Trying to compile "screendump" for iOS 14; "error: import of C++ module '<C++ module>' appears within extern "C" language"

[InfiniteBSOD]

Hello,

This is my first venture into trying to compile an iOS application so sorry for the WoT.

macOS: Ventura 13.6.1 on Apple Silicon (MBP 16" 2021 M1 Pro)
iOS: 15.3.1 on iPhone 7 Plus
Theos: 2.5.0
Jailbreak: palera1n-c
Package manager: Sileo

What am I trying accomplish:
To run the iOS-app (req. jailbreak) "Screendump" to remote control my iPhone.

What I've tried:

• Added the "alias20" repo to Sileo;
  https://alias20.gitlab.io/apt/
• Installed "screendump (iOS 13+)" version "0.0.3d-1" from the repo above.
• Activated it ("Settings" > "screendump" > "Enabled")
• Trying accessing it using VNC Viewer; "The connection was refused from your computer".

Read this:
https://www.reddit.com/r/jailbreak/comments/14camur/tutorial_get_screendump_vnc_working_on_ios_15/
did this:

• iproxy 2222 44 -u
• ssh mobile@
• <pass is set when launching the "Palera1n"-app for the first time on my phone I believe>
• su root
• <pass for "root" is set through "sudo passwd root" using the "mobile"-user>
• curl https://raw.githubusercontent.com/thesteveway/screendump/master/screendump/en.plist -o en.plist && ldid -Sen.plist /usr/libexec/screendumpd
  returns
  (ldid: /usr/libexec/screendumpd: No such file or directory)
• Ok, checking "Sileo" > "Packages" > "screendump" > "Show package contents" returns;

/
 var/
  jb/
   Library/
    LaunchDaemons/
     com.julioverne.screendumpd.plist
    PreferenceLoader/
     Preferences/
      screendump/
       Preferences.plist
       ScreenDump@2x.png
   usr/
    libexec/
     screendumpd

• Ok, checking "/var/jb/usr/libexec/" for "screendumpd"; it exists but not in "/usr/libexec/screendumpd", running;
  curl https://raw.githubusercontent.com/thesteveway/screendump/master/screendump/en.plist -o en.plist && ldid -Sen.plist /var/jb//usr/libexec/screendumpd
  returns
  ' '
• Toggled slider for "screendumpd" from "on" to "off" and "on" again.
• Trying accessing it using VNC Viewer; "The connection was refused from your computer".

Ok (now for the theos-part):

• Cloned this;
  git clone https://github.com/julioverne/screendump.git
• Whilst in this directory in Terminal:
  /Users/InfiniteBSOD/Documents/git/screendump/screendump
  executed:
  make
  returned:
  > Making all for tool screendumpd… ==> Error: File /mnt/d/codes/screendump/main.mm does not exist. make[1]: *** [before-screendumpd-all] Error 1 make: *** [screendumpd.all.tool.variables] Error 2
• Ok, edited the "Makefile" from this;

TARGET = iphone:11.2:10.0

include $(THEOS)/makefiles/common.mk

TOOL_NAME = screendumpd
$(TOOL_NAME)_FILES = /mnt/d/codes/screendump/main.mm
$(TOOL_NAME)_FRAMEWORKS := IOSurface IOKit
$(TOOL_NAME)_PRIVATE_FRAMEWORKS := IOMobileFramebuffer IOSurface
$(TOOL_NAME)_OBJCFLAGS += -I/mnt/d/codes/screendump/vncbuild/include -Iinclude
$(TOOL_NAME)_LDFLAGS += -Wl,-segalign,4000 -L/mnt/d/codes/screendump/vncbuild/lib  -lvncserver -lpng -llzo2 -ljpeg -lssl -lcrypto -lz
$(TOOL_NAME)_CFLAGS = -w
$(TOOL_NAME)_CODESIGN_FLAGS = "-Sen.plist"
$(TOOL_NAME)_INSTALL_PATH = /usr/libexec
export ARCHS = arm64
$(TOOL_NAME)_ARCHS = arm64

include $(THEOS_MAKE_PATH)/tool.mk

to this:

TARGET = iphone:11.2:10.0

include $(THEOS)/makefiles/common.mk

TOOL_NAME = screendumpd
$(TOOL_NAME)_FILES = main.mm
$(TOOL_NAME)_FRAMEWORKS := IOSurface IOKit
$(TOOL_NAME)_PRIVATE_FRAMEWORKS := IOMobileFramebuffer IOSurface
$(TOOL_NAME)_OBJCFLAGS += -I vncbuild/include -I include
$(TOOL_NAME)_LDFLAGS += -Wl,-segalign,4000 -L vncbuild/lib  -lvncserver -lpng -llzo2 -ljpeg -lssl -lcrypto -lz
$(TOOL_NAME)_CFLAGS = -w
$(TOOL_NAME)_CODESIGN_FLAGS = "-Sen.plist"
$(TOOL_NAME)_INSTALL_PATH = /usr/libexec
export ARCHS = arm64
$(TOOL_NAME)_ARCHS = arm64

include $(THEOS_MAKE_PATH)/tool.mk

• ran "make" which returned this:

==> Notice: Build may be slow as Theos isn’t using all available CPU cores on this computer. Consider upgrading GNU Make: https://theos.dev/docs/parallel-building
> Making all for tool screendumpd…
==> Linking tool screendumpd (arm64)…
ld: warning: -multiply_defined is obsolete
ld: framework 'IOMobileFramebuffer' not found
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make[3]: *** [/Users/InfiniteBSOD/Documents/git/screendump/screendump/.theos/obj/debug/arm64/screendumpd] Error 1
make[2]: *** [/Users/InfiniteBSOD/Documents/git/screendump/screendump/.theos/obj/debug/arm64/screendumpd] Error 2
make[1]: *** [internal-tool-all_] Error 2
make: *** [screendumpd.all.tool.variables] Error 2

• Ok, I remembered I downloaded the iPhoneSDK for "11.2:10.0" from here:
  https://github.com/okanon/iPhoneOS.sdk/tree/master
  but then read it didn't include "IOMobileFramebuffer" so downloaded the closest SDK (iPhoneOS11.4.sdk) from here;
  https://github.com/theos/sdks
  and edited my "Makefile" replacing:
  TARGET = iphone:11.2:10.0
  with
  TARGET = iphone:latest:11.4
• ran "make" again which returned this:

==> Notice: Build may be slow as Theos isn’t using all available CPU cores on this computer. Consider upgrading GNU Make: https://theos.dev/docs/parallel-building
==> Warning: Building for iOS 11.4, but the current toolchain can’t produce arm64e binaries for iOS earlier than 14.0. More information: https://theos.dev/docs/arm64e-deployment
> Making all for tool screendumpd…
==> Compiling main.mm (arm64)…
In file included from main.mm:2:
/Users/InfiniteBSOD/theos/vendor/include/substrate.h:45:1: error: import of C++ module 'MachO.nlist' appears within extern "C" language linkage specification [-Wmodule-import-in-extern-c]
#include <mach-o/nlist.h>
^
/Users/InfiniteBSOD/theos/vendor/include/substrate.h:43:1: note: extern "C" language linkage specification begins here
extern "C" {
^
In file included from main.mm:3:
In file included from vncbuild/include/rfb/rfb.h:44:
vncbuild/include/rfb/rfbproto.h:74:1: error: import of C++ module 'zlib' appears within extern "C" language linkage specification [-Wmodule-import-in-extern-c]
#include <zlib.h>
^
vncbuild/include/rfb/rfb.h:37:1: note: extern "C" language linkage specification begins here
extern "C"
^
In file included from main.mm:3:
In file included from vncbuild/include/rfb/rfb.h:44:
vncbuild/include/rfb/rfbproto.h:96:1: error: import of C++ module 'Darwin.POSIX.sys.time' appears within extern "C" language linkage specification [-Wmodule-import-in-extern-c]
#include <sys/time.h>
^
vncbuild/include/rfb/rfb.h:37:1: note: extern "C" language linkage specification begins here
extern "C"
^
In file included from main.mm:3:
In file included from vncbuild/include/rfb/rfb.h:44:
vncbuild/include/rfb/rfbproto.h:99:1: error: import of C++ module 'Darwin.POSIX.netinet.in' appears within extern "C" language linkage specification [-Wmodule-import-in-extern-c]
#include <netinet/in.h>
^
vncbuild/include/rfb/rfb.h:37:1: note: extern "C" language linkage specification begins here
extern "C"
^
vncbuild/include/rfb/rfb.h:52:1: error: import of C++ module 'Darwin.POSIX.sys.types' appears within extern "C" language linkage specification [-Wmodule-import-in-extern-c]
#include <sys/types.h>
^
vncbuild/include/rfb/rfb.h:37:1: note: extern "C" language linkage specification begins here
extern "C"
^
vncbuild/include/rfb/rfb.h:66:1: error: import of C++ module 'Darwin.POSIX.pthread.pthread' appears within extern "C" language linkage specification [-Wmodule-import-in-extern-c]
#include <pthread.h>
^
vncbuild/include/rfb/rfb.h:37:1: note: extern "C" language linkage specification begins here
extern "C"
^
main.mm:8:8: error: declaration of 'NSString' must be imported from module 'ObjectiveC.NSObject' before it is required
static NSString *CCSPassword = nil;
       ^
/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS17.0.sdk/usr/include/objc/NSObject.h:13:8: note: declaration here is not visible
@class NSString, NSMethodSignature, NSInvocation;
       ^
main.mm:12:8: error: unknown type name 'NSLock'
static NSLock *lock;
       ^
main.mm:25:8: error: a type specifier is required for all declarations
static CFTypeRef (*$GSSystemCopyCapability)(CFStringRef);
~~~~~~ ^
main.mm:25:20: error: use of undeclared identifier '$GSSystemCopyCapability'
static CFTypeRef (*$GSSystemCopyCapability)(CFStringRef);
                   ^
main.mm:25:44: error: expected ';' after top level declarator
static CFTypeRef (*$GSSystemCopyCapability)(CFStringRef);
                                           ^
                                           ;
main.mm:26:8: error: a type specifier is required for all declarations
static CFTypeRef (*$GSSystemGetCapability)(CFStringRef);
~~~~~~ ^
main.mm:26:20: error: use of undeclared identifier '$GSSystemGetCapability'
static CFTypeRef (*$GSSystemGetCapability)(CFStringRef);
                   ^
main.mm:26:43: error: expected ';' after top level declarator
static CFTypeRef (*$GSSystemGetCapability)(CFStringRef);
                                          ^
                                          ;
main.mm:27:33: error: unknown type name 'CFStringRef'
static BOOL (*$MGGetBoolAnswer)(CFStringRef);
                                ^
main.mm:33:8: error: unknown type name 'CFStringRef'
extern CFStringRef kIOSurfaceMemoryRegion;
       ^
main.mm:34:14: error: unknown type name 'CFStringRef'
extern const CFStringRef kIOSurfaceIsGlobal;
             ^
main.mm:36:83: error: unknown type name 'CGSize'
extern "C" void IOMobileFramebufferGetDisplaySize(IOMobileFramebufferRef connect, CGSize *size);
                                                                                  ^
main.mm:37:58: error: use of undeclared identifier 'allocator'; did you mean 'alloca'?
extern "C" int IOSurfaceAcceleratorCreate(CFAllocatorRef allocator, int type, IOSurfaceAcceleratorRef *accel);
                                                         ^~~~~~~~~
                                                         alloca
/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS17.0.sdk/usr/include/alloca.h:32:7: note: 'alloca' declared here
void    *alloca(size_t);                /* built-in for gcc */
         ^
fatal error: too many errors emitted, stopping now [-ferror-limit=]
20 errors generated.
make[3]: *** [/Users/InfiniteBSOD/Documents/git/screendump/screendump/.theos/obj/debug/arm64/main.mm.b6b33328.o] Error 1
make[2]: *** [/Users/InfiniteBSOD/Documents/git/screendump/screendump/.theos/obj/debug/arm64/screendumpd] Error 2
make[1]: *** [internal-tool-all_] Error 2
make: *** [screendumpd.all.tool.variables] Error 2

• Read this:
  "Warning: Building for iOS 11.4, but the current toolchain can’t produce arm64e binaries for iOS earlier than 14.0. More information: https://theos.dev/docs/arm64e-deployment"
• Downloaded "iPhoneOS14.5.sdk" from https://github.com/theos/sdks/tree/master
• Ok, edited "Makefile" from:
  TARGET = iphone:latest:11.4
  with
  TARGET = iphone:latest:14.5
  and re-ran "make" which returned;

'==> Notice: Build may be slow as Theos isn’t using all available CPU cores on this computer. Consider upgrading GNU Make: https://theos.dev/docs/parallel-building
> Making all for tool screendumpd…
==> Compiling main.mm (arm64)…
In file included from main.mm:2:
/Users/InfiniteBSOD/theos/vendor/include/substrate.h:45:1: error: import of C++ module 'MachO.nlist' appears within extern "C" language linkage specification [-Wmodule-import-in-extern-c]
#include <mach-o/nlist.h>
^
/Users/InfiniteBSOD/theos/vendor/include/substrate.h:43:1: note: extern "C" language linkage specification begins here
extern "C" {
^
In file included from main.mm:3:
In file included from vncbuild/include/rfb/rfb.h:44:
vncbuild/include/rfb/rfbproto.h:74:1: error: import of C++ module 'zlib' appears within extern "C" language linkage specification [-Wmodule-import-in-extern-c]
#include <zlib.h>
^
vncbuild/include/rfb/rfb.h:37:1: note: extern "C" language linkage specification begins here
extern "C"
^
In file included from main.mm:3:
In file included from vncbuild/include/rfb/rfb.h:44:
vncbuild/include/rfb/rfbproto.h:96:1: error: import of C++ module 'Darwin.POSIX.sys.time' appears within extern "C" language linkage specification [-Wmodule-import-in-extern-c]
#include <sys/time.h>
^
vncbuild/include/rfb/rfb.h:37:1: note: extern "C" language linkage specification begins here
extern "C"
^
In file included from main.mm:3:
In file included from vncbuild/include/rfb/rfb.h:44:
vncbuild/include/rfb/rfbproto.h:99:1: error: import of C++ module 'Darwin.POSIX.netinet.in' appears within extern "C" language linkage specification [-Wmodule-import-in-extern-c]
#include <netinet/in.h>
^
vncbuild/include/rfb/rfb.h:37:1: note: extern "C" language linkage specification begins here
extern "C"
^
vncbuild/include/rfb/rfb.h:52:1: error: import of C++ module 'Darwin.POSIX.sys.types' appears within extern "C" language linkage specification [-Wmodule-import-in-extern-c]
#include <sys/types.h>
^
vncbuild/include/rfb/rfb.h:37:1: note: extern "C" language linkage specification begins here
extern "C"
^
vncbuild/include/rfb/rfb.h:66:1: error: import of C++ module 'Darwin.POSIX.pthread.pthread' appears within extern "C" language linkage specification [-Wmodule-import-in-extern-c]
#include <pthread.h>
^
vncbuild/include/rfb/rfb.h:37:1: note: extern "C" language linkage specification begins here
extern "C"
^
main.mm:8:8: error: declaration of 'NSString' must be imported from module 'ObjectiveC.NSObject' before it is required
static NSString *CCSPassword = nil;
       ^
/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS17.0.sdk/usr/include/objc/NSObject.h:13:8: note: declaration here is not visible
@class NSString, NSMethodSignature, NSInvocation;
       ^
main.mm:12:8: error: unknown type name 'NSLock'
static NSLock *lock;
       ^
main.mm:25:8: error: a type specifier is required for all declarations
static CFTypeRef (*$GSSystemCopyCapability)(CFStringRef);
~~~~~~ ^
main.mm:25:20: error: use of undeclared identifier '$GSSystemCopyCapability'
static CFTypeRef (*$GSSystemCopyCapability)(CFStringRef);
                   ^
main.mm:25:44: error: expected ';' after top level declarator
static CFTypeRef (*$GSSystemCopyCapability)(CFStringRef);
                                           ^
                                           ;
main.mm:26:8: error: a type specifier is required for all declarations
static CFTypeRef (*$GSSystemGetCapability)(CFStringRef);
~~~~~~ ^
main.mm:26:20: error: use of undeclared identifier '$GSSystemGetCapability'
static CFTypeRef (*$GSSystemGetCapability)(CFStringRef);
                   ^
main.mm:26:43: error: expected ';' after top level declarator
static CFTypeRef (*$GSSystemGetCapability)(CFStringRef);
                                          ^
                                          ;
main.mm:27:33: error: unknown type name 'CFStringRef'
static BOOL (*$MGGetBoolAnswer)(CFStringRef);
                                ^
main.mm:33:8: error: unknown type name 'CFStringRef'
extern CFStringRef kIOSurfaceMemoryRegion;
       ^
main.mm:34:14: error: unknown type name 'CFStringRef'
extern const CFStringRef kIOSurfaceIsGlobal;
             ^
main.mm:36:83: error: unknown type name 'CGSize'
extern "C" void IOMobileFramebufferGetDisplaySize(IOMobileFramebufferRef connect, CGSize *size);
                                                                                  ^
main.mm:37:58: error: use of undeclared identifier 'allocator'; did you mean 'alloca'?
extern "C" int IOSurfaceAcceleratorCreate(CFAllocatorRef allocator, int type, IOSurfaceAcceleratorRef *accel);
                                                         ^~~~~~~~~
                                                         alloca
/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS17.0.sdk/usr/include/alloca.h:32:7: note: 'alloca' declared here
void    *alloca(size_t);                /* built-in for gcc */
         ^
fatal error: too many errors emitted, stopping now [-ferror-limit=]
20 errors generated.
make[3]: *** [/Users/InfiniteBSOD/Documents/git/screendump/screendump/.theos/obj/debug/arm64/main.mm.1ce67a9c.o] Error 1
make[2]: *** [/Users/InfiniteBSOD/Documents/git/screendump/screendump/.theos/obj/debug/arm64/screendumpd] Error 2
make[1]: *** [internal-tool-all_] Error 2
make: *** [screendumpd.all.tool.variables] Error 2

So I'm trying to resolve:
error: import of C++ module '<C++ module>' appears within extern "C" language linkage specification
but I'm out of luck.

I have never tried to compile a iOS-application from source before, I am doing this because I think it is fun and to learn something new so these errors might be obvious, I might be barking up a wrong tree in that it would not work even if I'm able to "fix" all the errors in the code and "update" it to be able to be compiled for iOS 14.0 but would appreciate help regardless.

Best Regards - InfiniteBSOD

[kargoo]

(base) zhs@zhsdeMacBook-Pro screendump % cat Makefile
TARGET = iphone:11.4:10.0

include $(THEOS)/makefiles/common.mk

TOOL_NAME = screendumpd
$(TOOL_NAME)_FILES = main.mm
$(TOOL_NAME)_FRAMEWORKS := IOSurface IOKit
$(TOOL_NAME)_PRIVATE_FRAMEWORKS := IOMobileFramebuffer IOSurface
$(TOOL_NAME)_OBJCFLAGS += -Ivncbuild/include -Iinclude
$(TOOL_NAME)_LDFLAGS += -Wl,-segalign,4000 -Lvncbuild/lib -lvncserver -lpng -llzo2 -ljpeg -lssl -lcrypto -lz
$(TOOL_NAME)_CFLAGS = -w
$(TOOL_NAME)_CODESIGN_FLAGS = "-Sen.plist"
$(TOOL_NAME)_INSTALL_PATH = /usr/libexec
export ARCHS = arm64
$(TOOL_NAME)_ARCHS = arm64

include $(THEOS_MAKE_PATH)/tool.mk
(base) zhs@zhsdeMacBook-Pro screendump % make package
==> Notice: Build may be slow as Theos isn’t using all available CPU cores on this computer. Consider upgrading GNU Make: https://theos.dev/docs/parallel-building

Making all for tool screendumpd…
==> Compiling main.mm (arm64)…
==> Linking tool screendumpd (arm64)…
ld: warning: -multiply_defined is obsolete
==> Generating debug symbols for screendumpd…
==> Merging tool screendumpd…
==> Signing screendumpd…
Making stage for tool screendumpd…
dm.pl: building package com.julioverne.screendump13:iphoneos-arm' in ./packages/com.julioverne.screendump13_0.0.3d-4+debug_iphoneos-arm.deb'
(base) zhs@zhsdeMacBook-Pro screendump % ls /opt/theos/lib
IOMobileFramebuffer.framework