Add macOS port for arm64 (Apple Silicon) and x86-64

meson.build

@@ -11,8 +11,10 @@ project('cimba', ['c'],
         ]
 )
 
-# We also need the portable Netwide Assembler for assembly code
-add_languages('nasm', required : true, native : true)
+# We also need the portable Netwide Assembler for the x86-64 assembly code
+if host_machine.cpu_family() == 'x86_64'
+    add_languages('nasm', required : true, native : true)
+endif
 
 # Try to find CUDA, but don't fail if it's missing
 add_languages('cuda', required : false, native : true)
@@ -33,11 +35,18 @@ cc = meson.get_compiler('c')
 # Flags common to all build types
 common_flags = [
     '-Wno-pedantic',
-    '-D_POSIX_C_SOURCE=200809L',
     '-fno-semantic-interposition',
     '-ffp-contract=off',
 ]
 
+if host_machine.system() == 'darwin'
+    # Keep Darwin extensions such as pthread_get_stackaddr_np() and
+    # arc4random_buf() visible
+    common_flags += '-D_DARWIN_C_SOURCE'
+else
+    common_flags += '-D_POSIX_C_SOURCE=200809L'
+endif
+
 # Flags per build type
 # 'debug'    : full asserts and logging, no optimization
 # 'release'  : standard optimized build, release asserts only

src/cimba.c

@@ -23,6 +23,7 @@
 
 #include <inttypes.h>
 #include <pthread.h>
+#include <setjmp.h>
 #include <stdint.h>
 
 #include "cimba.h"
@@ -75,9 +76,16 @@ static uint64_t leaking_trials;
 static CMB_THREAD_LOCAL cimba_trial_cleanup_func *trial_cleanup_func = NULL;
 static CMB_THREAD_LOCAL void *trial_cleanup_arg = NULL;
 
+#if CMI_ARCH == CMI_ARM64
+/* Clang does not implement __builtin_setjmp on AArch64, use the libc version */
+static CMB_THREAD_LOCAL jmp_buf recovery_buf;
+#define recovery_set()   setjmp(recovery_buf)
+#define recovery_jump()  longjmp(recovery_buf, 1)
+#else
 static CMB_THREAD_LOCAL intptr_t recovery_buf[5];
 #define recovery_set()   __builtin_setjmp((void **)recovery_buf)
 #define recovery_jump()  __builtin_longjmp((void **)recovery_buf, 1)
+#endif
 
 extern void cmi_coroutine_recovery_prepare(void *stack_marker);
 extern void cmi_coroutine_recovery_finalize(void *stack_marker);

src/cmi_config.h

@@ -23,34 +23,41 @@
 
 /*
  * Supported toolchains:
- *   - Architecture:     x86-64 / AMD64
- *   - Operating system: Linux, or Windows via MinGW-w64
+ *   - Architecture:     x86-64 / AMD64, or arm64 (Apple Silicon)
+ *   - Operating system: Linux, Windows via MinGW-w64, or macOS
  *   - Compiler:         GCC or Clang, C11 or later
  *                       (the library itself is built as C23)
  *
  * In particular, MSVC is not supported.
  */
 
 /*
- * Identify the processor architecture. So far, only AMD64/x86-64 is supported.
+ * Identify the processor architecture. AMD64/x86-64 everywhere, and arm64 on
+ * macOS (Apple Silicon).
  */
 #define CMI_AMD64 1
+#define CMI_ARM64 2
 #if (defined (__amd64__) || defined (__amd64) || defined (__x86_64__) || \
      defined (__x86_64) || defined (_M_X64) || defined (_M_AMD64))
   #define CMI_ARCH CMI_AMD64
+#elif defined (__aarch64__) || defined (__arm64__)
+  #define CMI_ARCH CMI_ARM64
 #else
   #error "Platform architecture not yet supported."
 #endif
 
 /*
- * Identify the operating system. So far, only Linux and Windows are supported.
+ * Identify the operating system. Linux, Windows, and macOS are supported.
  */
 #define CMI_LINUX 1
 #define CMI_WINDOWS 2
+#define CMI_MACOS 3
 #if defined (__linux__) || defined (__linux) || defined (linux)
   #define CMI_OS CMI_LINUX
 #elif defined (_WIN64) || defined (_WIN32) || defined (__WIN32__)
   #define CMI_OS CMI_WINDOWS
+#elif defined (__APPLE__) && defined (__MACH__)
+  #define CMI_OS CMI_MACOS
 #else
   #error "Platform operating system not yet supported."
 #endif

src/meson.build

@@ -66,7 +66,8 @@ if host_machine.system() == 'windows'
 elif lto_feature.enabled() or (lto_feature.auto() and get_option('buildtype').startswith('release'))
     cimba_lto = ['b_lto=true']
     if get_option('default_library') != 'shared'
-        cimba_lto_args = ['-ffat-lto-objects']
+        # Apple Clang does not accept -ffat-lto-objects
+        cimba_lto_args = cc.get_supported_arguments('-ffat-lto-objects')
     endif
 endif
 

src/port/aarch64/macos/cmb_random_hwseed.c

@@ -0,0 +1,19 @@
+/*
+ * Random seed generation for macOS.
+ *
+ * Copyright (c) FBarrca 2026.
+ * Licensed under the Apache License, Version 2.0.
+ */
+
+#include <stdlib.h>
+
+#include "cmb_assert.h"
+#include "cmb_random.h"
+
+uint64_t cmb_random_hwseed(void)
+{
+    uint64_t seed = 0u;
+    arc4random_buf(&seed, sizeof(seed));
+    cmb_assert_debug(seed != 0u);
+    return seed;
+}

src/port/aarch64/macos/cmi_coroutine_context.S

@@ -0,0 +1,63 @@
+/*
+ * Context switch and coroutine trampoline for arm64 macOS.
+ *
+ * Copyright (c) FBarrca 2026.
+ * Licensed under the Apache License, Version 2.0.
+ */
+
+.text
+.p2align 2
+
+.globl _cmi_coroutine_context_switch
+_cmi_coroutine_context_switch:
+    sub sp, sp, #176
+    stp x19, x20, [sp, #0]
+    stp x21, x22, [sp, #16]
+    stp x23, x24, [sp, #32]
+    stp x25, x26, [sp, #48]
+    stp x27, x28, [sp, #64]
+    stp x29, x30, [sp, #80]
+    stp d8, d9, [sp, #96]
+    stp d10, d11, [sp, #112]
+    stp d12, d13, [sp, #128]
+    stp d14, d15, [sp, #144]
+    mrs x9, fpcr
+    mrs x10, fpsr
+    stp x9, x10, [sp, #160]
+
+    mov x9, sp
+    str x9, [x0]
+    ldr x9, [x1]
+    mov sp, x9
+
+    ldp x9, x10, [sp, #160]
+    msr fpcr, x9
+    msr fpsr, x10
+    ldp d14, d15, [sp, #144]
+    ldp d12, d13, [sp, #128]
+    ldp d10, d11, [sp, #112]
+    ldp d8, d9, [sp, #96]
+    ldp x29, x30, [sp, #80]
+    ldp x27, x28, [sp, #64]
+    ldp x25, x26, [sp, #48]
+    ldp x23, x24, [sp, #32]
+    ldp x21, x22, [sp, #16]
+    ldp x19, x20, [sp, #0]
+    add sp, sp, #176
+
+    mov x0, x2
+    ret
+
+.p2align 2
+.globl _cmi_coroutine_trampoline
+_cmi_coroutine_trampoline:
+    stp x29, x30, [sp, #-16]!
+    mov x29, sp
+    mov x0, x20
+    mov x1, x21
+    blr x19
+    mov x16, x22
+    ldp x29, x30, [sp], #16
+    br x16
+
+.subsections_via_symbols