From b4851a6c7d07086dd170a8de8e963de88ebfcd30 Mon Sep 17 00:00:00 2001
From: James Cherry <cherry@parallaxsw.com>
Date: Wed, 11 Nov 2020 08:32:25 -0700
Subject: [PATCH] flex disable register decls

---
 CMakeLists.txt              | 3 +++
 liberty/LibertyExprLex.ll   | 1 +
 liberty/LibertyLex.ll       | 1 +
 parasitics/SpefLex.ll       | 1 +
 sdf/SdfLex.ll               | 1 +
 util/FlexDisableRegister.hh | 5 +++++
 verilog/VerilogLex.ll       | 1 +
 7 files changed, 13 insertions(+)
 create mode 100644 util/FlexDisableRegister.hh

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 25845d68..69243504 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -236,6 +236,9 @@ set(STA_TCL_FILES
 #
 ################################################################
 
+# Earlier versions of flex use 'register' declarations are deprecated in c++11
+# and  illegal in c++17.
+#find_package(FLEX 2.6.4)
 find_package(FLEX)
 find_package(BISON)
 
diff --git a/liberty/LibertyExprLex.ll b/liberty/LibertyExprLex.ll
index 9388620d..ab588a24 100644
--- a/liberty/LibertyExprLex.ll
+++ b/liberty/LibertyExprLex.ll
@@ -18,6 +18,7 @@
 
 // Liberty function expression lexical analyzer
 
+#include "util/FlexDisableRegister.hh"
 #include "Debug.hh"
 #include "StringUtil.hh"
 #include "liberty/LibertyExprPvt.hh"
diff --git a/liberty/LibertyLex.ll b/liberty/LibertyLex.ll
index a2cc0373..092aafb7 100644
--- a/liberty/LibertyLex.ll
+++ b/liberty/LibertyLex.ll
@@ -18,6 +18,7 @@
 #include <ctype.h>
 #include <string.h>
 
+#include "util/FlexDisableRegister.hh"
 #include "liberty/LibertyParser.hh"
 #include "LibertyParse.hh"
 
diff --git a/parasitics/SpefLex.ll b/parasitics/SpefLex.ll
index 3c64a848..1bfbc115 100644
--- a/parasitics/SpefLex.ll
+++ b/parasitics/SpefLex.ll
@@ -19,6 +19,7 @@
 #include <string.h>
 #include <string>
 
+#include "util/FlexDisableRegister.hh"
 #include "StringUtil.hh"
 #include "parasitics/SpefReaderPvt.hh"
 #include "SpefParse.hh"
diff --git a/sdf/SdfLex.ll b/sdf/SdfLex.ll
index 14b9876a..e893af61 100644
--- a/sdf/SdfLex.ll
+++ b/sdf/SdfLex.ll
@@ -16,6 +16,7 @@
 // You should have received a copy of the GNU General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
+#include "util/FlexDisableRegister.hh"
 #include "sdf/Sdf.hh"
 #include "SdfParse.hh"
 
diff --git a/util/FlexDisableRegister.hh b/util/FlexDisableRegister.hh
new file mode 100644
index 00000000..bf90316a
--- /dev/null
+++ b/util/FlexDisableRegister.hh
@@ -0,0 +1,5 @@
+// workaround for flex versions that insert register declarations
+#if !(YY_FLEX_MAJOR_VERSION >= 2 && YY_FLEX_MINOR_VERSION >= 6) && __cplusplus > 199711L
+#define register
+#endif
+
diff --git a/verilog/VerilogLex.ll b/verilog/VerilogLex.ll
index 797feb2f..c1491a0d 100644
--- a/verilog/VerilogLex.ll
+++ b/verilog/VerilogLex.ll
@@ -16,6 +16,7 @@
 // You should have received a copy of the GNU General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
+#include "util/FlexDisableRegister.hh"
 #include "Debug.hh"
 #include "VerilogNamespace.hh"
 #include "verilog/VerilogReaderPvt.hh"