1 files changed, 45 insertions, 0 deletions
diff --git a/common/str_ring_buffer.h b/common/str_ring_buffer.h
new file mode 100644
index 00000000..9a16fe14
--- /dev/null
+++ b/common/str_ring_buffer.h
@@ -0,0 +1,45 @@
+/*
+ *  nextpnr -- Next Generation Place and Route
+ *
+ *  Copyright (C) 2018  Clifford Wolf <clifford@symbioticeda.com>
+ *  Copyright (C) 2018  Serge Bazanski <q3k@symbioticeda.com>
+ *
+ *  Permission to use, copy, modify, and/or distribute this software for any
+ *  purpose with or without fee is hereby granted, provided that the above
+ *  copyright notice and this permission notice appear in all copies.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+#ifndef STR_RING_BUFFER_H
+#define STR_RING_BUFFER_H
+
+#include <array>
+#include <string>
+
+#include "nextpnr_namespaces.h"
+
+NEXTPNR_NAMESPACE_BEGIN
+
+// A ring buffer of strings, so we can return a simple const char * pointer for %s formatting - inspired by how logging
+// in Yosys works Let's just hope noone tries to log more than 100 things in one call....
+class StrRingBuffer
+{
+  private:
+    static const size_t N = 100;
+    std::array<std::string, N> buffer;
+    size_t index = 0;
+
+  public:
+    std::string &next();
+};
+
+NEXTPNR_NAMESPACE_END
+
+#endif /* STR_RING_BUFFER_H */