Disable creation of new variables after creation of the objective function

This can reveal bugs in constraints that accidentally include Ti.

2 files changed, 14 insertions, 1 deletions

diff --git a/native/include/lp_common.h b/native/include/lp_common.h
index 16aad8a..f5b49d9 100644
--- a/native/include/lp_common.h
+++ b/native/include/lp_common.h
@@ -23,10 +23,12 @@ class VarMapper {
 private:
         hashmap<uint64_t, unsigned int> map;
         unsigned int next_var;
+        bool sealed;
 
         void insert(uint64_t key)
         {
                 assert(next_var < UINT_MAX);
+                assert(!sealed);
 
                 unsigned int idx = next_var++;
                 map[key] = idx;
@@ -45,7 +47,7 @@ private:
 
 public:
         VarMapper(unsigned int start_var = 0)
-                : next_var(start_var)
+                : next_var(start_var), sealed(false)
         {}
 
         unsigned int lookup(unsigned int task_id, unsigned int res_id, unsigned int req_id,
@@ -57,6 +59,12 @@ public:
                 return map[key];
         }
 
+        // stop new IDs from being generated
+        void seal()
+        {
+                sealed = true;
+        }
+
         void clear()
         {
                 map.clear();
diff --git a/native/src/blocking/linprog/lp_common.cpp b/native/src/blocking/linprog/lp_common.cpp
index 808ff28..eca5cc2 100644
--- a/native/src/blocking/linprog/lp_common.cpp
+++ b/native/src/blocking/linprog/lp_common.cpp
@@ -59,6 +59,11 @@ void set_blocking_objective(
                         }
                 }
         }
+#ifndef CONFIG_MERGED_LINPROGS
+        // We have enumerated all relevant variables. Do not allow any more to
+        // be created.
+        vars.seal();
+#endif
 }
 
 // Constraint 1 in [Brandenburg 2013]