Don't use any syntactic sugar for dynamic attrs

This doesn't change any functionality but moves some behavior out of the
parser and into the evaluator in order to simplify the code.

Signed-off-by: Shea Levy <shea@shealevy.com>

1 files changed, 17 insertions, 3 deletions

diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc
index cd3edecaa7..3d8ee99340 100644
--- a/src/libexpr/eval.cc
+++ b/src/libexpr/eval.cc
@@ -129,6 +129,18 @@ string showType(const Value & v)
 }
 
 
+Symbol getName(const AttrName & name, EvalState & state, Env & env) {
+    if (name.symbol.set()) {
+        return name.symbol;
+    } else {
+        Value nameValue;
+        name.expr->eval(state, env, nameValue);
+        state.forceStringNoCtx(nameValue);
+        return state.symbols.create(nameValue.string.s);
+    }
+}
+
+
 EvalState::EvalState()
     : sWith(symbols.create("<with>"))
     , sOutPath(symbols.create("outPath"))
@@ -683,17 +695,18 @@ void ExprSelect::eval(EvalState & state, Env & env, Value & v)
         foreach (AttrPath::const_iterator, i, attrPath) {
             nrLookups++;
             Bindings::iterator j;
+            Symbol name = getName(*i, state, env);
             if (def) {
                 state.forceValue(*vAttrs);
                 if (vAttrs->type != tAttrs ||
-                    (j = vAttrs->attrs->find(*i)) == vAttrs->attrs->end())
+                    (j = vAttrs->attrs->find(name)) == vAttrs->attrs->end())
                 {
                     def->eval(state, env, v);
                     return;
                 }
             } else {
                 state.forceAttrs(*vAttrs);
-                if ((j = vAttrs->attrs->find(*i)) == vAttrs->attrs->end())
+                if ((j = vAttrs->attrs->find(name)) == vAttrs->attrs->end())
                     throwEvalError("attribute `%1%' missing", showAttrPath(attrPath));
             }
             vAttrs = j->value;
@@ -724,8 +737,9 @@ void ExprOpHasAttr::eval(EvalState & state, Env & env, Value & v)
     foreach (AttrPath::const_iterator, i, attrPath) {
         state.forceValue(*vAttrs);
         Bindings::iterator j;
+        Symbol name = getName(*i, state, env);
         if (vAttrs->type != tAttrs ||
-            (j = vAttrs->attrs->find(*i)) == vAttrs->attrs->end())
+            (j = vAttrs->attrs->find(name)) == vAttrs->attrs->end())
         {
             mkBool(v, false);
             return;