Merge remote-tracking branch 'upstream/master' into lfs

src/libexpr/build-utils-meson

@@ -1 +0,0 @@
-../../build-utils-meson

src/libexpr/eval.cc

@@ -347,6 +347,16 @@ void EvalState::allowPath(const StorePath & storePath)
         rootFS2->allowPrefix(CanonPath(store->toRealPath(storePath)));
 }
 
+void EvalState::allowClosure(const StorePath & storePath)
+{
+    if (!rootFS.dynamic_pointer_cast<AllowListSourceAccessor>()) return;
+
+    StorePathSet closure;
+    store->computeFSClosure(storePath, closure);
+    for (auto & p : closure)
+        allowPath(p);
+}
+
 void EvalState::allowAndSetStorePathString(const StorePath & storePath, Value & v)
 {
     allowPath(storePath);
@@ -3099,10 +3109,7 @@ std::optional<SourcePath> EvalState::resolveLookupPathPath(const LookupPath::Pat
             allowPath(path.path.abs());
             if (store->isInStore(path.path.abs())) {
                 try {
-                    StorePathSet closure;
-                    store->computeFSClosure(store->toStorePath(path.path.abs()).first, closure);
-                    for (auto & p : closure)
-                        allowPath(p);
+                    allowClosure(store->toStorePath(path.path.abs()).first);
                 } catch (InvalidPath &) { }
             }
         }
@@ -3178,5 +3185,14 @@ std::ostream & operator << (std::ostream & str, const ExternalValueBase & v) {
     return v.print(str);
 }
 
+void forceNoNullByte(std::string_view s)
+{
+    if (s.find('\0') != s.npos) {
+        using namespace std::string_view_literals;
+        auto str = replaceStrings(std::string(s), "\0"sv, "␀"sv);
+        throw Error("input string '%s' cannot be represented as Nix string because it contains null bytes", str);
+    }
+}
+
 
 }

src/libexpr/eval.hh

@@ -400,6 +400,11 @@ public:
      */
     void allowPath(const StorePath & storePath);
 
+    /**
+     * Allow access to the closure of a store path.
+     */
+    void allowClosure(const StorePath & storePath);
+
     /**
      * Allow access to a store path and return it as a string.
      */

src/libexpr/json-to-value.cc

@@ -50,6 +50,7 @@ class JSONSax : nlohmann::json_sax<json> {
     public:
         void key(string_t & name, EvalState & state)
         {
+            forceNoNullByte(name);
             attrs.insert_or_assign(state.symbols.create(name), &value(state));
         }
     };
@@ -122,6 +123,7 @@ public:
 
     bool string(string_t & val) override
     {
+        forceNoNullByte(val);
         rs->value(state).mkString(val);
         rs->add();
         return true;

src/libexpr/lexer-helpers.hh

@@ -1,5 +1,13 @@
 #pragma once
 
+#include <cstddef>
+
+// inluding the generated headers twice leads to errors
+#ifndef BISON_HEADER
+#  include "lexer-tab.hh"
+#  include "parser-tab.hh"
+#endif
+
 namespace nix::lexer::internal {
 
 void initLoc(YYLTYPE * loc);

src/libexpr/meson.build

@@ -14,7 +14,7 @@ project('nix-expr', 'cpp',
 
 cxx = meson.get_compiler('cpp')
 
-subdir('build-utils-meson/deps-lists')
+subdir('nix-meson-build-support/deps-lists')
 
 configdata = configuration_data()
 
@@ -25,7 +25,7 @@ deps_public_maybe_subproject = [
   dependency('nix-store'),
   dependency('nix-fetchers'),
 ]
-subdir('build-utils-meson/subprojects')
+subdir('nix-meson-build-support/subprojects')
 
 boost = dependency(
   'boost',
@@ -77,7 +77,7 @@ add_project_arguments(
   language : 'cpp',
 )
 
-subdir('build-utils-meson/common')
+subdir('nix-meson-build-support/common')
 
 parser_tab = custom_target(
   input : 'parser.y',
@@ -121,7 +121,7 @@ lexer_tab = custom_target(
   install_dir : get_option('includedir') / 'nix',
 )
 
-subdir('build-utils-meson/generate-header')
+subdir('nix-meson-build-support/generate-header')
 
 generated_headers = []
 foreach header : [
@@ -205,4 +205,4 @@ install_headers(headers, subdir : 'nix', preserve_path : true)
 
 libraries_private = []
 
-subdir('build-utils-meson/export')
+subdir('nix-meson-build-support/export')

src/libexpr/nix-meson-build-support

@@ -0,0 +1 @@
+../../nix-meson-build-support

src/libexpr/nixexpr.hh

@@ -168,7 +168,7 @@ struct ExprVar : Expr
        the set stored in the environment that is `level` levels up
        from the current one.*/
     Level level;
-    Displacement displ;
+    Displacement displ = 0;
 
     ExprVar(Symbol name) : name(name) { };
     ExprVar(const PosIdx & pos, Symbol name) : pos(pos), name(name) { };
@@ -242,7 +242,7 @@ struct ExprAttrs : Expr
         Kind kind;
         Expr * e;
         PosIdx pos;
-        Displacement displ; // displacement
+        Displacement displ = 0; // displacement
         AttrDef(Expr * e, const PosIdx & pos, Kind kind = Kind::Plain)
             : kind(kind), e(e), pos(pos) { };
         AttrDef() { };

src/libexpr/package.nix

@@ -40,8 +40,8 @@ mkMesonLibrary (finalAttrs: {
 
   workDir = ./.;
   fileset = fileset.unions [
-    ../../build-utils-meson
-    ./build-utils-meson
+    ../../nix-meson-build-support
+    ./nix-meson-build-support
     ../../.version
     ./.version
     ./meson.build

src/libexpr/primops.cc

@@ -119,11 +119,9 @@ StringMap EvalState::realiseContext(const NixStringContext & context, StorePathS
     if (store != buildStore) copyClosure(*buildStore, *store, outputsToCopyAndAllow);
 
     if (isIFD) {
-        for (auto & outputPath : outputsToCopyAndAllow) {
-            /* Add the output of this derivations to the allowed
-            paths. */
-            allowPath(outputPath);
-        }
+        /* Allow access to the output closures of this derivation. */
+        for (auto & outputPath : outputsToCopyAndAllow)
+            allowClosure(outputPath);
     }
 
     return res;
@@ -1100,7 +1098,7 @@ static RegisterPrimOp primop_warn({
     .name = "__warn",
     .args = {"e1", "e2"},
     .doc = R"(
-      Evaluate *e1*, which must be a string and print iton standard error as a warning.
+      Evaluate *e1*, which must be a string, and print it on standard error as a warning.
       Then return *e2*.
       This function is useful for non-critical situations where attention is advisable.
 
@@ -3259,23 +3257,19 @@ static RegisterPrimOp primop_isList({
     .fun = prim_isList,
 });
 
-static void elemAt(EvalState & state, const PosIdx pos, Value & list, int n, Value & v)
-{
-    state.forceList(list, pos, "while evaluating the first argument passed to builtins.elemAt");
-    if (n < 0 || (unsigned int) n >= list.listSize())
-        state.error<EvalError>(
-            "list index %1% is out of bounds",
-            n
-        ).atPos(pos).debugThrow();
-    state.forceValue(*list.listElems()[n], pos);
-    v = *list.listElems()[n];
-}
-
 /* Return the n-1'th element of a list. */
 static void prim_elemAt(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
-    NixInt::Inner elem = state.forceInt(*args[1], pos, "while evaluating the second argument passed to builtins.elemAt").value;
-    elemAt(state, pos, *args[0], elem, v);
+    NixInt::Inner n = state.forceInt(*args[1], pos, "while evaluating the second argument passed to 'builtins.elemAt'").value;
+    state.forceList(*args[0], pos, "while evaluating the first argument passed to 'builtins.elemAt'");
+    if (n < 0 || (unsigned int) n >= args[0]->listSize())
+        state.error<EvalError>(
+            "'builtins.elemAt' called with index %d on a list of size %d",
+            n,
+            args[0]->listSize()
+        ).atPos(pos).debugThrow();
+    state.forceValue(*args[0]->listElems()[n], pos);
+    v = *args[0]->listElems()[n];
 }
 
 static RegisterPrimOp primop_elemAt({
@@ -3291,7 +3285,13 @@ static RegisterPrimOp primop_elemAt({
 /* Return the first element of a list. */
 static void prim_head(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
-    elemAt(state, pos, *args[0], 0, v);
+    state.forceList(*args[0], pos, "while evaluating the first argument passed to 'builtins.head'");
+    if (args[0]->listSize() == 0)
+        state.error<EvalError>(
+            "'builtins.head' called on an empty list"
+        ).atPos(pos).debugThrow();
+    state.forceValue(*args[0]->listElems()[0], pos);
+    v = *args[0]->listElems()[0];
 }
 
 static RegisterPrimOp primop_head({
@@ -3310,9 +3310,9 @@ static RegisterPrimOp primop_head({
    don't want to use it!  */
 static void prim_tail(EvalState & state, const PosIdx pos, Value * * args, Value & v)
 {
-    state.forceList(*args[0], pos, "while evaluating the first argument passed to builtins.tail");
+    state.forceList(*args[0], pos, "while evaluating the first argument passed to 'builtins.tail'");
     if (args[0]->listSize() == 0)
-        state.error<EvalError>("'tail' called on an empty list").atPos(pos).debugThrow();
+        state.error<EvalError>("'builtins.tail' called on an empty list").atPos(pos).debugThrow();
 
     auto list = state.buildList(args[0]->listSize() - 1);
     for (const auto & [n, v] : enumerate(list))

src/libexpr/primops/fromTOML.cc

@@ -28,8 +28,10 @@ static void prim_fromTOML(EvalState & state, const PosIdx pos, Value * * args, V
 
                     auto attrs = state.buildBindings(size);
 
-                    for(auto & elem : table)
+                    for(auto & elem : table) {
+                        forceNoNullByte(elem.first);
                         visit(attrs.alloc(elem.first), elem.second);
+                    }
 
                     v.mkAttrs(attrs);
                 }
@@ -54,7 +56,11 @@ static void prim_fromTOML(EvalState & state, const PosIdx pos, Value * * args, V
                 v.mkFloat(toml::get<NixFloat>(t));
                 break;;
             case toml::value_t::string:
-                v.mkString(toml::get<std::string>(t));
+                {
+                    auto s = toml::get<std::string_view>(t);
+                    forceNoNullByte(s);
+                    v.mkString(s);
+                }
                 break;;
             case toml::value_t::local_datetime:
             case toml::value_t::offset_datetime:
@@ -66,7 +72,9 @@ static void prim_fromTOML(EvalState & state, const PosIdx pos, Value * * args, V
                         attrs.alloc("_type").mkString("timestamp");
                         std::ostringstream s;
                         s << t;
-                        attrs.alloc("value").mkString(toView(s));
+                        auto str = toView(s);
+                        forceNoNullByte(str);
+                        attrs.alloc("value").mkString(str);
                         v.mkAttrs(attrs);
                     } else {
                         throw std::runtime_error("Dates and times are not supported");

src/libexpr/print-options.hh

@@ -5,6 +5,7 @@
  */
 
 #include <limits>
+#include <stddef.h>
 
 namespace nix {
 

src/libexpr/value.hh

@@ -510,4 +510,6 @@ typedef std::shared_ptr<Value *> RootValue;
 
 RootValue allocRootValue(Value * v);
 
+void forceNoNullByte(std::string_view s);
+
 }