libexpr: sort binding name in debugger

not doing this exposes the binding name order to the annoying
interference of parse order on symbol order, which wouldn't be so bad if
it didn't make the tests less reliable and, importantly, dependent on
linker behavior (due to primop initialization being done in static
initializer, and the order of static initializers being defined only
within a single translation unit).

fixes #143

Change-Id: I3cf417893fbcf19e9ad3ff8986deb7cbcf3ca511

src/libexpr/eval.cc

@@ -677,12 +677,21 @@ std::optional<EvalState::Doc> EvalState::getDoc(Value & v)
 }
 
 
+static std::set<std::string_view> sortedBindingNames(const SymbolTable & st, const StaticEnv & se)
+{
+    std::set<std::string_view> bindings;
+    for (auto [symbol, displ] : se.vars)
+        bindings.emplace(st[symbol]);
+    return bindings;
+}
+
+
 // just for the current level of StaticEnv, not the whole chain.
 void printStaticEnvBindings(const SymbolTable & st, const StaticEnv & se)
 {
     std::cout << ANSI_MAGENTA;
-    for (auto & i : se.vars)
+    for (auto & i : sortedBindingNames(st, se))
-        std::cout << st[i.first] << " ";
+        std::cout << i << " ";
     std::cout << ANSI_NORMAL;
     std::cout << std::endl;
 }
@@ -691,13 +700,14 @@ void printStaticEnvBindings(const SymbolTable & st, const StaticEnv & se)
 void printWithBindings(const SymbolTable & st, const Env & env)
 {
     if (!env.values[0]->isThunk()) {
+        std::set<std::string_view> bindings;
+        for (const auto & attr : *env.values[0]->attrs)
+            bindings.emplace(st[attr.name]);
+
         std::cout << "with: ";
         std::cout << ANSI_MAGENTA;
-        Bindings::iterator j = env.values[0]->attrs->begin();
+        for (auto & i : bindings)
-        while (j != env.values[0]->attrs->end()) {
+            std::cout << i << " ";
-            std::cout << st[j->name] << " ";
-            ++j;
-        }
         std::cout << ANSI_NORMAL;
         std::cout << std::endl;
     }
@@ -718,9 +728,9 @@ void printEnvBindings(const SymbolTable & st, const StaticEnv & se, const Env &
         std::cout << ANSI_MAGENTA;
         // for the top level, don't print the double underscore ones;
         // they are in builtins.
-        for (auto & i : se.vars)
+        for (auto & i : sortedBindingNames(st, se))
-            if (!std::string_view(st[i.first]).starts_with("__"))
+            if (!i.starts_with("__"))
-                std::cout << st[i.first] << " ";
+                std::cout << i << " ";
         std::cout << ANSI_NORMAL;
         std::cout << std::endl;
         if (se.isWith)

tests/functional/repl_characterization/data/regression_9918.test

@@ -10,7 +10,7 @@ We expect to be able to see locals like r in the debugger:
 
   nix-repl> :env
   Env level 0
-  static: x r
+  static: r x
 
   Env level 1
-  builtins true false null scopedImport import isNull break abort throw derivationStrict placeholder baseNameOf dirOf removeAttrs map toString fetchMercurial fetchTree fetchTarball fetchGit fromTOML derivation
+  abort baseNameOf break builtins derivation derivationStrict dirOf false fetchGit fetchMercurial fetchTarball fetchTree fromTOML import isNull map null placeholder removeAttrs scopedImport throw toString true

tests/functional/repl_characterization/data/stack_vars.test

@@ -14,7 +14,7 @@ as it is in scope.
   static: a b
 
   Env level 2
-  builtins true false null scopedImport import isNull break abort throw derivationStrict placeholder baseNameOf dirOf removeAttrs map toString fetchMercurial fetchTree fetchTarball fetchGit fromTOML derivation
+  abort baseNameOf break builtins derivation derivationStrict dirOf false fetchGit fetchMercurial fetchTarball fetchTree fromTOML import isNull map null placeholder removeAttrs scopedImport throw toString true
 
   nix-repl> meow
   2
@@ -35,7 +35,7 @@ If we :st past the frame in the backtrace with the meow in it, the meow should n
   static: a b
 
   Env level 1
-  builtins true false null scopedImport import isNull break abort throw derivationStrict placeholder baseNameOf dirOf removeAttrs map toString fetchMercurial fetchTree fetchTarball fetchGit fromTOML derivation
+  abort baseNameOf break builtins derivation derivationStrict dirOf false fetchGit fetchMercurial fetchTarball fetchTree fromTOML import isNull map null placeholder removeAttrs scopedImport throw toString true
 
   nix-repl> :c
   trace: before inner break
@@ -52,7 +52,7 @@ If we :st past the frame in the backtrace with the meow in it, the meow should n
   static: a b
 
   Env level 2
-  builtins true false null scopedImport import isNull break abort throw derivationStrict placeholder baseNameOf dirOf removeAttrs map toString fetchMercurial fetchTree fetchTarball fetchGit fromTOML derivation
+  abort baseNameOf break builtins derivation derivationStrict dirOf false fetchGit fetchMercurial fetchTarball fetchTree fromTOML import isNull map null placeholder removeAttrs scopedImport throw toString true
 
   nix-repl> meow'
   3
@@ -71,4 +71,4 @@ If we :st past the frame in the backtrace with the meow in it, the meow should n
   static: a b
 
   Env level 1
-  builtins true false null scopedImport import isNull break abort throw derivationStrict placeholder baseNameOf dirOf removeAttrs map toString fetchMercurial fetchTree fetchTarball fetchGit fromTOML derivation
+  abort baseNameOf break builtins derivation derivationStrict dirOf false fetchGit fetchMercurial fetchTarball fetchTree fromTOML import isNull map null placeholder removeAttrs scopedImport throw toString true