commit 1fcea38b3a838de6cad23c83c892a1ce2d1272f5
author laurentlb <laurentlb@google.com> Mon Jun 19 16:02:42 2017 +0200
committer Philipp Wollermann <philwo@google.com> Mon Jun 19 18:25:15 2017 +0200
tree 45d75eb067129011332acf7e2b4c1dd71bdfa9b5
parent 77c9f5ec751f4adf3a8095e2e2943ec59dc12d26

Make equality, comparison and 'in' operators not associative.

I'm not using a --incompatible-change flag because it's not available in the
parser. We could pass it, but I think this is trivial to fix and unlikely to
happen in real code (if it does, there was most likely a bug).

RELNOTES[INC]:
  Operators for equality, comparison, 'in' and 'not in' are no longer associative,
  e.g.  x < y < z  is now a syntax error. Before, it was parsed as:  (x < y) < z.

PiperOrigin-RevId: 159422042

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

diff --git a/src/test/java/com/google/devtools/build/lib/syntax/ParserTest.java b/src/test/java/com/google/devtools/build/lib/syntax/ParserTest.java
index b5eedb2..20a7084 100644
--- a/src/test/java/com/google/devtools/build/lib/syntax/ParserTest.java
+++ b/src/test/java/com/google/devtools/build/lib/syntax/ParserTest.java
@@ -120,6 +120,35 @@
   }
 
   @Test
+  public void testNonAssociativeOperators() throws Exception {
+    setFailFast(false);
+
+    parseExpression("0 < 2 < 4");
+    assertContainsError("Operator '<' is not associative with operator '<'");
+    clearEvents();
+
+    parseExpression("0 == 2 < 4");
+    assertContainsError("Operator '==' is not associative with operator '<'");
+    clearEvents();
+
+    parseExpression("1 in [1, 2] == True");
+    assertContainsError("Operator 'in' is not associative with operator '=='");
+    clearEvents();
+
+    parseExpression("1 >= 2 <= 3");
+    assertContainsError("Operator '>=' is not associative with operator '<='");
+    clearEvents();
+  }
+
+  @Test
+  public void testNonAssociativeOperatorsWithParens() throws Exception {
+    parseExpression("(0 < 2) < 4");
+    parseExpression("(0 == 2) < 4");
+    parseExpression("(1 in [1, 2]) == True");
+    parseExpression("1 >= (2 <= 3)");
+  }
+
+  @Test
   public void testUnaryMinusExpr() throws Exception {
     FuncallExpression e = (FuncallExpression) parseExpression("-5");
     FuncallExpression e2 = (FuncallExpression) parseExpression("- 5");