* unix/tclLoadDyld.c: use dlfcn API on Mac OS X 10.4 and later; fix

	issues with loading from memory on intel and 64bit; add debug messages.

	* tests/load.test: add test load-10.1 for loading from vfs.

1 files changed, 368 insertions, 171 deletions

diff --git a/unix/tclLoadDyld.c b/unix/tclLoadDyld.c
index f538968..898e208 100644
--- a/unix/tclLoadDyld.c
+++ b/unix/tclLoadDyld.c
@@ -3,7 +3,7 @@
  *
  *	This procedure provides a version of the TclLoadFile that works with
  *	Apple's dyld dynamic loading.
- *	Original version of his file (now superseded long ago) provided by
+ *	Original version of his file (superseded long ago) provided by
  *	Wilfredo Sanchez (wsanchez@apple.com).
  *
  * Copyright (c) 1995 Apple Computer, Inc.
@@ -12,10 +12,50 @@
  * See the file "license.terms" for information on usage and redistribution of
  * this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclLoadDyld.c,v 1.26 2007/04/23 20:37:10 das Exp $
+ * RCS: @(#) $Id: tclLoadDyld.c,v 1.27 2007/08/14 06:33:57 das Exp $
  */
 
 #include "tclInt.h"
+
+#ifndef MODULE_SCOPE
+#define MODULE_SCOPE extern
+#endif
+
+#ifndef TCL_DYLD_USE_DLFCN
+/*
+ * Use preferred dlfcn API on 10.4 and later
+ */
+#   if !defined(NO_DLFCN_H) && MAC_OS_X_VERSION_MAX_ALLOWED >= 1040
+#	define TCL_DYLD_USE_DLFCN 1
+#   else
+#	define TCL_DYLD_USE_DLFCN 0
+#   endif
+#endif
+#ifndef TCL_DYLD_USE_NSMODULE
+/*
+ * Use deprecated NSModule API only to support 10.3 and earlier:
+ */
+#   if MAC_OS_X_VERSION_MIN_REQUIRED < 1040
+#	define TCL_DYLD_USE_NSMODULE 1
+#   else
+#	define TCL_DYLD_USE_NSMODULE 0
+#   endif
+#endif
+
+#if TCL_DYLD_USE_DLFCN
+#include <dlfcn.h>
+#if defined(HAVE_WEAK_IMPORT) && MAC_OS_X_VERSION_MIN_REQUIRED < 1040
+/*
+ * Support for weakly importing dlfcn API.
+ */
+extern void *dlopen(const char *path, int mode) WEAK_IMPORT_ATTRIBUTE;
+extern void *dlsym(void *handle, const char *symbol) WEAK_IMPORT_ATTRIBUTE;
+extern int dlclose(void *handle) WEAK_IMPORT_ATTRIBUTE;
+extern char *dlerror(void) WEAK_IMPORT_ATTRIBUTE;
+#endif
+#endif
+
+#if TCL_DYLD_USE_NSMODULE || defined(TCL_LOAD_FROM_MEMORY)
 #include <mach-o/dyld.h>
 #include <mach-o/fat.h>
 #include <mach-o/swap.h>
@@ -27,16 +67,33 @@ typedef struct Tcl_DyldModuleHandle {
     struct Tcl_DyldModuleHandle *nextPtr;
     NSModule module;
 } Tcl_DyldModuleHandle;
+#endif /* TCL_DYLD_USE_NSMODULE */
 
 typedef struct Tcl_DyldLoadHandle {
-    CONST struct mach_header *dyldLibHeader;
+#if TCL_DYLD_USE_DLFCN
+    void *dlHandle;
+#endif
+#if TCL_DYLD_USE_NSMODULE || defined(TCL_LOAD_FROM_MEMORY)
+    const struct mach_header *dyldLibHeader;
     Tcl_DyldModuleHandle *modulePtr;
+#endif
 } Tcl_DyldLoadHandle;
 
-#ifdef TCL_LOAD_FROM_MEMORY
+#if (TCL_DYLD_USE_DLFCN && MAC_OS_X_VERSION_MIN_REQUIRED < 1040) || \
+	defined(TCL_LOAD_FROM_MEMORY)
 MODULE_SCOPE long tclMacOSXDarwinRelease;
 #endif
+
+#ifdef TCL_DEBUG_LOAD
+#define TclLoadDbgMsg(m, ...) do { \
+	    fprintf(stderr, "%s:%d: %s(): " m ".\n", \
+	    strrchr(__FILE__, '/')+1, __LINE__, __func__, ##__VA_ARGS__); \
+	} while (0)
+#else
+#define TclLoadDbgMsg(m, ...)
+#endif
 
+#if TCL_DYLD_USE_NSMODULE || defined(TCL_LOAD_FROM_MEMORY)
 /*
  *----------------------------------------------------------------------
  *
@@ -75,6 +132,7 @@ DyldOFIErrorMsg(
 	return "unknown error";
     }
 }
+#endif /* TCL_DYLD_USE_NSMODULE */
 
 /*
  *----------------------------------------------------------------------
@@ -99,7 +157,7 @@ TclpDlopen(
     Tcl_Interp *interp,		/* Used for error reporting. */
     Tcl_Obj *pathPtr,		/* Name of the file containing the desired
 				 * code (UTF-8). */
-    Tcl_LoadHandle *loadHandle,	/* Filled with token for dynamically loaded
+    Tcl_LoadHandle *loadHandle, /* Filled with token for dynamically loaded
 				 * file which will be passed back to
 				 * (*unloadProcPtr)() to unload the file. */
     Tcl_FSUnloadFileProc **unloadProcPtr)
@@ -108,10 +166,23 @@ TclpDlopen(
 				 * file. */
 {
     Tcl_DyldLoadHandle *dyldLoadHandle;
-    CONST struct mach_header *dyldLibHeader;
-    NSObjectFileImage dyldObjFileImage = NULL;
+#if TCL_DYLD_USE_DLFCN
+    void *dlHandle = NULL;
+#endif
+#if TCL_DYLD_USE_NSMODULE || defined(TCL_LOAD_FROM_MEMORY)
+    const struct mach_header *dyldLibHeader = NULL;
     Tcl_DyldModuleHandle *modulePtr = NULL;
-    CONST char *native;
+#endif
+#if TCL_DYLD_USE_NSMODULE
+    NSLinkEditErrors editError;
+    int errorNumber;
+    const char *errorName, *objFileImageErrMsg = NULL;
+#endif
+    const char *errMsg = NULL;
+    int result;
+    Tcl_DString ds;
+    char *fileName = NULL;
+    const char *nativePath, *nativeFileName = NULL;
 
     /*
      * First try the full path the user gave us. This is particularly
@@ -119,92 +190,139 @@ TclpDlopen(
      * relative path.
      */
 
-    native = Tcl_FSGetNativePath(pathPtr);
-    dyldLibHeader = NSAddImage(native, NSADDIMAGE_OPTION_RETURN_ON_ERROR);
+    nativePath = Tcl_FSGetNativePath(pathPtr);
 
-    if (!dyldLibHeader) {
-	NSLinkEditErrors editError;
-	int errorNumber;
-	CONST char *name, *msg, *objFileImageErrMsg = NULL;
-
-	NSLinkEditError(&editError, &errorNumber, &name, &msg);
-
-	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.
-	     */
-
-	    Tcl_DString ds;
-	    char *fileName = Tcl_GetString(pathPtr);
-	    CONST char *native =
-		    Tcl_UtfToExternalDString(NULL, fileName, -1, &ds);
-
-	    dyldLibHeader = NSAddImage(native, NSADDIMAGE_OPTION_WITH_SEARCHING
-		    | NSADDIMAGE_OPTION_RETURN_ON_ERROR);
-	    Tcl_DStringFree(&ds);
-	    if (!dyldLibHeader) {
-		NSLinkEditError(&editError, &errorNumber, &name, &msg);
-	    }
-	} else if ((editError == NSLinkEditFileFormatError
-		&& errorNumber == EBADMACHO)
-		|| editError == NSLinkEditOtherError){
+#if TCL_DYLD_USE_DLFCN
+#if MAC_OS_X_VERSION_MIN_REQUIRED < 1040
+    if (tclMacOSXDarwinRelease >= 8)
+#endif
+    {
+	dlHandle = dlopen(nativePath, RTLD_NOW | RTLD_LOCAL);
+	if (!dlHandle) {
 	    /*
-	     * The requested file was found but was not of type MH_DYLIB,
-	     * attempt to load it as a MH_BUNDLE.
+	     * 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.
 	     */
 
-	    NSObjectFileImageReturnCode err =
-		    NSCreateObjectFileImageFromFile(native, &dyldObjFileImage);
-	    objFileImageErrMsg = DyldOFIErrorMsg(err);
+	    fileName = Tcl_GetString(pathPtr);
+	    nativeFileName = Tcl_UtfToExternalDString(NULL, fileName, -1, &ds);
+	    dlHandle = dlopen(nativeFileName, RTLD_NOW | RTLD_LOCAL);
 	}
-
-	if (!dyldLibHeader && !dyldObjFileImage) {
-	    Tcl_AppendResult(interp, msg, NULL);
-	    if (msg && *msg) {
-		Tcl_AppendResult(interp, "\n", NULL);
-	    }
-	    if (objFileImageErrMsg) {
-		Tcl_AppendResult(interp,
-			"NSCreateObjectFileImageFromFile() error: ",
-			objFileImageErrMsg, NULL);
+	if (dlHandle) {
+	    TclLoadDbgMsg("dlopen() successful");
+	} else {
+	    errMsg = dlerror();
+	    TclLoadDbgMsg("dlopen() failed: %s", errMsg);
+	}
+    }
+    if (!dlHandle)
+#endif /* TCL_DYLD_USE_DLFCN */
+    {
+#if TCL_DYLD_USE_NSMODULE
+	dyldLibHeader = NSAddImage(nativePath,
+		NSADDIMAGE_OPTION_RETURN_ON_ERROR);
+	if (dyldLibHeader) {
+	    TclLoadDbgMsg("NSAddImage() successful");
+	} else {
+	    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.
+		 */
+
+		if (!fileName) {
+		    fileName = Tcl_GetString(pathPtr);
+		    nativeFileName = Tcl_UtfToExternalDString(NULL, fileName,
+			    -1, &ds);
+		}
+		dyldLibHeader = NSAddImage(nativeFileName,
+			NSADDIMAGE_OPTION_WITH_SEARCHING |
+			NSADDIMAGE_OPTION_RETURN_ON_ERROR);
+		if (dyldLibHeader) {
+		    TclLoadDbgMsg("NSAddImage() successful");
+		} else {
+		    NSLinkEditError(&editError, &errorNumber, &errorName,
+			    &errMsg);
+		    TclLoadDbgMsg("NSAddImage() failed: %s", 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) {
+		    TclLoadDbgMsg("NSCreateObjectFileImageFromFile() "
+			    "successful");
+		    module = NSLinkModule(dyldObjFileImage, nativePath,
+			    NSLINKMODULE_OPTION_BINDNOW
+			    | NSLINKMODULE_OPTION_RETURN_ON_ERROR);
+		    NSDestroyObjectFileImage(dyldObjFileImage);
+		    if (module) {
+			modulePtr = (Tcl_DyldModuleHandle *)
+				ckalloc(sizeof(Tcl_DyldModuleHandle));
+			modulePtr->module = module;
+			modulePtr->nextPtr = NULL;
+			TclLoadDbgMsg("NSLinkModule() successful");
+		    } else {
+			NSLinkEditError(&editError, &errorNumber, &errorName,
+				&errMsg);
+			TclLoadDbgMsg("NSLinkModule() failed: %s", errMsg);
+		    }
+		} else {
+		    objFileImageErrMsg = DyldOFIErrorMsg(err);
+		    TclLoadDbgMsg("NSCreateObjectFileImageFromFile() failed: "
+			    "%s", objFileImageErrMsg);
+		}
 	    }
-	    return TCL_ERROR;
 	}
+#endif /* TCL_DYLD_USE_NSMODULE */
     }
-
-    if (dyldObjFileImage) {
-	NSModule module;
-
-	module = NSLinkModule(dyldObjFileImage, native,
-		NSLINKMODULE_OPTION_BINDNOW
-		| NSLINKMODULE_OPTION_RETURN_ON_ERROR);
-	NSDestroyObjectFileImage(dyldObjFileImage);
-
-	if (!module) {
-	    NSLinkEditErrors editError;
-	    int errorNumber;
-	    CONST char *name, *msg;
-
-	    NSLinkEditError(&editError, &errorNumber, &name, &msg);
-	    Tcl_AppendResult(interp, msg, NULL);
-	    return TCL_ERROR;
+    if (0
+#if TCL_DYLD_USE_DLFCN
+	    || dlHandle
+#endif
+#if TCL_DYLD_USE_NSMODULE
+	    || dyldLibHeader || modulePtr
+#endif
+    ) {
+	dyldLoadHandle = (Tcl_DyldLoadHandle *)
+		ckalloc(sizeof(Tcl_DyldLoadHandle));
+#if TCL_DYLD_USE_DLFCN
+	dyldLoadHandle->dlHandle = dlHandle;
+#endif
+#if TCL_DYLD_USE_NSMODULE || defined(TCL_LOAD_FROM_MEMORY)
+	dyldLoadHandle->dyldLibHeader = dyldLibHeader;
+	dyldLoadHandle->modulePtr = modulePtr;
+#endif
+	*loadHandle = (Tcl_LoadHandle) dyldLoadHandle;
+	*unloadProcPtr = &TclpUnloadFile;
+	result = TCL_OK;
+    } else {
+	Tcl_AppendResult(interp, errMsg, NULL);
+#if TCL_DYLD_USE_NSMODULE
+	if (objFileImageErrMsg) {
+	    Tcl_AppendResult(interp, "\nNSCreateObjectFileImageFromFile() "
+		    "error: ", objFileImageErrMsg, NULL);
 	}
-
-	modulePtr = (Tcl_DyldModuleHandle *)
-		ckalloc(sizeof(Tcl_DyldModuleHandle));
-	modulePtr->module = module;
-	modulePtr->nextPtr = NULL;
+#endif
+	result = TCL_ERROR;
     }
-
-    dyldLoadHandle = (Tcl_DyldLoadHandle *)
-	    ckalloc(sizeof(Tcl_DyldLoadHandle));
-    dyldLoadHandle->dyldLibHeader = dyldLibHeader;
-    dyldLoadHandle->modulePtr = modulePtr;
-    *loadHandle = (Tcl_LoadHandle) dyldLoadHandle;
-    *unloadProcPtr = &TclpUnloadFile;
-    return TCL_OK;
+    if(fileName) {
+	Tcl_DStringFree(&ds);
+    }
+    return result;
 }
 
 /*
@@ -229,68 +347,97 @@ TclpFindSymbol(
     Tcl_LoadHandle loadHandle,	/* Handle from TclpDlopen. */
     CONST char *symbol)		/* Symbol name to look up. */
 {
-    NSSymbol nsSymbol;
-    CONST char *native;
-    Tcl_DString newName, ds;
-    Tcl_PackageInitProc *proc = NULL;
     Tcl_DyldLoadHandle *dyldLoadHandle = (Tcl_DyldLoadHandle *) loadHandle;
-
-    /*
-     * dyld adds an underscore to the beginning of symbol names.
-     */
+    Tcl_PackageInitProc *proc = NULL;
+    const char *errMsg = NULL;
+    Tcl_DString ds;
+    const char *native;
 
     native = Tcl_UtfToExternalDString(NULL, symbol, -1, &ds);
-    Tcl_DStringInit(&newName);
-    Tcl_DStringAppend(&newName, "_", 1);
-    native = Tcl_DStringAppend(&newName, native, -1);
-
-    if (dyldLoadHandle->dyldLibHeader) {
-	nsSymbol = NSLookupSymbolInImage(dyldLoadHandle->dyldLibHeader, native,
-		NSLOOKUPSYMBOLINIMAGE_OPTION_BIND_NOW |
-		NSLOOKUPSYMBOLINIMAGE_OPTION_RETURN_ON_ERROR);
-	if (nsSymbol) {
-	    /*
-	     * Until dyld supports unloading of MY_DYLIB binaries, the
-	     * following is not needed.
-	     */
+#if TCL_DYLD_USE_DLFCN
+    if (dyldLoadHandle->dlHandle) {
+	proc = dlsym(dyldLoadHandle->dlHandle, native);
+	if (proc) {
+	    TclLoadDbgMsg("dlsym() successful");
+	} else {
+	    errMsg = dlerror();
+	    TclLoadDbgMsg("dlsym() failed: %s", errMsg);
+	}
+    } else
+#endif /* TCL_DYLD_USE_DLFCN */
+    {
+#if TCL_DYLD_USE_NSMODULE || defined(TCL_LOAD_FROM_MEMORY)
+	NSSymbol nsSymbol = NULL;
+	Tcl_DString newName;
 
-#ifdef DYLD_SUPPORTS_DYLIB_UNLOADING
-	    NSModule module = NSModuleForSymbol(nsSymbol);
-	    Tcl_DyldModuleHandle *modulePtr = dyldLoadHandle->modulePtr;
+	/*
+	 * dyld adds an underscore to the beginning of symbol names.
+	 */
 
-	    while (modulePtr != NULL) {
-		if (module == modulePtr->module) {
-		    break;
+	Tcl_DStringInit(&newName);
+	Tcl_DStringAppend(&newName, "_", 1);
+	native = Tcl_DStringAppend(&newName, native, -1);
+	if (dyldLoadHandle->dyldLibHeader) {
+	    nsSymbol = NSLookupSymbolInImage(dyldLoadHandle->dyldLibHeader,
+		    native, NSLOOKUPSYMBOLINIMAGE_OPTION_BIND_NOW |
+		    NSLOOKUPSYMBOLINIMAGE_OPTION_RETURN_ON_ERROR);
+	    if (nsSymbol) {
+		TclLoadDbgMsg("NSLookupSymbolInImage() successful");
+#ifdef DYLD_SUPPORTS_DYLIB_UNLOADING
+		/*
+		 * Until dyld supports unloading of MY_DYLIB binaries, the
+		 * following is not needed.
+		 */
+
+		NSModule module = NSModuleForSymbol(nsSymbol);
+		Tcl_DyldModuleHandle *modulePtr = dyldLoadHandle->modulePtr;
+
+		while (modulePtr != NULL) {
+		    if (module == modulePtr->module) {
+			break;
+		    }
+		    modulePtr = modulePtr->nextPtr;
+		}
+		if (modulePtr == NULL) {
+		    modulePtr = (Tcl_DyldModuleHandle *)
+			    ckalloc(sizeof(Tcl_DyldModuleHandle));
+		    modulePtr->module = module;
+		    modulePtr->nextPtr = dyldLoadHandle->modulePtr;
+		    dyldLoadHandle->modulePtr = modulePtr;
 		}
-		modulePtr = modulePtr->nextPtr;
-	    }
-	    if (modulePtr == NULL) {
-		modulePtr = (Tcl_DyldModuleHandle *)
-			ckalloc(sizeof(Tcl_DyldModuleHandle));
-		modulePtr->module = module;
-		modulePtr->nextPtr = dyldLoadHandle->modulePtr;
-		dyldLoadHandle->modulePtr = modulePtr;
-	    }
 #endif /* DYLD_SUPPORTS_DYLIB_UNLOADING */
+	    } else {
+		NSLinkEditErrors editError;
+		int errorNumber;
+		const char *errorName;
 
-	} else {
-	    NSLinkEditErrors editError;
-	    int errorNumber;
-	    CONST char *name, *msg;
-
-	    NSLinkEditError(&editError, &errorNumber, &name, &msg);
-	    Tcl_AppendResult(interp, msg, NULL);
+		NSLinkEditError(&editError, &errorNumber, &errorName, &errMsg);
+		TclLoadDbgMsg("NSLookupSymbolInImage() failed: %s", errMsg);
+	    }
+	} else if (dyldLoadHandle->modulePtr) {
+	    nsSymbol = NSLookupSymbolInModule(
+		    dyldLoadHandle->modulePtr->module, native);
+	    if (nsSymbol) {
+		TclLoadDbgMsg("NSLookupSymbolInModule() successful");
+	    } else {
+		TclLoadDbgMsg("NSLookupSymbolInModule() failed");
+	    }
 	}
-    } else {
-	nsSymbol = NSLookupSymbolInModule(dyldLoadHandle->modulePtr->module,
-		native);
-    }
-    if (nsSymbol) {
-	proc = NSAddressOfSymbol(nsSymbol);
+	if (nsSymbol) {
+	    proc = NSAddressOfSymbol(nsSymbol);
+	    if (proc) {
+		TclLoadDbgMsg("NSAddressOfSymbol() successful");
+	    } else {
+		TclLoadDbgMsg("NSAddressOfSymbol() failed");
+	    }
+	}
+	Tcl_DStringFree(&newName);
+#endif /* TCL_DYLD_USE_NSMODULE */
     }
-    Tcl_DStringFree(&newName);
     Tcl_DStringFree(&ds);
-
+    if (errMsg) {
+	Tcl_AppendResult(interp, errMsg, NULL);
+    }
     return proc;
 }
 
@@ -321,16 +468,39 @@ TclpUnloadFile(
 				 * that represents the loaded file. */
 {
     Tcl_DyldLoadHandle *dyldLoadHandle = (Tcl_DyldLoadHandle *) loadHandle;
-    Tcl_DyldModuleHandle *modulePtr = dyldLoadHandle->modulePtr;
 
-    while (modulePtr != NULL) {
-	void *ptr;
+#if TCL_DYLD_USE_DLFCN
+    if (dyldLoadHandle->dlHandle) {
+	int result;
 
-	NSUnLinkModule(modulePtr->module,
-		NSUNLINKMODULE_OPTION_RESET_LAZY_REFERENCES);
-	ptr = modulePtr;
-	modulePtr = modulePtr->nextPtr;
-	ckfree(ptr);
+	result = dlclose(dyldLoadHandle->dlHandle);
+	if (!result) {
+	    TclLoadDbgMsg("dlclose() successful");
+	} else {
+	    TclLoadDbgMsg("dlclose() failed: %s", dlerror());
+	}
+    } else
+#endif /* TCL_DYLD_USE_DLFCN */
+    {
+#if TCL_DYLD_USE_NSMODULE || defined(TCL_LOAD_FROM_MEMORY)
+	Tcl_DyldModuleHandle *modulePtr = dyldLoadHandle->modulePtr;
+
+	while (modulePtr != NULL) {
+	    void *ptr;
+	    bool result;
+
+	    result = NSUnLinkModule(modulePtr->module,
+		    NSUNLINKMODULE_OPTION_RESET_LAZY_REFERENCES);
+	    if (result) {
+		TclLoadDbgMsg("NSUnLinkModule() successful");
+	    } else {
+		TclLoadDbgMsg("NSUnLinkModule() failed");
+	    }
+	    ptr = modulePtr;
+	    modulePtr = modulePtr->nextPtr;
+	    ckfree(ptr);
+	}
+#endif /* TCL_DYLD_USE_NSMODULE */
     }
     ckfree((char*) dyldLoadHandle);
 }
@@ -434,7 +604,7 @@ TclpLoadMemory(
     int codeSize,		/* Size of code data read into buffer or -1 if
 				 * an error occurred and the buffer should
 				 * just be freed. */
-    Tcl_LoadHandle *loadHandle,	/* Filled with token for dynamically loaded
+    Tcl_LoadHandle *loadHandle, /* Filled with token for dynamically loaded
 				 * file which will be passed back to
 				 * (*unloadProcPtr)() to unload the file. */
     Tcl_FSUnloadFileProc **unloadProcPtr)
@@ -446,7 +616,7 @@ TclpLoadMemory(
     NSObjectFileImage dyldObjFileImage = NULL;
     Tcl_DyldModuleHandle *modulePtr;
     NSModule module;
-    CONST char *objFileImageErrMsg = NULL;
+    const char *objFileImageErrMsg = NULL;
 
     /*
      * Try to create an object file image that we can load from.
@@ -454,64 +624,88 @@ TclpLoadMemory(
 
     if (codeSize >= 0) {
 	NSObjectFileImageReturnCode err = NSObjectFileImageSuccess;
-	CONST struct fat_header *fh = buffer;
+	const struct fat_header *fh = buffer;
 	uint32_t ms = 0;
 #ifndef __LP64__
-	CONST struct mach_header *mh = NULL;
-	#define mh_magic OSSwapHostToBigInt32(MH_MAGIC)
+	const struct mach_header *mh = NULL;
 	#define mh_size  sizeof(struct mach_header)
+	#define mh_magic MH_MAGIC
+	#define arch_abi 0
 #else
-	CONST struct mach_header_64 *mh = NULL;
-	#define mh_magic OSSwapHostToBigInt32(MH_MAGIC_64)
+	const struct mach_header_64 *mh = NULL;
 	#define mh_size  sizeof(struct mach_header_64)
+	#define mh_magic MH_MAGIC_64
+	#define arch_abi CPU_ARCH_ABI64
 #endif
-	
+
 	if ((size_t) codeSize >= sizeof(struct fat_header)
 		&& fh->magic == OSSwapHostToBigInt32(FAT_MAGIC)) {
+	    uint32_t fh_nfat_arch = OSSwapBigToHostInt32(fh->nfat_arch);
+
 	    /*
 	     * Fat binary, try to find mach_header for our architecture
 	     */
-	    uint32_t fh_nfat_arch = OSSwapBigToHostInt32(fh->nfat_arch);
-	    
-	    if ((size_t) codeSize >= sizeof(struct fat_header) + 
+
+	    TclLoadDbgMsg("Fat binary, %d archs", fh_nfat_arch);
+	    if ((size_t) codeSize >= sizeof(struct fat_header) +
 		    fh_nfat_arch * sizeof(struct fat_arch)) {
 		void *fatarchs = (char*)buffer + sizeof(struct fat_header);
-		CONST NXArchInfo *arch = NXGetLocalArchInfo();
+		const NXArchInfo *arch = NXGetLocalArchInfo();
 		struct fat_arch *fa;
-		
+
 		if (fh->magic != FAT_MAGIC) {
 		    swap_fat_arch(fatarchs, fh_nfat_arch, arch->byteorder);
 		}
-		fa = NXFindBestFatArch(arch->cputype, arch->cpusubtype,
-			fatarchs, fh_nfat_arch);
+		fa = NXFindBestFatArch(arch->cputype | arch_abi,
+			arch->cpusubtype, fatarchs, fh_nfat_arch);
 		if (fa) {
+		    TclLoadDbgMsg("NXFindBestFatArch() successful: "
+			    "local cputype %d subtype %d, "
+			    "fat cputype %d subtype %d",
+			    arch->cputype | arch_abi, arch->cpusubtype,
+			    fa->cputype, fa->cpusubtype);
 		    mh = (void*)((char*)buffer + fa->offset);
 		    ms = fa->size;
 		} else {
+		    TclLoadDbgMsg("NXFindBestFatArch() failed");
 		    err = NSObjectFileImageInappropriateFile;
 		}
 		if (fh->magic != FAT_MAGIC) {
 		    swap_fat_arch(fatarchs, fh_nfat_arch, arch->byteorder);
 		}
 	    } else {
+		TclLoadDbgMsg("Fat binary header failure");
 		err = NSObjectFileImageInappropriateFile;
 	    }
 	} else {
 	    /*
 	     * Thin binary
 	     */
+
+	    TclLoadDbgMsg("Thin binary");
 	    mh = buffer;
 	    ms = codeSize;
 	}
 	if (ms && !(ms >= mh_size && mh->magic == mh_magic &&
-		 mh->filetype == OSSwapHostToBigInt32(MH_BUNDLE))) {
+		 mh->filetype == MH_BUNDLE)) {
+	    TclLoadDbgMsg("Inappropriate file: magic %x filetype %d",
+		    mh->magic, mh->filetype);
 	    err = NSObjectFileImageInappropriateFile;
 	}
 	if (err == NSObjectFileImageSuccess) {
 	    err = NSCreateObjectFileImageFromMemory(buffer, codeSize,
 		    &dyldObjFileImage);
+	    if (err == NSObjectFileImageSuccess) {
+		TclLoadDbgMsg("NSCreateObjectFileImageFromMemory() "
+			"successful");
+	    } else {
+		objFileImageErrMsg = DyldOFIErrorMsg(err);
+		TclLoadDbgMsg("NSCreateObjectFileImageFromMemory() failed: %s",
+			objFileImageErrMsg);
+	    }
+	} else {
+	    objFileImageErrMsg = DyldOFIErrorMsg(err);
 	}
-	objFileImageErrMsg = DyldOFIErrorMsg(err);
     }
 
     /*
@@ -522,9 +716,8 @@ TclpLoadMemory(
     if (dyldObjFileImage == NULL) {
 	vm_deallocate(mach_task_self(), (vm_address_t) buffer, size);
 	if (objFileImageErrMsg != NULL) {
-	    Tcl_AppendResult(interp,
-		    "NSCreateObjectFileImageFromMemory() error: ",
-		    objFileImageErrMsg, NULL);
+	    Tcl_AppendResult(interp, "NSCreateObjectFileImageFromMemory() "
+		    "error: ", objFileImageErrMsg, NULL);
 	}
 	return TCL_ERROR;
     }
@@ -536,14 +729,16 @@ TclpLoadMemory(
     module = NSLinkModule(dyldObjFileImage, "[Memory Based Bundle]",
 	    NSLINKMODULE_OPTION_BINDNOW | NSLINKMODULE_OPTION_RETURN_ON_ERROR);
     NSDestroyObjectFileImage(dyldObjFileImage);
-
-    if (!module) {
+    if (module) {
+	TclLoadDbgMsg("NSLinkModule() successful");
+    } else {
 	NSLinkEditErrors editError;
 	int errorNumber;
-	CONST char *name, *msg;
+	const char *errorName, *errMsg;
 
-	NSLinkEditError(&editError, &errorNumber, &name, &msg);
-	Tcl_AppendResult(interp, msg, NULL);
+	NSLinkEditError(&editError, &errorNumber, &errorName, &errMsg);
+	TclLoadDbgMsg("NSLinkModule() failed: %s", errMsg);
+	Tcl_AppendResult(interp, errMsg, NULL);
 	return TCL_ERROR;
     }
 
@@ -554,21 +749,23 @@ TclpLoadMemory(
     modulePtr = (Tcl_DyldModuleHandle *) ckalloc(sizeof(Tcl_DyldModuleHandle));
     modulePtr->module = module;
     modulePtr->nextPtr = NULL;
-
     dyldLoadHandle = (Tcl_DyldLoadHandle *)
 	    ckalloc(sizeof(Tcl_DyldLoadHandle));
+#if TCL_DYLD_USE_DLFCN
+    dyldLoadHandle->dlHandle = NULL;
+#endif
     dyldLoadHandle->dyldLibHeader = NULL;
     dyldLoadHandle->modulePtr = modulePtr;
     *loadHandle = (Tcl_LoadHandle) dyldLoadHandle;
     *unloadProcPtr = &TclpUnloadFile;
     return TCL_OK;
 }
-#endif
+#endif /* TCL_LOAD_FROM_MEMORY */
 
 /*
  * Local Variables:
  * mode: c
  * c-basic-offset: 4
- * fill-column: 78
+ * fill-column: 79
  * End:
  */