From 8bae779bb85df2175a47b148dbb2f10ce7d6f03a Mon Sep 17 00:00:00 2001
From: Robert O'Callahan <rocallahan@google.com>
Date: Fri, 29 Aug 2025 04:34:41 +0000
Subject: [PATCH] Fix Const::const_iterator tag to be
 bidirectional_iterator_tag

---
 kernel/rtlil.cc |  6 +++---
 kernel/rtlil.h  | 10 +++++-----
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/kernel/rtlil.cc b/kernel/rtlil.cc
index 0250346d1..fc007c3bf 100644
--- a/kernel/rtlil.cc
+++ b/kernel/rtlil.cc
@@ -579,11 +579,11 @@ void RTLIL::Const::append(const RTLIL::Const &other) {
 }
 
 RTLIL::State RTLIL::Const::const_iterator::operator*() const {
-	if (auto bv = parent.get_if_bits())
+	if (auto bv = parent->get_if_bits())
 		return (*bv)[idx];
 
-	int char_idx = parent.get_str().size() - idx / 8 - 1;
-	bool bit = (parent.get_str()[char_idx] & (1 << (idx % 8)));
+	int char_idx = parent->get_str().size() - idx / 8 - 1;
+	bool bit = (parent->get_str()[char_idx] & (1 << (idx % 8)));
 	return bit ? State::S1 : State::S0;
 }
 
diff --git a/kernel/rtlil.h b/kernel/rtlil.h
index e36558359..f2279645e 100644
--- a/kernel/rtlil.h
+++ b/kernel/rtlil.h
@@ -789,17 +789,17 @@ public:
 
 	class const_iterator {
 	private:
-		const Const& parent;
+		const Const* parent;
 		size_t idx;
 
 	public:
-		using iterator_category = std::input_iterator_tag;
+		using iterator_category = std::bidirectional_iterator_tag;
 		using value_type = State;
 		using difference_type = std::ptrdiff_t;
 		using pointer = const State*;
 		using reference = const State&;
 
-		const_iterator(const Const& c, size_t i) : parent(c), idx(i) {}
+		const_iterator(const Const& c, size_t i) : parent(&c), idx(i) {}
 
 		State operator*() const;
 
@@ -810,10 +810,10 @@ public:
 		const_iterator& operator+=(int i) { idx += i; return *this; }
 
 		const_iterator operator+(int add) {
-			return const_iterator(parent, idx + add);
+			return const_iterator(*parent, idx + add);
 		}
 		const_iterator operator-(int sub) {
-			return const_iterator(parent, idx - sub);
+			return const_iterator(*parent, idx - sub);
 		}
 		int operator-(const const_iterator& other) {
 			return idx - other.idx;