Merge remote-tracking branch 'upstream/master' into indexed-store-path-outputs

9 files changed, 119 insertions, 40 deletions

diff --git a/src/libexpr/eval-cache.cc b/src/libexpr/eval-cache.cc
index d77b25898..0d83b6cfe 100644
--- a/src/libexpr/eval-cache.cc
+++ b/src/libexpr/eval-cache.cc
@@ -282,7 +282,7 @@ struct AttrDb
         auto queryAttribute(state->queryAttribute.use()(key.first)(symbols[key.second]));
         if (!queryAttribute.next()) return {};
 
-        auto rowId = (AttrType) queryAttribute.getInt(0);
+        auto rowId = (AttrId) queryAttribute.getInt(0);
         auto type = (AttrType) queryAttribute.getInt(1);
 
         switch (type) {
@@ -486,7 +486,7 @@ std::shared_ptr<AttrCursor> AttrCursor::maybeGetAttr(Symbol name, bool forceErro
                         return nullptr;
                     else if (std::get_if<failed_t>(&attr->second)) {
                         if (forceErrors)
-                            debug("reevaluating failed cached attribute '%s'");
+                            debug("reevaluating failed cached attribute '%s'", getAttrPathStr(name));
                         else
                             throw CachedEvalError("cached failure of attribute '%s'", getAttrPathStr(name));
                     } else
diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc
index 40462afdf..f485e2fed 100644
--- a/src/libexpr/eval.cc
+++ b/src/libexpr/eval.cc
@@ -464,9 +464,10 @@ EvalState::EvalState(
     , emptyBindings(0)
     , store(store)
     , buildStore(buildStore ? buildStore : store)
-    , debugRepl(0)
+    , debugRepl(nullptr)
     , debugStop(false)
     , debugQuit(false)
+    , trylevel(0)
     , regexCache(makeRegexCache())
 #if HAVE_BOEHMGC
     , valueAllocCache(std::allocate_shared<void *>(traceable_allocator<void *>(), nullptr))
@@ -832,7 +833,14 @@ void EvalState::runDebugRepl(const Error * error, const Env & env, const Expr &
         : nullptr;
 
     if (error)
-        printError("%s\n\n" ANSI_BOLD "Starting REPL to allow you to inspect the current state of the evaluator.\n" ANSI_NORMAL, error->what());
+    {
+        printError("%s\n\n", error->what());
+
+        if (trylevel > 0 && error->info().level != lvlInfo)
+            printError("This exception occurred in a 'tryEval' call. Use " ANSI_GREEN "--ignore-try" ANSI_NORMAL " to skip these.\n");
+
+        printError(ANSI_BOLD "Starting REPL to allow you to inspect the current state of the evaluator.\n" ANSI_NORMAL);
+    }
 
     auto se = getStaticEnv(expr);
     if (se) {
diff --git a/src/libexpr/eval.hh b/src/libexpr/eval.hh
index 7b8732169..f07f15d43 100644
--- a/src/libexpr/eval.hh
+++ b/src/libexpr/eval.hh
@@ -130,6 +130,7 @@ public:
     void (* debugRepl)(ref<EvalState> es, const ValMap & extraEnv);
     bool debugStop;
     bool debugQuit;
+    int trylevel;
     std::list<DebugTrace> debugTraces;
     std::map<const Expr*, const std::shared_ptr<const StaticEnv>> exprEnvs;
     const std::shared_ptr<const StaticEnv> getStaticEnv(const Expr & expr) const
@@ -150,7 +151,7 @@ public:
         if (debugRepl)
             runDebugRepl(&error, env, expr);
 
-        throw error;
+        throw std::move(error);
     }
 
     template<class E>
@@ -165,7 +166,7 @@ public:
             runDebugRepl(&e, last.env, last.expr);
         }
 
-        throw e;
+        throw std::move(e);
     }
 
 
@@ -646,6 +647,15 @@ struct EvalSettings : Config
 
     Setting<bool> useEvalCache{this, true, "eval-cache",
         "Whether to use the flake evaluation cache."};
+
+    Setting<bool> ignoreExceptionsDuringTry{this, false, "ignore-try",
+        R"(
+          If set to true, ignore exceptions inside 'tryEval' calls when evaluating nix expressions in
+          debug mode (using the --debugger flag). By default the debugger will pause on all exceptions.
+        )"};
+
+    Setting<bool> traceVerbose{this, false, "trace-verbose",
+        "Whether `builtins.traceVerbose` should trace its first argument when evaluated."};
 };
 
 extern EvalSettings evalSettings;
diff --git a/src/libexpr/flake/flake.cc b/src/libexpr/flake/flake.cc
index 35c841897..cc9be1336 100644
--- a/src/libexpr/flake/flake.cc
+++ b/src/libexpr/flake/flake.cc
@@ -384,6 +384,18 @@ LockedFlake lockFlake(
                 }
             }
 
+            /* Check whether this input has overrides for a
+               non-existent input. */
+            for (auto [inputPath, inputOverride] : overrides) {
+                auto inputPath2(inputPath);
+                auto follow = inputPath2.back();
+                inputPath2.pop_back();
+                if (inputPath2 == inputPathPrefix && !flakeInputs.count(follow))
+                    warn(
+                        "input '%s' has an override for a non-existent input '%s'",
+                        printInputPath(inputPathPrefix), follow);
+            }
+
             /* Go over the flake inputs, resolve/fetch them if
                necessary (i.e. if they're new or the flakeref changed
                from what's in the lock file). */
@@ -513,6 +525,15 @@ LockedFlake lockFlake(
                         if (!lockFlags.allowMutable && !input.ref->input.isLocked())
                             throw Error("cannot update flake input '%s' in pure mode", inputPathS);
 
+                        /* Note: in case of an --override-input, we use
+                            the *original* ref (input2.ref) for the
+                            "original" field, rather than the
+                            override. This ensures that the override isn't
+                            nuked the next time we update the lock
+                            file. That is, overrides are sticky unless you
+                            use --no-write-lock-file. */
+                        auto ref = input2.ref ? *input2.ref : *input.ref;
+
                         if (input.isFlake) {
                             Path localPath = parentPath;
                             FlakeRef localRef = *input.ref;
@@ -524,15 +545,7 @@ LockedFlake lockFlake(
 
                             auto inputFlake = getFlake(state, localRef, useRegistries, flakeCache, inputPath);
 
-                            /* Note: in case of an --override-input, we use
-                               the *original* ref (input2.ref) for the
-                               "original" field, rather than the
-                               override. This ensures that the override isn't
-                               nuked the next time we update the lock
-                               file. That is, overrides are sticky unless you
-                               use --no-write-lock-file. */
-                            auto childNode = std::make_shared<LockedNode>(
-                                inputFlake.lockedRef, input2.ref ? *input2.ref : *input.ref);
+                            auto childNode = std::make_shared<LockedNode>(inputFlake.lockedRef, ref);
 
                             node->inputs.insert_or_assign(id, childNode);
 
@@ -560,7 +573,7 @@ LockedFlake lockFlake(
                             auto [sourceInfo, resolvedRef, lockedRef] = fetchOrSubstituteTree(
                                 state, *input.ref, useRegistries, flakeCache);
                             node->inputs.insert_or_assign(id,
-                                std::make_shared<LockedNode>(lockedRef, *input.ref, false));
+                                std::make_shared<LockedNode>(lockedRef, ref, false));
                         }
                     }
 
diff --git a/src/libexpr/nixexpr.hh b/src/libexpr/nixexpr.hh
index 8813c61a9..5eb022770 100644
--- a/src/libexpr/nixexpr.hh
+++ b/src/libexpr/nixexpr.hh
@@ -150,16 +150,16 @@ struct Expr
 };
 
 #define COMMON_METHODS \
-    void show(const SymbolTable & symbols, std::ostream & str) const;    \
-    void eval(EvalState & state, Env & env, Value & v); \
-    void bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> & env);
+    void show(const SymbolTable & symbols, std::ostream & str) const override; \
+    void eval(EvalState & state, Env & env, Value & v) override; \
+    void bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> & env) override;
 
 struct ExprInt : Expr
 {
     NixInt n;
     Value v;
     ExprInt(NixInt n) : n(n) { v.mkInt(n); };
-    Value * maybeThunk(EvalState & state, Env & env);
+    Value * maybeThunk(EvalState & state, Env & env) override;
     COMMON_METHODS
 };
 
@@ -168,7 +168,7 @@ struct ExprFloat : Expr
     NixFloat nf;
     Value v;
     ExprFloat(NixFloat nf) : nf(nf) { v.mkFloat(nf); };
-    Value * maybeThunk(EvalState & state, Env & env);
+    Value * maybeThunk(EvalState & state, Env & env) override;
     COMMON_METHODS
 };
 
@@ -177,7 +177,7 @@ struct ExprString : Expr
     std::string s;
     Value v;
     ExprString(std::string s) : s(std::move(s)) { v.mkString(this->s.data()); };
-    Value * maybeThunk(EvalState & state, Env & env);
+    Value * maybeThunk(EvalState & state, Env & env) override;
     COMMON_METHODS
 };
 
@@ -186,7 +186,7 @@ struct ExprPath : Expr
     std::string s;
     Value v;
     ExprPath(std::string s) : s(std::move(s)) { v.mkPath(this->s.c_str()); };
-    Value * maybeThunk(EvalState & state, Env & env);
+    Value * maybeThunk(EvalState & state, Env & env) override;
     COMMON_METHODS
 };
 
@@ -213,7 +213,7 @@ struct ExprVar : Expr
 
     ExprVar(Symbol name) : name(name) { };
     ExprVar(const PosIdx & pos, Symbol name) : pos(pos), name(name) { };
-    Value * maybeThunk(EvalState & state, Env & env);
+    Value * maybeThunk(EvalState & state, Env & env) override;
     PosIdx getPos() const override { return pos; }
     COMMON_METHODS
 };
@@ -326,7 +326,7 @@ struct ExprLambda : Expr
         : pos(pos), formals(formals), body(body)
     {
     }
-    void setName(Symbol name);
+    void setName(Symbol name) override;
     std::string showNamePos(const EvalState & state) const;
     inline bool hasFormals() const { return formals != nullptr; }
     PosIdx getPos() const override { return pos; }
@@ -395,15 +395,15 @@ struct ExprOpNot : Expr
         Expr * e1, * e2; \
         name(Expr * e1, Expr * e2) : e1(e1), e2(e2) { }; \
         name(const PosIdx & pos, Expr * e1, Expr * e2) : pos(pos), e1(e1), e2(e2) { }; \
-        void show(const SymbolTable & symbols, std::ostream & str) const \
+        void show(const SymbolTable & symbols, std::ostream & str) const override \
         { \
             str << "("; e1->show(symbols, str); str << " " s " "; e2->show(symbols, str); str << ")"; \
         } \
-        void bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> & env)    \
+        void bindVars(EvalState & es, const std::shared_ptr<const StaticEnv> & env) override \
         { \
             e1->bindVars(es, env); e2->bindVars(es, env);    \
         } \
-        void eval(EvalState & state, Env & env, Value & v); \
+        void eval(EvalState & state, Env & env, Value & v) override; \
         PosIdx getPos() const override { return pos; } \
     };
 
diff --git a/src/libexpr/parser.y b/src/libexpr/parser.y
index 8cbc2da4d..7c9b5a2db 100644
--- a/src/libexpr/parser.y
+++ b/src/libexpr/parser.y
@@ -520,6 +520,12 @@ path_start
     $$ = new ExprPath(path);
   }
   | HPATH {
+    if (evalSettings.pureEval) {
+        throw Error(
+            "the path '%s' can not be resolved in pure mode",
+            std::string_view($1.p, $1.l)
+        );
+    }
     Path path(getHome() + std::string($1.p + 1, $1.l - 1));
     $$ = new ExprPath(path);
   }
diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc
index eea274301..bc253d0a3 100644
--- a/src/libexpr/primops.cc
+++ b/src/libexpr/primops.cc
@@ -851,6 +851,18 @@ static RegisterPrimOp primop_floor({
 static void prim_tryEval(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
     auto attrs = state.buildBindings(2);
+
+    /* increment state.trylevel, and decrement it when this function returns. */
+    MaintainCount trylevel(state.trylevel);
+
+    void (* savedDebugRepl)(ref<EvalState> es, const ValMap & extraEnv) = nullptr;
+    if (state.debugRepl && evalSettings.ignoreExceptionsDuringTry)
+    {
+        /* to prevent starting the repl from exceptions withing a tryEval, null it. */
+        savedDebugRepl = state.debugRepl;
+        state.debugRepl = nullptr;
+    }
+
     try {
         state.forceValue(*args[0], pos);
         attrs.insert(state.sValue, args[0]);
@@ -859,6 +871,11 @@ static void prim_tryEval(EvalState & state, const PosIdx pos, Value * * args, Va
         attrs.alloc(state.sValue).mkBool(false);
         attrs.alloc("success").mkBool(false);
     }
+
+    // restore the debugRepl pointer if we saved it earlier.
+    if (savedDebugRepl)
+        state.debugRepl = savedDebugRepl;
+
     v.mkAttrs(attrs);
 }
 
@@ -970,6 +987,15 @@ static RegisterPrimOp primop_trace({
 });
 
 
+/* Takes two arguments and evaluates to the second one. Used as the
+ * builtins.traceVerbose implementation when --trace-verbose is not enabled
+ */
+static void prim_second(EvalState & state, const PosIdx pos, Value * * args, Value & v)
+{
+    state.forceValue(*args[1], pos);
+    v = *args[1];
+}
+
 /*************************************************************
  * Derivations
  *************************************************************/
@@ -3926,6 +3952,18 @@ void EvalState::createBaseEnv()
         addPrimOp("__exec", 1, prim_exec);
     }
 
+    addPrimOp({
+        .fun = evalSettings.traceVerbose ? prim_trace : prim_second,
+        .arity = 2,
+        .name = "__traceVerbose",
+        .args = { "e1", "e2" },
+        .doc = R"(
+          Evaluate *e1* and print its abstract syntax representation on standard
+          error if `--trace-verbose` is enabled. Then return *e2*. This function
+          is useful for debugging.
+        )",
+    });
+
     /* Add a value containing the current Nix expression search path. */
     mkList(v, searchPath.size());
     int n = 0;
diff --git a/src/libexpr/primops/fetchTree.cc b/src/libexpr/primops/fetchTree.cc
index e5eeea520..84e7f5c02 100644
--- a/src/libexpr/primops/fetchTree.cc
+++ b/src/libexpr/primops/fetchTree.cc
@@ -364,6 +364,10 @@ static RegisterPrimOp primop_fetchGit({
           A Boolean parameter that specifies whether submodules should be
           checked out. Defaults to `false`.
 
+        - shallow\
+          A Boolean parameter that specifies whether fetching a shallow clone
+          is allowed. Defaults to `false`.
+
         - allRefs\
           Whether to fetch all refs of the repository. With this argument being
           true, it's possible to load a `rev` from *any* `ref` (by default only
diff --git a/src/libexpr/tests/primops.cc b/src/libexpr/tests/primops.cc
index f65b6593d..16cf66d2c 100644
--- a/src/libexpr/tests/primops.cc
+++ b/src/libexpr/tests/primops.cc
@@ -540,22 +540,22 @@ namespace nix {
         ASSERT_THAT(v, IsStringEq(output));
     }
 
-#define CASE(input, output) (std::make_tuple(std::string_view("builtins.toString " #input), std::string_view(output)))
+#define CASE(input, output) (std::make_tuple(std::string_view("builtins.toString " input), std::string_view(output)))
     INSTANTIATE_TEST_SUITE_P(
             toString,
             ToStringPrimOpTest,
             testing::Values(
-                CASE("foo", "foo"),
-                CASE(1, "1"),
-                CASE([1 2 3], "1 2 3"),
-                CASE(.123, "0.123000"),
-                CASE(true, "1"),
-                CASE(false, ""),
-                CASE(null, ""),
-                CASE({ v = "bar"; __toString = self: self.v; }, "bar"),
-                CASE({ v = "bar"; __toString = self: self.v; outPath = "foo"; }, "bar"),
-                CASE({ outPath = "foo"; }, "foo"),
-                CASE(./test, "/test")
+                CASE(R"("foo")", "foo"),
+                CASE(R"(1)", "1"),
+                CASE(R"([1 2 3])", "1 2 3"),
+                CASE(R"(.123)", "0.123000"),
+                CASE(R"(true)", "1"),
+                CASE(R"(false)", ""),
+                CASE(R"(null)", ""),
+                CASE(R"({ v = "bar"; __toString = self: self.v; })", "bar"),
+                CASE(R"({ v = "bar"; __toString = self: self.v; outPath = "foo"; })", "bar"),
+                CASE(R"({ outPath = "foo"; })", "foo"),
+                CASE(R"(./test)", "/test")
             )
     );
 #undef CASE