optinoal error; compiles

5 files changed, 42 insertions, 37 deletions

diff --git a/src/libcmd/command.cc b/src/libcmd/command.cc
index 252bc1fad..ed8f6d295 100644
--- a/src/libcmd/command.cc
+++ b/src/libcmd/command.cc
@@ -63,7 +63,7 @@ EvalCommand::EvalCommand()
     });
 }
 
-extern std::function<void(const Error & error, const Env & env, const Expr & expr)> debuggerHook;
+extern std::function<void(const Error * error, const Env & env, const Expr & expr)> debuggerHook;
 
 ref<EvalState> EvalCommand::getEvalState()
 {
@@ -76,13 +76,14 @@ ref<EvalState> EvalCommand::getEvalState()
 #endif
                 searchPath, getEvalStore(), getStore());
         if (startReplOnEvalErrors)
-            debuggerHook = [evalState{ref<EvalState>(evalState)}](const Error & error, const Env & env, const Expr & expr) {
-                printError("%s\n\n" ANSI_BOLD "Starting REPL to allow you to inspect the current state of the evaluator.\n" ANSI_NORMAL, error.what());
+            debuggerHook = [evalState{ref<EvalState>(evalState)}](const Error * error, const Env & env, const Expr & expr) {
+                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());
 
                 if (expr.staticenv)
                 {
                     auto vm = mapStaticEnvBindings(*expr.staticenv.get(), env);
-                    runRepl(evalState,  &error, expr, *vm);
+                    runRepl(evalState, error, expr, *vm);
                 }
             };
     }
diff --git a/src/libcmd/repl.cc b/src/libcmd/repl.cc
index fdd63621f..e66cf4430 100644
--- a/src/libcmd/repl.cc
+++ b/src/libcmd/repl.cc
@@ -917,19 +917,23 @@ void runRepl(
 {
     auto repl = std::make_unique<NixRepl>(evalState);
 
-    repl->debugError = debugError;
+    // repl->debugError = debugError;
 
     repl->initEnv();
 
-    // tack on a final DebugTrace for the error position.
-    DebugTraceStacker ldts(
-          *evalState,
-          DebugTrace 
-                {.pos = debugError->info().errPos,
-                 .expr = expr,
-                 .env = *repl->env,
-                 .hint = debugError->info().msg
-                });
+    // auto dts = debugError ? 
+    //     std::unique_ptr<DebugTraceStacker>(
+    //         // tack on a final DebugTrace for the error position.
+    //         new DebugTraceStacker(
+    //               *evalState,
+    //               DebugTrace
+    //                     {.pos = debugError->info().errPos,
+    //                      .expr = expr,
+    //                      .env = *repl->env,
+    //                      .hint = debugError->info().msg
+    //                     })
+    //         )
+    //     : nullptr;
 
     // add 'extra' vars.
     std::set<std::string> names;
diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc
index e01147169..7b3745e52 100644
--- a/src/libexpr/eval.cc
+++ b/src/libexpr/eval.cc
@@ -36,7 +36,7 @@
 
 namespace nix {
 
-std::function<void(const Error & error, const Env & env, const Expr & expr)> debuggerHook;
+std::function<void(const Error * error, const Env & env, const Expr & expr)> debuggerHook;
 
 static char * dupString(const char * s)
 {
@@ -756,7 +756,7 @@ LocalNoInlineNoReturn(void throwEvalError(const char * s, const string & s2, Env
     auto error = EvalError(s, s2);
 
     if (debuggerHook && expr)
-        debuggerHook(error, env, *expr);
+        debuggerHook(&error, env, *expr);
     throw error;
 }
 
@@ -768,7 +768,7 @@ LocalNoInlineNoReturn(void throwEvalError(const Pos & pos, const char * s, const
     });
 
     if (debuggerHook && expr)
-        debuggerHook(error, env, *expr);
+        debuggerHook(&error, env, *expr);
 
     throw error;
 }
@@ -778,7 +778,7 @@ LocalNoInlineNoReturn(void throwEvalError(const char * s, const string & s2, con
     auto error = EvalError(s, s2, s3);
 
     if (debuggerHook && expr)
-        debuggerHook(error, env, *expr);
+        debuggerHook(&error, env, *expr);
 
     throw error;
 }
@@ -791,7 +791,7 @@ LocalNoInlineNoReturn(void throwEvalError(const Pos & pos, const char * s, const
     });
 
     if (debuggerHook && expr)
-        debuggerHook(error, env, *expr);
+        debuggerHook(&error, env, *expr);
 
     throw error;
 }
@@ -805,7 +805,7 @@ LocalNoInlineNoReturn(void throwEvalError(const Pos & p1, const char * s, const
     });
 
     if (debuggerHook && expr)
-        debuggerHook(error, env, *expr);
+        debuggerHook(&error, env, *expr);
 
     throw error;
 }
@@ -818,7 +818,7 @@ LocalNoInlineNoReturn(void throwTypeError(const Pos & pos, const char * s, Env &
     });
 
     if (debuggerHook && expr)
-        debuggerHook(error, env, *expr);
+        debuggerHook(&error, env, *expr);
 
     throw error;
 }
@@ -831,7 +831,7 @@ LocalNoInlineNoReturn(void throwTypeError(const Pos & pos, const char * s, const
     });
 
     if (debuggerHook && expr)
-        debuggerHook(error, env, *expr);
+        debuggerHook(&error, env, *expr);
 
     throw error;
 }
@@ -844,7 +844,7 @@ LocalNoInlineNoReturn(void throwTypeError(const Pos & pos, const char * s, const
     });
 
     if (debuggerHook && expr)
-        debuggerHook(error, env, *expr);
+        debuggerHook(&error, env, *expr);
 
     throw error;
 }
@@ -857,7 +857,7 @@ LocalNoInlineNoReturn(void throwTypeError(const Pos & pos, const char * s, const
     });
 
     if (debuggerHook && expr)
-        debuggerHook(error, env, *expr);
+        debuggerHook(&error, env, *expr);
 
     throw error;
 }
@@ -870,7 +870,7 @@ LocalNoInlineNoReturn(void throwAssertionError(const Pos & pos, const char * s,
     });
 
     if (debuggerHook && expr)
-        debuggerHook(error, env, *expr);
+        debuggerHook(&error, env, *expr);
 
     throw error;
 }
@@ -883,7 +883,7 @@ LocalNoInlineNoReturn(void throwUndefinedVarError(const Pos & pos, const char *
     });
 
     if (debuggerHook && expr) {
-        debuggerHook(error, env, *expr);
+        debuggerHook(&error, env, *expr);
     }
 
     throw error;
@@ -897,7 +897,7 @@ LocalNoInlineNoReturn(void throwMissingArgumentError(const Pos & pos, const char
     });
 
     if (debuggerHook && expr)
-        debuggerHook(error, env, *expr);
+        debuggerHook(&error, env, *expr);
 
     throw error;
 }
@@ -926,6 +926,13 @@ LocalNoInline(std::unique_ptr<DebugTraceStacker>
                 }));
 }
 
+DebugTraceStacker::DebugTraceStacker(EvalState &evalState, DebugTrace t)
+:evalState(evalState), trace(t)
+{
+    evalState.debugTraces.push_front(t);
+    if (debuggerHook)
+        debuggerHook(0, t.env, t.expr);
+}
 
 void mkString(Value & v, const char * s)
 {
diff --git a/src/libexpr/eval.hh b/src/libexpr/eval.hh
index 3c74bb4a1..1a097ab8c 100644
--- a/src/libexpr/eval.hh
+++ b/src/libexpr/eval.hh
@@ -24,7 +24,7 @@ enum RepairFlag : bool;
 
 typedef void (* PrimOpFun) (EvalState & state, const Pos & pos, Value * * args, Value & v);
 
-extern std::function<void(const Error & error, const Env & env, const Expr & expr)> debuggerHook;
+extern std::function<void(const Error * error, const Env & env, const Expr & expr)> debuggerHook;
 void printStaticEnvBindings(const Expr &expr);
 void printStaticEnvBindings(const StaticEnv &se, int lvl = 0);
 
@@ -414,14 +414,7 @@ private:
 
 class DebugTraceStacker {
     public:
-        DebugTraceStacker(EvalState &evalState, DebugTrace t)
-        :evalState(evalState), trace(t)
-        {
-         
-            // evalState.debuggerHook(const Error & error, const Env & env, const Expr & expr);
-
-            evalState.debugTraces.push_front(t);
-        }
+        DebugTraceStacker(EvalState &evalState, DebugTrace t);
         ~DebugTraceStacker() 
         {
             // assert(evalState.debugTraces.front() == trace);
diff --git a/src/libexpr/nixexpr.hh b/src/libexpr/nixexpr.hh
index c4c459f0b..8012c616e 100644
--- a/src/libexpr/nixexpr.hh
+++ b/src/libexpr/nixexpr.hh
@@ -18,7 +18,7 @@ MakeError(UndefinedVarError, Error);
 MakeError(MissingArgumentError, EvalError);
 MakeError(RestrictedPathError, Error);
 
-extern std::function<void(const Error & error, const Env & env, const Expr & expr)> debuggerHook;
+extern std::function<void(const Error * error, const Env & env, const Expr & expr)> debuggerHook;
 
 /* Position objects. */