From 8a121803f5226d2c49c8a3562216aff73670e88d Mon Sep 17 00:00:00 2001
From: Wilson Snyder <wsnyder@wsnyder.org>
Date: Thu, 19 Dec 2024 20:56:47 -0500
Subject: [PATCH] Add configure CFG_CXX_VERSION

---
 configure.ac            | 6 ++++--
 include/verilated.mk.in | 6 ++++++
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/configure.ac b/configure.ac
index 1f0897f7f..83b5ea21b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -176,8 +176,10 @@ AC_PROG_CXX
 AC_PROG_INSTALL
 
 AC_LANG_PUSH(C++)
-cxx_version=$($CXX --version | head -1)
-AC_MSG_RESULT([compiler is $CXX --version = $cxx_version])
+CFG_CXX_VERSION=`$CXX --version | head -1`
+AC_MSG_RESULT([compiler $CXX --version = $CFG_CXX_VERSION])
+AC_SUBST(CFG_CXX_VERSION)
+
 AC_MSG_CHECKING([that C++ compiler can compile simple program])
 AC_RUN_IFELSE(
    [AC_LANG_SOURCE([int main() { return 0; }])],
diff --git a/include/verilated.mk.in b/include/verilated.mk.in
index a38afe987..a99873f15 100644
--- a/include/verilated.mk.in
+++ b/include/verilated.mk.in
@@ -23,6 +23,12 @@ PYTHON3 = @PYTHON3@
 CFG_WITH_CCWARN = @CFG_WITH_CCWARN@
 CFG_WITH_LONGTESTS = @CFG_WITH_LONGTESTS@
 
+# Compiler version found during configure. This make variable is not used
+# here, but note that if this differs from what `$(CXX) --version` prints,
+# then there may be strange results such as unexpected warnings, as
+# configure determines compiler characteristics.
+CFG_CXX_VERSION = "@CFG_CXX_VERSION@"
+
 # Compiler flags to enable profiling
 CFG_CXXFLAGS_PROFILE = @CFG_CXXFLAGS_PROFILE@
 # Select language required to compile (often empty)