remove lazy-pos forceValue

almost all uses of this are interactive, except for deepSeq. deepSeq is
going to be expensive and rare enough to not care much about, and
Value::determinePos should usually be cheap enough to not be too much of
a burden in any case.

src/libcmd/installable-flake.cc

@@ -52,7 +52,7 @@ Value * InstallableFlake::getFlakeOutputs(EvalState & state, const flake::Locked
     auto aOutputs = vFlake->attrs->get(state.symbols.create("outputs"));
     assert(aOutputs);
 
-    state.forceValue(*aOutputs->value, [&]() { return aOutputs->value->determinePos(noPos); });
+    state.forceValue(*aOutputs->value, aOutputs->value->determinePos(noPos));
 
     return aOutputs->value;
 }

src/libcmd/repl.cc

@@ -888,7 +888,7 @@ void NixRepl::evalString(std::string s, Value & v)
 {
     Expr * e = parseString(s);
     e->eval(*state, *env, v);
-    state->forceValue(v, [&]() { return v.determinePos(noPos); });
+    state->forceValue(v, v.determinePos(noPos));
 }
 
 
@@ -907,7 +907,7 @@ std::ostream & NixRepl::printValue(std::ostream & str, Value & v, unsigned int m
     str.flush();
     checkInterrupt();
 
-    state->forceValue(v, [&]() { return v.determinePos(noPos); });
+    state->forceValue(v, v.determinePos(noPos));
 
     switch (v.type()) {
 

src/libexpr/eval-inline.hh

@@ -81,15 +81,7 @@ Env & EvalState::allocEnv(size_t size)
 }
 
 
-[[gnu::always_inline]]
 void EvalState::forceValue(Value & v, const PosIdx pos)
-{
-    forceValue(v, [&]() { return pos; });
-}
-
-
-template<typename Callable>
-void EvalState::forceValue(Value & v, Callable getPos)
 {
     if (v.isThunk()) {
         Env * env = v.thunk.env;
@@ -110,7 +102,7 @@ void EvalState::forceValue(Value & v, Callable getPos)
             // only one black hole can *throw* in any given eval stack so we need not
             // check whether the position is set already.
             if (v.isBlackhole())
-                e.err.errPos = positions[getPos()];
+                e.err.errPos = positions[pos];
             throw;
         }
     }

src/libexpr/eval.cc

@@ -2044,7 +2044,7 @@ void EvalState::forceValueDeep(Value & v)
     recurse = [&](Value & v) {
         if (!seen.insert(&v).second) return;
 
-        forceValue(v, [&]() { return v.determinePos(noPos); });
+        forceValue(v, v.determinePos(noPos));
 
         if (v.type() == nAttrs) {
             for (auto & i : *v.attrs)

src/libexpr/eval.hh

@@ -473,9 +473,6 @@ public:
      */
     inline void forceValue(Value & v, const PosIdx pos);
 
-    template <typename Callable>
-    inline void forceValue(Value & v, Callable getPos);
-
     /**
      * Force a value, then recursively force list elements and
      * attributes.

src/libexpr/get-drvs.cc

@@ -198,7 +198,7 @@ StringSet DrvInfo::queryMetaNames()
 
 bool DrvInfo::checkMeta(Value & v)
 {
-    state->forceValue(v, [&]() { return v.determinePos(noPos); });
+    state->forceValue(v, v.determinePos(noPos));
     if (v.type() == nList) {
         for (auto elem : v.listItems())
             if (!checkMeta(*elem)) return false;
@@ -304,7 +304,7 @@ static bool getDerivation(EvalState & state, Value & v,
     bool ignoreAssertionFailures)
 {
     try {
-        state.forceValue(v, [&]() { return v.determinePos(noPos); });
+        state.forceValue(v, v.determinePos(noPos));
         if (!state.isDerivation(v)) return true;
 
         /* Remove spurious duplicates (e.g., a set like `rec { x =

src/nix-build/nix-build.cc

@@ -350,7 +350,7 @@ static void main_nix_build(int argc, char * * argv)
                 takesNixShellAttr(vRoot) ? *autoArgsWithInNixShell : *autoArgs,
                 vRoot
             ).first);
-            state->forceValue(v, [&]() { return v.determinePos(noPos); });
+            state->forceValue(v, v.determinePos(noPos));
             getDerivations(
                 *state,
                 v,

src/nix-env/user-env.cc

@@ -128,7 +128,7 @@ bool createUserEnv(EvalState & state, DrvInfos & elems,
 
     /* Evaluate it. */
     debug("evaluating user environment builder");
-    state.forceValue(topLevel, [&]() { return topLevel.determinePos(noPos); });
+    state.forceValue(topLevel, topLevel.determinePos(noPos));
     NixStringContext context;
     Attr & aDrvPath(*topLevel.attrs->find(state.sDrvPath));
     auto topLevelDrv = state.coerceToStorePath(aDrvPath.pos, *aDrvPath.value, context, "");

src/nix-instantiate/nix-instantiate.cc

@@ -40,7 +40,7 @@ void processExpr(EvalState & state, const Strings & attrPaths,
 
     for (auto & i : attrPaths) {
         Value & v(*findAlongAttrPath(state, i, autoArgs, vRoot).first);
-        state.forceValue(v, [&]() { return v.determinePos(noPos); });
+        state.forceValue(v, v.determinePos(noPos));
 
         NixStringContext context;
         if (evalOnly) {