Merged R8864

src/libexpr/eval.cc

@@ -478,7 +478,7 @@ LocalNoInline(Expr evalCall(EvalState & state, Expr fun, Expr arg))
     }
 
     else throwTypeError(
-        "the left-hand side of the function call is neither a function nor a primop (built-in operation) but %1%",
+        "attempt to call something which is neither a function nor a primop (built-in operation) but %1%",
         showType(fun));
 }
 

src/libexpr/parser.y

@@ -249,6 +249,7 @@ expr_list
 formals
   : formal ',' formals { $$ = ATinsert($3, $1); } /* idem - right recursive */
   | formal { $$ = ATinsert(ATempty, $1); }
+  | { $$ = ATempty; }
   ;
 
 formal

src/libexpr/primops.cc

@@ -116,6 +116,18 @@ static Expr prim_isNull(EvalState & state, const ATermVector & args)
 }
 
 
+/* Determine whether the argument is a function. */
+static Expr prim_isFunction(EvalState & state, const ATermVector & args)
+{
+    Expr e = evalExpr(state, args[0]);
+    ATermList formals;
+    ATerm name, body, pos;
+    return makeBool(
+        matchFunction(e, formals, body, pos) ||
+        matchFunction1(e, name, body, pos));
+}
+
+
 static Path findDependency(Path dir, string dep)
 {
     if (dep[0] == '/') throw EvalError(
@@ -1032,6 +1044,7 @@ void EvalState::addPrimOps()
     // Miscellaneous
     addPrimOp("import", 1, prim_import);
     addPrimOp("isNull", 1, prim_isNull);
+    addPrimOp("__isFunction", 1, prim_isFunction);
     addPrimOp("dependencyClosure", 1, prim_dependencyClosure);
     addPrimOp("abort", 1, prim_abort);
     addPrimOp("throw", 1, prim_throw);

src/libstore/db.cc

@@ -145,6 +145,15 @@ Database::~Database()
 
 void openEnv(DbEnv * & env, const string & path, u_int32_t flags)
 {
+    try {
+        createDirs(path);
+    } catch (SysError & e) {
+        if (e.errNo == EPERM || e.errNo == EACCES)
+            throw DbNoPermission(format("cannot create the Nix database in `%1%'") % path);
+        else
+            throw;
+    }
+        
     try {
         env->open(path.c_str(),
             DB_INIT_LOCK | DB_INIT_LOG | DB_INIT_MPOOL | DB_INIT_TXN |

src/libstore/gc.cc

@@ -97,6 +97,11 @@ Path addPermRoot(const Path & _storePath, const Path & _gcRoot,
     Path gcRoot(canonPath(_gcRoot));
     assertStorePath(storePath);
 
+    if (isInStore(gcRoot))
+        throw Error(format(
+                "creating a garbage collector root (%1%) in the Nix store is forbidden "
+                "(are you running nix-build inside the store?)") % gcRoot);
+
     if (indirect) {
         createSymlink(gcRoot, storePath, true);
         store->addIndirectRoot(gcRoot);
@@ -114,7 +119,6 @@ Path addPermRoot(const Path & _storePath, const Path & _gcRoot,
         }
             
         createSymlink(gcRoot, storePath, false);
-
     }
 
     /* Check that the root can be found by the garbage collector. */

src/libstore/local-store.hh

@@ -13,7 +13,7 @@ class Transaction;
 
 
 /* Nix store and database schema version.  Version 1 (or 0) was Nix <=
-   0.7.  Version 2 was Nix 0.8 and 0.8.  Version 3 is Nix 0.10 and
+   0.7.  Version 2 was Nix 0.8 and 0.9.  Version 3 is Nix 0.10 and
    up. */
 const int nixSchemaVersion = 3;