Split nextpnr.h to allow for linear inclusion.

"nextpnr.h" is no longer the god header.  Important improvements:

 - Functions in log.h can be used without including
   BaseCtx/Arch/Context. This means that log_X functions can be called
   without included "nextpnr.h"

 - NPNR_ASSERT can be used without including "nextpnr.h" by including
   "nextpnr_assertions.h".  This allows NPNR_ASSERT to be used safely in
   any header file.

 - Types defined in "archdefs.h" are now available without including
   BaseCtx/Arch/Context.  This means that utility classes that will be
   used inside of BaseCtx/Arch/Context can be defined safely in a
   self-contained header.

Signed-off-by: Keith Rothman <537074+litghost@users.noreply.github.com>

1 files changed, 34 insertions, 0 deletions

diff --git a/common/str_ring_buffer.cc b/common/str_ring_buffer.cc
new file mode 100644
index 00000000..f5534296
--- /dev/null
+++ b/common/str_ring_buffer.cc
@@ -0,0 +1,34 @@
+/*
+ *  nextpnr -- Next Generation Place and Route
+ *
+ *  Copyright (C) 2018  Clifford Wolf <clifford@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.
+ *
+ */
+
+#include "str_ring_buffer.h"
+
+#include "nextpnr_namespaces.h"
+
+NEXTPNR_NAMESPACE_BEGIN
+
+std::string &StrRingBuffer::next()
+{
+    std::string &s = buffer.at(index++);
+    if (index >= N)
+        index = 0;
+    return s;
+}
+
+NEXTPNR_NAMESPACE_END