BuildFileAST.eval() doesn't execute the code when there's a static er…

…ror.

This has no visible effect on Bazel (eval is used just for internal
expressions that don't fail), and is therefore not tested.

It will be tested when we add tests to the standalone Skylark interpreter.

--
PiperOrigin-RevId: 147495990
MOS_MIGRATED_REVID=147495990

src/main/java/com/google/devtools/build/lib/syntax/BuildFileAST.java

@@ -339,11 +339,17 @@ public static boolean checkSyntax(ParserInputSource input, EventHandler eventHan
     return last;
   }
 
+  /**
+   * Evaluates the lines from input and return the value of the last statement if it's an
+   * Expression or else null. In case of error (either during validation or evaluation), it
+   * throws an EvalException.
+   */
+  @Nullable
   public static Object eval(Environment env, String... input)
       throws EvalException, InterruptedException {
     BuildFileAST ast = parseSkylarkString(env.getEventHandler(), input);
     ValidationEnvironment valid = new ValidationEnvironment(env);
-    valid.validateAst(ast.getStatements(), env.getEventHandler());
+    valid.validateAst(ast.getStatements());
     return ast.eval(env);
   }
 

src/test/java/com/google/devtools/build/lib/syntax/EnvironmentTest.java

@@ -298,8 +298,8 @@ public void testReadOnly() throws Exception {
     try {
       BuildFileAST.eval(env, "special_var = 41");
       throw new AssertionError("failed to fail");
-    } catch (IllegalArgumentException e) {
-      assertThat(e.getMessage()).contains("ERROR 1:1: Variable special_var is read only");
+    } catch (EvalException e) {
+      assertThat(e.getMessage()).contains("Variable special_var is read only");
     }
 
     try {

src/test/java/com/google/devtools/build/lib/syntax/EvaluationTest.java

@@ -477,8 +477,9 @@ public void testRecursiveTupleDestructuring() throws Exception {
 
   @Test
   public void testListComprehensionModifiesGlobalEnv() throws Exception {
-    new SkylarkTest().update("x", 42).testIfErrorContains("ERROR 1:1: Variable x is read only",
-        "[x + 1 for x in [1,2,3]]");
+    new SkylarkTest()
+        .update("x", 42)
+        .testIfErrorContains("Variable x is read only", "[x + 1 for x in [1,2,3]]");
     new BuildTest().update("x", 42).setUp("y =[x + 1 for x in [1,2,3]]")
         .testExactOrder("y", 2, 3, 4).testLookup("x", 3); // (x is global)
   }

src/test/java/com/google/devtools/build/lib/syntax/MethodLibraryTest.java

@@ -504,20 +504,14 @@ public void testBooleanUnsupportedOperationFails() throws Exception {
 
   @Test
   public void testPyStringJoin() throws Exception {
-    new BothModesTest().testStatement("'-'.join([ 'a', 'b', 'c' ])", "a-b-c");
+    new BothModesTest().testStatement("'-'.join(['a', 'b', 'c'])", "a-b-c");
   }
 
   @Test
   public void testPyStringGlobalJoin() throws Exception {
-    // TODO(bazel-team): BUILD and Skylark should use the same code path (and same error message).
-    new BuildTest()
-        .testIfErrorContains("name 'join' is not defined", "join(' ', [ 'a', 'b', 'c' ])");
-
-    new SkylarkTest()
-        .testIfErrorContains(
-            "ERROR 1:1: name 'join' is not defined", "join(' ', [ 'a', 'b', 'c' ])");
-
-    new BothModesTest().testStatement("' '.join([ 'a', 'b', 'c' ])", "a b c");
+    new BothModesTest()
+        .testIfErrorContains("name 'join' is not defined", "join(' ', ['a', 'b', 'c'])")
+        .testStatement("' '.join(['a', 'b', 'c'])", "a b c");
   }
 
   @Test

src/test/java/com/google/devtools/build/lib/syntax/SkylarkEvaluationTest.java

@@ -1230,9 +1230,7 @@ public void testListComprehensionsMultipleVariablesFail() throws Exception {
     // can't reuse the same local variable twice(!)
     new SkylarkTest()
         .testIfErrorContains(
-            "ERROR 2:1: Variable x is read only",
-            "[x + y for x, y in (1, 2)]",
-            "[x + y for x, y in (1, 2)]");
+            "Variable x is read only", "[x + y for x, y in (1, 2)]", "[x + y for x, y in (1, 2)]");
 
     new SkylarkTest()
         .testIfErrorContains("type 'int' is not a collection", "[x2 + y2 for x2, y2 in (1, 2)]");