = std::current_exception();
+                }
+            }
+
+            found = s.find('/');
+            if (found != std::string::npos) {
                 try {
                     result.push_back(std::make_shared<InstallableStorePath>(store, store->followLinksToStorePath(s)));
                     continue;
@@ -840,20 +872,20 @@ std::shared_ptr<Installable> SourceExprCommand::parseInstallable(
     return installables.front();
 }
 
-BuiltPaths Installable::build(
+std::vector<BuiltPathWithResult> Installable::build(
     ref<Store> evalStore,
     ref<Store> store,
     Realise mode,
     const std::vector<std::shared_ptr<Installable>> & installables,
     BuildMode bMode)
 {
-    BuiltPaths res;
-    for (auto & [_, builtPath] : build2(evalStore, store, mode, installables, bMode))
-        res.push_back(builtPath);
+    std::vector<BuiltPathWithResult> res;
+    for (auto & [_, builtPathWithResult] : build2(evalStore, store, mode, installables, bMode))
+        res.push_back(builtPathWithResult);
     return res;
 }
 
-std::vector<std::pair<std::shared_ptr<Installable>, BuiltPath>> Installable::build2(
+std::vector<std::pair<std::shared_ptr<Installable>, BuiltPathWithResult>> Installable::build2(
     ref<Store> evalStore,
     ref<Store> store,
     Realise mode,
@@ -873,7 +905,7 @@ std::vector<std::pair<std::shared_ptr<Installable>, BuiltPath>> Installable::bui
         }
     }
 
-    std::vector<std::pair<std::shared_ptr<Installable>, BuiltPath>> res;
+    std::vector<std::pair<std::shared_ptr<Installable>, BuiltPathWithResult>> res;
 
     switch (mode) {
 
@@ -914,10 +946,10 @@ std::vector<std::pair<std::shared_ptr<Installable>, BuiltPath>> Installable::bui
                                     output, *drvOutput->second);
                             }
                         }
-                        res.push_back({installable, BuiltPath::Built { bfd.drvPath, outputs }});
+                        res.push_back({installable, {.path = BuiltPath::Built { bfd.drvPath, outputs }}});
                     },
                     [&](const DerivedPath::Opaque & bo) {
-                        res.push_back({installable, BuiltPath::Opaque { bo.path }});
+                        res.push_back({installable, {.path = BuiltPath::Opaque { bo.path }}});
                     },
                 }, path.raw());
             }
@@ -927,7 +959,7 @@ std::vector<std::pair<std::shared_ptr<Installable>, BuiltPath>> Installable::bui
 
     case Realise::Outputs: {
         if (settings.printMissing)
-          printMissing(store, pathsToBuild, lvlInfo);
+            printMissing(store, pathsToBuild, lvlInfo);
 
         for (auto & buildResult : store->buildPathsWithResults(pathsToBuild, bMode, evalStore)) {
             if (!buildResult.success())
@@ -939,10 +971,10 @@ std::vector<std::pair<std::shared_ptr<Installable>, BuiltPath>> Installable::bui
                         std::map<std::string, StorePath> outputs;
                         for (auto & path : buildResult.builtOutputs)
                             outputs.emplace(path.first.outputName, path.second.outPath);
-                        res.push_back({installable, BuiltPath::Built { bfd.drvPath, outputs }});
+                        res.push_back({installable, {.path = BuiltPath::Built { bfd.drvPath, outputs }, .result = buildResult}});
                     },
                     [&](const DerivedPath::Opaque & bo) {
-                        res.push_back({installable, BuiltPath::Opaque { bo.path }});
+                        res.push_back({installable, {.path = BuiltPath::Opaque { bo.path }, .result = buildResult}});
                     },
                 }, buildResult.path.raw());
             }
@@ -965,9 +997,12 @@ BuiltPaths Installable::toBuiltPaths(
     OperateOn operateOn,
     const std::vector<std::shared_ptr<Installable>> & installables)
 {
-    if (operateOn == OperateOn::Output)
-        return Installable::build(evalStore, store, mode, installables);
-    else {
+    if (operateOn == OperateOn::Output) {
+        BuiltPaths res;
+        for (auto & p : Installable::build(evalStore, store, mode, installables))
+            res.push_back(p.path);
+        return res;
+    } else {
         if (mode == Realise::Nothing)
             settings.readOnlyMode = true;
 

src/libcmd/installables.hh

@@ -7,6 +7,7 @@
 #include "eval.hh"
 #include "store-api.hh"
 #include "flake/flake.hh"
+#include "build-result.hh"
 
 #include <optional>
 
@@ -51,6 +52,12 @@ enum class OperateOn {
     Derivation
 };
 
+struct BuiltPathWithResult
+{
+    BuiltPath path;
+    std::optional<BuildResult> result;
+};
+
 struct Installable
 {
     virtual ~Installable() { }
@@ -91,14 +98,14 @@ struct Installable
         return FlakeRef::fromAttrs({{"type","indirect"}, {"id", "nixpkgs"}});
     }
 
-    static BuiltPaths build(
+    static std::vector<BuiltPathWithResult> build(
         ref<Store> evalStore,
         ref<Store> store,
         Realise mode,
         const std::vector<std::shared_ptr<Installable>> & installables,
         BuildMode bMode = bmNormal);
 
-    static std::vector<std::pair<std::shared_ptr<Installable>, BuiltPath>> build2(
+    static std::vector<std::pair<std::shared_ptr<Installable>, BuiltPathWithResult>> build2(
         ref<Store> evalStore,
         ref<Store> store,
         Realise mode,

src/libcmd/local.mk

@@ -8,7 +8,7 @@ libcmd_SOURCES := $(wildcard $(d)/*.cc)
 
 libcmd_CXXFLAGS += -I src/libutil -I src/libstore -I src/libexpr -I src/libmain -I src/libfetchers -I src/nix
 
-libcmd_LDFLAGS = $(EDITLINE_LIBS) -llowdown -pthread
+libcmd_LDFLAGS = $(EDITLINE_LIBS) $(LOWDOWN_LIBS) -pthread
 
 libcmd_LIBS = libstore libutil libexpr libmain libfetchers
 

src/libcmd/repl.cc

@@ -215,17 +215,15 @@ static std::ostream & showDebugTrace(std::ostream & out, const PosTable & positi
     out << dt.hint.str() << "\n";
 
     // prefer direct pos, but if noPos then try the expr.
-    auto pos = *dt.pos
-        ? *dt.pos
-        : positions[dt.expr.getPos() ? dt.expr.getPos() : noPos];
+    auto pos = dt.pos
+        ? dt.pos
+        : static_cast<std::shared_ptr<AbstractPos>>(positions[dt.expr.getPos() ? dt.expr.getPos() : noPos]);
 
     if (pos) {
-        printAtPos(pos, out);
-
-        auto loc = getCodeLines(pos);
-        if (loc.has_value()) {
+        out << pos;
+        if (auto loc = pos->getCodeLines()) {
             out << "\n";
-            printCodeLines(out, "", pos, *loc);
+            printCodeLines(out, "", *pos, *loc);
             out << "\n";
         }
     }
@@ -270,6 +268,7 @@ void NixRepl::mainLoop()
             // ctrl-D should exit the debugger.
             state->debugStop = false;
             state->debugQuit = true;
+            logger->cout("");
             break;
         }
         try {
@@ -384,6 +383,10 @@ StringSet NixRepl::completePrefix(const std::string & prefix)
             i++;
         }
     } else {
+        /* Temporarily disable the debugger, to avoid re-entering readline. */
+        auto debug_repl = state->debugRepl;
+        state->debugRepl = nullptr;
+        Finally restoreDebug([&]() { state->debugRepl = debug_repl; });
         try {
             /* This is an expression that should evaluate to an
                attribute set.  Evaluate it to get the names of the
@@ -584,15 +587,17 @@ bool NixRepl::processLine(std::string line)
         Value v;
         evalString(arg, v);
 
-        const auto [file, line] = [&] () -> std::pair<std::string, uint32_t> {
+        const auto [path, line] = [&] () -> std::pair<Path, uint32_t> {
             if (v.type() == nPath || v.type() == nString) {
                 PathSet context;
-                auto filename = state->coerceToString(noPos, v, context, "while evaluating the filename to edit").toOwned();
-                state->symbols.create(filename);
-                return {filename, 0};
+                auto path = state->coerceToPath(noPos, v, context, "while evaluating the filename to edit");
+                return {path, 0};
             } else if (v.isLambda()) {
                 auto pos = state->positions[v.lambda.fun->pos];
-                return {pos.file, pos.line};
+                if (auto path = std::get_if<Path>(&pos.origin))
+                    return {*path, pos.line};
+                else
+                    throw Error("'%s' cannot be shown in an editor", pos);
             } else {
                 // assume it's a derivation
                 return findPackageFilename(*state, v, arg);
@@ -600,7 +605,7 @@ bool NixRepl::processLine(std::string line)
         }();
 
         // Open in EDITOR
-        auto args = editorFor(file, line);
+        auto args = editorFor(path, line);
         auto editor = args.front();
         args.pop_front();
 
@@ -782,7 +787,7 @@ void NixRepl::loadFlake(const std::string & flakeRefS)
             flake::LockFlags {
                 .updateLockFile = false,
                 .useRegistries = !evalSettings.pureEval,
-                .allowMutable  = !evalSettings.pureEval,
+                .allowUnlocked = !evalSettings.pureEval,
             }),
         v);
     addAttrsToScope(v);