From 7775d2806fe082626103f5abffd95fe9e1fccc27 Mon Sep 17 00:00:00 2001
From: Clifford Wolf <clifford@clifford.at>
Date: Thu, 11 Dec 2014 21:46:36 +0100
Subject: [PATCH] Added IdString::destruct_guard hack

---
 kernel/rtlil.cc |  1 +
 kernel/rtlil.h  | 13 +++++++++++++
 2 files changed, 14 insertions(+)

diff --git a/kernel/rtlil.cc b/kernel/rtlil.cc
index f5dbafe16..5c010dabf 100644
--- a/kernel/rtlil.cc
+++ b/kernel/rtlil.cc
@@ -27,6 +27,7 @@
 
 YOSYS_NAMESPACE_BEGIN
 
+RTLIL::IdString::destruct_guard_t RTLIL::IdString::destruct_guard;
 std::vector<int> RTLIL::IdString::global_refcount_storage_;
 std::vector<char*> RTLIL::IdString::global_id_storage_;
 std::map<char*, int, RTLIL::IdString::char_ptr_cmp> RTLIL::IdString::global_id_index_;
diff --git a/kernel/rtlil.h b/kernel/rtlil.h
index 0157f3b7c..29fa90692 100644
--- a/kernel/rtlil.h
+++ b/kernel/rtlil.h
@@ -85,6 +85,12 @@ namespace RTLIL
 			}
 		};
 
+		static struct destruct_guard_t {
+			bool ok = false;
+			destruct_guard_t() { ok = true; }
+			~destruct_guard_t() { ok = false; }
+		} destruct_guard;
+
 		static std::vector<int> global_refcount_storage_;
 		static std::vector<char*> global_id_storage_;
 		static std::map<char*, int, char_ptr_cmp> global_id_index_;
@@ -98,6 +104,8 @@ namespace RTLIL
 
 		static inline int get_reference(const char *p)
 		{
+			log_assert(destruct_guard.ok);
+
 			if (p[0]) {
 				log_assert(p[1] != 0);
 				log_assert(p[0] == '$' || p[0] == '\\');
@@ -126,6 +134,11 @@ namespace RTLIL
 
 		static inline void put_reference(int idx)
 		{
+			// put_reference() may be called from destructors after the destructor of
+			// global_refcount_storage_ has been run. in this case we simply do nothing.
+			if (!destruct_guard.ok)
+				return;
+
 			log_assert(global_refcount_storage_.at(idx) > 0);
 
 			if (--global_refcount_storage_.at(idx) != 0)
-- 
2.30.2