Throw a static error when lvalue of an augmented assignment is a list.
RELNOTES:
When the lvalue of an augmented assignment is a list, we now throw an error
before evaluating the code (e.g. `a, b += 2, 3`).
PiperOrigin-RevId: 165906611
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/ValidationEnvironment.java b/src/main/java/com/google/devtools/build/lib/syntax/ValidationEnvironment.java
index 4415a85..6f5eb9c 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/ValidationEnvironment.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/ValidationEnvironment.java
@@ -158,6 +158,16 @@
super.visit(node);
}
+ @Override
+ public void visit(AugmentedAssignmentStatement node) {
+ if (node.getLValue().getExpression() instanceof ListLiteral) {
+ throw new ValidationException(
+ node.getLocation(), "cannot perform augmented assignment on a list or tuple expression");
+ }
+ // Other bad cases are handled when visiting the LValue node.
+ super.visit(node);
+ }
+
/** Returns true if the current block is the top level i.e. has no parent. */
private boolean isTopLevel() {
return block.parent == null;
diff --git a/src/test/java/com/google/devtools/build/lib/syntax/SkylarkEvaluationTest.java b/src/test/java/com/google/devtools/build/lib/syntax/SkylarkEvaluationTest.java
index 374ac78..bd43adb 100644
--- a/src/test/java/com/google/devtools/build/lib/syntax/SkylarkEvaluationTest.java
+++ b/src/test/java/com/google/devtools/build/lib/syntax/SkylarkEvaluationTest.java
@@ -964,7 +964,8 @@
@Test
public void testInvalidAugmentedAssignment_ListLiteral() throws Exception {
- new SkylarkTest().testIfErrorContains("cannot perform augmented assignment on a list literal",
+ new SkylarkTest().testIfErrorContains(
+ "cannot perform augmented assignment on a list or tuple expression",
"def f(a, b):",
" [a, b] += []",
"f(1, 2)");
diff --git a/src/test/java/com/google/devtools/build/lib/syntax/ValidationTest.java b/src/test/java/com/google/devtools/build/lib/syntax/ValidationTest.java
index 014d3be..604c53f 100644
--- a/src/test/java/com/google/devtools/build/lib/syntax/ValidationTest.java
+++ b/src/test/java/com/google/devtools/build/lib/syntax/ValidationTest.java
@@ -39,6 +39,11 @@
}
@Test
+ public void testAugmentedAssignmentWithMultipleLValues() {
+ checkError("cannot perform augmented assignment on a list or tuple expression", "a, b += 2, 3");
+ }
+
+ @Test
public void testReturnOutsideFunction() throws Exception {
checkError("Return statements must be inside a function", "return 2\n");
}
