fix Issue 6356 - Pure/nothrow/@safe-inference failed for a template f…

…unction if it is instantiated without evaluating at the global scope

src/expression.c

@@ -974,7 +974,7 @@ Type *functionParameters(Loc loc, Scope *sc, TypeFunction *tf,
                         t = t->semantic(loc, sc);
                         bool isSafe = fd ? fd->isSafe() : tf->trust == TRUSTsafe;
                         VarDeclaration *v = new VarDeclaration(loc, t, id,
-                            isSafe ? NULL : new VoidInitializer(loc));
+                            (isSafe && sc->func) ? NULL : new VoidInitializer(loc));
                         v->storage_class |= STCctfe;
                         v->semantic(sc);
                         v->parent = sc->parent;

src/template.c

@@ -2162,6 +2162,16 @@ FuncDeclaration *TemplateDeclaration::deduceFunctionTemplate(Scope *sc, Loc loc,
         if (tf->next)
             fd_best->type = tf->semantic(loc, sc);
     }
+    if (fd_best->scope)
+    {
+        TemplateInstance *spec = fd_best->isSpeculative();
+        int olderrs = global.errors;
+        fd_best->semantic3(fd_best->scope);
+        // Update the template instantiation with the number
+        // of errors which occured.
+        if (spec && global.errors != olderrs)
+            spec->errors = global.errors - olderrs;
+    }
 
     return fd_best;
 

test/runnable/xtest46.d

@@ -4769,6 +4769,26 @@ void test6056()
     bar6056(&foo6056);
 }
 
+/***************************************************/
+// 6356
+
+int f6356()(int a)
+{
+    return a*a;
+}
+
+alias f6356!() g6356;     // comment this out to eliminate the errors
+
+pure nothrow @safe int i6356()
+{
+    return f6356(1);
+}
+
+void test6356()
+{
+    assert(i6356() == 1);
+}
+
 /***************************************************/
 // 7108
 
@@ -5701,6 +5721,7 @@ int main()
     test2856();
     test3091();
     test6056();
+    test6356();
     test7073();
     test7150();
     test7160();