[GR-18449] Assigning to a literal should raise error.

Author: ppisl

graalpython/com.oracle.graal.python.test/src/com/oracle/graal/python/test/parser/AssignmentTests.java

@@ -167,4 +167,33 @@ public void augassign14() throws Exception {
                                         "    cls_or_self, *rest = args");
     }
 
+    @Test
+    public void assignToLiteral01() throws Exception {
+        checkSyntaxErrorMessage("1 = 1", "SyntaxError: can't assign to literal");
+    }
+
+    @Test
+    public void assignToLiteral02() throws Exception {
+        checkSyntaxErrorMessage("1.1 = 1", "SyntaxError: can't assign to literal");
+    }
+
+    @Test
+    public void assignToLiteral03() throws Exception {
+        checkSyntaxErrorMessage("'' = 1", "SyntaxError: can't assign to literal");
+    }
+
+    @Test
+    public void assignToLiteral04() throws Exception {
+        checkSyntaxErrorMessage("f'' = 1", "SyntaxError: can't assign to literal");
+    }
+
+    @Test
+    public void assignToLiteral05() throws Exception {
+        checkSyntaxErrorMessage("'' f'' = 1", "SyntaxError: can't assign to literal");
+    }
+
+    @Test
+    public void assignToKeyword01() throws Exception {
+        checkSyntaxErrorMessage("True = 1", "SyntaxError: can't assign to keyword");
+    }
 }

graalpython/com.oracle.graal.python.test/src/com/oracle/graal/python/test/parser/ParserTestBase.java

@@ -59,6 +59,7 @@
 import java.nio.CharBuffer;
 import java.util.Arrays;
 import java.util.List;
+import org.junit.Assert;
 import static org.junit.Assert.assertTrue;
 import org.junit.Rule;
 import org.junit.rules.TestName;
@@ -146,6 +147,18 @@ public void checkSyntaxError(String source) throws Exception {
         assertTrue("Expected SyntaxError was not thrown.", thrown);
     }
 
+    public void checkSyntaxErrorMessage(String source, String expectedMessage) throws Exception {
+        boolean thrown = false;
+        try {
+            parseNew(source, name.getMethodName(), PythonParser.ParserMode.File);
+        } catch (PException e) {
+            thrown = e.isSyntaxError();
+            Assert.assertEquals(expectedMessage, e.getMessage());
+        }
+
+        assertTrue("Expected SyntaxError was not thrown.", thrown);
+    }
+
     public void saveNewTreeResult(File testFile, boolean goldenFileNextToTestFile) throws Exception {
         assertTrue("The test files " + testFile.getAbsolutePath() + " was not found.", testFile.exists());
         TruffleFile src = context.getEnv().getInternalTruffleFile(testFile.getAbsolutePath());

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/Python3Core.java

@@ -671,7 +671,7 @@ public SourceSection getSourceSection() {
         instance.setAttribute("text", section.isAvailable() ? source.getCharacters(section.getStartLine()) : "");
         instance.setAttribute("lineno", section.getStartLine());
         instance.setAttribute("offset", section.getStartColumn());
-        instance.setAttribute("msg", section.getCharIndex() == source.getLength() ? "unexpected EOF while parsing" : "invalid syntax");
+        instance.setAttribute("msg", section.getCharIndex() == source.getLength() ? "unexpected EOF while parsing" : message != null ? message : "invalid syntax");
         throw PException.fromObject(instance, location);
     }
 }

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/parser/sst/FactorySSTVisitor.java

@@ -218,7 +218,13 @@ public PNode visit(AssertSSTNode node) {
     public PNode visit(AssignmentSSTNode node) {
         ExpressionNode[] lhs = new ExpressionNode[node.lhs.length];
         for (int i = 0; i < node.lhs.length; i++) {
-            lhs[i] = (ExpressionNode) node.lhs[i].accept(this);
+            SSTNode sstLhs = node.lhs[i];
+            if (sstLhs instanceof StringLiteralSSTNode || sstLhs instanceof NumberLiteralSSTNode || sstLhs instanceof FloatLiteralSSTNode) {
+                errors.raiseInvalidSyntax(source, createSourceSection(node.startOffset, node.endOffset), "can't assign to literal");
+            } else if (sstLhs instanceof BooleanLiteralSSTNode) {
+                errors.raiseInvalidSyntax(source, createSourceSection(node.startOffset, node.endOffset), "can't assign to keyword");
+            }
+            lhs[i] = (ExpressionNode) sstLhs.accept(this);
         }
         ExpressionNode rhs = (ExpressionNode) node.rhs.accept(this);