Fix findFile(), coerceToPath()

src/libcmd/common-eval-args.cc

@@ -89,17 +89,18 @@ Bindings * MixEvalArgs::getAutoArgs(EvalState & state)
     return res.finish();
 }
 
-Path lookupFileArg(EvalState & state, std::string_view s)
+SourcePath lookupFileArg(EvalState & state, std::string_view s)
 {
     if (isUri(s)) {
-        return state.store->toRealPath(
-            fetchers::downloadTarball(
-                state.store, resolveUri(s), "source", false).first.storePath);
+        auto storePath = fetchers::downloadTarball(
+            state.store, resolveUri(s), "source", false).first.storePath;
+        auto & accessor = state.registerAccessor(makeFSInputAccessor(state.store->toRealPath(storePath)));
+        return {accessor, "/"};
     } 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
-        return absPath(std::string(s));
+        return state.rootPath(absPath(std::string(s)));
 }
 
 }

src/libcmd/common-eval-args.hh

@@ -7,6 +7,7 @@ namespace nix {
 class Store;
 class EvalState;
 class Bindings;
+struct SourcePath;
 
 struct MixEvalArgs : virtual Args
 {
@@ -22,6 +23,6 @@ private:
     std::map<std::string, std::string> autoArgs;
 };
 
-Path lookupFileArg(EvalState & state, std::string_view s);
+SourcePath lookupFileArg(EvalState & state, std::string_view s);
 
 }

src/libcmd/installables.cc

@@ -210,8 +210,7 @@ void SourceExprCommand::completeInstallable(std::string_view prefix)
         Expr *e =
             state->parseExprFromFile(
                 resolveExprPath(
-                    state->rootPath(
-                        lookupFileArg(*state, *file))));
+                    lookupFileArg(*state, *file)));
 
         Value root;
         state->eval(e, root);
@@ -762,7 +761,7 @@ std::vector<std::shared_ptr<Installable>> SourceExprCommand::parseInstallables(
             state->eval(e, *vFile);
         }
         else if (file)
-            state->evalFile(state->rootPath(lookupFileArg(*state, *file)), *vFile);
+            state->evalFile(lookupFileArg(*state, *file), *vFile);
         else {
             auto e = state->parseExprFromString(*expr, absPath("."));
             state->eval(e, *vFile);

src/libexpr/eval.cc

@@ -485,22 +485,22 @@ EvalState::EvalState(
 
     if (rootFS->hasAccessControl()) {
         for (auto & i : searchPath) {
-            auto r = resolveSearchPathElem(i);
-            if (!r.first) continue;
-
-            auto path = r.second;
-
-            if (store->isInStore(r.second)) {
-                try {
-                    StorePathSet closure;
-                    store->computeFSClosure(store->toStorePath(r.second).first, closure);
-                    for (auto & path : closure)
-                        allowPath(path);
-                } catch (InvalidPath &) {
-                    allowPath(r.second);
-                }
-            } else
-                allowPath(r.second);
+            if (auto path = resolveSearchPathElem(i)) {
+                // FIXME
+                #if 0
+                if (store->isInStore(*path)) {
+                    try {
+                        StorePathSet closure;
+                        store->computeFSClosure(store->toStorePath(*path).first, closure);
+                        for (auto & p : closure)
+                            allowPath(p);
+                    } catch (InvalidPath &) {
+                        allowPath(*r);
+                    }
+                } else
+                    allowPath(*r);
+                #endif
+            }
         }
     }
 
@@ -1812,10 +1812,7 @@ void ExprConcatStrings::eval(EvalState & state, Env & env, Value & v)
                 state.throwEvalError(i_pos, "cannot add %1% to a float", showType(vTmp));
         } else {
             if (s.empty()) s.reserve(es->size());
-            /* Skip canonization of first path, which would only be
-               non-canonical in the first place if it's coming from a
-               ./${foo} type path. */
-            auto part = state.coerceToString(i_pos, vTmp, context, false, firstType == nString, !first);
+            auto part = state.coerceToString(i_pos, vTmp, context, false, firstType == nString);
             sSize += part->size();
             s.emplace_back(std::move(part));
         }
@@ -2017,7 +2014,7 @@ std::optional<std::string> EvalState::tryAttrsToString(const PosIdx pos, Value &
 }
 
 BackedStringView EvalState::coerceToString(const PosIdx pos, Value & v, PathSet & context,
-    bool coerceMore, bool copyToStore, bool canonicalizePath)
+    bool coerceMore, bool copyToStore)
 {
     forceValue(v, pos);
 
@@ -2105,11 +2102,28 @@ StorePath EvalState::copyPathToStore(PathSet & context, const SourcePath & path)
 
 SourcePath EvalState::coerceToPath(const PosIdx pos, Value & v, PathSet & context)
 {
-    auto path = coerceToString(pos, v, context, false, false).toOwned();
-    if (path == "" || path[0] != '/')
-        throwEvalError(pos, "string '%1%' doesn't represent an absolute path", path);
-    // FIXME
-    return rootPath(path);
+    forceValue(v, pos);
+
+    if (v.type() == nString) {
+        copyContext(v, context);
+        return {*rootFS, v.string.s};
+    }
+
+    if (v.type() == nPath)
+        return v.path();
+
+    #if 0
+    if (v.type() == nAttrs) {
+        auto maybeString = tryAttrsToString(pos, v, context, coerceMore, copyToStore);
+        if (maybeString)
+            return std::move(*maybeString);
+        auto i = v.attrs->find(sOutPath);
+        if (i == v.attrs->end()) throwTypeError(pos, "cannot coerce a set to a string");
+        return coerceToString(pos, *i->value, context, coerceMore, copyToStore);
+    }
+    #endif
+
+    throwTypeError(pos, "cannot coerce %1% to a path", v);
 }
 
 

src/libexpr/eval.hh

@@ -50,14 +50,15 @@ struct Env
 void copyContext(const Value & v, PathSet & context);
 
 
-std::ostream & printValue(const EvalState & state, std::ostream & str, const Value & v);
-std::string printValue(const EvalState & state, const Value & v);
-
-
+// FIXME: maybe change this to an std::variant<SourcePath, URL>.
 typedef std::pair<std::string, std::string> SearchPathElem;
 typedef std::list<SearchPathElem> SearchPath;
 
 
+std::ostream & printValue(const EvalState & state, std::ostream & str, const Value & v);
+std::string printValue(const EvalState & state, const Value & v);
+
+
 /* Initialise the Boehm GC, if applicable. */
 void initGC();
 
@@ -130,7 +131,7 @@ private:
 
     SearchPath searchPath;
 
-    std::map<std::string, std::pair<bool, std::string>> searchPathResolved;
+    std::map<std::string, std::optional<SourcePath>> searchPathResolved;
 
     /* Cache used by checkSourcePath(). */
     std::unordered_map<Path, Path> resolvedPaths;
@@ -209,11 +210,11 @@ public:
     void resetFileCache();
 
     /* Look up a file in the search path. */
-    Path findFile(const std::string_view path);
-    Path findFile(SearchPath & searchPath, const std::string_view path, const PosIdx pos = noPos);
+    SourcePath findFile(const std::string_view path);
+    SourcePath findFile(SearchPath & searchPath, const std::string_view path, const PosIdx pos = noPos);
 
     /* If the specified search path element is a URI, download it. */
-    std::pair<bool, std::string> resolveSearchPathElem(const SearchPathElem & elem);
+    std::optional<SourcePath> resolveSearchPathElem(const SearchPathElem & elem);
 
     /* Evaluate an expression to normal form, storing the result in
        value `v'. */
@@ -303,8 +304,7 @@ public:
        booleans and lists to a string.  If `copyToStore' is set,
        referenced paths are copied to the Nix store as a side effect. */
     BackedStringView coerceToString(const PosIdx pos, Value & v, PathSet & context,
-        bool coerceMore = false, bool copyToStore = true,
-        bool canonicalizePath = true);
+        bool coerceMore = false, bool copyToStore = true);
 
     StorePath copyPathToStore(PathSet & context, const SourcePath & path);
 

src/libexpr/flake/flake.cc

@@ -268,7 +268,7 @@ static Flake readFlake(
                 PathSet emptyContext = {};
                 flake.config.settings.emplace(
                     state.symbols[setting.name],
-                    state.coerceToString(setting.pos, *setting.value, emptyContext, false, true, true) .toOwned());
+                    state.coerceToString(setting.pos, *setting.value, emptyContext, false, true).toOwned());
             }
             else if (setting.value->type() == nInt)
                 flake.config.settings.emplace(

src/libexpr/parser.y

@@ -759,13 +759,13 @@ void EvalState::addToSearchPath(const std::string & s)
 }
 
 
-Path EvalState::findFile(const std::string_view path)
+SourcePath EvalState::findFile(const std::string_view path)
 {
     return findFile(searchPath, path);
 }
 
 
-Path EvalState::findFile(SearchPath & searchPath, const std::string_view path, const PosIdx pos)
+SourcePath EvalState::findFile(SearchPath & searchPath, const std::string_view path, const PosIdx pos)
 {
     for (auto & i : searchPath) {
         std::string suffix;
@@ -778,15 +778,14 @@ Path EvalState::findFile(SearchPath & searchPath, const std::string_view path, c
                 continue;
             suffix = path.size() == s ? "" : concatStrings("/", path.substr(s));
         }
-        auto r = resolveSearchPathElem(i);
-        if (!r.first) continue;
-        Path res = r.second + suffix;
-        if (pathExists(res)) return canonPath(res);
+        if (auto path = resolveSearchPathElem(i)) {
+            auto res = path->append("/" + suffix);
+            if (res.pathExists()) return res;
+        }
     }
 
     if (hasPrefix(path, "nix/"))
-        abort();
-        //return packPath(SourcePath {corepkgsFS, (std::string) path.substr(3)});
+        return {*corepkgsFS, (std::string) path.substr(3)};
 
     throw ThrownError({
         .msg = hintfmt(evalSettings.pureEval
@@ -798,38 +797,39 @@ Path EvalState::findFile(SearchPath & searchPath, const std::string_view path, c
 }
 
 
-std::pair<bool, std::string> EvalState::resolveSearchPathElem(const SearchPathElem & elem)
+std::optional<SourcePath> EvalState::resolveSearchPathElem(const SearchPathElem & elem)
 {
     auto i = searchPathResolved.find(elem.second);
     if (i != searchPathResolved.end()) return i->second;
 
-    std::pair<bool, std::string> res;
+    std::optional<SourcePath> res;
 
     if (isUri(elem.second)) {
         try {
-            res = { true, store->toRealPath(fetchers::downloadTarball(
-                        store, resolveUri(elem.second), "source", false).first.storePath) };
+            auto storePath = fetchers::downloadTarball(
+                store, resolveUri(elem.second), "source", false).first.storePath;
+            auto & accessor = registerAccessor(makeFSInputAccessor(store->toRealPath(storePath)));
+            res.emplace(SourcePath {accessor, "/"});
         } catch (FileTransferError & e) {
             logWarning({
                 .msg = hintfmt("Nix search path entry '%1%' cannot be downloaded, ignoring", elem.second)
             });
-            res = { false, "" };
         }
     } else {
-        auto path = absPath(elem.second);
-        if (pathExists(path))
-            res = { true, path };
+        auto path = rootPath(absPath(elem.second));
+        if (path.pathExists())
+            res.emplace(path);
         else {
             logWarning({
                 .msg = hintfmt("Nix search path entry '%1%' does not exist, ignoring", elem.second)
             });
-            res = { false, "" };
         }
     }
 
-    debug(format("resolved search path element '%s' to '%s'") % elem.second % res.second);
+    if (res)
+        debug("resolved search path element '%s' to '%s'", elem.second, *res);
 
-    searchPathResolved[elem.second] = res;
+    searchPathResolved.emplace(elem.second, res);
     return res;
 }
 

src/libexpr/primops.cc

@@ -113,6 +113,7 @@ static SourcePath realisePath(EvalState & state, const PosIdx pos, Value & v, co
     }();
 
     try {
+        #if 0
         if (!context.empty()) {
             auto rewrites = state.realiseContext(context);
             // FIXME: check that path.accessor == rootFS?
@@ -120,6 +121,7 @@ static SourcePath realisePath(EvalState & state, const PosIdx pos, Value & v, co
             // FIXME: return store accessor
             return state.rootPath(realPath);
         } else
+        #endif
             return path;
     } catch (Error & e) {
         e.addTrace(state.positions[pos], "while realising the context of path '%s'", path);
@@ -1545,12 +1547,7 @@ static void prim_findFile(EvalState & state, const PosIdx pos, Value * * args, V
 
     auto path = state.forceStringNoCtx(*args[1], pos);
 
-    #if 0
-    // FIXME: checkSourcePath?
     v.mkPath(state.findFile(searchPath, path, pos));
-    #endif
-
-    throw ThrownError("findFile('%s'): not implemented", path);
 }
 
 static RegisterPrimOp primop_findFile(RegisterPrimOp::Info {

src/nix-build/nix-build.cc

@@ -307,9 +307,8 @@ static void main_nix_build(int argc, char * * argv)
                     exprs.push_back(
                         state->parseExprFromFile(
                             resolveExprPath(
-                                state->rootPath(
-                                    lookupFileArg(*state,
-                                        inShebang && !packages ? absPath(i, absPath(dirOf(script))) : i)))));
+                                lookupFileArg(*state,
+                                    inShebang && !packages ? absPath(i, absPath(dirOf(script))) : i))));
             }
         }
 

src/nix-env/nix-env.cc

@@ -1475,7 +1475,9 @@ static int main_nix_env(int argc, char * * argv)
         globals.state->repair = repair;
 
         if (file != "")
-            globals.instSource.nixExprPath = lookupFileArg(*globals.state, file);
+            // FIXME: check that the accessor returned by
+            // lookupFileArg() is the root FS.
+            globals.instSource.nixExprPath = lookupFileArg(*globals.state, file).path;
 
         globals.instSource.autoArgs = myArgs.getAutoArgs(*globals.state);
 

src/nix-instantiate/nix-instantiate.cc

@@ -167,9 +167,8 @@ static int main_nix_instantiate(int argc, char * * argv)
 
         if (findFile) {
             for (auto & i : files) {
-                Path p = state->findFile(i);
-                if (p == "") throw Error("unable to find '%1%'", i);
-                std::cout << p << std::endl;
+                auto p = state->findFile(i);
+                std::cout << p.readFile() << std::endl;
             }
             return 0;
         }
@@ -184,7 +183,7 @@ static int main_nix_instantiate(int argc, char * * argv)
         for (auto & i : files) {
             Expr * e = fromArgs
                 ? state->parseExprFromString(i, absPath("."))
-                : state->parseExprFromFile(resolveExprPath(state->rootPath(lookupFileArg(*state, i))));
+                : state->parseExprFromFile(resolveExprPath(lookupFileArg(*state, i)));
             processExpr(*state, attrPaths, parseOnly, strict, autoArgs,
                 evalOnly, outputKind, xmlOutputSourceLocation, e);
         }

src/nix/prefetch.cc

@@ -195,7 +195,7 @@ static int main_nix_prefetch_url(int argc, char * * argv)
             Value vRoot;
             state->evalFile(
                 resolveExprPath(
-                    state->rootPath(lookupFileArg(*state, args.empty() ? "." : args[0]))),
+                    lookupFileArg(*state, args.empty() ? "." : args[0])),
                 vRoot);
             Value & v(*findAlongAttrPath(*state, attrPath, autoArgs, vRoot).first);
             state->forceAttrs(v, noPos);

src/nix/repl.cc

@@ -636,7 +636,7 @@ void NixRepl::loadFile(const Path & path)
     loadedFiles.remove(path);
     loadedFiles.push_back(path);
     Value v, v2;
-    state->evalFile(state->rootPath(lookupFileArg(*state, path)), v);
+    state->evalFile(lookupFileArg(*state, path), v);
     state->autoCallFunction(*autoArgs, v, v2);
     addAttrsToScope(v2);
 }