From d8c061e044a07f7516d76df12bc6920f4f04e5ff Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <eelco.dolstra@logicblox.com>
Date: Mon, 26 May 2014 17:14:28 +0200
Subject: [PATCH] Remove ExprBuiltin

It's slower than ExprVar since it doesn't compute a static
displacement. Since we're not using the throw primop in the
implementation of <...> anymore, it's also not really needed.
---
 src/libexpr/eval.cc    | 11 -----------
 src/libexpr/nixexpr.cc |  9 ---------
 src/libexpr/nixexpr.hh |  7 -------
 src/libexpr/parser.y   | 16 ++++++++--------
 4 files changed, 8 insertions(+), 35 deletions(-)

diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc
index b6b69c2bd..81ce7d9a3 100644
--- a/src/libexpr/eval.cc
+++ b/src/libexpr/eval.cc
@@ -1004,17 +1004,6 @@ void ExprOpNot::eval(EvalState & state, Env & env, Value & v)
 }
 
 
-void ExprBuiltin::eval(EvalState & state, Env & env, Value & v)
-{
-    // Not a hot path at all, but would be nice to access state.baseEnv directly
-    Env *baseEnv = &env;
-    while (baseEnv->up) baseEnv = baseEnv->up;
-    Bindings::iterator binding = baseEnv->values[0]->attrs->find(name);
-    assert(binding != baseEnv->values[0]->attrs->end());
-    v = *binding->value;
-}
-
-
 void ExprOpEq::eval(EvalState & state, Env & env, Value & v)
 {
     Value v1; e1->eval(state, env, v1);
diff --git a/src/libexpr/nixexpr.cc b/src/libexpr/nixexpr.cc
index d40250d87..b916a26d2 100644
--- a/src/libexpr/nixexpr.cc
+++ b/src/libexpr/nixexpr.cc
@@ -123,11 +123,6 @@ void ExprOpNot::show(std::ostream & str)
     str << "! " << *e;
 }
 
-void ExprBuiltin::show(std::ostream & str)
-{
-    str << "builtins." << name;
-}
-
 void ExprConcatStrings::show(std::ostream & str)
 {
     bool first = true;
@@ -342,10 +337,6 @@ void ExprOpNot::bindVars(const StaticEnv & env)
     e->bindVars(env);
 }
 
-void ExprBuiltin::bindVars(const StaticEnv & env)
-{
-}
-
 void ExprConcatStrings::bindVars(const StaticEnv & env)
 {
     foreach (vector<Expr *>::iterator, i, *es)
diff --git a/src/libexpr/nixexpr.hh b/src/libexpr/nixexpr.hh
index 8826ad232..3df9dd47f 100644
--- a/src/libexpr/nixexpr.hh
+++ b/src/libexpr/nixexpr.hh
@@ -272,13 +272,6 @@ struct ExprOpNot : Expr
     COMMON_METHODS
 };
 
-struct ExprBuiltin : Expr
-{
-    Symbol name;
-    ExprBuiltin(const Symbol & name) : name(name) { };
-    COMMON_METHODS
-};
-
 #define MakeBinOp(name, s) \
     struct Expr##name : Expr \
     { \
diff --git a/src/libexpr/parser.y b/src/libexpr/parser.y
index 134d68d6e..a27c53043 100644
--- a/src/libexpr/parser.y
+++ b/src/libexpr/parser.y
@@ -328,13 +328,13 @@ expr_if
 
 expr_op
   : '!' expr_op %prec NOT { $$ = new ExprOpNot($2); }
-| '-' expr_op %prec NEGATE { $$ = new ExprApp(CUR_POS, new ExprApp(new ExprBuiltin(data->symbols.create("sub")), new ExprInt(0)), $2); }
+  | '-' expr_op %prec NEGATE { $$ = new ExprApp(CUR_POS, new ExprApp(new ExprVar(data->symbols.create("__sub")), new ExprInt(0)), $2); }
   | expr_op EQ expr_op { $$ = new ExprOpEq($1, $3); }
   | expr_op NEQ expr_op { $$ = new ExprOpNEq($1, $3); }
-  | expr_op '<' expr_op { $$ = new ExprApp(CUR_POS, new ExprApp(new ExprBuiltin(data->symbols.create("lessThan")), $1), $3); }
-  | expr_op LEQ expr_op { $$ = new ExprOpNot(new ExprApp(CUR_POS, new ExprApp(new ExprBuiltin(data->symbols.create("lessThan")), $3), $1)); }
-  | expr_op '>' expr_op { $$ = new ExprApp(CUR_POS, new ExprApp(new ExprBuiltin(data->symbols.create("lessThan")), $3), $1); }
-  | expr_op GEQ expr_op { $$ = new ExprOpNot(new ExprApp(CUR_POS, new ExprApp(new ExprBuiltin(data->symbols.create("lessThan")), $1), $3)); }
+  | expr_op '<' expr_op { $$ = new ExprApp(CUR_POS, new ExprApp(new ExprVar(data->symbols.create("__lessThan")), $1), $3); }
+  | expr_op LEQ expr_op { $$ = new ExprOpNot(new ExprApp(CUR_POS, new ExprApp(new ExprVar(data->symbols.create("__lessThan")), $3), $1)); }
+  | expr_op '>' expr_op { $$ = new ExprApp(CUR_POS, new ExprApp(new ExprVar(data->symbols.create("__lessThan")), $3), $1); }
+  | expr_op GEQ expr_op { $$ = new ExprOpNot(new ExprApp(CUR_POS, new ExprApp(new ExprVar(data->symbols.create("__lessThan")), $1), $3)); }
   | expr_op AND expr_op { $$ = new ExprOpAnd(CUR_POS, $1, $3); }
   | expr_op OR expr_op { $$ = new ExprOpOr(CUR_POS, $1, $3); }
   | expr_op IMPL expr_op { $$ = new ExprOpImpl(CUR_POS, $1, $3); }
@@ -346,9 +346,9 @@ expr_op
       l->push_back($3);
       $$ = new ExprConcatStrings(CUR_POS, false, l);
     }
-  | expr_op '-' expr_op { $$ = new ExprApp(CUR_POS, new ExprApp(new ExprBuiltin(data->symbols.create("sub")), $1), $3); }
-  | expr_op '*' expr_op { $$ = new ExprApp(CUR_POS, new ExprApp(new ExprBuiltin(data->symbols.create("mul")), $1), $3); }
-  | expr_op '/' expr_op { $$ = new ExprApp(CUR_POS, new ExprApp(new ExprBuiltin(data->symbols.create("div")), $1), $3); }
+  | expr_op '-' expr_op { $$ = new ExprApp(CUR_POS, new ExprApp(new ExprVar(data->symbols.create("__sub")), $1), $3); }
+  | expr_op '*' expr_op { $$ = new ExprApp(CUR_POS, new ExprApp(new ExprVar(data->symbols.create("__mul")), $1), $3); }
+  | expr_op '/' expr_op { $$ = new ExprApp(CUR_POS, new ExprApp(new ExprVar(data->symbols.create("__div")), $1), $3); }
   | expr_op CONCAT expr_op { $$ = new ExprOpConcatLists(CUR_POS, $1, $3); }
   | expr_app
   ;