From 6854cd7127c3876c5f945fd2bd30180dcfa7fb75 Mon Sep 17 00:00:00 2001
From: Ioannis Paraskevakos <iparask@princeton.edu>
Date: Wed, 10 Jul 2024 16:37:36 -0400
Subject: [PATCH 1/2] disable openmp when Mac with M chip

---
 cython/cmisc_core.c  |  9 ++++++++-
 cython/srcsim_core.c | 10 +++++++++-
 meson.build          |  8 ++++++--
 3 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/cython/cmisc_core.c b/cython/cmisc_core.c
index c73a0a1f..b5cf3140 100644
--- a/cython/cmisc_core.c
+++ b/cython/cmisc_core.c
@@ -3,7 +3,14 @@
 #include <stdio.h>
 #include <stdint.h>
 #include <string.h>
-#include <omp.h>
+
+#ifdef _NOOPENMP
+    typedef int omp_int_t;
+    inline omp_int_t omp_get_thread_num() { return 0;}
+    inline omp_int_t omp_get_max_threads() { return 1;}
+#else
+    #include <omp.h>
+#endif
 
 int min(int a, int b) { return a < b ? a : b; }
 int max(int a, int b) { return a > b ? a : b; }
diff --git a/cython/srcsim_core.c b/cython/srcsim_core.c
index 8b6ff8cb..8e32abd3 100644
--- a/cython/srcsim_core.c
+++ b/cython/srcsim_core.c
@@ -36,7 +36,15 @@
 #include <string.h>
 #include <math.h>
 #include <sys/time.h>
-#include <omp.h>
+
+#ifdef _NOOPENMP
+    typedef int omp_int_t;
+    inline omp_int_t omp_get_thread_num() { return 0;}
+    inline omp_int_t omp_get_max_threads() { return 1;}
+#else
+    #include <omp.h>
+#endif
+
 #include "srcsim_core.h"
 
 // Precompute profile levels down to 1e-10 of the abspeak. Beyond that
diff --git a/meson.build b/meson.build
index b8d28333..5f9bd10c 100644
--- a/meson.build
+++ b/meson.build
@@ -19,7 +19,8 @@ py = import('python').find_installation(pure: false)
 
 # Dependencies
 py_dep = py.dependency()
-omp_dep = dependency('openmp')
+# message('Machine', host_machine.system(), 'CPU type', host_machine.cpu_family())
+omp_dep = dependency('openmp', required : false)
 
 # Libraries
 cc = meson.get_compiler('c')
@@ -27,7 +28,10 @@ c_m_dep = cc.find_library('m', required: true)
 
 fc = meson.get_compiler('fortran')
 fortran_m_dep = fc.find_library('m', required: true)
-
+if not omp_dep.found()
+    warning('It seems this is a Macbook with M type processor, moving forward without openmp.')
+    add_project_arguments(['-D_NOOPENMP','-Wno-error=incompatible-function-pointer-types'], language : ['c', 'cpp'])
+endif
 # Directories
 library_install_dir = py.get_install_dir() / 'pixell'
 

From 98f1de9890ac5dae519fdf04b968553742997d12 Mon Sep 17 00:00:00 2001
From: Ioannis Paraskevakos <iparask@princeton.edu>
Date: Thu, 11 Jul 2024 11:50:29 -0400
Subject: [PATCH 2/2] Error messages for when openmp is not there and windows
 are detected

---
 meson.build | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/meson.build b/meson.build
index 5f9bd10c..58bb758a 100644
--- a/meson.build
+++ b/meson.build
@@ -28,10 +28,16 @@ c_m_dep = cc.find_library('m', required: true)
 
 fc = meson.get_compiler('fortran')
 fortran_m_dep = fc.find_library('m', required: true)
-if not omp_dep.found()
+
+if not omp_dep.found() and host_machine.system() == 'darwin' and host_machine.cpu_family() == 'aarch64'
     warning('It seems this is a Macbook with M type processor, moving forward without openmp.')
     add_project_arguments(['-D_NOOPENMP','-Wno-error=incompatible-function-pointer-types'], language : ['c', 'cpp'])
+elif not omp_dep.found() and host_machine.system() != 'windows'
+    error('OpenMP is required but not found. Please install OpenMP libraries')
+elif host_machine.system() == 'windows'
+    error('Windows systems are not supported')
 endif
+
 # Directories
 library_install_dir = py.get_install_dir() / 'pixell'