guile3.patch

# Written and placed in public domain by Jeffrey Walton.
# This patch starts fixing some issues with Guile 3 and JIT.
# JIT does not work yet. Configure with --disable-jit.
--- libguile/jit.c
+++ libguile/jit.c
@@ -42,6 +42,10 @@
 
 #include "jit.h"
 
+#if defined(__APPLE__)
+# include <TargetConditionals.h>
+# include <pthread.h>
+#endif
 
 
 
@@ -292,6 +300,37 @@
 #define LENGTH_DOP3(a,b,c) 3
 #define LENGTH_DOP4(a,b,c,d) 4
 
+#define GUILE_UNUSED(x) ((void)(x))
+
+inline int
+apple_mmap_write (void *base, size_t len)
+{
+  GUILE_UNUSED(base); GUILE_UNUSED(len);
+#if defined(TARGET_OSX)
+  if (__builtin_available(macOS 11, *) &&
+    pthread_jit_write_protect_supported_np())
+      return pthread_jit_write_protect_np(false);
+  else
+#endif
+    return 0;
+}
+
+inline int
+apple_mmap_execute (void *base, size_t len)
+{
+  GUILE_UNUSED(base); GUILE_UNUSED(len);
+#if defined(TARGET_OSX)
+  if (__builtin_available(macOS 11, *) &&
+    pthread_jit_write_protect_supported_np()) {
+      int ret = pthread_jit_write_protect_np(true);
+      sys_icache_invalidate(base, len);
+      return ret;
+	}
+  else
+#endif
+    return 0;
+}
+
 static const uint8_t op_lengths[256] = {
 #define OP_LENGTH(code, cname, name, arity) LENGTH_##arity,
 FOR_EACH_VM_OPERATION(OP_LENGTH)
@@ -1338,9 +1375,17 @@
   ret->used = 0;
   ret->size = size;
   ret->prev = prev;
+
+#if defined(TARGET_OSX) && defined(MAP_JIT)
+  /* MAP_JIT will succeed, even with W+X */
+  ret->base = mmap (NULL, ret->size,
+                    PROT_EXEC | PROT_READ | PROT_WRITE,
+                    MAP_JIT | MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+#else
   ret->base = mmap (NULL, ret->size,
                     PROT_EXEC | PROT_READ | PROT_WRITE,
                     MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+#endif
 
   if (ret->base == MAP_FAILED)
     {
@@ -1372,8 +1417,12 @@
 
       uint8_t *ret = jit_address (j->jit);
 
+      apple_mmap_write(arena->base, arena->size);
+
       emit (j);
 
+      apple_mmap_execute(arena->base, arena->size);
+
       size_t size;
       if (!jit_has_overflow (j->jit) && jit_end (j->jit, &size))
         {