test_grammar test fix

Author: Michal Medvecky

graalpython/com.oracle.graal.python.test/src/tests/unittest_tags_bytecode_dsl/test_grammar.txt

@@ -2,6 +2,8 @@ test.test_grammar.GrammarTests.test_additive_ops @ linux-x86_64
 test.test_grammar.GrammarTests.test_annotations_inheritance @ linux-x86_64
 test.test_grammar.GrammarTests.test_assert @ linux-x86_64
 test.test_grammar.GrammarTests.test_assert_failures @ linux-x86_64
+test.test_grammar.GrammarTests.test_assert_syntax_warnings @ linux-x86_64
+test.test_grammar.GrammarTests.test_assert_warning_promotes_to_syntax_error @ linux-x86_64
 test.test_grammar.GrammarTests.test_async_await @ linux-x86_64
 test.test_grammar.GrammarTests.test_async_for @ linux-x86_64
 test.test_grammar.GrammarTests.test_async_with @ linux-x86_64

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/compiler/bytecode_dsl/RootNodeCompiler.java

@@ -2909,6 +2909,9 @@ private void checkAnnSubscr(ExprTy expr) {
         public Void visit(StmtTy.Assert node) {
             if (ctx.optimizationLevel <= 0) {
                 boolean newStatement = beginSourceSection(node, b);
+                if (node.test instanceof ExprTy.Tuple && ((Tuple) node.test).elements.length > 0) {
+                    ctx.errorCallback.onWarning(WarningType.Syntax, currentLocation, "assertion is always true, perchance remove parentheses?");
+                }
                 b.beginIfThen();
 
                 b.beginNot();