#include "tclInt.h"

#ifndef MODULE_SCOPE
#   define MODULE_SCOPE extern
#endif

/*
 * Use preferred dlfcn API on 10.4 and later
 */

#ifndef TCL_DYLD_USE_DLFCN
#   ifdef NO_DLFCN_H
#	define TCL_DYLD_USE_DLFCN 0
#   else
#	define TCL_DYLD_USE_DLFCN 1
#   endif
#endif

/*
 * Use deprecated NSModule API only to support 10.3 and earlier:
 */

#ifndef TCL_DYLD_USE_NSMODULE
#   define TCL_DYLD_USE_NSMODULE 0
#endif

/*
 * Use includes for the API we're using.
 */

#if TCL_DYLD_USE_DLFCN
#   include <dlfcn.h>
#endif /* TCL_DYLD_USE_DLFCN */

#if TCL_DYLD_USE_NSMODULE || defined(TCL_LOAD_FROM_MEMORY)
#if defined (__clang__) || ((__GNUC__)  && ((__GNUC__ > 4) || ((__GNUC__ == 4) && (__GNUC_MINOR__ > 5))))
#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
#endif
#include <mach-o/dyld.h>
#include <mach-o/fat.h>
#include <mach-o/swap.h>
#include <mach-o/arch.h>
#include <libkern/OSByteOrder.h>
#include <mach/mach.h>

typedef struct Tcl_DyldModuleHandle {
    struct Tcl_DyldModuleHandle *nextPtr;
    NSModule module;
} Tcl_DyldModuleHandle;
#endif /* TCL_DYLD_USE_NSMODULE || TCL_LOAD_FROM_MEMORY */

typedef struct {
    void *dlHandle;
#if TCL_DYLD_USE_NSMODULE || defined(TCL_LOAD_FROM_MEMORY)
    const struct mach_header *dyldLibHeader;
    Tcl_DyldModuleHandle *modulePtr;
#endif
} Tcl_DyldLoadHandle;

#if TCL_DYLD_USE_DLFCN || defined(TCL_LOAD_FROM_MEMORY)
MODULE_SCOPE long	tclMacOSXDarwinRelease;
#endif

/*
 * Static functions defined in this file.
 */

static void *		FindSymbol(Tcl_Interp *interp,
			    Tcl_LoadHandle loadHandle, const char *symbol);
static void		UnloadFile(Tcl_LoadHandle handle);

 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

#if TCL_DYLD_USE_NSMODULE || defined(TCL_LOAD_FROM_MEMORY)
static const char *
DyldOFIErrorMsg(
    int err)
{
    switch(err) {
    case NSObjectFileImageSuccess:
	return NULL;

	return "bad object file format";
    case NSObjectFileImageAccess:
	return "cannot read object file";
    default:
	return "unknown error";
    }
}
#endif /* TCL_DYLD_USE_NSMODULE || TCL_LOAD_FROM_MEMORY */

/*
 *----------------------------------------------------------------------
 *
 * TclpDlopen --
 *
 *	Dynamically loads a binary code file into memory and returns a handle

				 * function which should be used for this
				 * file. */
    int flags)
{
    Tcl_DyldLoadHandle *dyldLoadHandle;
    Tcl_LoadHandle newHandle;
    void *dlHandle = NULL;
#if TCL_DYLD_USE_NSMODULE || defined(TCL_LOAD_FROM_MEMORY)
    const struct mach_header *dyldLibHeader = NULL;
    Tcl_DyldModuleHandle *modulePtr = NULL;
#endif
#if TCL_DYLD_USE_NSMODULE
    NSLinkEditErrors editError;
    int errorNumber;
    const char *errorName, *objFileImageErrMsg = NULL;
#endif /* TCL_DYLD_USE_NSMODULE */
    const char *errMsg = NULL;
    int result;
    Tcl_DString ds;
    const char *nativePath, *nativeFileName = NULL;
#if TCL_DYLD_USE_DLFCN
    int dlopenflags = 0;
#endif /* TCL_DYLD_USE_DLFCN */

    /*
     * First try the full path the user gave us. This is particularly
     * important if the cwd is inside a vfs, and we are trying to load using a
     * relative path.
     */

    nativePath = (const char *)Tcl_FSGetNativePath(pathPtr);
    nativeFileName = Tcl_UtfToExternalDString(NULL, Tcl_GetString(pathPtr),
	    TCL_INDEX_NONE, &ds);

#if TCL_DYLD_USE_DLFCN
    /*
     * Use (RTLD_NOW|RTLD_LOCAL) as default, see [Bug #3216070]
     */

    if (flags & TCL_LOAD_GLOBAL) {
	dlopenflags |= RTLD_GLOBAL;
    } else {

	 */

	dlHandle = dlopen(nativeFileName, dlopenflags);
	if (!dlHandle) {
	    errMsg = dlerror();
	}
    }
#endif /* TCL_DYLD_USE_DLFCN */

    if (!dlHandle) {
#if TCL_DYLD_USE_NSMODULE
	dyldLibHeader = NSAddImage(nativePath,
		NSADDIMAGE_OPTION_RETURN_ON_ERROR);
	if (!dyldLibHeader) {
	    NSLinkEditError(&editError, &errorNumber, &errorName, &errMsg);
	    if (editError == NSLinkEditFileAccessError) {
		/*
		 * The requested file was not found. Let the OS loader examine
		 * the binary search path for whatever string the user gave us
		 * which hopefully refers to a file on the binary path.
		 */

		dyldLibHeader = NSAddImage(nativeFileName,
			NSADDIMAGE_OPTION_WITH_SEARCHING |
			NSADDIMAGE_OPTION_RETURN_ON_ERROR);
		if (!dyldLibHeader) {
		    NSLinkEditError(&editError, &errorNumber, &errorName,
			    &errMsg);
		}
	    } else if ((editError == NSLinkEditFileFormatError
		    && errorNumber == EBADMACHO)
		    || editError == NSLinkEditOtherError){
		NSObjectFileImageReturnCode err;
		NSObjectFileImage dyldObjFileImage;
		NSModule module;

		/*
		 * The requested file was found but was not of type MH_DYLIB,
		 * attempt to load it as a MH_BUNDLE.
		 */

		err = NSCreateObjectFileImageFromFile(nativePath,
			&dyldObjFileImage);
		if (err == NSObjectFileImageSuccess && dyldObjFileImage) {
		    int nsflags = NSLINKMODULE_OPTION_RETURN_ON_ERROR;
		    if (!(flags & 1)) {
			nsflags |= NSLINKMODULE_OPTION_PRIVATE;
		    }
		    if (!(flags & 2)) {
			nsflags |= NSLINKMODULE_OPTION_BINDNOW;
		    }
		    module = NSLinkModule(dyldObjFileImage, nativePath, nsflags);
		    NSDestroyObjectFileImage(dyldObjFileImage);
		    if (module) {
			modulePtr = (Tcl_DyldModuleHandle *)ckalloc(sizeof(Tcl_DyldModuleHandle));
			modulePtr->module = module;
			modulePtr->nextPtr = NULL;
		    } else {
			NSLinkEditError(&editError, &errorNumber, &errorName,
				&errMsg);
		    }
		} else {
		    objFileImageErrMsg = DyldOFIErrorMsg(err);
		}
	    }
	}
#endif /* TCL_DYLD_USE_NSMODULE */
    }

    if (dlHandle
#if TCL_DYLD_USE_NSMODULE
	    || dyldLibHeader || modulePtr
#endif /* TCL_DYLD_USE_NSMODULE */
    ) {
	dyldLoadHandle = (Tcl_DyldLoadHandle *)ckalloc(sizeof(Tcl_DyldLoadHandle));
	dyldLoadHandle->dlHandle = dlHandle;
#if TCL_DYLD_USE_NSMODULE || defined(TCL_LOAD_FROM_MEMORY)
	dyldLoadHandle->dyldLibHeader = dyldLibHeader;
	dyldLoadHandle->modulePtr = modulePtr;
#endif /* TCL_DYLD_USE_NSMODULE || TCL_LOAD_FROM_MEMORY */
	newHandle = (Tcl_LoadHandle)ckalloc(sizeof(*newHandle));
	newHandle->clientData = dyldLoadHandle;
	newHandle->findSymbolProcPtr = &FindSymbol;
	newHandle->unloadFileProcPtr = &UnloadFile;
	*unloadProcPtr = &UnloadFile;
	*loadHandle = newHandle;
	result = TCL_OK;
    } else {
	Tcl_Obj *errObj;

	TclNewObj(errObj);
	if (errMsg != NULL) {
	    Tcl_AppendToObj(errObj, errMsg, TCL_INDEX_NONE);
	}
#if TCL_DYLD_USE_NSMODULE
	if (objFileImageErrMsg) {
	    Tcl_AppendPrintfToObj(errObj,
		    "\nNSCreateObjectFileImageFromFile() error: %s",
		    objFileImageErrMsg);
	}
#endif /* TCL_DYLD_USE_NSMODULE */
	Tcl_SetObjResult(interp, errObj);
	result = TCL_ERROR;
    }

    Tcl_DStringFree(&ds);
    return result;
}

    Tcl_LibraryInitProc *proc = NULL;
    const char *errMsg = NULL;
    Tcl_DString ds;
    const char *native;

    native = Tcl_UtfToExternalDString(NULL, symbol, TCL_INDEX_NONE, &ds);
    if (dyldLoadHandle->dlHandle) {
#if TCL_DYLD_USE_DLFCN
	proc = (Tcl_LibraryInitProc *)dlsym(dyldLoadHandle->dlHandle, native);
	if (!proc) {
	    errMsg = dlerror();
	}
#endif /* TCL_DYLD_USE_DLFCN */
    } else {
#if TCL_DYLD_USE_NSMODULE || defined(TCL_LOAD_FROM_MEMORY)
	NSSymbol nsSymbol = NULL;
	Tcl_DString newName;

	/*
	 * dyld adds an underscore to the beginning of symbol names.
	 */

	    nsSymbol = NSLookupSymbolInModule(
		    dyldLoadHandle->modulePtr->module, native);
	}
	if (nsSymbol) {
	    proc = (Tcl_LibraryInitProc *)NSAddressOfSymbol(nsSymbol);
	}
	Tcl_DStringFree(&newName);
#endif /* TCL_DYLD_USE_NSMODULE */
    }
    Tcl_DStringFree(&ds);
    if (errMsg && (interp != NULL)) {
	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
		"cannot find symbol \"%s\": %s", symbol, errMsg));
	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "LOAD_SYMBOL", symbol,
		(char *)NULL);

    Tcl_LoadHandle loadHandle)	/* loadHandle returned by a previous call to
				 * TclpDlopen(). The loadHandle is a token
				 * that represents the loaded file. */
{
    Tcl_DyldLoadHandle *dyldLoadHandle = (Tcl_DyldLoadHandle *)loadHandle->clientData;

    if (dyldLoadHandle->dlHandle) {
#if TCL_DYLD_USE_DLFCN
	(void) dlclose(dyldLoadHandle->dlHandle);
#endif /* TCL_DYLD_USE_DLFCN */
    } else {
#if TCL_DYLD_USE_NSMODULE || defined(TCL_LOAD_FROM_MEMORY)
	Tcl_DyldModuleHandle *modulePtr = dyldLoadHandle->modulePtr;

	while (modulePtr != NULL) {
	    void *ptr = modulePtr;

	    (void) NSUnLinkModule(modulePtr->module,
		    NSUNLINKMODULE_OPTION_RESET_LAZY_REFERENCES);
	    modulePtr = modulePtr->nextPtr;
	    ckfree(ptr);
	}
#endif /* TCL_DYLD_USE_NSMODULE */
    }
    ckfree(dyldLoadHandle);
    ckfree(loadHandle);
}

/*
 *----------------------------------------------------------------------

MODULE_SCOPE void *
TclpLoadMemoryGetBuffer(
    size_t size)			/* Size of desired buffer. */
{
    void *buffer = NULL;

    /*
     * NSCreateObjectFileImageFromMemory is available but always fails
     * prior to Darwin 7.
     */
    if (tclMacOSXDarwinRelease >= 7) {
	/*
	 * We must allocate the buffer using vm_allocate, because
	 * NSCreateObjectFileImageFromMemory will dispose of it using
	 * vm_deallocate.
	 */

	if (vm_allocate(mach_task_self(), (vm_address_t *) &buffer, size, 1)) {
	    buffer = NULL;
	}
    }
    return buffer;
}
#endif /* TCL_LOAD_FROM_MEMORY */

/*
 *----------------------------------------------------------------------