SQL: Relax StackOverflow circuit breaker for constants (#38572)

Constant numbers (of any form: integers, decimals, negatives,
scientific) and strings shouldn't increase the depth counters
as they don't contribute to the increment of the stack depth.

Fixes: #38571

Author: matriv

x-pack/plugin/sql/src/main/java/org/elasticsearch/xpack/sql/parser/SqlParser.java

@@ -36,8 +36,6 @@
 import org.elasticsearch.xpack.sql.parser.SqlBaseParser.StatementContext;
 import org.elasticsearch.xpack.sql.parser.SqlBaseParser.StatementDefaultContext;
 import org.elasticsearch.xpack.sql.parser.SqlBaseParser.UnquoteIdentifierContext;
-import org.elasticsearch.xpack.sql.parser.SqlBaseParser.ValueExpressionContext;
-import org.elasticsearch.xpack.sql.parser.SqlBaseParser.ValueExpressionDefaultContext;
 import org.elasticsearch.xpack.sql.plan.logical.LogicalPlan;
 import org.elasticsearch.xpack.sql.proto.SqlTypedParamValue;
 
@@ -241,7 +239,6 @@ static class CircuitBreakerListener extends SqlBaseBaseListener {
             ENTER_EXIT_RULE_MAPPING.put(StatementDefaultContext.class.getSimpleName(), StatementContext.class.getSimpleName());
             ENTER_EXIT_RULE_MAPPING.put(QueryPrimaryDefaultContext.class.getSimpleName(), QueryTermContext.class.getSimpleName());
             ENTER_EXIT_RULE_MAPPING.put(BooleanDefaultContext.class.getSimpleName(), BooleanExpressionContext.class.getSimpleName());
-            ENTER_EXIT_RULE_MAPPING.put(ValueExpressionDefaultContext.class.getSimpleName(), ValueExpressionContext.class.getSimpleName());
         }
 
         private boolean insideIn = false;
@@ -264,6 +261,9 @@ public void enterEveryRule(ParserRuleContext ctx) {
             if (ctx.getClass() != UnquoteIdentifierContext.class &&
                 ctx.getClass() != QuoteIdentifierContext.class &&
                 ctx.getClass() != BackQuotedIdentifierContext.class &&
+                ctx.getClass() != SqlBaseParser.ConstantContext.class &&
+                ctx.getClass() != SqlBaseParser.NumberContext.class &&
+                ctx.getClass() != SqlBaseParser.ValueExpressionContext.class &&
                 (insideIn == false || ctx.getClass() != PrimaryExpressionContext.class)) {
 
                 int currentDepth = depthCounts.putOrAdd(ctx.getClass().getSimpleName(), (short) 1, (short) 1);

x-pack/plugin/sql/src/test/java/org/elasticsearch/xpack/sql/parser/SqlParserTests.java

@@ -287,9 +287,18 @@ public void testLimitToPreventStackOverflowFromLargeComplexSubselectTree() {
     }
 
     public void testLimitStackOverflowForInAndLiteralsIsNotApplied() {
-        int noChildren = 100_000;
+        int noChildren = 10_000;
         LogicalPlan plan = parseStatement("SELECT * FROM t WHERE a IN(" +
-            Joiner.on(",").join(nCopies(noChildren, "a + b")) + ")");
+            Joiner.on(",").join(nCopies(noChildren, "a + 10")) + "," +
+            Joiner.on(",").join(nCopies(noChildren, "-(-a - 10)")) + "," +
+            Joiner.on(",").join(nCopies(noChildren, "20")) + "," +
+            Joiner.on(",").join(nCopies(noChildren, "-20")) + "," +
+            Joiner.on(",").join(nCopies(noChildren, "20.1234")) + "," +
+            Joiner.on(",").join(nCopies(noChildren, "-20.4321")) + "," +
+            Joiner.on(",").join(nCopies(noChildren, "1.1234E56")) + "," +
+            Joiner.on(",").join(nCopies(noChildren, "-1.4321E-65")) + "," +
+            Joiner.on(",").join(nCopies(noChildren, "'foo'")) + "," +
+            Joiner.on(",").join(nCopies(noChildren, "'bar'")) + ")");
 
         assertEquals(With.class, plan.getClass());
         assertEquals(Project.class, ((With) plan).child().getClass());
@@ -298,8 +307,17 @@ public void testLimitStackOverflowForInAndLiteralsIsNotApplied() {
         assertEquals(In.class, filter.condition().getClass());
         In in = (In) filter.condition();
         assertEquals("?a", in.value().toString());
-        assertEquals(noChildren, in.list().size());
-        assertThat(in.list().get(0).toString(), startsWith("(a) + (b)#"));
+        assertEquals(noChildren * 2 + 8, in.list().size());
+        assertThat(in.list().get(0).toString(), startsWith("(a) + 10#"));
+        assertThat(in.list().get(noChildren).toString(), startsWith("-(-?a) - 10#"));
+        assertEquals("20", in.list().get(noChildren * 2).toString());
+        assertEquals("-20", in.list().get(noChildren * 2 + 1).toString());
+        assertEquals("20.1234", in.list().get(noChildren * 2 + 2).toString());
+        assertEquals("-20.4321", in.list().get(noChildren * 2 + 3).toString());
+        assertEquals("1.1234E56", in.list().get(noChildren * 2 + 4).toString());
+        assertEquals("-1.4321E-65", in.list().get(noChildren * 2 + 5).toString());
+        assertEquals("foo", in.list().get(noChildren * 2 + 6).toString());
+        assertEquals("bar", in.list().get(noChildren * 2 + 7).toString());
     }
 
     public void testDecrementOfDepthCounter() {