Account for multi-dfa case with ANCHORED_DELAY

Specifically, we must set build_context::floatingMinLiteralMatchOffset
to 1 when thew anchored table contains multiple DFAs, as they can
produce unordered matches.

This check was already been done, but too late to affect the generation
of ANCHORED_DELAY instructions.

src/rose/rose_build_anchored.cpp

@@ -235,13 +235,9 @@ u32 anchoredStateSize(const anchored_matcher_info *atable) {
     return curr->state_offset + nfa->scratchStateSize;
 }
 
-bool anchoredIsMulti(const RoseEngine &engine) {
+bool anchoredIsMulti(const anchored_matcher_info *atable) {
-    const struct anchored_matcher_info *curr
+    return atable && atable->next_offset;
-        = (const anchored_matcher_info *)getALiteralMatcher(&engine);
+}
-
-    return curr && curr->next_offset;
- }
-
 
 namespace {
 

src/rose/rose_build_anchored.h

@@ -51,7 +51,12 @@ aligned_unique_ptr<anchored_matcher_info>
 buildAnchoredAutomataMatcher(RoseBuildImpl &build, size_t *asize);
 
 u32 anchoredStateSize(const anchored_matcher_info *atable);
-bool anchoredIsMulti(const RoseEngine &engine);
+
+/**
+ * \brief True if there is an anchored matcher and it consists of multiple
+ * DFAs.
+ */
+bool anchoredIsMulti(const anchored_matcher_info *atable);
 
 #define ANCHORED_FAIL    0
 #define ANCHORED_SUCCESS 1

src/rose/rose_build_bytecode.cpp

@@ -2243,7 +2243,15 @@ void enforceEngineSizeLimit(const NFA *n, const size_t nfa_size, const Grey &gre
 }
 
 static
-u32 findMinFloatingLiteralMatch(const RoseBuildImpl &build) {
+u32 findMinFloatingLiteralMatch(const RoseBuildImpl &build,
+                                const anchored_matcher_info *atable) {
+    if (anchoredIsMulti(atable)) {
+        DEBUG_PRINTF("multiple anchored dfas\n");
+        /* We must regard matches from other anchored tables as unordered, as
+         * we do for floating matches. */
+        return 1;
+    }
+
     const RoseGraph &g = build.g;
     u32 minWidth = ROSE_BOUND_INF;
     for (auto v : vertices_range(g)) {
@@ -4036,7 +4044,8 @@ aligned_unique_ptr<RoseEngine> RoseBuildImpl::buildFinalEngine(u32 minWidth) {
     aligned_unique_ptr<HWLM> sbtable = buildSmallBlockMatcher(*this, &sbsize);
 
     build_context bc;
-    bc.floatingMinLiteralMatchOffset = findMinFloatingLiteralMatch(*this);
+    bc.floatingMinLiteralMatchOffset =
+        findMinFloatingLiteralMatch(*this, atable.get());
 
     // Build NFAs
     set<u32> no_retrigger_queues;
@@ -4363,12 +4372,8 @@ aligned_unique_ptr<RoseEngine> RoseBuildImpl::buildFinalEngine(u32 minWidth) {
     write_out(&engine->state_init, (char *)engine.get(), state_scatter,
               state_scatter_aux_offset);
 
-    if (anchoredIsMulti(*engine)) {
+    if (anchoredIsMulti(atable.get())) {
-        DEBUG_PRINTF("multiple anchored dfas\n");
         engine->maxSafeAnchoredDROffset = 1;
-        engine->floatingMinLiteralMatchOffset = 1; /* regard matches from other
-                                                      anchored tables as
-                                                      floating as unordered. */
     } else {
         /* overly conservative, really need the min offset of non dr anchored
            matches */