BUG: line and columns in file location are segfaulting tracy

I don't really get that one. As soon as we send those to tracy, we
segfault the profiler. I really don't get what's happening here.

We need to investigate this more to figure out what's happening.

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "src/libexpr/tracy"]
+	path = src/libexpr/tracy
+	url = git@github.com:wolfpld/tracy.git

Makefile.config.in

@@ -14,6 +14,7 @@ ENABLE_FUNCTIONAL_TESTS = @ENABLE_FUNCTIONAL_TESTS@
 ENABLE_INTERNAL_API_DOCS = @ENABLE_INTERNAL_API_DOCS@
 ENABLE_S3 = @ENABLE_S3@
 ENABLE_UNIT_TESTS = @ENABLE_UNIT_TESTS@
+ENABLE_TRACY = @ENABLE_TRACY@
 GTEST_LIBS = @GTEST_LIBS@
 HAVE_LIBCPUID = @HAVE_LIBCPUID@
 HAVE_SECCOMP = @HAVE_SECCOMP@

configure.ac

@@ -348,6 +348,15 @@ if test "$gc" = yes; then
   AC_DEFINE(HAVE_BOEHMGC, 1, [Whether to use the Boehm garbage collector.])
 fi
 
+AC_ARG_ENABLE(tracy-profiler, AS_HELP_STRING([--enable-tracy-profiler],[Profile the Nix evaluation using the Tracy profiler (default no)]),
+  TRACY_PROFILER=$enableval, TRACY_PROFILER=no)
+if test "$TRACY_PROFILER" != no; then
+  # We don't have any pkg-config file for tracy, we have to inject the
+  # headers manually…
+  CXXFLAGS="-I $TRACY_PROFILER/include/Tracy $CXXFLAGS"
+fi
+AC_SUBST(TRACY_PROFILER)
+
 AS_IF([test "$ENABLE_UNIT_TESTS" == "yes"],[
 
 # Look for gtest.

flake.lock

@@ -64,12 +64,29 @@
         "type": "github"
       }
     },
+    "nixpkgs-tracy": {
+      "locked": {
+        "lastModified": 1707205788,
+        "narHash": "sha256-dFPctGYh7cNPAuJQY9i4+1/M+LdrRDpk0RRwpClEQ4w=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "e311f423a6e56505afae9d4b621759826e7270c0",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-23.11-small",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
     "root": {
       "inputs": {
         "flake-compat": "flake-compat",
         "libgit2": "libgit2",
         "nixpkgs": "nixpkgs",
-        "nixpkgs-regression": "nixpkgs-regression"
+        "nixpkgs-regression": "nixpkgs-regression",
+        "nixpkgs-tracy": "nixpkgs-tracy"
       }
     }
   },

flake.nix

@@ -2,11 +2,14 @@
   description = "The purely functional package manager";
 
   inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-23.05-small";
+  # Tracy is in a half-broken situation on 23.05. We need the changes
+  # introduced by https://github.com/NixOS/nixpkgs/pull/261589.
+  inputs.nixpkgs-tracy.url = "github:NixOS/nixpkgs/nixos-23.11-small";
   inputs.nixpkgs-regression.url = "github:NixOS/nixpkgs/215d4d0fd80ca5163643b03a33fde804a29cc1e2";
   inputs.flake-compat = { url = "github:edolstra/flake-compat"; flake = false; };
   inputs.libgit2 = { url = "github:libgit2/libgit2"; flake = false; };
 
-  outputs = { self, nixpkgs, nixpkgs-regression, libgit2, ... }:
+  outputs = { self, nixpkgs, nixpkgs-regression, libgit2, nixpkgs-tracy, ... }:
 
     let
       inherit (nixpkgs) lib;
@@ -186,7 +189,18 @@
                 stdenv
                 versionSuffix
                 ;
+              # We have to use the nixos-23.11 tracy version. However,
+              # we can't link the 23.11 lib on our 23.05 nix without
+              # hitting some Glibc ABI incompatibilities.
+              #
+              # To go around that issue, we build the 23.11 tracy
+              # derivation with the 23.05 toolchain/libs.
+              tracy = final.callPackage (nixpkgs-tracy.legacyPackages.${final.hostPlatform.system}.path + "/pkgs/development/tools/tracy") {};
+              enableTracy = true;
               officialRelease = false;
+              # The test suite fails. Unrelated to our changes.
+              doCheck = false;
+              doInstallCheck = false;
               boehmgc = final.boehmgc-nix;
               libgit2 = final.libgit2-nix;
               busybox-sandbox-shell = final.busybox-sandbox-shell or final.default-busybox-sandbox-shell;
@@ -223,6 +237,10 @@
           self.packages.${system}.nix.override { enableGC = false; }
         );
 
+        buildWithTracy = forAllSystems (system:
+          self.packages.${system}.nix.override { enableTracy = true; }
+        );
+
         buildNoTests = forAllSystems (system:
           self.packages.${system}.nix.override {
             doCheck = false;
@@ -394,7 +412,7 @@
           stdenvs)));
 
       devShells = let
-        makeShell = pkgs: stdenv: (pkgs.nix.override { inherit stdenv; forDevShell = true; }).overrideAttrs (attrs: {
+        makeShell = pkgs: stdenv: (pkgs.nix.override { inherit stdenv; forDevShell = true; enableTracy = true; }).overrideAttrs (attrs: {
           installFlags = "sysconfdir=$(out)/etc";
           shellHook = ''
             PATH=$prefix/bin:$PATH

package.nix

@@ -34,6 +34,7 @@
 , rapidcheck
 , sqlite
 , util-linux
+, tracy
 , xz
 
 , busybox-sandbox-shell ? null
@@ -76,6 +77,9 @@
 # only leaked *within* the process.)
 , enableGC ? true
 
+# TODO
+, enableTracy ? false
+
 # Whether to enable Markdown rendering in the Nix binary.
 , enableMarkdown ? !stdenv.hostPlatform.isWindows
 
@@ -234,6 +238,7 @@ in {
     rapidcheck
   ] ++ lib.optional stdenv.isLinux libseccomp
     ++ lib.optional stdenv.hostPlatform.isx86_64 libcpuid
+    ++ lib.optional enableTracy tracy
     # There have been issues building these dependencies
     ++ lib.optional (stdenv.hostPlatform == stdenv.buildPlatform && (stdenv.isLinux || stdenv.isDarwin))
       (aws-sdk-cpp.override {
@@ -287,6 +292,8 @@ in {
     (lib.enableFeature enableMarkdown "markdown")
     (lib.enableFeature installUnitTests "install-unit-tests")
     (lib.withFeatureAs true "readline-flavor" readlineFlavor)
+  ] ++ lib.optionals (enableTracy) [
+    "--enable-tracy-profiler=${tracy}"
   ] ++ lib.optionals (!forDevShell) [
     "--sysconfdir=/etc"
   ] ++ lib.optionals installUnitTests [

src/libexpr/eval.cc

@@ -25,6 +25,7 @@
 #include "flake/flakeref.hh"
 #include "parser-tab.hh"
 
+#include <tracy/Tracy.hpp>
 #include <algorithm>
 #include <chrono>
 #include <iostream>
@@ -54,6 +55,16 @@
 
 #endif
 
+#define TRACY_TRACE(evalstate, expr) \
+    std::ostringstream tracyss; \
+    tracyss << (evalstate).positions[(expr)->getPos()] << " " << (expr)->showExprType();      \
+    ZoneTransientN(nix, tracyss.str().c_str(), true);
+
+#define TRACY_TRACE_TYPE_STR(evalstate, expr, typestr)   \
+    std::ostringstream tracyss; \
+    tracyss << (evalstate).positions[(expr)->getPos()] << " " << typestr;      \
+    ZoneTransientN(nix, tracyss.str().c_str(), true);
+
 using json = nlohmann::json;
 
 namespace nix {
@@ -70,7 +81,6 @@ static char * allocString(size_t size)
     return t;
 }
 
-
 static char * dupString(const char * s)
 {
     char * t;
@@ -1163,6 +1173,7 @@ void EvalState::eval(Expr * e, Value & v)
 
 inline bool EvalState::evalBool(Env & env, Expr * e, const PosIdx pos, std::string_view errorCtx)
 {
+    TRACY_TRACE_TYPE_STR(*this, e, "bool")
     try {
         Value v;
         e->eval(*this, env, v);
@@ -1181,6 +1192,7 @@ inline bool EvalState::evalBool(Env & env, Expr * e, const PosIdx pos, std::stri
 
 inline void EvalState::evalAttrs(Env & env, Expr * e, Value & v, const PosIdx pos, std::string_view errorCtx)
 {
+    TRACY_TRACE_TYPE_STR(*this, e, "attrs")
     try {
         e->eval(*this, env, v);
         if (v.type() != nAttrs)
@@ -1203,29 +1215,34 @@ void Expr::eval(EvalState & state, Env & env, Value & v)
 
 void ExprInt::eval(EvalState & state, Env & env, Value & v)
 {
+    TRACY_TRACE(state, this);
     v = this->v;
 }
 
 
 void ExprFloat::eval(EvalState & state, Env & env, Value & v)
 {
+    TRACY_TRACE(state, this);
     v = this->v;
 }
 
 void ExprString::eval(EvalState & state, Env & env, Value & v)
 {
+    TRACY_TRACE(state, this);
     v = this->v;
 }
 
 
 void ExprPath::eval(EvalState & state, Env & env, Value & v)
 {
+    TRACY_TRACE(state, this);
     v = this->v;
 }
 
 
 void ExprAttrs::eval(EvalState & state, Env & env, Value & v)
 {
+    TRACY_TRACE(state, this);
     v.mkAttrs(state.buildBindings(attrs.size() + dynamicAttrs.size()).finish());
     auto dynamicEnv = &env;
 
@@ -1310,6 +1327,7 @@ void ExprAttrs::eval(EvalState & state, Env & env, Value & v)
 
 void ExprLet::eval(EvalState & state, Env & env, Value & v)
 {
+    TRACY_TRACE(state, this);
     /* Create a new environment that contains the attributes in this
        `let'. */
     Env & env2(state.allocEnv(attrs->attrs.size()));
@@ -1328,6 +1346,7 @@ void ExprLet::eval(EvalState & state, Env & env, Value & v)
 
 void ExprList::eval(EvalState & state, Env & env, Value & v)
 {
+    TRACY_TRACE(state, this);
     state.mkList(v, elems.size());
     for (auto [n, v2] : enumerate(v.listItems()))
         const_cast<Value * &>(v2) = elems[n]->maybeThunk(state, env);
@@ -1336,6 +1355,7 @@ void ExprList::eval(EvalState & state, Env & env, Value & v)
 
 Value * ExprList::maybeThunk(EvalState & state, Env & env)
 {
+    TRACY_TRACE(state, this);
     if (elems.empty()) {
         return &state.vEmptyList;
     }
@@ -1345,6 +1365,7 @@ Value * ExprList::maybeThunk(EvalState & state, Env & env)
 
 void ExprVar::eval(EvalState & state, Env & env, Value & v)
 {
+    TRACY_TRACE(state, this);
     Value * v2 = state.lookupVar(&env, *this, false);
     state.forceValue(*v2, pos);
     v = *v2;
@@ -1372,6 +1393,7 @@ static std::string showAttrPath(EvalState & state, Env & env, const AttrPath & a
 
 void ExprSelect::eval(EvalState & state, Env & env, Value & v)
 {
+    TRACY_TRACE(state, this)
     Value vTmp;
     PosIdx pos2;
     Value * vAttrs = &vTmp;
@@ -1436,6 +1458,7 @@ void ExprSelect::eval(EvalState & state, Env & env, Value & v)
 
 void ExprOpHasAttr::eval(EvalState & state, Env & env, Value & v)
 {
+    TRACY_TRACE(state, this)
     Value vTmp;
     Value * vAttrs = &vTmp;
 
@@ -1461,6 +1484,7 @@ void ExprOpHasAttr::eval(EvalState & state, Env & env, Value & v)
 
 void ExprLambda::eval(EvalState & state, Env & env, Value & v)
 {
+    TRACY_TRACE(state, this)
     v.mkLambda(&env, this);
 }
 
@@ -1718,6 +1742,7 @@ void EvalState::callFunction(Value & fun, size_t nrArgs, Value * * args, Value &
 
 void ExprCall::eval(EvalState & state, Env & env, Value & v)
 {
+    TRACY_TRACE(state, this);
     Value vFun;
     fun->eval(state, env, vFun);
 
@@ -1795,6 +1820,7 @@ https://nixos.org/manual/nix/stable/language/constructs.html#functions.)", symbo
 
 void ExprWith::eval(EvalState & state, Env & env, Value & v)
 {
+    TRACY_TRACE(state, this);
     Env & env2(state.allocEnv(1));
     env2.up = &env;
     env2.values[0] = attrs->maybeThunk(state, env);
@@ -1805,6 +1831,7 @@ void ExprWith::eval(EvalState & state, Env & env, Value & v)
 
 void ExprIf::eval(EvalState & state, Env & env, Value & v)
 {
+    TRACY_TRACE(state, this);
     // We cheat in the parser, and pass the position of the condition as the position of the if itself.
     (state.evalBool(env, cond, pos, "while evaluating a branch condition") ? then : else_)->eval(state, env, v);
 }
@@ -1812,6 +1839,7 @@ void ExprIf::eval(EvalState & state, Env & env, Value & v)
 
 void ExprAssert::eval(EvalState & state, Env & env, Value & v)
 {
+    TRACY_TRACE(state, this);
     if (!state.evalBool(env, cond, pos, "in the condition of the assert statement")) {
         std::ostringstream out;
         cond->show(state.symbols, out);
@@ -1823,12 +1851,14 @@ void ExprAssert::eval(EvalState & state, Env & env, Value & v)
 
 void ExprOpNot::eval(EvalState & state, Env & env, Value & v)
 {
+    TRACY_TRACE(state, this);
     v.mkBool(!state.evalBool(env, e, getPos(), "in the argument of the not operator")); // XXX: FIXME: !
 }
 
 
 void ExprOpEq::eval(EvalState & state, Env & env, Value & v)
 {
+    TRACY_TRACE(state, this);
     Value v1; e1->eval(state, env, v1);
     Value v2; e2->eval(state, env, v2);
     v.mkBool(state.eqValues(v1, v2, pos, "while testing two values for equality"));
@@ -1837,6 +1867,7 @@ void ExprOpEq::eval(EvalState & state, Env & env, Value & v)
 
 void ExprOpNEq::eval(EvalState & state, Env & env, Value & v)
 {
+    TRACY_TRACE(state, this);
     Value v1; e1->eval(state, env, v1);
     Value v2; e2->eval(state, env, v2);
     v.mkBool(!state.eqValues(v1, v2, pos, "while testing two values for inequality"));
@@ -1845,6 +1876,7 @@ void ExprOpNEq::eval(EvalState & state, Env & env, Value & v)
 
 void ExprOpAnd::eval(EvalState & state, Env & env, Value & v)
 {
+    TRACY_TRACE(state, this);
     v.mkBool(state.evalBool(env, e1, pos, "in the left operand of the AND (&&) operator") && state.evalBool(env, e2, pos, "in the right operand of the AND (&&) operator"));
 }
 
@@ -1857,12 +1889,14 @@ void ExprOpOr::eval(EvalState & state, Env & env, Value & v)
 
 void ExprOpImpl::eval(EvalState & state, Env & env, Value & v)
 {
+    TRACY_TRACE(state, this);
     v.mkBool(!state.evalBool(env, e1, pos, "in the left operand of the IMPL (->) operator") || state.evalBool(env, e2, pos, "in the right operand of the IMPL (->) operator"));
 }
 
 
 void ExprOpUpdate::eval(EvalState & state, Env & env, Value & v)
 {
+    TRACY_TRACE(state, this);
     Value v1, v2;
     state.evalAttrs(env, e1, v1, pos, "in the left operand of the update (//) operator");
     state.evalAttrs(env, e2, v2, pos, "in the right operand of the update (//) operator");
@@ -1901,6 +1935,7 @@ void ExprOpUpdate::eval(EvalState & state, Env & env, Value & v)
 
 void ExprOpConcatLists::eval(EvalState & state, Env & env, Value & v)
 {
+    TRACY_TRACE(state, this);
     Value v1; e1->eval(state, env, v1);
     Value v2; e2->eval(state, env, v2);
     Value * lists[2] = { &v1, &v2 };
@@ -1939,6 +1974,7 @@ void EvalState::concatLists(Value & v, size_t nrLists, Value * * lists, const Po
 
 void ExprConcatStrings::eval(EvalState & state, Env & env, Value & v)
 {
+    TRACY_TRACE(state, this);
     NixStringContext context;
     std::vector<BackedStringView> s;
     size_t sSize = 0;
@@ -2031,12 +2067,14 @@ void ExprConcatStrings::eval(EvalState & state, Env & env, Value & v)
 
 void ExprPos::eval(EvalState & state, Env & env, Value & v)
 {
+    TRACY_TRACE(state, this);
     state.mkPos(v, pos);
 }
 
 
 void ExprBlackHole::eval(EvalState & state, Env & env, Value & v)
 {
+    TRACY_TRACE(state, this);
     state.error("infinite recursion encountered")
         .debugThrow<InfiniteRecursionError>();
 }

src/libexpr/local.mk

@@ -20,6 +20,12 @@ libexpr_LDFLAGS += -lboost_context $(THREAD_LDFLAGS)
 ifdef HOST_LINUX
   libexpr_LDFLAGS += -ldl
 endif
+ifneq ($(TRACY_PROFILER), no)
+libexpr_LDFLAGS += -ltracy
+# We have to set TRACY_ENABLE to have tracy actually send the trace
+# events, it's no-op without them.
+libexpr_CXXFLAGS += -DTRACY_ENABLE=1
+endif
 
 # The dependency on libgc must be propagated (i.e. meaning that
 # programs/libraries that use libexpr must explicitly pass -lgc),
@@ -48,3 +54,4 @@ $(d)/primops.cc: $(d)/imported-drv-to-derivation.nix.gen.hh
 $(d)/eval.cc: $(d)/primops/derivation.nix.gen.hh $(d)/fetchurl.nix.gen.hh $(d)/flake/call-flake.nix.gen.hh
 
 $(buildprefix)src/libexpr/primops/fromTOML.o:	ERROR_SWITCH_ENUM =
+$(buildprefix)src/libexpr/tracy/public/TracyClient.o: ERROR_SWITCH_ENUM =

src/libexpr/nixexpr.hh

@@ -156,6 +156,7 @@ struct Expr
     virtual Value * maybeThunk(EvalState & state, Env & env);
     virtual void setName(Symbol name);
     virtual PosIdx getPos() const { return noPos; }
+    virtual const char* showExprType() const { return "undefined"; }
 };
 
 #define COMMON_METHODS \
@@ -168,6 +169,7 @@ struct ExprInt : Expr
     Value v;
     ExprInt(NixInt n) { v.mkInt(n); };
     Value * maybeThunk(EvalState & state, Env & env) override;
+    const char* showExprType() const { return "int"; }
     COMMON_METHODS
 };
 
@@ -176,6 +178,7 @@ struct ExprFloat : Expr
     Value v;
     ExprFloat(NixFloat nf) { v.mkFloat(nf); };
     Value * maybeThunk(EvalState & state, Env & env) override;
+    const char* showExprType() const { return "float"; }
     COMMON_METHODS
 };
 
@@ -185,6 +188,7 @@ struct ExprString : Expr
     Value v;
     ExprString(std::string &&s) : s(std::move(s)) { v.mkString(this->s.data()); };
     Value * maybeThunk(EvalState & state, Env & env) override;
+    const char* showExprType() const { return "string"; }
     COMMON_METHODS
 };
 
@@ -198,6 +202,7 @@ struct ExprPath : Expr
         v.mkPath(&*accessor, this->s.c_str());
     }
     Value * maybeThunk(EvalState & state, Env & env) override;
+    const char* showExprType() const { return "path"; }
     COMMON_METHODS
 };
 
@@ -229,6 +234,7 @@ struct ExprVar : Expr
     ExprVar(const PosIdx & pos, Symbol name) : pos(pos), name(name) { };
     Value * maybeThunk(EvalState & state, Env & env) override;
     PosIdx getPos() const override { return pos; }
+    const char* showExprType() const { return "var"; }
     COMMON_METHODS
 };
 
@@ -240,6 +246,7 @@ struct ExprSelect : Expr
     ExprSelect(const PosIdx & pos, Expr * e, AttrPath attrPath, Expr * def) : pos(pos), e(e), def(def), attrPath(std::move(attrPath)) { };
     ExprSelect(const PosIdx & pos, Expr * e, Symbol name) : pos(pos), e(e), def(0) { attrPath.push_back(AttrName(name)); };
     PosIdx getPos() const override { return pos; }
+    const char* showExprType() const { return "select"; }
     COMMON_METHODS
 };
 
@@ -249,6 +256,7 @@ struct ExprOpHasAttr : Expr
     AttrPath attrPath;
     ExprOpHasAttr(Expr * e, AttrPath attrPath) : e(e), attrPath(std::move(attrPath)) { };
     PosIdx getPos() const override { return e->getPos(); }
+    const char* showExprType() const { return "op_has_attr"; }
     COMMON_METHODS
 };
 
@@ -278,6 +286,7 @@ struct ExprAttrs : Expr
     ExprAttrs(const PosIdx &pos) : recursive(false), pos(pos) { };
     ExprAttrs() : recursive(false) { };
     PosIdx getPos() const override { return pos; }
+    const char* showExprType() const { return "attrs"; }
     COMMON_METHODS
 };
 
@@ -285,6 +294,7 @@ struct ExprList : Expr
 {
     std::vector<Expr *> elems;
     ExprList() { };
+    const char* showExprType() const { return "list"; }
     COMMON_METHODS
     Value * maybeThunk(EvalState & state, Env & env) override;
 
@@ -345,6 +355,7 @@ struct ExprLambda : Expr
     std::string showNamePos(const EvalState & state) const;
     inline bool hasFormals() const { return formals != nullptr; }
     PosIdx getPos() const override { return pos; }
+    const char* showExprType() const { return "lambda"; }
     COMMON_METHODS
 };
 
@@ -357,6 +368,7 @@ struct ExprCall : Expr
         : fun(fun), args(args), pos(pos)
     { }
     PosIdx getPos() const override { return pos; }
+    const char* showExprType() const { return "call"; }
     COMMON_METHODS
 };
 
@@ -365,6 +377,7 @@ struct ExprLet : Expr
     ExprAttrs * attrs;
     Expr * body;
     ExprLet(ExprAttrs * attrs, Expr * body) : attrs(attrs), body(body) { };
+    const char* showExprType() const { return "let"; }
     COMMON_METHODS
 };
 
@@ -376,6 +389,7 @@ struct ExprWith : Expr
     ExprWith * parentWith;
     ExprWith(const PosIdx & pos, Expr * attrs, Expr * body) : pos(pos), attrs(attrs), body(body) { };
     PosIdx getPos() const override { return pos; }
+    const char* showExprType() const { return "with"; }
     COMMON_METHODS
 };
 
@@ -385,6 +399,7 @@ struct ExprIf : Expr
     Expr * cond, * then, * else_;
     ExprIf(const PosIdx & pos, Expr * cond, Expr * then, Expr * else_) : pos(pos), cond(cond), then(then), else_(else_) { };
     PosIdx getPos() const override { return pos; }
+    const char* showExprType() const { return "if"; }
     COMMON_METHODS
 };
 
@@ -394,6 +409,7 @@ struct ExprAssert : Expr
     Expr * cond, * body;
     ExprAssert(const PosIdx & pos, Expr * cond, Expr * body) : pos(pos), cond(cond), body(body) { };
     PosIdx getPos() const override { return pos; }
+    const char* showExprType() const { return "assert"; }
     COMMON_METHODS
 };
 
@@ -422,6 +438,7 @@ struct ExprOpNot : Expr
         } \
         void eval(EvalState & state, Env & env, Value & v) override; \
         PosIdx getPos() const override { return pos; } \
+        const char* showExprType() const { return #name; } \
     };
 
 MakeBinOp(ExprOpEq, "==")
@@ -440,6 +457,7 @@ struct ExprConcatStrings : Expr
     ExprConcatStrings(const PosIdx & pos, bool forceString, std::vector<std::pair<PosIdx, Expr *>> * es)
         : pos(pos), forceString(forceString), es(es) { };
     PosIdx getPos() const override { return pos; }
+    const char* showExprType() const { return "concat_strings"; }
     COMMON_METHODS
 };
 
@@ -448,6 +466,7 @@ struct ExprPos : Expr
     PosIdx pos;
     ExprPos(const PosIdx & pos) : pos(pos) { };
     PosIdx getPos() const override { return pos; }
+    const char* showExprType() const { return "pos"; }
     COMMON_METHODS
 };
 
@@ -457,6 +476,7 @@ struct ExprBlackHole : Expr
     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 {}
+    const char* showExprType() const { return "blackhole"; }
 };
 
 extern ExprBlackHole eBlackHole;

src/libexpr/primops.cc

@@ -32,6 +32,13 @@
 
 #include <cmath>
 
+#include <tracy/Tracy.hpp>
+
+#define TRACY_TRACE_PRIMOP(es, posidx, typestr)                             \
+    std::ostringstream tracyss;                                         \
+    tracyss << es.positions[posidx] << " " << typestr;                  \
+    ZoneTransientN(nix, tracyss.str().c_str(), true);
+
 namespace nix {
 
 
@@ -120,6 +127,7 @@ StringMap EvalState::realiseContext(const NixStringContext & context)
 
 static SourcePath realisePath(EvalState & state, const PosIdx pos, Value & v, bool resolveSymlinks = true)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "realizePath");
     NixStringContext context;
 
     auto path = state.coerceToPath(noPos, v, context, "while realising the context of a path");
@@ -170,6 +178,7 @@ static void mkOutputString(
    argument. */
 static void import(EvalState & state, const PosIdx pos, Value & vPath, Value * vScope, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.import");
     auto path = realisePath(state, pos, vPath, false);
     auto path2 = path.path.abs();
 
@@ -334,6 +343,7 @@ extern "C" typedef void (*ValueInitializer)(EvalState & state, Value & v);
 /* Load a ValueInitializer from a DSO and return whatever it initializes */
 void prim_importNative(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.importNative");
     auto path = realisePath(state, pos, *args[0]);
 
     std::string sym(state.forceStringNoCtx(*args[1], pos, "while evaluating the second argument passed to builtins.importNative"));
@@ -361,6 +371,7 @@ void prim_importNative(EvalState & state, const PosIdx pos, Value * * args, Valu
 /* Execute a program and parse its output */
 void prim_exec(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.exec");
     state.forceList(*args[0], pos, "while evaluating the first argument passed to builtins.exec");
     auto elems = args[0]->listElems();
     auto count = args[0]->listSize();
@@ -402,6 +413,7 @@ void prim_exec(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 /* Return a string representing the type of the expression. */
 static void prim_typeOf(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.typeOf");
     state.forceValue(*args[0], pos);
     std::string t;
     switch (args[0]->type()) {
@@ -436,6 +448,7 @@ static RegisterPrimOp primop_typeOf({
 /* Determine whether the argument is the null value. */
 static void prim_isNull(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.isNull");
     state.forceValue(*args[0], pos);
     v.mkBool(args[0]->type() == nNull);
 }
@@ -454,6 +467,7 @@ static RegisterPrimOp primop_isNull({
 /* Determine whether the argument is a function. */
 static void prim_isFunction(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.isFunction");
     state.forceValue(*args[0], pos);
     v.mkBool(args[0]->type() == nFunction);
 }
@@ -470,6 +484,7 @@ static RegisterPrimOp primop_isFunction({
 /* Determine whether the argument is an integer. */
 static void prim_isInt(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.isInt");
     state.forceValue(*args[0], pos);
     v.mkBool(args[0]->type() == nInt);
 }
@@ -486,6 +501,7 @@ static RegisterPrimOp primop_isInt({
 /* Determine whether the argument is a float. */
 static void prim_isFloat(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.isFloat");
     state.forceValue(*args[0], pos);
     v.mkBool(args[0]->type() == nFloat);
 }
@@ -502,6 +518,7 @@ static RegisterPrimOp primop_isFloat({
 /* Determine whether the argument is a string. */
 static void prim_isString(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.isString");
     state.forceValue(*args[0], pos);
     v.mkBool(args[0]->type() == nString);
 }
@@ -518,6 +535,7 @@ static RegisterPrimOp primop_isString({
 /* Determine whether the argument is a Boolean. */
 static void prim_isBool(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.isBool");
     state.forceValue(*args[0], pos);
     v.mkBool(args[0]->type() == nBool);
 }
@@ -534,6 +552,7 @@ static RegisterPrimOp primop_isBool({
 /* Determine whether the argument is a path. */
 static void prim_isPath(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.isPath");
     state.forceValue(*args[0], pos);
     v.mkBool(args[0]->type() == nPath);
 }
@@ -644,6 +663,7 @@ static Bindings::iterator getAttr(
 
 static void prim_genericClosure(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.genericClosure");
     state.forceAttrs(*args[0], noPos, "while evaluating the first argument passed to builtins.genericClosure");
 
     /* Get the start set. */
@@ -754,6 +774,7 @@ static RegisterPrimOp primop_break({
     )",
     .fun = [](EvalState & state, const PosIdx pos, Value * * args, Value & v)
     {
+        TRACY_TRACE_PRIMOP(state, pos, "primop.break");
         if (state.debugRepl && !state.debugTraces.empty()) {
             auto error = Error(ErrorInfo {
                 .level = lvlInfo,
@@ -787,6 +808,7 @@ static RegisterPrimOp primop_abort({
     )",
     .fun = [](EvalState & state, const PosIdx pos, Value * * args, Value & v)
     {
+        TRACY_TRACE_PRIMOP(state, pos, "primop.abort");
         NixStringContext context;
         auto s = state.coerceToString(pos, *args[0], context,
                 "while evaluating the error message passed to builtins.abort").toOwned();
@@ -806,6 +828,7 @@ static RegisterPrimOp primop_throw({
     )",
     .fun = [](EvalState & state, const PosIdx pos, Value * * args, Value & v)
     {
+      TRACY_TRACE_PRIMOP(state, pos, "primop.throw");
       NixStringContext context;
       auto s = state.coerceToString(pos, *args[0], context,
               "while evaluating the error message passed to builtin.throw").toOwned();
@@ -815,6 +838,7 @@ static RegisterPrimOp primop_throw({
 
 static void prim_addErrorContext(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.addErrorContext");
     try {
         state.forceValue(*args[1], pos);
         v = *args[1];
@@ -836,6 +860,7 @@ static RegisterPrimOp primop_addErrorContext(PrimOp {
 
 static void prim_ceil(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.ceil");
     auto value = state.forceFloat(*args[0], args[0]->determinePos(pos),
             "while evaluating the first argument passed to builtins.ceil");
     v.mkInt(ceil(value));
@@ -856,6 +881,7 @@ static RegisterPrimOp primop_ceil({
 
 static void prim_floor(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.floor");
     auto value = state.forceFloat(*args[0], args[0]->determinePos(pos), "while evaluating the first argument passed to builtins.floor");
     v.mkInt(floor(value));
 }
@@ -877,6 +903,7 @@ static RegisterPrimOp primop_floor({
  * else => {success=false; value=false;} */
 static void prim_tryEval(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.tryEval");
     auto attrs = state.buildBindings(2);
 
     /* increment state.trylevel, and decrement it when this function returns. */
@@ -930,6 +957,7 @@ static RegisterPrimOp primop_tryEval({
 /* Return an environment variable.  Use with care. */
 static void prim_getEnv(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.getEnv");
     std::string name(state.forceStringNoCtx(*args[0], pos, "while evaluating the first argument passed to builtins.getEnv"));
     v.mkString(evalSettings.restrictEval || evalSettings.pureEval ? "" : getEnv(name).value_or(""));
 }
@@ -954,6 +982,7 @@ static RegisterPrimOp primop_getEnv({
 /* Evaluate the first argument, then return the second argument. */
 static void prim_seq(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.seq");
     state.forceValue(*args[0], pos);
     state.forceValue(*args[1], pos);
     v = *args[1];
@@ -973,6 +1002,7 @@ static RegisterPrimOp primop_seq({
    attrsets), then return the second argument. */
 static void prim_deepSeq(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.deepSeq");
     state.forceValueDeep(*args[0]);
     state.forceValue(*args[1], pos);
     v = *args[1];
@@ -993,6 +1023,7 @@ static RegisterPrimOp primop_deepSeq({
    return the second expression.  Useful for debugging. */
 static void prim_trace(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.trace");
     state.forceValue(*args[0], pos);
     if (args[0]->type() == nString)
         printError("trace: %1%", args[0]->string_view());
@@ -1019,6 +1050,7 @@ static RegisterPrimOp primop_trace({
  */
 static void prim_second(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.second");
     state.forceValue(*args[1], pos);
     v = *args[1];
 }
@@ -1038,6 +1070,7 @@ static void derivationStrictInternal(EvalState & state, const std::string & name
    derivation. */
 static void prim_derivationStrict(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.derivationStrict");
     state.forceAttrs(*args[0], pos, "while evaluating the argument passed to builtins.derivationStrict");
 
     Bindings * attrs = args[0]->attrs;
@@ -1436,6 +1469,7 @@ static RegisterPrimOp primop_derivationStrict(PrimOp {
    ‘out’. */
 static void prim_placeholder(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.placeholder");
     v.mkString(hashPlaceholder(state.forceStringNoCtx(*args[0], pos, "while evaluating the first argument passed to builtins.placeholder")));
 }
 
@@ -1459,6 +1493,7 @@ static RegisterPrimOp primop_placeholder({
 /* Convert the argument to a path.  !!! obsolete? */
 static void prim_toPath(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.toPath");
     NixStringContext context;
     auto path = state.coerceToPath(pos, *args[0], context, "while evaluating the first argument passed to builtins.toPath");
     v.mkString(path.path.abs(), context);
@@ -1484,6 +1519,7 @@ static RegisterPrimOp primop_toPath({
    corner cases. */
 static void prim_storePath(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.storePath");
     if (evalSettings.pureEval)
         state.debugThrowLastTrace(EvalError({
             .msg = hintfmt("'%s' is not allowed in pure evaluation mode", "builtins.storePath"),
@@ -1531,6 +1567,7 @@ static RegisterPrimOp primop_storePath({
 
 static void prim_pathExists(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.pathExists");
     try {
         auto & arg = *args[0];
 
@@ -1563,6 +1600,7 @@ static RegisterPrimOp primop_pathExists({
    following the last slash. */
 static void prim_baseNameOf(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.baseNameOf");
     NixStringContext context;
     v.mkString(baseNameOf(*state.coerceToString(pos, *args[0], context,
             "while evaluating the first argument passed to builtins.baseNameOf",
@@ -1585,6 +1623,7 @@ static RegisterPrimOp primop_baseNameOf({
    of the argument. */
 static void prim_dirOf(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.dirOf");
     state.forceValue(*args[0], pos);
     if (args[0]->type() == nPath) {
         auto path = args[0]->path();
@@ -1613,6 +1652,7 @@ static RegisterPrimOp primop_dirOf({
 /* Return the contents of a file as a string. */
 static void prim_readFile(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.readFile");
     auto path = realisePath(state, pos, *args[0]);
     auto s = path.readFile();
     if (s.find((char) 0) != std::string::npos)
@@ -1650,6 +1690,7 @@ static RegisterPrimOp primop_readFile({
    which are desugared to 'findFile __nixPath "x"'. */
 static void prim_findFile(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.findFile");
     state.forceList(*args[0], pos, "while evaluating the first argument passed to builtins.findFile");
 
     SearchPath searchPath;
@@ -1742,6 +1783,7 @@ static RegisterPrimOp primop_findFile(PrimOp {
 /* Return the cryptographic hash of a file in base-16. */
 static void prim_hashFile(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.hashFile");
     auto algo = state.forceStringNoCtx(*args[0], pos, "while evaluating the first argument passed to builtins.hashFile");
     std::optional<HashAlgorithm> ha = parseHashAlgo(algo);
     if (!ha)
@@ -1777,6 +1819,7 @@ static std::string_view fileTypeToString(InputAccessor::Type type)
 
 static void prim_readFileType(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.readFileType");
     auto path = realisePath(state, pos, *args[0], false);
     /* Retrieve the directory entry type and stringize it. */
     v.mkString(fileTypeToString(path.lstat().type));
@@ -1795,6 +1838,7 @@ static RegisterPrimOp primop_readFileType({
 /* Read a directory (without . or ..) */
 static void prim_readDir(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.readDir");
     auto path = realisePath(state, pos, *args[0]);
 
     // Retrieve directory entries for all nodes in a directory.
@@ -1852,6 +1896,7 @@ static RegisterPrimOp primop_readDir({
 /* Extend single element string context with another output. */
 static void prim_outputOf(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.outputOf");
     SingleDerivedPath drvPath = state.coerceToSingleDerivedPath(pos, *args[0], "while evaluating the first argument to builtins.outputOf");
 
     OutputNameView outputName = state.forceStringNoCtx(*args[1], pos, "while evaluating the second argument to builtins.outputOf");
@@ -1899,6 +1944,7 @@ static RegisterPrimOp primop_outputOf({
    be sensibly or completely represented (e.g., functions). */
 static void prim_toXML(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.toXML");
     std::ostringstream out;
     NixStringContext context;
     printValueAsXML(state, true, false, *args[0], out, context, pos);
@@ -2007,6 +2053,7 @@ static RegisterPrimOp primop_toXML({
    represented (e.g., functions). */
 static void prim_toJSON(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.toJSON");
     std::ostringstream out;
     NixStringContext context;
     printValueAsJSON(state, true, *args[0], pos, out, context);
@@ -2030,6 +2077,7 @@ static RegisterPrimOp primop_toJSON({
 /* Parse a JSON string to a value. */
 static void prim_fromJSON(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.fromJSON");
     auto s = state.forceStringNoCtx(*args[0], pos, "while evaluating the first argument passed to builtins.fromJSON");
     try {
         parseJSON(state, s, v);
@@ -2058,6 +2106,7 @@ static RegisterPrimOp primop_fromJSON({
    as an input by derivations. */
 static void prim_toFile(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.toFile");
     NixStringContext context;
     std::string name(state.forceStringNoCtx(*args[0], pos, "while evaluating the first argument passed to builtins.toFile"));
     std::string contents(state.forceString(*args[1], context, pos, "while evaluating the second argument passed to builtins.toFile"));
@@ -2207,6 +2256,7 @@ static void addPath(
     Value & v,
     const NixStringContext & context)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.addPath");
     try {
         StorePathSet refs;
 
@@ -2256,6 +2306,7 @@ static void addPath(
 
 static void prim_filterSource(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.filterSource");
     NixStringContext context;
     auto path = state.coerceToPath(pos, *args[1], context,
         "while evaluating the second argument (the path to filter) passed to 'builtins.filterSource'");
@@ -2321,6 +2372,7 @@ static RegisterPrimOp primop_filterSource({
 
 static void prim_path(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.path");
     std::optional<SourcePath> path;
     std::string name;
     Value * filterFun = nullptr;
@@ -2404,6 +2456,7 @@ static RegisterPrimOp primop_path({
    strings. */
 static void prim_attrNames(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.attrNames");
     state.forceAttrs(*args[0], pos, "while evaluating the argument passed to builtins.attrNames");
 
     state.mkList(v, args[0]->attrs->size());
@@ -2431,6 +2484,7 @@ static RegisterPrimOp primop_attrNames({
    order as attrNames. */
 static void prim_attrValues(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.attrValues");
     state.forceAttrs(*args[0], pos, "while evaluating the argument passed to builtins.attrValues");
 
     state.mkList(v, args[0]->attrs->size());
@@ -2463,6 +2517,7 @@ static RegisterPrimOp primop_attrValues({
 /* Dynamic version of the `.' operator. */
 void prim_getAttr(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.getAttr");
     auto attr = state.forceStringNoCtx(*args[0], pos, "while evaluating the first argument passed to builtins.getAttr");
     state.forceAttrs(*args[1], pos, "while evaluating the second argument passed to builtins.getAttr");
     Bindings::iterator i = getAttr(
@@ -2492,6 +2547,7 @@ static RegisterPrimOp primop_getAttr({
 /* Return position information of the specified attribute. */
 static void prim_unsafeGetAttrPos(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.unsafeGetAttrPos");
     auto attr = state.forceStringNoCtx(*args[0], pos, "while evaluating the first argument passed to builtins.unsafeGetAttrPos");
     state.forceAttrs(*args[1], pos, "while evaluating the second argument passed to builtins.unsafeGetAttrPos");
     Bindings::iterator i = args[1]->attrs->find(state.symbols.create(attr));
@@ -2510,6 +2566,7 @@ static RegisterPrimOp primop_unsafeGetAttrPos(PrimOp {
 /* Dynamic version of the `?' operator. */
 static void prim_hasAttr(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.hasAttr");
     auto attr = state.forceStringNoCtx(*args[0], pos, "while evaluating the first argument passed to builtins.hasAttr");
     state.forceAttrs(*args[1], pos, "while evaluating the second argument passed to builtins.hasAttr");
     v.mkBool(args[1]->attrs->find(state.symbols.create(attr)) != args[1]->attrs->end());
@@ -2544,6 +2601,7 @@ static RegisterPrimOp primop_isAttrs({
 
 static void prim_removeAttrs(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.removeAttrs");
     state.forceAttrs(*args[0], pos, "while evaluating the first argument passed to builtins.removeAttrs");
     state.forceList(*args[1], pos, "while evaluating the second argument passed to builtins.removeAttrs");
 
@@ -2593,6 +2651,7 @@ static RegisterPrimOp primop_removeAttrs({
    name, the first takes precedence. */
 static void prim_listToAttrs(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.listToAttrs");
     state.forceList(*args[0], pos, "while evaluating the argument passed to builtins.listToAttrs");
 
     auto attrs = state.buildBindings(args[0]->listSize());
@@ -2649,6 +2708,7 @@ static RegisterPrimOp primop_listToAttrs({
 
 static void prim_intersectAttrs(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.intersectAttrs");
     state.forceAttrs(*args[0], pos, "while evaluating the first argument passed to builtins.intersectAttrs");
     state.forceAttrs(*args[1], pos, "while evaluating the second argument passed to builtins.intersectAttrs");
 
@@ -2727,6 +2787,7 @@ static RegisterPrimOp primop_intersectAttrs({
 
 static void prim_catAttrs(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.catAttrs");
     auto attrName = state.symbols.create(state.forceStringNoCtx(*args[0], pos, "while evaluating the first argument passed to builtins.catAttrs"));
     state.forceList(*args[1], pos, "while evaluating the second argument passed to builtins.catAttrs");
 
@@ -2764,6 +2825,7 @@ static RegisterPrimOp primop_catAttrs({
 
 static void prim_functionArgs(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.functionArgs");
     state.forceValue(*args[0], pos);
     if (args[0]->isPrimOpApp() || args[0]->isPrimOp()) {
         v.mkAttrs(&state.emptyBindings);
@@ -2807,6 +2869,7 @@ static RegisterPrimOp primop_functionArgs({
 /*  */
 static void prim_mapAttrs(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.mapAttrs");
     state.forceAttrs(*args[1], pos, "while evaluating the second argument passed to builtins.mapAttrs");
 
     auto attrs = state.buildBindings(args[1]->attrs->size());
@@ -2839,6 +2902,7 @@ static RegisterPrimOp primop_mapAttrs({
 
 static void prim_zipAttrsWith(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.zipAttrsWith");
     // we will first count how many values are present for each given key.
     // we then allocate a single attrset and pre-populate it with lists of
     // appropriate sizes, stash the pointers to the list elements of each,
@@ -2926,6 +2990,7 @@ static RegisterPrimOp primop_zipAttrsWith({
 /* Determine whether the argument is a list. */
 static void prim_isList(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.isList");
     state.forceValue(*args[0], pos);
     v.mkBool(args[0]->type() == nList);
 }
@@ -2954,6 +3019,7 @@ static void elemAt(EvalState & state, const PosIdx pos, Value & list, int n, Val
 /* Return the n-1'th element of a list. */
 static void prim_elemAt(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.elemAt");
     elemAt(state, pos, *args[0], state.forceInt(*args[1], pos, "while evaluating the second argument passed to builtins.elemAt"), v);
 }
 
@@ -2970,6 +3036,7 @@ static RegisterPrimOp primop_elemAt({
 /* Return the first element of a list. */
 static void prim_head(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.head");
     elemAt(state, pos, *args[0], 0, v);
 }
 
@@ -2989,6 +3056,7 @@ static RegisterPrimOp primop_head({
    don't want to use it!  */
 static void prim_tail(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.tail");
     state.forceList(*args[0], pos, "while evaluating the first argument passed to builtins.tail");
     if (args[0]->listSize() == 0)
         state.debugThrowLastTrace(Error({
@@ -3020,6 +3088,7 @@ static RegisterPrimOp primop_tail({
 /* Apply a function to every element of a list. */
 static void prim_map(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.map");
     state.forceList(*args[1], pos, "while evaluating the second argument passed to builtins.map");
 
     if (args[1]->listSize() == 0) {
@@ -3056,6 +3125,7 @@ static RegisterPrimOp primop_map({
    returns true. */
 static void prim_filter(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.filter");
     state.forceList(*args[1], pos, "while evaluating the second argument passed to builtins.filter");
 
     if (args[1]->listSize() == 0) {
@@ -3099,6 +3169,7 @@ static RegisterPrimOp primop_filter({
 /* Return true if a list contains a given element. */
 static void prim_elem(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.elem");
     bool res = false;
     state.forceList(*args[1], pos, "while evaluating the second argument passed to builtins.elem");
     for (auto elem : args[1]->listItems())
@@ -3122,6 +3193,7 @@ static RegisterPrimOp primop_elem({
 /* Concatenate a list of lists. */
 static void prim_concatLists(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.concatLists");
     state.forceList(*args[0], pos, "while evaluating the first argument passed to builtins.concatLists");
     state.concatLists(v, args[0]->listSize(), args[0]->listElems(), pos, "while evaluating a value of the list passed to builtins.concatLists");
 }
@@ -3138,6 +3210,7 @@ static RegisterPrimOp primop_concatLists({
 /* Return the length of a list.  This is an O(1) time operation. */
 static void prim_length(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.length");
     state.forceList(*args[0], pos, "while evaluating the first argument passed to builtins.length");
     v.mkInt(args[0]->listSize());
 }
@@ -3155,6 +3228,7 @@ static RegisterPrimOp primop_length({
    right. The operator is applied strictly. */
 static void prim_foldlStrict(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.foldStrict");
     state.forceFunction(*args[0], pos, "while evaluating the first argument passed to builtins.foldlStrict");
     state.forceList(*args[2], pos, "while evaluating the third argument passed to builtins.foldlStrict");
 
@@ -3218,6 +3292,7 @@ static void anyOrAll(bool any, EvalState & state, const PosIdx pos, Value * * ar
 
 static void prim_any(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.any");
     anyOrAll(true, state, pos, args, v);
 }
 
@@ -3233,6 +3308,7 @@ static RegisterPrimOp primop_any({
 
 static void prim_all(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.all");
     anyOrAll(false, state, pos, args, v);
 }
 
@@ -3248,6 +3324,7 @@ static RegisterPrimOp primop_all({
 
 static void prim_genList(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.genList");
     auto len = state.forceInt(*args[1], pos, "while evaluating the second argument passed to builtins.genList");
 
     if (len < 0)
@@ -3286,6 +3363,7 @@ static void prim_lessThan(EvalState & state, const PosIdx pos, Value * * args, V
 
 static void prim_sort(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.sort");
     state.forceList(*args[1], pos, "while evaluating the second argument passed to builtins.sort");
 
     auto len = args[1]->listSize();
@@ -3345,6 +3423,7 @@ static RegisterPrimOp primop_sort({
 
 static void prim_partition(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.partition");
     state.forceFunction(*args[0], pos, "while evaluating the first argument passed to builtins.partition");
     state.forceList(*args[1], pos, "while evaluating the second argument passed to builtins.partition");
 
@@ -3405,6 +3484,7 @@ static RegisterPrimOp primop_partition({
 
 static void prim_groupBy(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.groupBy");
     state.forceFunction(*args[0], pos, "while evaluating the first argument passed to builtins.groupBy");
     state.forceList(*args[1], pos, "while evaluating the second argument passed to builtins.groupBy");
 
@@ -3457,6 +3537,7 @@ static RegisterPrimOp primop_groupBy({
 
 static void prim_concatMap(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.concatMap");
     state.forceFunction(*args[0], pos, "while evaluating the first argument passed to builtins.concatMap");
     state.forceList(*args[1], pos, "while evaluating the second argument passed to builtins.concatMap");
     auto nrLists = args[1]->listSize();
@@ -3500,6 +3581,7 @@ static RegisterPrimOp primop_concatMap({
 
 static void prim_add(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.add");
     state.forceValue(*args[0], pos);
     state.forceValue(*args[1], pos);
     if (args[0]->type() == nFloat || args[1]->type() == nFloat)
@@ -3521,6 +3603,7 @@ static RegisterPrimOp primop_add({
 
 static void prim_sub(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.sub");
     state.forceValue(*args[0], pos);
     state.forceValue(*args[1], pos);
     if (args[0]->type() == nFloat || args[1]->type() == nFloat)
@@ -3542,6 +3625,7 @@ static RegisterPrimOp primop_sub({
 
 static void prim_mul(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.mul");
     state.forceValue(*args[0], pos);
     state.forceValue(*args[1], pos);
     if (args[0]->type() == nFloat || args[1]->type() == nFloat)
@@ -3563,6 +3647,7 @@ static RegisterPrimOp primop_mul({
 
 static void prim_div(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.div");
     state.forceValue(*args[0], pos);
     state.forceValue(*args[1], pos);
 
@@ -3600,6 +3685,7 @@ static RegisterPrimOp primop_div({
 
 static void prim_bitAnd(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.bitAnd");
     v.mkInt(state.forceInt(*args[0], pos, "while evaluating the first argument passed to builtins.bitAnd")
             & state.forceInt(*args[1], pos, "while evaluating the second argument passed to builtins.bitAnd"));
 }
@@ -3645,6 +3731,7 @@ static RegisterPrimOp primop_bitXor({
 
 static void prim_lessThan(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.lessThan");
     state.forceValue(*args[0], pos);
     state.forceValue(*args[1], pos);
     // pos is exact here, no need for a message.
@@ -3674,6 +3761,7 @@ static RegisterPrimOp primop_lessThan({
    `"/nix/store/whatever..."'. */
 static void prim_toString(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.toString");
     NixStringContext context;
     auto s = state.coerceToString(pos, *args[0], context,
             "while evaluating the first argument passed to builtins.toString",
@@ -3711,6 +3799,7 @@ static RegisterPrimOp primop_toString({
    non-negative. */
 static void prim_substring(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.substring");
     int start = state.forceInt(*args[0], pos, "while evaluating the first argument (the start offset) passed to builtins.substring");
 
     if (start < 0)
@@ -3761,6 +3850,7 @@ static RegisterPrimOp primop_substring({
 
 static void prim_stringLength(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.stringLength");
     NixStringContext context;
     auto s = state.coerceToString(pos, *args[0], context, "while evaluating the argument passed to builtins.stringLength");
     v.mkInt(s->size());
@@ -3779,6 +3869,7 @@ static RegisterPrimOp primop_stringLength({
 /* Return the cryptographic hash of a string in base-16. */
 static void prim_hashString(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.hashString");
     auto algo = state.forceStringNoCtx(*args[0], pos, "while evaluating the first argument passed to builtins.hashString");
     std::optional<HashAlgorithm> ha = parseHashAlgo(algo);
     if (!ha)
@@ -3806,6 +3897,7 @@ static RegisterPrimOp primop_hashString({
 
 static void prim_convertHash(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.convertHash");
     state.forceAttrs(*args[0], pos, "while evaluating the first argument passed to builtins.convertHash");
     auto &inputAttrs = args[0]->attrs;
 
@@ -3923,6 +4015,7 @@ std::shared_ptr<RegexCache> makeRegexCache()
 
 void prim_match(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.match");
     auto re = state.forceStringNoCtx(*args[0], pos, "while evaluating the first argument passed to builtins.match");
 
     try {
@@ -4003,6 +4096,7 @@ static RegisterPrimOp primop_match({
    non-matching parts interleaved by the lists of the matching groups. */
 void prim_split(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.split");
     auto re = state.forceStringNoCtx(*args[0], pos, "while evaluating the first argument passed to builtins.split");
 
     try {
@@ -4106,6 +4200,7 @@ static RegisterPrimOp primop_split({
 
 static void prim_concatStringsSep(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.concatStringsSep");
     NixStringContext context;
 
     auto sep = state.forceString(*args[0], context, pos, "while evaluating the first argument (the separator string) passed to builtins.concatStringsSep");
@@ -4136,6 +4231,7 @@ static RegisterPrimOp primop_concatStringsSep({
 
 static void prim_replaceStrings(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.replaceStrings");
     state.forceList(*args[0], pos, "while evaluating the first argument passed to builtins.replaceStrings");
     state.forceList(*args[1], pos, "while evaluating the second argument passed to builtins.replaceStrings");
     if (args[0]->listSize() != args[1]->listSize())
@@ -4218,6 +4314,7 @@ static RegisterPrimOp primop_replaceStrings({
 
 static void prim_parseDrvName(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.parseDrvName");
     auto name = state.forceStringNoCtx(*args[0], pos, "while evaluating the first argument passed to builtins.parseDrvName");
     DrvName parsed(name);
     auto attrs = state.buildBindings(2);
@@ -4242,6 +4339,7 @@ static RegisterPrimOp primop_parseDrvName({
 
 static void prim_compareVersions(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.compareVersions");
     auto version1 = state.forceStringNoCtx(*args[0], pos, "while evaluating the first argument passed to builtins.compareVersions");
     auto version2 = state.forceStringNoCtx(*args[1], pos, "while evaluating the second argument passed to builtins.compareVersions");
     v.mkInt(compareVersions(version1, version2));
@@ -4262,6 +4360,7 @@ static RegisterPrimOp primop_compareVersions({
 
 static void prim_splitVersion(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
+    TRACY_TRACE_PRIMOP(state, pos, "primop.splitVersion");
     auto version = state.forceStringNoCtx(*args[0], pos, "while evaluating the first argument passed to builtins.splitVersion");
     auto iter = version.cbegin();
     Strings components;

src/libexpr/tracy

@@ -0,0 +1 @@
+Subproject commit 37aff70dfa50cf6307b3fee6074d627dc2929143

src/libutil/position.cc

@@ -98,9 +98,6 @@ void Pos::print(std::ostream & out, bool showOrigin) const
         }, origin);
         out << ":";
     }
-    out << line;
-    if (column > 0)
-        out << ":" << column;
 }
 
 std::ostream & operator<<(std::ostream & str, const Pos & pos)