From e3e659ca834411bd56bb288223f64e7f978575b1 Mon Sep 17 00:00:00 2001
From: stchaker <stchaker@mit.edu>
Date: Tue, 4 Apr 2023 16:58:28 -0400
Subject: [PATCH] avoid python C API segfault on intel mac

---
 include/openmc/settings.h | 7 ++++++-
 src/initialize.cpp        | 1 +
 src/settings.cpp          | 2 ++
 3 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/include/openmc/settings.h b/include/openmc/settings.h
index 806288efe5..9cd2f7c2d3 100644
--- a/include/openmc/settings.h
+++ b/include/openmc/settings.h
@@ -68,7 +68,12 @@ extern std::string path_input;  //!< directory where main .xml files resides
 extern std::string path_output; //!< directory where output files are written
 extern std::string path_particle_restart; //!< path to a particle restart file
 extern std::string path_sourcepoint;      //!< path to a source file
-extern "C" std::string path_statepoint;   //!< path to a statepoint file
+extern std::string path_statepoint;       //!< path to a statepoint file
+
+// This is required because the c_str() may not be the first thing in
+// std::string. Sometimes it is, but it seems libc++ may not be like that
+// on some computers, like the intel Mac.
+extern "C" char const* path_statepoint_c; //!< C pointer to statepoint file name
 
 extern "C" int32_t n_inactive;         //!< number of inactive batches
 extern "C" int32_t max_lost_particles; //!< maximum number of lost particles
diff --git a/src/initialize.cpp b/src/initialize.cpp
index 6383af64ea..da35d4ff6a 100644
--- a/src/initialize.cpp
+++ b/src/initialize.cpp
@@ -193,6 +193,7 @@ int parse_command_line(int argc, char* argv[])
         // Set path and flag for type of run
         if (filetype == "statepoint") {
           settings::path_statepoint = argv[i];
+          settings::path_statepoint_c = settings::path_statepoint.c_str();
           settings::restart_run = true;
         } else if (filetype == "particle restart") {
           settings::path_particle_restart = argv[i];
diff --git a/src/settings.cpp b/src/settings.cpp
index 2f8fbd1d09..cf678d4047 100644
--- a/src/settings.cpp
+++ b/src/settings.cpp
@@ -82,6 +82,8 @@ std::string path_output;
 std::string path_particle_restart;
 std::string path_sourcepoint;
 std::string path_statepoint;
+std::string empty_string = "";
+char const* path_statepoint_c {empty_string.c_str()};
 
 int32_t n_inactive {0};
 int32_t max_lost_particles {10};