generator: include first-check for rules with non-external predicates

JetBrains · May 18, 2018 · 51f18c8 · 51f18c8
1 parent a2227fd
commit 51f18c8
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Showing 2 changed files with 14 additions and 8 deletions.
diff --git a/src/org/intellij/grammar/analysis/BnfFirstNextAnalyzer.java b/src/org/intellij/grammar/analysis/BnfFirstNextAnalyzer.java
@@ -304,7 +304,7 @@ else if (expression instanceof BnfPredicate) {
       Set<BnfExpression> conditions = calcFirstInner(predicateExpression, newExprSet(), visited, null);
       Set<BnfExpression> next;
       List<BnfExpression> externalCond = Collections.emptyList();
-      List<BnfExpression> externalNext;
+      List<BnfExpression> externalNext = Collections.emptyList();
       if (!visited.add(predicateExpression)) {
         skip = true;
         next = Collections.emptySet();
@@ -320,7 +320,7 @@ else if (expression instanceof BnfPredicate) {
         visited.remove(predicateExpression);
         externalCond = filterExternalMethods(conditions);
         externalNext = filterExternalMethods(next);
-        if (!skip) skip = !externalNext.isEmpty() || !externalCond.isEmpty();
+        if (!skip) skip = !externalCond.isEmpty();
       }
       Set<BnfExpression> mixed = newExprSet();
       if (elementType == BnfTypes.BNF_OP_AND) {
@@ -337,10 +337,15 @@ else if (!conditions.contains(BNF_MATCHES_EOF)) {
             mixed.addAll(conditions);
           }
           else {
-            mixed.addAll(next);
-            mixed.retainAll(conditions);
-            if (mixed.isEmpty() && !involvesTextMatching(conditions)) {
-              mixed.add(BNF_MATCHES_NOTHING);
+            if (externalNext.isEmpty()) {
+              mixed.addAll(next);
+              mixed.retainAll(conditions);
+              if (mixed.isEmpty() && !involvesTextMatching(conditions)) {
+                mixed.add(BNF_MATCHES_NOTHING);
+              }
+            }
+            else {
+              mixed.addAll(conditions);
             }
           }
         }

diff --git a/tests/org/intellij/grammar/BnfFirstNextTest.java b/tests/org/intellij/grammar/BnfFirstNextTest.java
@@ -42,8 +42,9 @@ protected void setUp() throws Exception {
   public void testAndOrNot2() { doFirstTest("r ::= Y? (!X | &X) X", "X", "Y"); }
   public void testNotOrNot3() { doFirstTest("r ::= Y? (!X | !X) X", MATCHES_NOTHING, "Y"); }
   public void testNotText() { doFirstTest("r ::= !'a' s external s ::= parseA", "#parseA"); }
-  public void testAndText() { doFirstTest("r ::= &'a' s external s ::= parseA", "#parseA"); }
-  public void testAndExternal() { doFirstTest("r ::= &A s external s ::= parseA", "#parseA"); }
+  public void testAndText() { doFirstTest("r ::= &'a' s external s ::= parseA", "'a'"); }
+  public void testAndExternal() { doFirstTest("r ::= &A s external s ::= parseA", "A"); }
+  public void testAndExternalPredicate() { doFirstTest("r ::= &p s external s ::= parseA external p ::= parseB", "#parseA", "#parseB"); }
   public void testNotSeqTrivial() { doFirstTest("r ::= !(X) (X Z)", MATCHES_NOTHING); }
   public void testNotSeq() { doFirstTest("r ::= !(X Y) (X Z)", "X"); }
   public void testAndSeq() { doFirstTest("r ::= (&(X | Y) | !X) X", "X"); }