From 648a3c48247ad9ba1ec0386843a9813a47436050 Mon Sep 17 00:00:00 2001
From: Alex Coyte <a.coyte@intel.com>
Date: Thu, 15 Sep 2016 11:22:29 +1000
Subject: [PATCH] UE-3025: There is no need to prune tops from non-triggered
 graphs

---
 src/nfagraph/ng_limex.cpp             | 3 +++
 src/rose/rose_build_role_aliasing.cpp | 8 ++++++++
 2 files changed, 11 insertions(+)

diff --git a/src/nfagraph/ng_limex.cpp b/src/nfagraph/ng_limex.cpp
index b9f3434b..c6e4c24e 100644
--- a/src/nfagraph/ng_limex.cpp
+++ b/src/nfagraph/ng_limex.cpp
@@ -512,6 +512,9 @@ u32 isImplementableNFA(const NGHolder &g, const ReportManager *rm,
     if (!cc.grey.allowLimExNFA) {
         return false;
     }
+
+    assert(!can_never_match(g));
+
     // Quick check: we can always implement an NFA with less than NFA_MAX_STATES
     // states. Note that top masks can generate extra states, so we account for
     // those here too.
diff --git a/src/rose/rose_build_role_aliasing.cpp b/src/rose/rose_build_role_aliasing.cpp
index 66e44b3e..6a0c767d 100644
--- a/src/rose/rose_build_role_aliasing.cpp
+++ b/src/rose/rose_build_role_aliasing.cpp
@@ -863,6 +863,12 @@ void pruneUnusedTops(CastleProto &castle, const RoseGraph &g,
 static
 void pruneUnusedTops(NGHolder &h, const RoseGraph &g,
                      const set<RoseVertex> &verts) {
+    if (!is_triggered(h)) {
+        DEBUG_PRINTF("not triggered, no tops\n");
+        return;
+    }
+    assert(isCorrectlyTopped(h));
+    DEBUG_PRINTF("prunning unused tops\n");
     ue2::flat_set<u32> used_tops;
     for (auto v : verts) {
         assert(g[v].left.graph.get() == &h);
@@ -2023,6 +2029,7 @@ void aliasRoles(RoseBuildImpl &build, bool mergeRoses) {
     const CompileContext &cc = build.cc;
     RoseGraph &g = build.g;
     assert(!hasOrphanedTops(build));
+    assert(canImplementGraphs(build));
 
     if (!cc.grey.roseRoleAliasing || !cc.grey.roseGraphReduction) {
         return;
@@ -2057,6 +2064,7 @@ void aliasRoles(RoseBuildImpl &build, bool mergeRoses) {
     DEBUG_PRINTF("killed %zu vertices\n", dead.size());
     build.removeVertices(dead);
     assert(!hasOrphanedTops(build));
+    assert(canImplementGraphs(build));
 }
 
 } // namespace ue2