Fix compilation on ios (#167)

This aims to address #163

CMakeLists.txt

@@ -99,6 +99,10 @@ if(UNIX AND NOT APPLE)
   endif()
 endif()
 
+if(APPLE)
+  check_support(HAS_MACH_VM has_mach_vm.cpp "" "" "")
+endif()
+
 # =============================================== Autoconfig unwinding ===============================================
 # Unwind back-ends
 if(
@@ -340,6 +344,10 @@ if(HAS_DLADDR1)
   target_compile_definitions(${target_name} PUBLIC CPPTRACE_HAS_DLADDR1)
 endif()
 
+if(HAS_MACH_VM)
+  target_compile_definitions(${target_name} PUBLIC HAS_MACH_VM)
+endif()
+
 # Symbols
 if(CPPTRACE_GET_SYMBOLS_WITH_LIBBACKTRACE)
   if(NOT HAS_BACKTRACE)

cmake/has_mach_vm.cpp

@@ -0,0 +1,23 @@
+#include <mach/mach.h>
+#include <mach/mach_vm.h>
+#include <cstdint>
+
+int main() {
+    mach_vm_size_t vmsize;
+    uintptr_t addr = reinterpret_cast<uintptr_t>(&vmsize);
+    uintptr_t page_addr = addr & ~(4096 - 1);
+    mach_vm_address_t address = (mach_vm_address_t)page_addr;
+    vm_region_basic_info_data_t info;
+    mach_msg_type_number_t info_count =
+        sizeof(size_t) == 8 ? VM_REGION_BASIC_INFO_COUNT_64 : VM_REGION_BASIC_INFO_COUNT;
+    memory_object_name_t object;
+    mach_vm_region(
+        mach_task_self(),
+        &address,
+        &vmsize,
+        VM_REGION_BASIC_INFO,
+        (vm_region_info_t)&info,
+        &info_count,
+        &object
+    );
+}

src/from_current.cpp

@@ -20,7 +20,9 @@
   #include <unistd.h>
   #if IS_APPLE
    #include <mach/mach.h>
+   #ifdef HAS_MACH_VM
     #include <mach/mach_vm.h>
+   #endif
   #else
    #include <fstream>
    #include <iomanip>
@@ -112,13 +114,24 @@ namespace cpptrace {
         #if IS_APPLE
         int get_page_protections(void* page) {
             // https://stackoverflow.com/a/12627784/15675011
+            #ifdef HAS_MACH_VM
             mach_vm_size_t vmsize;
             mach_vm_address_t address = (mach_vm_address_t)page;
+            #else
+            vm_size_t vmsize;
+            vm_address_t address = (vm_address_t)page;
+            #endif
             vm_region_basic_info_data_t info;
             mach_msg_type_number_t info_count =
                 sizeof(size_t) == 8 ? VM_REGION_BASIC_INFO_COUNT_64 : VM_REGION_BASIC_INFO_COUNT;
             memory_object_name_t object;
-            kern_return_t status = mach_vm_region(
+            kern_return_t status =
+            #ifdef HAS_MACH_VM
+            mach_vm_region
+            #else
+            vm_region_64
+            #endif
+            (
                 mach_task_self(),
                 &address,
                 &vmsize,