fix: emit missing DFA_UNROLLED helpers in APT matchers

AGENTS.md

@@ -88,6 +88,8 @@ the repo carries only the distilled knowledge. Use it instead of re-deriving:
 
 
 
+
+
 
 
 

reggie-codegen/src/main/java/com/datadoghq/reggie/codegen/codegen/DFAUnrolledBytecodeGenerator.java

@@ -1718,9 +1718,13 @@ private void generateFindMatchFromMethodTagged(ClassWriter cw, String className)
    * Generates a private {@code findMatchFromForMatch} variant that uses the tagged DFA WITHOUT
    * priority-cut. Used by {@link #generateMatchMethod} for full-input (match()) semantics: the
    * caller must verify that the returned match spans the entire input, but the TDFA must not commit
-   * early to a shorter high-priority prefix match.
+   * early to a shorter high-priority prefix match. No-op unless the tagged DFA is used with groups
+   * (the only case where {@link #generateMatchMethod} calls it).
    */
   public void generateFindMatchFromMethodTaggedNoCut(ClassWriter cw, String className) {
+    if (!(useTaggedDFA && groupCount > 0)) {
+      return;
+    }
     this.ownerInternalName = className;
     generateFindMatchFromMethodTaggedImpl(
         cw, className, "findMatchFromForMatch", ACC_PRIVATE, false);

reggie-processor/src/main/java/com/datadoghq/reggie/processor/ReggieMatcherBytecodeGenerator.java

@@ -459,6 +459,9 @@ public byte[] generate() throws Exception {
         unrolledGen.generateFindFromMethod(cw, getJavaClassName());
         unrolledGen.generateMatchesAtStartMethod(cw);
         unrolledGen.generateMatchMethod(cw, getJavaClassName());
+        // Private findMatchFromForMatch helper called by tagged match() (same as RuntimeCompiler);
+        // no-op for non-tagged DFAs
+        unrolledGen.generateFindMatchFromMethodTaggedNoCut(cw, getJavaClassName());
         unrolledGen.generateMatchesBoundedMethod(cw, getJavaClassName());
         unrolledGen.generateMatchBoundedMethod(cw, getJavaClassName());
         unrolledGen.generateFindMatchMethod(cw, getJavaClassName());
@@ -468,6 +471,9 @@ public byte[] generate() throws Exception {
         // findAll/replaceAll/split use throws NoSuchMethodError
         unrolledGen.generateFindLongestMatchEndMethod(cw, getJavaClassName());
         unrolledGen.generateFindBoundsFromMethod(cw, getJavaClassName());
+        // Static lookup tables for range-heavy charsets referenced by the methods above (same as
+        // RuntimeCompiler); must follow every generate*Method. No-op when none were needed.
+        unrolledGen.generateLookupTables(cw);
         break;
 
       case DFA_SWITCH:

reggie-processor/src/test/java/com/datadoghq/reggie/processor/ReggieMatcherBytecodeGeneratorTest.java

@@ -17,6 +17,7 @@
 
 import static org.junit.jupiter.api.Assertions.*;
 
+import com.datadoghq.reggie.runtime.MatchResult;
 import com.datadoghq.reggie.runtime.ReggieMatcher;
 import java.lang.reflect.Method;
 import org.junit.jupiter.api.Test;
@@ -595,6 +596,36 @@ void twoProviderClassesWithSameMethodNameProduceDistinctMatchers() throws Except
         (Boolean) matchesB.invoke(matcherB, "123"), "ProviderB_ValueMatcher must not match digits");
   }
 
+  /**
+   * Tagged DFA_UNROLLED match() calls the private {@code findMatchFromForMatch} helper; the APT
+   * path must emit it (as RuntimeCompiler does) or match() throws NoSuchMethodError.
+   */
+  @Test
+  void taggedDfaUnrolledMatchHelperIsGenerated() throws Exception {
+    Object matcher = compile("(?i)^https?://", "TaggedUnrolledMatchMatcher");
+    Method match = matcher.getClass().getMethod("match", String.class);
+
+    Object result = match.invoke(matcher, "https://");
+    assertNotNull(result);
+    assertEquals(8, ((MatchResult) result).end());
+    assertNotNull(match.invoke(matcher, "http://"));
+    assertNull(match.invoke(matcher, "https://example.com"));
+    assertNull(match.invoke(matcher, "ftp://"));
+  }
+
+  /**
+   * DFA_UNROLLED matches range-heavy charsets through static {@code $cs_N} lookup tables; the APT
+   * path must emit them (as RuntimeCompiler does) or matching throws NoSuchFieldError.
+   */
+  @Test
+  void dfaUnrolledLookupTablesAreGenerated() throws Exception {
+    Object matcher = compile(".*[\\p{IsAlphabetic}].*", "HugeCharsetMatcher");
+    Method matches = matcher.getClass().getMethod("matches", String.class);
+    assertTrue((Boolean) matches.invoke(matcher, "a1"));
+    assertTrue((Boolean) matches.invoke(matcher, "1\u00e9"));
+    assertFalse((Boolean) matches.invoke(matcher, "123"));
+  }
+
   // --- Tests for Fix 1: resolveRealization() must honour needsFallback() for PIKEVM_CAPTURE ---
 
   @Test