No global settings in libnixfetchers and libnixflake

Progress on #5638

There are still a global fetcher and eval settings, but they are pushed
down into `libnixcmd`, which is a lot less bad a place for this sort of
thing.

Continuing process pioneered in
52bfccf8d8.

src/libexpr/eval-settings.cc

@@ -1,5 +1,4 @@
 #include "users.hh"
-#include "config-global.hh"
 #include "globals.hh"
 #include "profiles.hh"
 #include "eval.hh"

src/libexpr/eval.cc

@@ -217,9 +217,11 @@ static constexpr size_t BASE_ENV_SIZE = 128;
 EvalState::EvalState(
     const LookupPath & _lookupPath,
     ref<Store> store,
+    const fetchers::Settings & fetchSettings,
     const EvalSettings & settings,
     std::shared_ptr<Store> buildStore)
-    : settings{settings}
+    : fetchSettings{fetchSettings}
+    , settings{settings}
     , sWith(symbols.create("<with>"))
     , sOutPath(symbols.create("outPath"))
     , sDrvPath(symbols.create("drvPath"))

src/libexpr/eval.hh

@@ -30,6 +30,7 @@ namespace nix {
 constexpr size_t maxPrimOpArity = 8;
 
 class Store;
+namespace fetchers { struct Settings; }
 struct EvalSettings;
 class EvalState;
 class StorePath;
@@ -43,7 +44,7 @@ namespace eval_cache {
 /**
  * Function that implements a primop.
  */
-typedef void (* PrimOpFun) (EvalState & state, const PosIdx pos, Value * * args, Value & v);
+using PrimOpFun = void(EvalState & state, const PosIdx pos, Value * * args, Value & v);
 
 /**
  * Info about a primitive operation, and its implementation
@@ -84,7 +85,7 @@ struct PrimOp
     /**
      * Implementation of the primop.
      */
-    std::function<std::remove_pointer<PrimOpFun>::type> fun;
+    std::function<PrimOpFun> fun;
 
     /**
      * Optional experimental for this to be gated on.
@@ -162,6 +163,7 @@ struct DebugTrace {
 class EvalState : public std::enable_shared_from_this<EvalState>
 {
 public:
+    const fetchers::Settings & fetchSettings;
     const EvalSettings & settings;
     SymbolTable symbols;
     PosTable positions;
@@ -353,6 +355,7 @@ public:
     EvalState(
         const LookupPath & _lookupPath,
         ref<Store> store,
+        const fetchers::Settings & fetchSettings,
         const EvalSettings & settings,
         std::shared_ptr<Store> buildStore = nullptr);
     ~EvalState();

src/libexpr/primops/fetchMercurial.cc

@@ -62,7 +62,7 @@ static void prim_fetchMercurial(EvalState & state, const PosIdx pos, Value * * a
     attrs.insert_or_assign("name", std::string(name));
     if (ref) attrs.insert_or_assign("ref", *ref);
     if (rev) attrs.insert_or_assign("rev", rev->gitRev());
-    auto input = fetchers::Input::fromAttrs(std::move(attrs));
+    auto input = fetchers::Input::fromAttrs(state.fetchSettings, std::move(attrs));
 
     auto [storePath, input2] = input.fetchToStore(state.store);
 

src/libexpr/primops/fetchTree.cc

@@ -85,7 +85,7 @@ static void fetchTree(
     Value & v,
     const FetchTreeParams & params = FetchTreeParams{}
 ) {
-    fetchers::Input input;
+    fetchers::Input input { state.fetchSettings };
     NixStringContext context;
     std::optional<std::string> type;
     if (params.isFetchGit) type = "git";
@@ -148,7 +148,7 @@ static void fetchTree(
                     "attribute 'name' isn’t supported in call to 'fetchTree'"
                 ).atPos(pos).debugThrow();
 
-        input = fetchers::Input::fromAttrs(std::move(attrs));
+        input = fetchers::Input::fromAttrs(state.fetchSettings, std::move(attrs));
     } else {
         auto url = state.coerceToString(pos, *args[0], context,
                 "while evaluating the first argument passed to the fetcher",
@@ -161,13 +161,13 @@ static void fetchTree(
             if (!attrs.contains("exportIgnore") && (!attrs.contains("submodules") || !*fetchers::maybeGetBoolAttr(attrs, "submodules"))) {
                 attrs.emplace("exportIgnore", Explicit<bool>{true});
             }
-            input = fetchers::Input::fromAttrs(std::move(attrs));
+            input = fetchers::Input::fromAttrs(state.fetchSettings, std::move(attrs));
         } else {
             if (!experimentalFeatureSettings.isEnabled(Xp::Flakes))
                 state.error<EvalError>(
                     "passing a string argument to 'fetchTree' requires the 'flakes' experimental feature"
                 ).atPos(pos).debugThrow();
-            input = fetchers::Input::fromURL(url);
+            input = fetchers::Input::fromURL(state.fetchSettings, url);
         }
     }