Merge 8.7

23 files changed, 396 insertions, 292 deletions

diff --git a/unix/configure b/unix/configure
index f4073cd..892288d 100755
--- a/unix/configure
+++ b/unix/configure
@@ -5036,7 +5036,7 @@ fi
     if test "$GCC" = yes; then :
 
 	CFLAGS_OPTIMIZE=-O2
-	CFLAGS_WARNING="-Wall -Wwrite-strings -Wsign-compare -Wdeclaration-after-statement -Wpointer-arith"
+	CFLAGS_WARNING="-Wall -Wextra -Wwrite-strings -Wsign-compare -Wpointer-arith"
 
 else
 
diff --git a/unix/tcl.m4 b/unix/tcl.m4
index 1bf731e..7f4f70b 100644
--- a/unix/tcl.m4
+++ b/unix/tcl.m4
@@ -93,7 +93,7 @@ AC_DEFUN([SC_PATH_TCLCONFIG], [
 			`ls -d /usr/local/lib 2>/dev/null` \
 			`ls -d /usr/contrib/lib 2>/dev/null` \
 			`ls -d /usr/pkg/lib 2>/dev/null` \
-			`ls -d /usr/lib/tcl8.7 2>/dev/null` \
+			`ls -d /usr/lib/tcl9.0 2>/dev/null` \
 			`ls -d /usr/lib 2>/dev/null` \
 			`ls -d /usr/lib64 2>/dev/null` \
 			`ls -d /usr/local/lib/tcl9.0 2>/dev/null` \
@@ -229,8 +229,8 @@ AC_DEFUN([SC_PATH_TKCONFIG], [
 			`ls -d /usr/lib/tk8.7 2>/dev/null` \
 			`ls -d /usr/lib 2>/dev/null` \
 			`ls -d /usr/lib64 2>/dev/null` \
-			`ls -d /usr/local/lib/tk9.0 2>/dev/null` \
-			`ls -d /usr/local/lib/tcl/tk9.0 2>/dev/null` \
+			`ls -d /usr/local/lib/tk8.7 2>/dev/null` \
+			`ls -d /usr/local/lib/tcl/tk8.7 2>/dev/null` \
 			; do
 		    if test -f "$i/tkConfig.sh" ; then
 			ac_cv_c_tkconfig="`(cd $i; pwd)`"
@@ -966,7 +966,15 @@ AC_DEFUN([SC_CONFIG_CFLAGS], [
     CFLAGS_DEBUG=-g
     AS_IF([test "$GCC" = yes], [
 	CFLAGS_OPTIMIZE=-O2
-	CFLAGS_WARNING="-Wall -Wwrite-strings -Wsign-compare -Wdeclaration-after-statement -Wpointer-arith"
+	CFLAGS_WARNING="-Wall -Wextra -Wwrite-strings -Wpointer-arith"
+	case "${CC}" in
+	    *++)
+		;;
+	    *)
+		CFLAGS_WARNING="${CFLAGS_WARNING} -Wc++-compat -Wdeclaration-after-statement"
+		;;
+	esac
+
     ], [
 	CFLAGS_OPTIMIZE=-O
 	CFLAGS_WARNING=""
diff --git a/unix/tclEpollNotfy.c b/unix/tclEpollNotfy.c
index 4d75781..f1d8cca 100644
--- a/unix/tclEpollNotfy.c
+++ b/unix/tclEpollNotfy.c
@@ -16,7 +16,9 @@
 #ifndef HAVE_COREFOUNDATION	/* Darwin/Mac OS X CoreFoundation notifier is
 				 * in tclMacOSXNotify.c */
 #if defined(NOTIFIER_EPOLL) && TCL_THREADS
-#define _GNU_SOURCE		/* For pipe2(2) */
+#ifndef _GNU_SOURCE
+#   define _GNU_SOURCE		/* For pipe2(2) */
+#endif
 #include <fcntl.h>
 #include <signal.h>
 #include <sys/epoll.h>
@@ -238,7 +240,7 @@ PlatformEventsControl(
 	newEvent.events |= EPOLLOUT;
     }
     if (isNew) {
-        newPedPtr = Tcl_Alloc(sizeof(*newPedPtr));
+        newPedPtr = (struct PlatformEventData *)Tcl_Alloc(sizeof(struct PlatformEventData));
         newPedPtr->filePtr = filePtr;
         newPedPtr->tsdPtr = tsdPtr;
 	filePtr->pedPtr = newPedPtr;
@@ -370,7 +372,7 @@ PlatformEventsInit(void)
     if (errno) {
 	Tcl_Panic("Tcl_InitNotifier: %s", "could not create mutex");
     }
-    filePtr = Tcl_Alloc(sizeof(*filePtr));
+    filePtr = (FileHandler *)Tcl_Alloc(sizeof(FileHandler));
 #ifdef HAVE_EVENTFD
     tsdPtr->triggerEventFd = eventfd(0, EFD_CLOEXEC | EFD_NONBLOCK);
     if (tsdPtr->triggerEventFd <= 0) {
@@ -391,7 +393,7 @@ PlatformEventsInit(void)
     PlatformEventsControl(filePtr, tsdPtr, EPOLL_CTL_ADD, 1);
     if (!tsdPtr->readyEvents) {
         tsdPtr->maxReadyEvents = 512;
-	tsdPtr->readyEvents = Tcl_Alloc(
+	tsdPtr->readyEvents = (struct epoll_event *)Tcl_Alloc(
 		tsdPtr->maxReadyEvents * sizeof(tsdPtr->readyEvents[0]));
     }
     LIST_INIT(&tsdPtr->firstReadyFileHandlerPtr);
@@ -550,7 +552,7 @@ Tcl_CreateFileHandler(
 	    }
 	}
 	if (filePtr == NULL) {
-	    filePtr = Tcl_Alloc(sizeof(FileHandler));
+	    filePtr = (FileHandler *)Tcl_Alloc(sizeof(FileHandler));
 	    filePtr->fd = fd;
 	    filePtr->readyMask = 0;
 	    filePtr->nextPtr = tsdPtr->firstFileHandlerPtr;
@@ -733,7 +735,7 @@ Tcl_WaitForEvent(
 	     */
 
 	    if (filePtr->readyMask == 0) {
-		FileHandlerEvent *fileEvPtr =
+		FileHandlerEvent *fileEvPtr = (FileHandlerEvent *)
 			Tcl_Alloc(sizeof(FileHandlerEvent));
 
 		fileEvPtr->header.proc = FileHandlerEventProc;
@@ -772,7 +774,7 @@ Tcl_WaitForEvent(
 	numFound = PlatformEventsWait(tsdPtr->readyEvents,
 		tsdPtr->maxReadyEvents, timeoutPtr);
 	for (numEvent = 0; numEvent < numFound; numEvent++) {
-	    pedPtr = tsdPtr->readyEvents[numEvent].data.ptr;
+	    pedPtr = (struct PlatformEventData*)tsdPtr->readyEvents[numEvent].data.ptr;
 	    filePtr = pedPtr->filePtr;
 	    mask = PlatformEventsTranslate(&tsdPtr->readyEvents[numEvent]);
 #ifdef HAVE_EVENTFD
@@ -810,7 +812,7 @@ Tcl_WaitForEvent(
 	     */
 
 	    if (filePtr->readyMask == 0) {
-		FileHandlerEvent *fileEvPtr =
+		FileHandlerEvent *fileEvPtr = (FileHandlerEvent *)
 			Tcl_Alloc(sizeof(FileHandlerEvent));
 
 		fileEvPtr->header.proc = FileHandlerEventProc;
diff --git a/unix/tclKqueueNotfy.c b/unix/tclKqueueNotfy.c
index bbb8061..6361d63 100644
--- a/unix/tclKqueueNotfy.c
+++ b/unix/tclKqueueNotfy.c
@@ -222,7 +222,7 @@ PlatformEventsControl(
     struct stat fdStat;
 
     if (isNew) {
-        newPedPtr = Tcl_Alloc(sizeof(*newPedPtr));
+        newPedPtr = (struct PlatformEventData *)Tcl_Alloc(sizeof(struct PlatformEventData));
         newPedPtr->filePtr = filePtr;
         newPedPtr->tsdPtr = tsdPtr;
         filePtr->pedPtr = newPedPtr;
@@ -409,13 +409,13 @@ PlatformEventsInit(void)
     } else if (fcntl(tsdPtr->eventsFd, F_SETFD, FD_CLOEXEC) == -1) {
 	Tcl_Panic("fcntl: %s", strerror(errno));
     }
-    filePtr = Tcl_Alloc(sizeof(*filePtr));
+    filePtr = (FileHandler *)Tcl_Alloc(sizeof(FileHandler));
     filePtr->fd = tsdPtr->triggerPipe[0];
     filePtr->mask = TCL_READABLE;
     PlatformEventsControl(filePtr, tsdPtr, EV_ADD, 1);
     if (!tsdPtr->readyEvents) {
         tsdPtr->maxReadyEvents = 512;
-	tsdPtr->readyEvents = Tcl_Alloc(
+	tsdPtr->readyEvents = (struct kevent *)Tcl_Alloc(
 		tsdPtr->maxReadyEvents * sizeof(tsdPtr->readyEvents[0]));
     }
     LIST_INIT(&tsdPtr->firstReadyFileHandlerPtr);
@@ -580,7 +580,7 @@ Tcl_CreateFileHandler(
 	    }
 	}
 	if (filePtr == NULL) {
-	    filePtr = Tcl_Alloc(sizeof(FileHandler));
+	    filePtr = (FileHandler *)Tcl_Alloc(sizeof(FileHandler));
 	    filePtr->fd = fd;
 	    filePtr->readyMask = 0;
 	    filePtr->nextPtr = tsdPtr->firstFileHandlerPtr;
@@ -768,7 +768,7 @@ Tcl_WaitForEvent(
 	     */
 
 	    if (filePtr->readyMask == 0) {
-		FileHandlerEvent *fileEvPtr =
+		FileHandlerEvent *fileEvPtr = (FileHandlerEvent *)
 			Tcl_Alloc(sizeof(FileHandlerEvent));
 
 		fileEvPtr->header.proc = FileHandlerEventProc;
@@ -828,7 +828,7 @@ Tcl_WaitForEvent(
 	     */
 
 	    if (filePtr->readyMask == 0) {
-		FileHandlerEvent *fileEvPtr =
+		FileHandlerEvent *fileEvPtr = (FileHandlerEvent *)
 			Tcl_Alloc(sizeof(FileHandlerEvent));
 
 		fileEvPtr->header.proc = FileHandlerEventProc;
diff --git a/unix/tclLoadDl.c b/unix/tclLoadDl.c
index d68df76..4b8fca6 100644
--- a/unix/tclLoadDl.c
+++ b/unix/tclLoadDl.c
@@ -83,7 +83,7 @@ TclpDlopen(
      * relative path.
      */
 
-    native = Tcl_FSGetNativePath(pathPtr);
+    native = (const char *)Tcl_FSGetNativePath(pathPtr);
     /*
      * Use (RTLD_NOW|RTLD_LOCAL) as default, see [Bug #3216070]
      */
@@ -131,7 +131,7 @@ TclpDlopen(
 	}
 	return TCL_ERROR;
     }
-    newHandle = Tcl_Alloc(sizeof(*newHandle));
+    newHandle = (Tcl_LoadHandle)Tcl_Alloc(sizeof(*newHandle));
     newHandle->clientData = handle;
     newHandle->findSymbolProcPtr = &FindSymbol;
     newHandle->unloadFileProcPtr = &UnloadFile;
@@ -188,6 +188,31 @@ FindSymbol(
 	proc = dlsym(handle, native);	/* INTL: Native. */
 	Tcl_DStringFree(&newName);
     }
+#ifdef __cplusplus
+    if (proc == NULL) {
+	char buf[32];
+	sprintf(buf, "%d", (int)Tcl_DStringLength(&ds));
+	Tcl_DStringInit(&newName);
+	TclDStringAppendLiteral(&newName, "__Z");
+	Tcl_DStringAppend(&newName, buf, -1);
+	Tcl_DStringAppend(&newName, Tcl_DStringValue(&ds), -1);
+	TclDStringAppendLiteral(&newName, "P10Tcl_Interp");
+	native = Tcl_DStringValue(&newName);
+	proc = dlsym(handle, native + 1);	/* INTL: Native. */
+	if (proc == NULL) {
+	    proc = dlsym(handle, native);	/* INTL: Native. */
+	}
+	if (proc == NULL) {
+	    TclDStringAppendLiteral(&newName, "i");
+	    native = Tcl_DStringValue(&newName);
+	    proc = dlsym(handle, native + 1);	/* INTL: Native. */
+	}
+	if (proc == NULL) {
+	    proc = dlsym(handle, native);	/* INTL: Native. */
+	}
+	Tcl_DStringFree(&newName);
+    }
+#endif
     Tcl_DStringFree(&ds);
     if (proc == NULL) {
 	const char *errorStr = dlerror();
@@ -261,6 +286,8 @@ TclGuessPackageName(
     Tcl_DString *bufPtr)	/* Initialized empty dstring. Append package
 				 * name to this if possible. */
 {
+    (void)fileName;
+    (void)bufPtr;
     return 0;
 }
 
diff --git a/unix/tclLoadDyld.c b/unix/tclLoadDyld.c
index af24841..dac4160 100644
--- a/unix/tclLoadDyld.c
+++ b/unix/tclLoadDyld.c
@@ -183,7 +183,7 @@ TclpDlopen(
      * relative path.
      */
 
-    nativePath = Tcl_FSGetNativePath(pathPtr);
+    nativePath = (const char *)Tcl_FSGetNativePath(pathPtr);
     nativeFileName = Tcl_UtfToExternalDString(NULL, TclGetString(pathPtr),
 	    -1, &ds);
 
@@ -258,7 +258,7 @@ TclpDlopen(
 		    module = NSLinkModule(dyldObjFileImage, nativePath, nsflags);
 		    NSDestroyObjectFileImage(dyldObjFileImage);
 		    if (module) {
-			modulePtr = Tcl_Alloc(sizeof(Tcl_DyldModuleHandle));
+			modulePtr = (Tcl_DyldModuleHandle *)Tcl_Alloc(sizeof(Tcl_DyldModuleHandle));
 			modulePtr->module = module;
 			modulePtr->nextPtr = NULL;
 		    } else {
@@ -278,13 +278,13 @@ TclpDlopen(
 	    || dyldLibHeader || modulePtr
 #endif /* TCL_DYLD_USE_NSMODULE */
     ) {
-	dyldLoadHandle = Tcl_Alloc(sizeof(Tcl_DyldLoadHandle));
+	dyldLoadHandle = (Tcl_DyldLoadHandle *)Tcl_Alloc(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_Alloc(sizeof(*newHandle));
+	newHandle = (Tcl_LoadHandle)Tcl_Alloc(sizeof(*newHandle));
 	newHandle->clientData = dyldLoadHandle;
 	newHandle->findSymbolProcPtr = &FindSymbol;
 	newHandle->unloadFileProcPtr = &UnloadFile;
@@ -334,7 +334,7 @@ FindSymbol(
     Tcl_LoadHandle loadHandle,	/* Handle from TclpDlopen. */
     const char *symbol)		/* Symbol name to look up. */
 {
-    Tcl_DyldLoadHandle *dyldLoadHandle = loadHandle->clientData;
+    Tcl_DyldLoadHandle *dyldLoadHandle = (Tcl_DyldLoadHandle *)loadHandle->clientData;
     Tcl_PackageInitProc *proc = NULL;
     const char *errMsg = NULL;
     Tcl_DString ds;
@@ -343,7 +343,7 @@ FindSymbol(
     native = Tcl_UtfToExternalDString(NULL, symbol, -1, &ds);
     if (dyldLoadHandle->dlHandle) {
 #if TCL_DYLD_USE_DLFCN
-	proc = dlsym(dyldLoadHandle->dlHandle, native);
+	proc = (Tcl_PackageInitProc *)dlsym(dyldLoadHandle->dlHandle, native);
 	if (!proc) {
 	    errMsg = dlerror();
 	}
@@ -381,7 +381,7 @@ FindSymbol(
 		    modulePtr = modulePtr->nextPtr;
 		}
 		if (modulePtr == NULL) {
-		    modulePtr = Tcl_Alloc(sizeof(Tcl_DyldModuleHandle));
+		    modulePtr = (Tcl_DyldModuleHandle *)Tcl_Alloc(sizeof(Tcl_DyldModuleHandle));
 		    modulePtr->module = module;
 		    modulePtr->nextPtr = dyldLoadHandle->modulePtr;
 		    dyldLoadHandle->modulePtr = modulePtr;
@@ -399,7 +399,7 @@ FindSymbol(
 		    dyldLoadHandle->modulePtr->module, native);
 	}
 	if (nsSymbol) {
-	    proc = NSAddressOfSymbol(nsSymbol);
+	    proc = (Tcl_PackageInitProc *)NSAddressOfSymbol(nsSymbol);
 	}
 	Tcl_DStringFree(&newName);
 #endif /* TCL_DYLD_USE_NSMODULE */
@@ -411,7 +411,7 @@ FindSymbol(
 	Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "LOAD_SYMBOL", symbol,
 		NULL);
     }
-    return proc;
+    return (void *)proc;
 }
 
 /*
@@ -440,7 +440,7 @@ UnloadFile(
 				 * TclpDlopen(). The loadHandle is a token
 				 * that represents the loaded file. */
 {
-    Tcl_DyldLoadHandle *dyldLoadHandle = loadHandle->clientData;
+    Tcl_DyldLoadHandle *dyldLoadHandle = (Tcl_DyldLoadHandle *)loadHandle->clientData;
 
     if (dyldLoadHandle->dlHandle) {
 #if TCL_DYLD_USE_DLFCN
@@ -491,6 +491,9 @@ TclGuessPackageName(
     Tcl_DString *bufPtr)	/* Initialized empty dstring. Append package
 				 * name to this if possible. */
 {
+    (void)fileName;
+    (void)bufPtr;
+
     return 0;
 }
 
@@ -513,10 +516,11 @@ TclGuessPackageName(
 #ifdef TCL_LOAD_FROM_MEMORY
 MODULE_SCOPE void *
 TclpLoadMemoryGetBuffer(
-    Tcl_Interp *interp,		/* Used for error reporting. */
+    Tcl_Interp *dummy,		/* Used for error reporting. */
     int size)			/* Size of desired buffer. */
 {
     void *buffer = NULL;
+    (void)dummy;
 
     /*
      * NSCreateObjectFileImageFromMemory is available but always fails
@@ -588,7 +592,7 @@ TclpLoadMemory(
 
     if (codeSize >= 0) {
 	NSObjectFileImageReturnCode err = NSObjectFileImageSuccess;
-	const struct fat_header *fh = buffer;
+	const struct fat_header *fh = (const struct fat_header *)buffer;
 	uint32_t ms = 0;
 #ifndef __LP64__
 	const struct mach_header *mh = NULL;
@@ -617,18 +621,18 @@ TclpLoadMemory(
 		struct fat_arch *fa;
 
 		if (fh->magic != FAT_MAGIC) {
-		    swap_fat_arch(fatarchs, fh_nfat_arch, arch->byteorder);
+		    swap_fat_arch((struct fat_arch *)fatarchs, fh_nfat_arch, arch->byteorder);
 		}
 		fa = NXFindBestFatArch(arch->cputype | arch_abi,
-			arch->cpusubtype, fatarchs, fh_nfat_arch);
+			arch->cpusubtype, (struct fat_arch *)fatarchs, fh_nfat_arch);
 		if (fa) {
-		    mh = (void *)((char *) buffer + fa->offset);
+		    mh = (const struct mach_header_64 *)((char *) buffer + fa->offset);
 		    ms = fa->size;
 		} else {
 		    err = NSObjectFileImageInappropriateFile;
 		}
 		if (fh->magic != FAT_MAGIC) {
-		    swap_fat_arch(fatarchs, fh_nfat_arch, arch->byteorder);
+		    swap_fat_arch((struct fat_arch *)fatarchs, fh_nfat_arch, arch->byteorder);
 		}
 	    } else {
 		err = NSObjectFileImageInappropriateFile;
@@ -638,7 +642,7 @@ TclpLoadMemory(
 	     * Thin binary
 	     */
 
-	    mh = buffer;
+	    mh = (const struct mach_header_64 *)buffer;
 	    ms = codeSize;
 	}
 	if (ms && !(ms >= mh_size && mh->magic == mh_magic &&
@@ -693,14 +697,14 @@ TclpLoadMemory(
      * Stash the module reference within the load handle we create and return.
      */
 
-    modulePtr = Tcl_Alloc(sizeof(Tcl_DyldModuleHandle));
+    modulePtr = (Tcl_DyldModuleHandle *)Tcl_Alloc(sizeof(Tcl_DyldModuleHandle));
     modulePtr->module = module;
     modulePtr->nextPtr = NULL;
-    dyldLoadHandle = Tcl_Alloc(sizeof(Tcl_DyldLoadHandle));
+    dyldLoadHandle = (Tcl_DyldLoadHandle *)Tcl_Alloc(sizeof(Tcl_DyldLoadHandle));
     dyldLoadHandle->dlHandle = NULL;
     dyldLoadHandle->dyldLibHeader = NULL;
     dyldLoadHandle->modulePtr = modulePtr;
-    newHandle = Tcl_Alloc(sizeof(*newHandle));
+    newHandle = (Tcl_LoadHandle)Tcl_Alloc(sizeof(*newHandle));
     newHandle->clientData = dyldLoadHandle;
     newHandle->findSymbolProcPtr = &FindSymbol;
     newHandle->unloadFileProcPtr = &UnloadFile;
diff --git a/unix/tclLoadNext.c b/unix/tclLoadNext.c
index 393bfc5..5fa9c21 100644
--- a/unix/tclLoadNext.c
+++ b/unix/tclLoadNext.c
@@ -101,7 +101,7 @@ TclpDlopen(
     }
     NXCloseMemory(errorStream, NX_FREEBUFFER);
 
-    newHandle = Tcl_Alloc(sizeof(Tcl_LoadHandle));
+    newHandle = (Tcl_LoadHandle) Tcl_Alloc(sizeof(*newHandle));
     newHandle->clientData = INT2PTR(1);
     newHandle->findSymbolProcPtr = &FindSymbol;
     newHandle->unloadFileProcPtr = &UnloadFile;
diff --git a/unix/tclLoadOSF.c b/unix/tclLoadOSF.c
index f67725f..a69a0be 100644
--- a/unix/tclLoadOSF.c
+++ b/unix/tclLoadOSF.c
@@ -128,7 +128,7 @@ TclpDlopen(
     } else {
 	pkg++;
     }
-    newHandle = Tcl_Alloc(sizeof(*newHandle));
+    newHandle = (Tcl_LoadHandle)Tcl_Alloc(sizeof(*newHandle));
     newHandle->clientData = pkg;
     newHandle->findSymbolProcPtr = &FindSymbol;
     newHandle->unloadFileProcPtr = &UnloadFile;
diff --git a/unix/tclLoadShl.c b/unix/tclLoadShl.c
index fc5f27c..534ca4d 100644
--- a/unix/tclLoadShl.c
+++ b/unix/tclLoadShl.c
@@ -97,7 +97,7 @@ TclpDlopen(
 		fileName, Tcl_PosixError(interp)));
 	return TCL_ERROR;
     }
-    newHandle = Tcl_Alloc(sizeof(*newHandle));
+    newHandle = (Tcl_LoadHandle)Tcl_Alloc(sizeof(*newHandle));
     newHandle->clientData = handle;
     newHandle->findSymbolProcPtr = &FindSymbol;
     newHandle->unloadFileProcPtr = *unloadProcPtr = &UnloadFile;
diff --git a/unix/tclSelectNotfy.c b/unix/tclSelectNotfy.c
index 62d77dd..2a22639 100644
--- a/unix/tclSelectNotfy.c
+++ b/unix/tclSelectNotfy.c
@@ -210,6 +210,9 @@ static int		FileHandlerEventProc(Tcl_Event *evPtr, int flags);
  */
 
 #if defined(__CYGWIN__)
+#ifdef __cplusplus
+extern "C" {
+#endif
 typedef struct {
     void *hwnd;			/* Messaging window. */
     unsigned int *message;	/* Message payload. */
@@ -260,9 +263,12 @@ extern unsigned char __stdcall	TranslateMessage(const MSG *);
  * Threaded-cygwin specific constants and functions in this file:
  */
 
-static const WCHAR className[] = L"TclNotifier";
+static const wchar_t className[] = L"TclNotifier";
 static DWORD __stdcall	NotifierProc(void *hwnd, unsigned int message,
 			    void *wParam, void *lParam);
+#ifdef __cplusplus
+}
+#endif
 #endif /* TCL_THREADS && __CYGWIN__ */
 
 
@@ -300,22 +306,22 @@ Tcl_InitNotifier(void)
 	 */
 	if (tsdPtr->waitCVinitialized == 0) {
 #ifdef __CYGWIN__
-	    WNDCLASSW class;
-
-	    class.style = 0;
-	    class.cbClsExtra = 0;
-	    class.cbWndExtra = 0;
-	    class.hInstance = TclWinGetTclInstance();
-	    class.hbrBackground = NULL;
-	    class.lpszMenuName = NULL;
-	    class.lpszClassName = className;
-	    class.lpfnWndProc = NotifierProc;
-	    class.hIcon = NULL;
-	    class.hCursor = NULL;
-
-	    RegisterClassW(&class);
-	    tsdPtr->hwnd = CreateWindowExW(NULL, class.lpszClassName,
-		    class.lpszClassName, 0, 0, 0, 0, 0, NULL, NULL,
+	    WNDCLASSW clazz;
+
+	    clazz.style = 0;
+	    clazz.cbClsExtra = 0;
+	    clazz.cbWndExtra = 0;
+	    clazz.hInstance = TclWinGetTclInstance();
+	    clazz.hbrBackground = NULL;
+	    clazz.lpszMenuName = NULL;
+	    clazz.lpszClassName = className;
+	    clazz.lpfnWndProc = (void *)NotifierProc;
+	    clazz.hIcon = NULL;
+	    clazz.hCursor = NULL;
+
+	    RegisterClassW(&clazz);
+	    tsdPtr->hwnd = CreateWindowExW(NULL, clazz.lpszClassName,
+		    clazz.lpszClassName, 0, 0, 0, 0, 0, NULL, NULL,
 		    TclWinGetTclInstance(), NULL);
 	    tsdPtr->event = CreateEventW(NULL, 1 /* manual */,
 		    0 /* !signaled */, NULL);
@@ -467,7 +473,7 @@ Tcl_CreateFileHandler(
 	    }
 	}
 	if (filePtr == NULL) {
-	    filePtr = Tcl_Alloc(sizeof(FileHandler));
+	    filePtr = (FileHandler *)Tcl_Alloc(sizeof(FileHandler));
 	    filePtr->fd = fd;
 	    filePtr->readyMask = 0;
 	    filePtr->nextPtr = tsdPtr->firstFileHandlerPtr;
@@ -880,7 +886,7 @@ Tcl_WaitForEvent(
 
 	    if (filePtr->readyMask == 0) {
 		FileHandlerEvent *fileEvPtr =
-			Tcl_Alloc(sizeof(FileHandlerEvent));
+			(FileHandlerEvent *)Tcl_Alloc(sizeof(FileHandlerEvent));
 
 		fileEvPtr->header.proc = FileHandlerEventProc;
 		fileEvPtr->fd = filePtr->fd;
@@ -922,7 +928,7 @@ Tcl_WaitForEvent(
 #if TCL_THREADS
 static TCL_NORETURN void
 NotifierThreadProc(
-    ClientData clientData)	/* Not used. */
+    ClientData dummy)	/* Not used. */
 {
     ThreadSpecificData *tsdPtr;
     fd_set readableMask;
@@ -931,9 +937,10 @@ NotifierThreadProc(
     int i;
     int fds[2], receivePipe;
     long found;
-    struct timeval poll = {0., 0.}, *timePtr;
+    struct timeval poll = {0, 0}, *timePtr;
     char buf[2];
     int numFdBits = 0;
+    (void)dummy;
 
     if (pipe(fds) != 0) {
 	Tcl_Panic("NotifierThreadProc: %s", "could not create trigger pipe");
diff --git a/unix/tclUnixChan.c b/unix/tclUnixChan.c
index f1838a2..2314ba3 100644
--- a/unix/tclUnixChan.c
+++ b/unix/tclUnixChan.c
@@ -119,27 +119,27 @@ typedef struct {
  * Static routines for this file:
  */
 
-static int		FileBlockModeProc(ClientData instanceData, int mode);
-static int		FileCloseProc(ClientData instanceData,
+static int		FileBlockModeProc(void *instanceData, int mode);
+static int		FileCloseProc(void *instanceData,
 			    Tcl_Interp *interp);
-static int		FileGetHandleProc(ClientData instanceData,
-			    int direction, ClientData *handlePtr);
-static int		FileInputProc(ClientData instanceData, char *buf,
+static int		FileGetHandleProc(void *instanceData,
+			    int direction, void **handlePtr);
+static int		FileInputProc(void *instanceData, char *buf,
 			    int toRead, int *errorCode);
-static int		FileOutputProc(ClientData instanceData,
+static int		FileOutputProc(void *instanceData,
 			    const char *buf, int toWrite, int *errorCode);
-static int		FileSeekProc(ClientData instanceData, long offset,
+static int		FileSeekProc(void *instanceData, long offset,
 			    int mode, int *errorCode);
-static int		FileTruncateProc(ClientData instanceData,
+static int		FileTruncateProc(void *instanceData,
 			    Tcl_WideInt length);
-static Tcl_WideInt	FileWideSeekProc(ClientData instanceData,
+static Tcl_WideInt	FileWideSeekProc(void *instanceData,
 			    Tcl_WideInt offset, int mode, int *errorCode);
-static void		FileWatchProc(ClientData instanceData, int mask);
+static void		FileWatchProc(void *instanceData, int mask);
 #ifdef SUPPORTS_TTY
-static int		TtyCloseProc(ClientData instanceData,
+static int		TtyCloseProc(void *instanceData,
 			    Tcl_Interp *interp);
 static void		TtyGetAttributes(int fd, TtyAttrs *ttyPtr);
-static int		TtyGetOptionProc(ClientData instanceData,
+static int		TtyGetOptionProc(void *instanceData,
 			    Tcl_Interp *interp, const char *optionName,
 			    Tcl_DString *dsPtr);
 static int		TtyGetBaud(speed_t speed);
@@ -149,7 +149,7 @@ static void		TtyModemStatusStr(int status, Tcl_DString *dsPtr);
 static int		TtyParseMode(Tcl_Interp *interp, const char *mode,
 			    TtyAttrs *ttyPtr);
 static void		TtySetAttributes(int fd, TtyAttrs *ttyPtr);
-static int		TtySetOptionProc(ClientData instanceData,
+static int		TtySetOptionProc(void *instanceData,
 			    Tcl_Interp *interp, const char *optionName,
 			    const char *value);
 #endif	/* SUPPORTS_TTY */
@@ -225,11 +225,11 @@ static const Tcl_ChannelType ttyChannelType = {
 	/* ARGSUSED */
 static int
 FileBlockModeProc(
-    ClientData instanceData,	/* File state. */
+    void *instanceData,	/* File state. */
     int mode)			/* The mode to set. Can be TCL_MODE_BLOCKING
 				 * or TCL_MODE_NONBLOCKING. */
 {
-    FileState *fsPtr = instanceData;
+    FileState *fsPtr = (FileState *)instanceData;
 
     if (TclUnixSetBlockingMode(fsPtr->fd, mode) < 0) {
 	return errno;
@@ -258,13 +258,13 @@ FileBlockModeProc(
 
 static int
 FileInputProc(
-    ClientData instanceData,	/* File state. */
+    void *instanceData,	/* File state. */
     char *buf,			/* Where to store data read. */
     int toRead,			/* How much space is available in the
 				 * buffer? */
     int *errorCodePtr)		/* Where to store error code. */
 {
-    FileState *fsPtr = instanceData;
+    FileState *fsPtr = (FileState *)instanceData;
     int bytesRead;		/* How many bytes were actually read from the
 				 * input device? */
 
@@ -305,12 +305,12 @@ FileInputProc(
 
 static int
 FileOutputProc(
-    ClientData instanceData,	/* File state. */
+    void *instanceData,	/* File state. */
     const char *buf,		/* The data buffer. */
     int toWrite,		/* How many bytes to write? */
     int *errorCodePtr)		/* Where to store error code. */
 {
-    FileState *fsPtr = instanceData;
+    FileState *fsPtr = (FileState *)instanceData;
     int written;
 
     *errorCodePtr = 0;
@@ -352,11 +352,12 @@ FileOutputProc(
 
 static int
 FileCloseProc(
-    ClientData instanceData,	/* File state. */
-    Tcl_Interp *interp)		/* For error reporting - unused. */
+    void *instanceData,	/* File state. */
+    Tcl_Interp *dummy)		/* For error reporting - unused. */
 {
-    FileState *fsPtr = instanceData;
+    FileState *fsPtr = (FileState *)instanceData;
     int errorCode = 0;
+    (void)dummy;
 
     Tcl_DeleteFileHandler(fsPtr->fd);
 
@@ -377,10 +378,10 @@ FileCloseProc(
 #ifdef SUPPORTS_TTY
 static int
 TtyCloseProc(
-    ClientData instanceData,
+    void *instanceData,
     Tcl_Interp *interp)
 {
-    TtyState *ttyPtr = instanceData;
+    TtyState *ttyPtr = (TtyState*)instanceData;
 
     /*
      * If we've been asked by the user to drain or flush, do so now.
@@ -435,13 +436,13 @@ TtyCloseProc(
 
 static int
 FileSeekProc(
-    ClientData instanceData,	/* File state. */
+    void *instanceData,	/* File state. */
     long offset,		/* Offset to seek to. */
     int mode,			/* Relative to where should we seek? Can be
 				 * one of SEEK_START, SEEK_SET or SEEK_END. */
     int *errorCodePtr)		/* To store error code. */
 {
-    FileState *fsPtr = instanceData;
+    FileState *fsPtr = (FileState *)instanceData;
     Tcl_WideInt oldLoc, newLoc;
 
     /*
@@ -496,13 +497,13 @@ FileSeekProc(
 
 static Tcl_WideInt
 FileWideSeekProc(
-    ClientData instanceData,	/* File state. */
+    void *instanceData,	/* File state. */
     Tcl_WideInt offset,		/* Offset to seek to. */
     int mode,			/* Relative to where should we seek? Can be
 				 * one of SEEK_START, SEEK_CUR or SEEK_END. */
     int *errorCodePtr)		/* To store error code. */
 {
-    FileState *fsPtr = instanceData;
+    FileState *fsPtr = (FileState *)instanceData;
     Tcl_WideInt newLoc;
 
     newLoc = TclOSseek(fsPtr->fd, (Tcl_SeekOffset) offset, mode);
@@ -530,12 +531,12 @@ FileWideSeekProc(
 
 static void
 FileWatchProc(
-    ClientData instanceData,	/* The file state. */
+    void *instanceData,	/* The file state. */
     int mask)			/* Events of interest; an OR-ed combination of
 				 * TCL_READABLE, TCL_WRITABLE and
 				 * TCL_EXCEPTION. */
 {
-    FileState *fsPtr = instanceData;
+    FileState *fsPtr = (FileState *)instanceData;
 
     /*
      * Make sure we only register for events that are valid on this file. Note
@@ -572,11 +573,11 @@ FileWatchProc(
 
 static int
 FileGetHandleProc(
-    ClientData instanceData,	/* The file state. */
+    void *instanceData,	/* The file state. */
     int direction,		/* TCL_READABLE or TCL_WRITABLE */
-    ClientData *handlePtr)	/* Where to store the handle. */
+    void **handlePtr)	/* Where to store the handle. */
 {
-    FileState *fsPtr = instanceData;
+    FileState *fsPtr = (FileState *)instanceData;
 
     if (direction & fsPtr->validMask) {
 	*handlePtr = INT2PTR(fsPtr->fd);
@@ -639,12 +640,12 @@ TtyModemStatusStr(
 
 static int
 TtySetOptionProc(
-    ClientData instanceData,	/* File state. */
+    void *instanceData,	/* File state. */
     Tcl_Interp *interp,		/* For error reporting - can be NULL. */
     const char *optionName,	/* Which option to set? */
     const char *value)		/* New value for option. */
 {
-    TtyState *fsPtr = instanceData;
+    TtyState *fsPtr = (TtyState *)instanceData;
     size_t len, vlen;
     TtyAttrs tty;
     int argc;
@@ -978,12 +979,12 @@ TtySetOptionProc(
 
 static int
 TtyGetOptionProc(
-    ClientData instanceData,	/* File state. */
+    void *instanceData,	/* File state. */
     Tcl_Interp *interp,		/* For error reporting - can be NULL. */
     const char *optionName,	/* Option to get. */
     Tcl_DString *dsPtr)		/* Where to store value(s). */
 {
-    TtyState *fsPtr = instanceData;
+    TtyState *fsPtr = (TtyState *)instanceData;
     size_t len;
     char buf[3*TCL_INTEGER_SPACE + 16];
     int valid = 0;		/* Flag if valid option parsed. */
@@ -1652,7 +1653,7 @@ TclpOpenFileChannel(
 	return NULL;
     }
 
-    native = Tcl_FSGetNativePath(pathPtr);
+    native = (const char *)Tcl_FSGetNativePath(pathPtr);
     if (native == NULL) {
 	if (interp != (Tcl_Interp *) NULL) {
 	    Tcl_AppendResult(interp, "couldn't open \"",
@@ -1712,7 +1713,7 @@ TclpOpenFileChannel(
 	sprintf(channelName, "file%d", fd);
     }
 
-    fsPtr = Tcl_Alloc(sizeof(TtyState));
+    fsPtr = (TtyState *)Tcl_Alloc(sizeof(TtyState));
     fsPtr->fileState.validMask = channelPermissions | TCL_EXCEPTION;
     fsPtr->fileState.fd = fd;
 #ifdef SUPPORTS_TTY
@@ -1763,7 +1764,7 @@ TclpOpenFileChannel(
 
 Tcl_Channel
 Tcl_MakeFileChannel(
-    ClientData handle,		/* OS level handle. */
+    void *handle,		/* OS level handle. */
     int mode)			/* ORed combination of TCL_READABLE and
 				 * TCL_WRITABLE to indicate file mode. */
 {
@@ -1792,7 +1793,7 @@ Tcl_MakeFileChannel(
 		&& (sockaddrLen > 0)
 		&& (sockaddr.sa_family == AF_INET
 			|| sockaddr.sa_family == AF_INET6)) {
-	    return TclpMakeTcpClientChannelMode(INT2PTR(fd), mode);
+	    return (Tcl_Channel)TclpMakeTcpClientChannelMode(INT2PTR(fd), mode);
 	}
 	goto normalChannelAfterAll;
     } else {
@@ -1801,7 +1802,7 @@ Tcl_MakeFileChannel(
 	sprintf(channelName, "file%d", fd);
     }
 
-    fsPtr = Tcl_Alloc(sizeof(TtyState));
+    fsPtr = (TtyState *)Tcl_Alloc(sizeof(TtyState));
     fsPtr->fileState.fd = fd;
     fsPtr->fileState.validMask = mode | TCL_EXCEPTION;
     fsPtr->fileState.channel = Tcl_CreateChannel(channelTypePtr, channelName,
@@ -1932,18 +1933,19 @@ Tcl_GetOpenFile(
     const char *chanID,		/* String that identifies file. */
     int forWriting,		/* 1 means the file is going to be used for
 				 * writing, 0 means for reading. */
-    int checkUsage,		/* 1 means verify that the file was opened in
+    int dummy,		/* 1 means verify that the file was opened in
 				 * a mode that allows the access specified by
 				 * "forWriting". Ignored, we always check that
 				 * the channel is open for the requested
 				 * mode. */
-    ClientData *filePtr)	/* Store pointer to FILE structure here. */
+    void **filePtr)	/* Store pointer to FILE structure here. */
 {
     Tcl_Channel chan;
     int chanMode, fd;
     const Tcl_ChannelType *chanTypePtr;
-    ClientData data;
+    void *data;
     FILE *f;
+    (void)dummy;
 
     chan = Tcl_GetChannel(interp, chanID, &chanMode);
     if (chan == NULL) {
@@ -2027,10 +2029,10 @@ Tcl_GetOpenFile(
 
 static int
 FileTruncateProc(
-    ClientData instanceData,
+    void *instanceData,
     Tcl_WideInt length)
 {
-    FileState *fsPtr = instanceData;
+    FileState *fsPtr = (FileState *)instanceData;
     int result;
 
 #ifdef HAVE_TYPE_OFF64_T
diff --git a/unix/tclUnixCompat.c b/unix/tclUnixCompat.c
index 9b8acc9..3b81e6f 100644
--- a/unix/tclUnixCompat.c
+++ b/unix/tclUnixCompat.c
@@ -116,10 +116,10 @@ static int		CopyString(const char *src, char *buf, int buflen);
 #endif
 
 #ifdef NEED_PW_CLEANER
-static void		FreePwBuf(ClientData ignored);
+static void		FreePwBuf(ClientData dummy);
 #endif
 #ifdef NEED_GR_CLEANER
-static void		FreeGrBuf(ClientData ignored);
+static void		FreeGrBuf(ClientData dummy);
 #endif
 #endif /* TCL_THREADS */
 
@@ -199,7 +199,7 @@ TclpGetPwNam(
 	if (tsdPtr->pbuflen < 1) {
 	    tsdPtr->pbuflen = 1024;
 	}
-	tsdPtr->pbuf = Tcl_Alloc(tsdPtr->pbuflen);
+	tsdPtr->pbuf = (char *)Tcl_Alloc(tsdPtr->pbuflen);
 	Tcl_CreateThreadExitHandler(FreePwBuf, NULL);
     }
     while (1) {
@@ -212,7 +212,7 @@ TclpGetPwNam(
 	    return NULL;
 	}
 	tsdPtr->pbuflen *= 2;
-	tsdPtr->pbuf = Tcl_Realloc(tsdPtr->pbuf, tsdPtr->pbuflen);
+	tsdPtr->pbuf = (char *)Tcl_Realloc(tsdPtr->pbuf, tsdPtr->pbuflen);
     }
     return (pwPtr != NULL ? &tsdPtr->pwd : NULL);
 
@@ -279,7 +279,7 @@ TclpGetPwUid(
 	if (tsdPtr->pbuflen < 1) {
 	    tsdPtr->pbuflen = 1024;
 	}
-	tsdPtr->pbuf = Tcl_Alloc(tsdPtr->pbuflen);
+	tsdPtr->pbuf = (char *)Tcl_Alloc(tsdPtr->pbuflen);
 	Tcl_CreateThreadExitHandler(FreePwBuf, NULL);
     }
     while (1) {
@@ -292,7 +292,7 @@ TclpGetPwUid(
 	    return NULL;
 	}
 	tsdPtr->pbuflen *= 2;
-	tsdPtr->pbuf = Tcl_Realloc(tsdPtr->pbuf, tsdPtr->pbuflen);
+	tsdPtr->pbuf = (char *)Tcl_Realloc(tsdPtr->pbuf, tsdPtr->pbuflen);
     }
     return (pwPtr != NULL ? &tsdPtr->pwd : NULL);
 
@@ -334,9 +334,10 @@ TclpGetPwUid(
 #ifdef NEED_PW_CLEANER
 static void
 FreePwBuf(
-    ClientData ignored)
+    ClientData dummy)
 {
     ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
+    (void)dummy;
 
     Tcl_Free(tsdPtr->pbuf);
 }
@@ -382,7 +383,7 @@ TclpGetGrNam(
 	if (tsdPtr->gbuflen < 1) {
 	    tsdPtr->gbuflen = 1024;
 	}
-	tsdPtr->gbuf = Tcl_Alloc(tsdPtr->gbuflen);
+	tsdPtr->gbuf = (char*)Tcl_Alloc(tsdPtr->gbuflen);
 	Tcl_CreateThreadExitHandler(FreeGrBuf, NULL);
     }
     while (1) {
@@ -395,7 +396,7 @@ TclpGetGrNam(
 	    return NULL;
 	}
 	tsdPtr->gbuflen *= 2;
-	tsdPtr->gbuf = Tcl_Realloc(tsdPtr->gbuf, tsdPtr->gbuflen);
+	tsdPtr->gbuf = (char *)Tcl_Realloc(tsdPtr->gbuf, tsdPtr->gbuflen);
     }
     return (grPtr != NULL ? &tsdPtr->grp : NULL);
 
@@ -462,7 +463,7 @@ TclpGetGrGid(
 	if (tsdPtr->gbuflen < 1) {
 	    tsdPtr->gbuflen = 1024;
 	}
-	tsdPtr->gbuf = Tcl_Alloc(tsdPtr->gbuflen);
+	tsdPtr->gbuf = (char*)Tcl_Alloc(tsdPtr->gbuflen);
 	Tcl_CreateThreadExitHandler(FreeGrBuf, NULL);
     }
     while (1) {
@@ -475,7 +476,7 @@ TclpGetGrGid(
 	    return NULL;
 	}
 	tsdPtr->gbuflen *= 2;
-	tsdPtr->gbuf = Tcl_Realloc(tsdPtr->gbuf, tsdPtr->gbuflen);
+	tsdPtr->gbuf = (char *)Tcl_Realloc(tsdPtr->gbuf, tsdPtr->gbuflen);
     }
     return (grPtr != NULL ? &tsdPtr->grp : NULL);
 
@@ -517,9 +518,10 @@ TclpGetGrGid(
 #ifdef NEED_GR_CLEANER
 static void
 FreeGrBuf(
-    ClientData ignored)
+    ClientData dummy)
 {
     ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
+    (void)dummy;
 
     Tcl_Free(tsdPtr->gbuf);
 }
diff --git a/unix/tclUnixFCmd.c b/unix/tclUnixFCmd.c
index b32a2a2..1e2156c 100644
--- a/unix/tclUnixFCmd.c
+++ b/unix/tclUnixFCmd.c
@@ -111,16 +111,8 @@ typedef int (TraversalProc)(Tcl_DString *srcPtr, Tcl_DString *dstPtr,
  * elsewhere in Tcl's core.
  */
 
-#ifdef DJGPP
-
-/*
- * See contrib/djgpp/tclDjgppFCmd.c for definition.
- */
-
-extern TclFileAttrProcs tclpFileAttrProcs[];
-extern const char *const tclpFileAttrStrings[];
+#ifndef DJGPP
 
-#else /* !DJGPP */
 enum {
 #if defined(__CYGWIN__)
     UNIX_ARCHIVE_ATTRIBUTE,
@@ -143,7 +135,6 @@ enum {
     UNIX_INVALID_ATTRIBUTE /* lint - last enum value needs no trailing , */
 };
 
-MODULE_SCOPE const char *const tclpFileAttrStrings[];
 const char *const tclpFileAttrStrings[] = {
 #if defined(__CYGWIN__)
     "-archive",
@@ -165,7 +156,6 @@ const char *const tclpFileAttrStrings[] = {
     NULL
 };
 
-MODULE_SCOPE const TclFileAttrProcs tclpFileAttrProcs[];
 const TclFileAttrProcs tclpFileAttrProcs[] = {
 #if defined(__CYGWIN__)
     {GetUnixFileAttributes, SetUnixFileAttributes},
@@ -334,8 +324,8 @@ TclpObjRenameFile(
     Tcl_Obj *srcPathPtr,
     Tcl_Obj *destPathPtr)
 {
-    return DoRenameFile(Tcl_FSGetNativePath(srcPathPtr),
-	    Tcl_FSGetNativePath(destPathPtr));
+    return DoRenameFile((const char *)Tcl_FSGetNativePath(srcPathPtr),
+	    (const char *)Tcl_FSGetNativePath(destPathPtr));
 }
 
 static int
@@ -450,14 +440,14 @@ TclpObjCopyFile(
     Tcl_Obj *srcPathPtr,
     Tcl_Obj *destPathPtr)
 {
-    const char *src = Tcl_FSGetNativePath(srcPathPtr);
+    const char *src = (const char *)Tcl_FSGetNativePath(srcPathPtr);
     Tcl_StatBuf srcStatBuf;
 
     if (TclOSlstat(src, &srcStatBuf) != 0) {		/* INTL: Native. */
 	return TCL_ERROR;
     }
 
-    return DoCopyFile(src, Tcl_FSGetNativePath(destPathPtr), &srcStatBuf);
+    return DoCopyFile(src, (const char *)Tcl_FSGetNativePath(destPathPtr), &srcStatBuf);
 }
 
 static int
@@ -613,7 +603,7 @@ TclUnixCopyFile(
     if (blockSize <= 0) {
 	blockSize = DEFAULT_COPY_BLOCK_SIZE;
     }
-    buffer = Tcl_Alloc(blockSize);
+    buffer = (char *)Tcl_Alloc(blockSize);
     while (1) {
 	nread = read(srcFd, buffer, blockSize);
 	if ((nread == TCL_IO_FAILURE) || (nread == 0)) {
@@ -712,7 +702,7 @@ int
 TclpObjCreateDirectory(
     Tcl_Obj *pathPtr)
 {
-    return DoCreateDirectory(Tcl_FSGetNativePath(pathPtr));
+    return DoCreateDirectory((const char *)Tcl_FSGetNativePath(pathPtr));
 }
 
 static int
@@ -1243,7 +1233,7 @@ TraversalCopy(
 static int
 TraversalDelete(
     Tcl_DString *srcPtr,	/* Source pathname (native). */
-    Tcl_DString *ignore,	/* Destination pathname (not used). */
+    Tcl_DString *dummy,	/* Destination pathname (not used). */
     const Tcl_StatBuf *statBufPtr,
 				/* Stat info for file specified by srcPtr. */
     int type,			/* Reason for call - see TraverseUnixTree(). */
@@ -1251,6 +1241,9 @@ TraversalDelete(
 				 * filled with UTF-8 name of file causing
 				 * error. */
 {
+    (void)dummy;
+    (void)statBufPtr;
+
     switch (type) {
     case DOTREE_F:
 	if (TclpDeleteFile(Tcl_DStringValue(srcPtr)) == 0) {
@@ -1299,6 +1292,7 @@ CopyFileAtts(
 {
     struct utimbuf tval;
     mode_t newMode;
+    (void)src;
 
     newMode = statBufPtr->st_mode
 	    & (S_ISUID | S_ISGID | S_IRWXU | S_IRWXG | S_IRWXO);
@@ -1357,6 +1351,7 @@ GetGroupAttribute(
     Tcl_StatBuf statBuf;
     struct group *groupPtr;
     int result;
+    (void)objIndex;
 
     result = TclpObjStat(fileName, &statBuf);
 
@@ -1411,6 +1406,7 @@ GetOwnerAttribute(
     Tcl_StatBuf statBuf;
     struct passwd *pwPtr;
     int result;
+    (void)objIndex;
 
     result = TclpObjStat(fileName, &statBuf);
 
@@ -1462,6 +1458,7 @@ GetPermissionsAttribute(
 {
     Tcl_StatBuf statBuf;
     int result;
+    (void)objIndex;
 
     result = TclpObjStat(fileName, &statBuf);
 
@@ -1505,6 +1502,7 @@ SetGroupAttribute(
     Tcl_WideInt gid;
     int result;
     const char *native;
+    (void)objIndex;
 
     if (Tcl_GetWideIntFromObj(NULL, attributePtr, &gid) != TCL_OK) {
 	Tcl_DString ds;
@@ -1532,7 +1530,7 @@ SetGroupAttribute(
 	gid = groupPtr->gr_gid;
     }
 
-    native = Tcl_FSGetNativePath(fileName);
+    native = (const char *)Tcl_FSGetNativePath(fileName);
     result = chown(native, (uid_t) -1, (gid_t) gid);	/* INTL: Native. */
 
     if (result != 0) {
@@ -1572,6 +1570,7 @@ SetOwnerAttribute(
     Tcl_WideInt uid;
     int result;
     const char *native;
+    (void)objIndex;
 
     if (Tcl_GetWideIntFromObj(NULL, attributePtr, &uid) != TCL_OK) {
 	Tcl_DString ds;
@@ -1599,7 +1598,7 @@ SetOwnerAttribute(
 	uid = pwPtr->pw_uid;
     }
 
-    native = Tcl_FSGetNativePath(fileName);
+    native = (const char *)Tcl_FSGetNativePath(fileName);
     result = chown(native, (uid_t) uid, (gid_t) -1);	/* INTL: Native. */
 
     if (result != 0) {
@@ -1642,6 +1641,7 @@ SetPermissionsAttribute(
     const char *native;
     const char *modeStringPtr = TclGetString(attributePtr);
     int scanned = TclParseAllWhiteSpace(modeStringPtr, -1);
+    (void)objIndex;
 
     /*
      * First supply support for octal number format
@@ -1693,7 +1693,7 @@ SetPermissionsAttribute(
 	}
     }
 
-    native = Tcl_FSGetNativePath(fileName);
+    native = (const char *)Tcl_FSGetNativePath(fileName);
     result = chmod(native, newMode);		/* INTL: Native. */
     if (result != 0) {
 	if (interp != NULL) {
@@ -1754,7 +1754,7 @@ TclpObjListVolumes(void)
 
 static int
 GetModeFromPermString(
-    Tcl_Interp *interp,		/* The interp we are using for errors. */
+    Tcl_Interp *dummy,		/* The interp we are using for errors. */
     const char *modeStringPtr, /* Permissions string */
     mode_t *modePtr)		/* pointer to the mode value */
 {
@@ -1763,6 +1763,7 @@ GetModeFromPermString(
 				 * is passed in), to allow for the chmod style
 				 * manipulation. */
     int i,n, who, op, what, op_found, who_found;
+    (void)dummy;
 
     /*
      * We start off checking for an "rwxrwxrwx" style permissions string
@@ -1941,7 +1942,7 @@ GetModeFromPermString(
 
 int
 TclpObjNormalizePath(
-    Tcl_Interp *interp,
+    Tcl_Interp *dummy,
     Tcl_Obj *pathPtr,		/* An unshared object containing the path to
 				 * normalize. */
     int nextCheckpoint)		/* offset to start at in pathPtr.  Must either
@@ -1960,6 +1961,7 @@ TclpObjNormalizePath(
 #ifndef NO_REALPATH
     char normPath[MAXPATHLEN];
 #endif
+    (void)dummy;
 
     currentPathEndPosition = path + nextCheckpoint;
     if (*currentPathEndPosition == '/') {
@@ -1972,7 +1974,7 @@ TclpObjNormalizePath(
 	 * Try to get the entire path in one go
 	 */
 
-	char *lastDir = strrchr(currentPathEndPosition, '/');
+	const char *lastDir = strrchr(currentPathEndPosition, '/');
 
 	if (lastDir != NULL) {
 	    nativePath = Tcl_UtfToExternalDString(NULL, path,
@@ -2174,7 +2176,7 @@ TclUnixOpenTemporaryFile(
     Tcl_Obj *extensionObj,
     Tcl_Obj *resultingNameObj)
 {
-    Tcl_DString template, tmp;
+    Tcl_DString templ, tmp;
     const char *string;
     int fd;
     size_t length;
@@ -2185,46 +2187,46 @@ TclUnixOpenTemporaryFile(
 
     if (dirObj) {
 	string = TclGetStringFromObj(dirObj, &length);
-	Tcl_UtfToExternalDString(NULL, string, length, &template);
+	Tcl_UtfToExternalDString(NULL, string, length, &templ);
     } else {
-	Tcl_DStringInit(&template);
-	Tcl_DStringAppend(&template, DefaultTempDir(), -1); /* INTL: native */
+	Tcl_DStringInit(&templ);
+	Tcl_DStringAppend(&templ, DefaultTempDir(), -1); /* INTL: native */
     }
 
-    TclDStringAppendLiteral(&template, "/");
+    TclDStringAppendLiteral(&templ, "/");
 
     if (basenameObj) {
 	string = TclGetStringFromObj(basenameObj, &length);
 	Tcl_UtfToExternalDString(NULL, string, length, &tmp);
-	TclDStringAppendDString(&template, &tmp);
+	TclDStringAppendDString(&templ, &tmp);
 	Tcl_DStringFree(&tmp);
     } else {
-	TclDStringAppendLiteral(&template, "tcl");
+	TclDStringAppendLiteral(&templ, "tcl");
     }
 
-    TclDStringAppendLiteral(&template, "_XXXXXX");
+    TclDStringAppendLiteral(&templ, "_XXXXXX");
 
 #ifdef HAVE_MKSTEMPS
     if (extensionObj) {
 	string = TclGetStringFromObj(extensionObj, &length);
 	Tcl_UtfToExternalDString(NULL, string, length, &tmp);
-	TclDStringAppendDString(&template, &tmp);
-	fd = mkstemps(Tcl_DStringValue(&template), Tcl_DStringLength(&tmp));
+	TclDStringAppendDString(&templ, &tmp);
+	fd = mkstemps(Tcl_DStringValue(&templ), Tcl_DStringLength(&tmp));
 	Tcl_DStringFree(&tmp);
     } else
 #endif
     {
-	fd = mkstemp(Tcl_DStringValue(&template));
+	fd = mkstemp(Tcl_DStringValue(&templ));
     }
 
     if (fd == -1) {
-	Tcl_DStringFree(&template);
+	Tcl_DStringFree(&templ);
 	return -1;
     }
 
     if (resultingNameObj) {
-	Tcl_ExternalToUtfDString(NULL, Tcl_DStringValue(&template),
-		Tcl_DStringLength(&template), &tmp);
+	Tcl_ExternalToUtfDString(NULL, Tcl_DStringValue(&templ),
+		Tcl_DStringLength(&templ), &tmp);
 	Tcl_SetStringObj(resultingNameObj, Tcl_DStringValue(&tmp),
 		Tcl_DStringLength(&tmp));
 	Tcl_DStringFree(&tmp);
@@ -2235,10 +2237,10 @@ TclUnixOpenTemporaryFile(
 	 * this!
 	 */
 
-	unlink(Tcl_DStringValue(&template));
+	unlink(Tcl_DStringValue(&templ));
 	errno = 0;
     }
-    Tcl_DStringFree(&template);
+    Tcl_DStringFree(&templ);
 
     return fd;
 }
@@ -2298,7 +2300,7 @@ TclpCreateTemporaryDirectory(
     Tcl_Obj *dirObj,
     Tcl_Obj *basenameObj)
 {
-    Tcl_DString template, tmp;
+    Tcl_DString templ, tmp;
     const char *string;
 
 #define DEFAULT_TEMP_DIR_PREFIX	"tcl"
@@ -2310,37 +2312,37 @@ TclpCreateTemporaryDirectory(
 
     if (dirObj) {
 	string = TclGetString(dirObj);
-	Tcl_UtfToExternalDString(NULL, string, dirObj->length, &template);
+	Tcl_UtfToExternalDString(NULL, string, dirObj->length, &templ);
     } else {
-	Tcl_DStringInit(&template);
-	Tcl_DStringAppend(&template, DefaultTempDir(), -1); /* INTL: native */
+	Tcl_DStringInit(&templ);
+	Tcl_DStringAppend(&templ, DefaultTempDir(), -1); /* INTL: native */
     }
 
-    if (Tcl_DStringValue(&template)[Tcl_DStringLength(&template) - 1] != '/') {
-	TclDStringAppendLiteral(&template, "/");
+    if (Tcl_DStringValue(&templ)[Tcl_DStringLength(&templ) - 1] != '/') {
+	TclDStringAppendLiteral(&templ, "/");
     }
 
     if (basenameObj) {
 	string = TclGetString(basenameObj);
 	if (basenameObj->length) {
 	    Tcl_UtfToExternalDString(NULL, string, basenameObj->length, &tmp);
-	    TclDStringAppendDString(&template, &tmp);
+	    TclDStringAppendDString(&templ, &tmp);
 	    Tcl_DStringFree(&tmp);
 	} else {
-	    TclDStringAppendLiteral(&template, DEFAULT_TEMP_DIR_PREFIX);
+	    TclDStringAppendLiteral(&templ, DEFAULT_TEMP_DIR_PREFIX);
 	}
     } else {
-	TclDStringAppendLiteral(&template, DEFAULT_TEMP_DIR_PREFIX);
+	TclDStringAppendLiteral(&templ, DEFAULT_TEMP_DIR_PREFIX);
     }
 
-    TclDStringAppendLiteral(&template, "_XXXXXX");
+    TclDStringAppendLiteral(&templ, "_XXXXXX");
 
     /*
      * Make the temporary directory.
      */
 
-    if (mkdtemp(Tcl_DStringValue(&template)) == NULL) {
-	Tcl_DStringFree(&template);
+    if (mkdtemp(Tcl_DStringValue(&templ)) == NULL) {
+	Tcl_DStringFree(&templ);
 	return NULL;
     }
 
@@ -2348,9 +2350,9 @@ TclpCreateTemporaryDirectory(
      * The template has been updated. Tell the caller what it was.
      */
 
-    Tcl_ExternalToUtfDString(NULL, Tcl_DStringValue(&template),
-	    Tcl_DStringLength(&template), &tmp);
-    Tcl_DStringFree(&template);
+    Tcl_ExternalToUtfDString(NULL, Tcl_DStringValue(&templ),
+	    Tcl_DStringLength(&templ), &tmp);
+    Tcl_DStringFree(&templ);
     return TclDStringToObj(&tmp);
 }
 
@@ -2372,11 +2374,11 @@ winPathFromObj(
     Tcl_Obj *fileName)
 {
     size_t size;
-    const char *native =  Tcl_FSGetNativePath(fileName);
+    const char *native =  (const char *)Tcl_FSGetNativePath(fileName);
     WCHAR *winPath;
 
     size = cygwin_conv_path(1, native, NULL, 0);
-    winPath = Tcl_Alloc(size);
+    winPath = (WCHAR *)Tcl_Alloc(size);
     cygwin_conv_path(1, native, winPath, size);
 
     return winPath;
@@ -2511,6 +2513,7 @@ GetUnixFileAttributes(
 {
     Tcl_StatBuf statBuf;
     int result;
+    (void)objIndex;
 
     result = TclpObjStat(fileName, &statBuf);
 
@@ -2553,6 +2556,7 @@ SetUnixFileAttributes(
     Tcl_StatBuf statBuf;
     int result, readonly;
     const char *native;
+    (void)objIndex;
 
     if (Tcl_GetBooleanFromObj(interp, attributePtr, &readonly) != TCL_OK) {
 	return TCL_ERROR;
@@ -2575,7 +2579,7 @@ SetUnixFileAttributes(
 	statBuf.st_flags &= ~UF_IMMUTABLE;
     }
 
-    native = Tcl_FSGetNativePath(fileName);
+    native = (const char *)Tcl_FSGetNativePath(fileName);
     result = chflags(native, statBuf.st_flags);		/* INTL: Native. */
     if (result != 0) {
 	if (interp != NULL) {
diff --git a/unix/tclUnixFile.c b/unix/tclUnixFile.c
index 944bec8..83c194a 100644
--- a/unix/tclUnixFile.c
+++ b/unix/tclUnixFile.c
@@ -44,6 +44,8 @@ TclpFindExecutable(
     size_t length;
     wchar_t buf[PATH_MAX];
     char name[PATH_MAX * 3 + 1];
+    (void)argv0;
+
     GetModuleFileNameW(NULL, buf, PATH_MAX);
     cygwin_conv_path(3, buf, name, PATH_MAX);
     length = strlen(name);
@@ -249,9 +251,9 @@ TclpMatchInDirectory(
 	Tcl_Obj *tailPtr;
 	const char *nativeTail;
 
-	native = Tcl_FSGetNativePath(pathPtr);
+	native = (const char *)Tcl_FSGetNativePath(pathPtr);
 	tailPtr = TclPathPart(interp, pathPtr, TCL_PATH_TAIL);
-	nativeTail = Tcl_FSGetNativePath(tailPtr);
+	nativeTail = (const char *)Tcl_FSGetNativePath(tailPtr);
 	matchResult = NativeMatchType(interp, native, nativeTail, types);
 	if (matchResult == 1) {
 	    Tcl_ListObjAppendElement(interp, resultPtr, pathPtr);
@@ -555,6 +557,8 @@ NativeMatchType(
 	    return matchResult;
 	}
     }
+#else
+    (void)interp;
 #endif /* MAC_OSX_TCL */
 
     return 1;
@@ -622,7 +626,7 @@ TclpObjAccess(
     Tcl_Obj *pathPtr,		/* Path of file to access */
     int mode)			/* Permission setting. */
 {
-    const char *path = Tcl_FSGetNativePath(pathPtr);
+    const char *path = (const char *)Tcl_FSGetNativePath(pathPtr);
 
     if (path == NULL) {
 	return -1;
@@ -650,7 +654,7 @@ int
 TclpObjChdir(
     Tcl_Obj *pathPtr)		/* Path to new working directory */
 {
-    const char *path = Tcl_FSGetNativePath(pathPtr);
+    const char *path = (const char *)Tcl_FSGetNativePath(pathPtr);
 
     if (path == NULL) {
 	return -1;
@@ -679,7 +683,7 @@ TclpObjLstat(
     Tcl_Obj *pathPtr,		/* Path of file to stat */
     Tcl_StatBuf *bufPtr)	/* Filled with results of stat call. */
 {
-    return TclOSlstat(Tcl_FSGetNativePath(pathPtr), bufPtr);
+    return TclOSlstat((const char *)Tcl_FSGetNativePath(pathPtr), bufPtr);
 }
 
 /*
@@ -720,7 +724,7 @@ TclpGetNativeCwd(
 #endif /* USEGETWD */
 
     if ((clientData == NULL) || strcmp(buffer, (const char *) clientData)) {
-	char *newCd = Tcl_Alloc(strlen(buffer) + 1);
+	char *newCd = (char*)Tcl_Alloc(strlen(buffer) + 1);
 
 	strcpy(newCd, buffer);
 	return newCd;
@@ -847,7 +851,7 @@ TclpObjStat(
     Tcl_Obj *pathPtr,		/* Path of file to stat */
     Tcl_StatBuf *bufPtr)	/* Filled with results of stat call. */
 {
-    const char *path = Tcl_FSGetNativePath(pathPtr);
+    const char *path = (const char *)Tcl_FSGetNativePath(pathPtr);
 
     if (path == NULL) {
 	return -1;
@@ -864,7 +868,7 @@ TclpObjLink(
     int linkAction)
 {
     if (toPtr != NULL) {
-	const char *src = Tcl_FSGetNativePath(pathPtr);
+	const char *src = (const char *)Tcl_FSGetNativePath(pathPtr);
 	const char *target = NULL;
 
 	if (src == NULL) {
@@ -910,7 +914,7 @@ TclpObjLink(
 	    Tcl_DecrRefCount(absPtr);
 	    Tcl_DecrRefCount(dirPtr);
 	} else {
-	    target = Tcl_FSGetNativePath(toPtr);
+	    target = (const char*)Tcl_FSGetNativePath(toPtr);
 	    if (target == NULL) {
 		return NULL;
 	    }
@@ -983,7 +987,7 @@ TclpObjLink(
 	}
 	Tcl_DecrRefCount(transPtr);
 
-	length = readlink(Tcl_FSGetNativePath(pathPtr), link, sizeof(link));
+	length = readlink((const char *)Tcl_FSGetNativePath(pathPtr), link, sizeof(link));
 	if (length < 0) {
 	    return NULL;
 	}
@@ -1019,6 +1023,7 @@ Tcl_Obj *
 TclpFilesystemPathType(
     Tcl_Obj *pathPtr)
 {
+    (void)pathPtr;
     /*
      * All native paths are of the same type.
      */
@@ -1116,7 +1121,7 @@ TclNativeCreateNativeRep(
 	return NULL;
     }
     Tcl_DecrRefCount(validPathPtr);
-    nativePathPtr = Tcl_Alloc(len);
+    nativePathPtr = (char *)Tcl_Alloc(len);
     memcpy(nativePathPtr, Tcl_DStringValue(&ds), len);
 
     Tcl_DStringFree(&ds);
@@ -1157,7 +1162,7 @@ TclNativeDupInternalRep(
 
     len = (strlen((const char*) clientData) + 1) * sizeof(char);
 
-    copy = Tcl_Alloc(len);
+    copy = (char *)Tcl_Alloc(len);
     memcpy(copy, clientData, len);
     return copy;
 }
@@ -1183,7 +1188,7 @@ TclpUtime(
     Tcl_Obj *pathPtr,		/* File to modify */
     struct utimbuf *tval)	/* New modification date structure */
 {
-    return utime(Tcl_FSGetNativePath(pathPtr), tval);
+    return utime((const char *)Tcl_FSGetNativePath(pathPtr), tval);
 }
 
 #ifdef __CYGWIN__
@@ -1194,7 +1199,7 @@ TclOSstat(
     void *cygstat)
 {
     struct stat buf;
-    Tcl_StatBuf *statBuf = cygstat;
+    Tcl_StatBuf *statBuf = (Tcl_StatBuf *)cygstat;
     int result = stat(name, &buf);
 
     statBuf->st_mode = buf.st_mode;
@@ -1217,7 +1222,7 @@ TclOSlstat(
     void *cygstat)
 {
     struct stat buf;
-    Tcl_StatBuf *statBuf = cygstat;
+    Tcl_StatBuf *statBuf = (Tcl_StatBuf *)cygstat;
     int result = lstat(name, &buf);
 
     statBuf->st_mode = buf.st_mode;
diff --git a/unix/tclUnixInit.c b/unix/tclUnixInit.c
index 2aa64bf..b37d4ad 100644
--- a/unix/tclUnixInit.c
+++ b/unix/tclUnixInit.c
@@ -31,6 +31,9 @@
 #endif
 
 #ifdef __CYGWIN__
+#ifdef __cplusplus
+extern "C" {
+#endif
 #ifdef __clang__
 #pragma clang diagnostic ignored "-Wignored-attributes"
 #endif
@@ -39,6 +42,9 @@ DLLIMPORT extern __stdcall void *GetModuleHandleW(const void *);
 DLLIMPORT extern __stdcall void FreeLibrary(void *);
 DLLIMPORT extern __stdcall void *GetProcAddress(void *, const char *);
 DLLIMPORT extern __stdcall void GetSystemInfo(void *);
+#ifdef __cplusplus
+}
+#endif
 
 #define NUMPROCESSORS 11
 static const char *const processors[NUMPROCESSORS] = {
@@ -539,7 +545,7 @@ TclpInitLibraryPath(
 
     *encodingPtr = Tcl_GetEncoding(NULL, NULL);
     str = TclGetStringFromObj(pathPtr, lengthPtr);
-    *valuePtr = Tcl_Alloc(*lengthPtr + 1);
+    *valuePtr = (char *)Tcl_Alloc(*lengthPtr + 1);
     memcpy(*valuePtr, str, *lengthPtr + 1);
     Tcl_DecrRefCount(pathPtr);
 }
@@ -1058,6 +1064,10 @@ MacOSXGetLibraryPath(
     foundInFramework = Tcl_MacOSXOpenVersionedBundleResources(interp,
 	    "com.tcltk.tcllibrary", TCL_FRAMEWORK_VERSION, 0, maxPathLen,
 	    tclLibPath);
+#else
+    (void)interp;
+    (void)maxPathLen;
+    (void)tclLibPath;
 #endif
 
     return foundInFramework;
diff --git a/unix/tclUnixNotfy.c b/unix/tclUnixNotfy.c
index 3817071..6b1ec3d 100644
--- a/unix/tclUnixNotfy.c
+++ b/unix/tclUnixNotfy.c
@@ -108,7 +108,7 @@ Tcl_AlertNotifier(
     } else {
 #ifdef NOTIFIER_SELECT
 #if TCL_THREADS
-	ThreadSpecificData *tsdPtr = clientData;
+	ThreadSpecificData *tsdPtr = (ThreadSpecificData *)clientData;
 
 	pthread_mutex_lock(&notifierMutex);
 	tsdPtr->eventReady = 1;
@@ -121,7 +121,7 @@ Tcl_AlertNotifier(
 	pthread_mutex_unlock(&notifierMutex);
 #endif /* TCL_THREADS */
 #else /* !NOTIFIER_SELECT */
-	ThreadSpecificData *tsdPtr = clientData;
+	ThreadSpecificData *tsdPtr = (ThreadSpecificData *)clientData;
 #if defined(NOTIFIER_EPOLL) && defined(HAVE_EVENTFD)
 	uint64_t eventFdVal = 1;
 	if (write(tsdPtr->triggerEventFd, &eventFdVal,
diff --git a/unix/tclUnixPipe.c b/unix/tclUnixPipe.c
index dfeee0c..55fd03d 100644
--- a/unix/tclUnixPipe.c
+++ b/unix/tclUnixPipe.c
@@ -48,16 +48,16 @@ typedef struct {
  * Declarations for local functions defined in this file:
  */
 
-static int		PipeBlockModeProc(ClientData instanceData, int mode);
-static int		PipeClose2Proc(ClientData instanceData,
+static int		PipeBlockModeProc(void *instanceData, int mode);
+static int		PipeClose2Proc(void *instanceData,
 			    Tcl_Interp *interp, int flags);
-static int		PipeGetHandleProc(ClientData instanceData,
-			    int direction, ClientData *handlePtr);
-static int		PipeInputProc(ClientData instanceData, char *buf,
+static int		PipeGetHandleProc(void *instanceData,
+			    int direction, void **handlePtr);
+static int		PipeInputProc(void *instanceData, char *buf,
 			    int toRead, int *errorCode);
-static int		PipeOutputProc(ClientData instanceData,
+static int		PipeOutputProc(void *instanceData,
 			    const char *buf, int toWrite, int *errorCode);
-static void		PipeWatchProc(ClientData instanceData, int mask);
+static void		PipeWatchProc(void *instanceData, int mask);
 static void		RestoreSignals(void);
 static int		SetupStdFile(TclFile file, int type);
 
@@ -107,7 +107,7 @@ TclpMakeFile(
     Tcl_Channel channel,	/* Channel to get file from. */
     int direction)		/* Either TCL_READABLE or TCL_WRITABLE. */
 {
-    ClientData data;
+    void *data;
 
     if (Tcl_GetChannelHandle(channel, direction, &data) != TCL_OK) {
 	return NULL;
@@ -271,6 +271,7 @@ TclpTempFileNameForLibrary(
     Tcl_Obj *path)		/* Path name of the library in the VFS. */
 {
     Tcl_Obj *retval = TclpTempFileName();
+    (void)path;
 
     if (retval == NULL) {
 	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
@@ -432,8 +433,8 @@ TclpCreateProcess(
      * deallocated later
      */
 
-    dsArray = TclStackAlloc(interp, argc * sizeof(Tcl_DString));
-    newArgv = TclStackAlloc(interp, (argc+1) * sizeof(char *));
+    dsArray = (Tcl_DString *)TclStackAlloc(interp, argc * sizeof(Tcl_DString));
+    newArgv = (char **)TclStackAlloc(interp, (argc+1) * sizeof(char *));
     newArgv[argc] = NULL;
     for (i = 0; i < argc; i++) {
 	newArgv[i] = Tcl_UtfToExternalDString(NULL, argv[i], -1, &dsArray[i]);
@@ -744,7 +745,7 @@ TclpCreateCommandChannel(
 {
     char channelName[16 + TCL_INTEGER_SPACE];
     int channelId;
-    PipeState *statePtr = Tcl_Alloc(sizeof(PipeState));
+    PipeState *statePtr = (PipeState *)Tcl_Alloc(sizeof(PipeState));
     int mode;
 
     statePtr->inFile = readFile;
@@ -813,6 +814,7 @@ Tcl_CreatePipe(
     int flags)			/* Reserved for future use. */
 {
     int fileNums[2];
+    (void)flags;
 
     if (pipe(fileNums) < 0) {
 	Tcl_SetObjResult(interp, Tcl_ObjPrintf("pipe creation failed: %s",
@@ -869,7 +871,7 @@ TclGetAndDetachPids(
 	return;
     }
 
-    pipePtr = Tcl_GetChannelInstanceData(chan);
+    pipePtr = (PipeState *)Tcl_GetChannelInstanceData(chan);
     TclNewObj(pidsObj);
     for (i = 0; i < pipePtr->numPids; i++) {
 	Tcl_ListObjAppendElement(NULL, pidsObj, Tcl_NewWideIntObj(
@@ -903,12 +905,12 @@ TclGetAndDetachPids(
 	/* ARGSUSED */
 static int
 PipeBlockModeProc(
-    ClientData instanceData,	/* Pipe state. */
+    void *instanceData,	/* Pipe state. */
     int mode)			/* The mode to set. Can be one of
 				 * TCL_MODE_BLOCKING or
 				 * TCL_MODE_NONBLOCKING. */
 {
-    PipeState *psPtr = instanceData;
+    PipeState *psPtr = (PipeState *)instanceData;
 
     if (psPtr->inFile
 	    && TclUnixSetBlockingMode(GetFd(psPtr->inFile), mode) < 0) {
@@ -943,11 +945,11 @@ PipeBlockModeProc(
 
 static int
 PipeClose2Proc(
-    ClientData instanceData,	/* The pipe to close. */
+    void *instanceData,	/* The pipe to close. */
     Tcl_Interp *interp,		/* For error reporting. */
     int flags)			/* Flags that indicate which side to close. */
 {
-    PipeState *pipePtr = instanceData;
+    PipeState *pipePtr = (PipeState *)instanceData;
     Tcl_Channel errChan;
     int errorCode, result;
 
@@ -1038,13 +1040,13 @@ PipeClose2Proc(
 
 static int
 PipeInputProc(
-    ClientData instanceData,	/* Pipe state. */
+    void *instanceData,	/* Pipe state. */
     char *buf,			/* Where to store data read. */
     int toRead,			/* How much space is available in the
 				 * buffer? */
     int *errorCodePtr)		/* Where to store error code. */
 {
-    PipeState *psPtr = instanceData;
+    PipeState *psPtr = (PipeState *)instanceData;
     int bytesRead;		/* How many bytes were actually read from the
 				 * input device? */
 
@@ -1089,12 +1091,12 @@ PipeInputProc(
 
 static int
 PipeOutputProc(
-    ClientData instanceData,	/* Pipe state. */
+    void *instanceData,	/* Pipe state. */
     const char *buf,		/* The data buffer. */
     int toWrite,		/* How many bytes to write? */
     int *errorCodePtr)		/* Where to store error code. */
 {
-    PipeState *psPtr = instanceData;
+    PipeState *psPtr = (PipeState *)instanceData;
     int written;
 
     *errorCodePtr = 0;
@@ -1134,12 +1136,12 @@ PipeOutputProc(
 
 static void
 PipeWatchProc(
-    ClientData instanceData,	/* The pipe state. */
+    void *instanceData,	/* The pipe state. */
     int mask)			/* Events of interest; an OR-ed combination of
 				 * TCL_READABLE, TCL_WRITABLE and
 				 * TCL_EXCEPTION. */
 {
-    PipeState *psPtr = instanceData;
+    PipeState *psPtr = (PipeState *)instanceData;
     int newmask;
 
     if (psPtr->inFile) {
@@ -1182,11 +1184,11 @@ PipeWatchProc(
 
 static int
 PipeGetHandleProc(
-    ClientData instanceData,	/* The pipe state. */
+    void *instanceData,	/* The pipe state. */
     int direction,		/* TCL_READABLE or TCL_WRITABLE */
-    ClientData *handlePtr)	/* Where to store the handle. */
+    void **handlePtr)	/* Where to store the handle. */
 {
-    PipeState *psPtr = instanceData;
+    PipeState *psPtr = (PipeState *)instanceData;
 
     if (direction == TCL_READABLE && psPtr->inFile) {
 	*handlePtr = INT2PTR(GetFd(psPtr->inFile));
@@ -1252,7 +1254,7 @@ Tcl_WaitPid(
 	/* ARGSUSED */
 int
 Tcl_PidObjCmd(
-    ClientData dummy,		/* Not used. */
+    void *dummy,		/* Not used. */
     Tcl_Interp *interp,		/* Current interpreter. */
     int objc,			/* Number of arguments. */
     Tcl_Obj *const *objv)	/* Argument strings. */
@@ -1261,6 +1263,7 @@ Tcl_PidObjCmd(
     PipeState *pipePtr;
     int i;
     Tcl_Obj *resultPtr;
+    (void)dummy;
 
     if (objc > 2) {
 	Tcl_WrongNumArgs(interp, 1, objv, "?channelId?");
@@ -1286,7 +1289,7 @@ Tcl_PidObjCmd(
 	 * Extract the process IDs from the pipe structure.
 	 */
 
-	pipePtr = Tcl_GetChannelInstanceData(chan);
+	pipePtr = (PipeState *)Tcl_GetChannelInstanceData(chan);
 	resultPtr = Tcl_NewObj();
 	for (i = 0; i < pipePtr->numPids; i++) {
 	    Tcl_ListObjAppendElement(NULL, resultPtr,
diff --git a/unix/tclUnixPort.h b/unix/tclUnixPort.h
index adbb7aa..1f8ff99 100644
--- a/unix/tclUnixPort.h
+++ b/unix/tclUnixPort.h
@@ -87,6 +87,9 @@ typedef off_t		Tcl_SeekOffset;
 
 #ifdef __CYGWIN__
 
+#ifdef __cplusplus
+extern "C" {
+#endif
     /* Make some symbols available without including <windows.h> */
 #   define DWORD unsigned int
 #   define CP_UTF8 65001
@@ -124,6 +127,9 @@ typedef off_t		Tcl_SeekOffset;
 #   define timezone _timezone
     extern int TclOSstat(const char *name, void *statBuf);
     extern int TclOSlstat(const char *name, void *statBuf);
+#ifdef __cplusplus
+}
+#endif
 #elif defined(HAVE_STRUCT_STAT64) && !defined(__APPLE__)
 #   define TclOSstat		stat64
 #   define TclOSlstat		lstat64
diff --git a/unix/tclUnixSock.c b/unix/tclUnixSock.c
index 29defff..0fa4edf 100644
--- a/unix/tclUnixSock.c
+++ b/unix/tclUnixSock.c
@@ -66,7 +66,7 @@ struct TcpState {
 
     Tcl_TcpAcceptProc *acceptProc;
                                 /* Proc to call on accept. */
-    ClientData acceptProcData;  /* The data for the accept proc. */
+    void *acceptProcData;  /* The data for the accept proc. */
 
     /*
      * Only needed for client sockets
@@ -130,24 +130,24 @@ struct TcpState {
  */
 
 static int		TcpConnect(Tcl_Interp *interp, TcpState *state);
-static void		TcpAccept(ClientData data, int mask);
-static int		TcpBlockModeProc(ClientData data, int mode);
-static int		TcpCloseProc(ClientData instanceData,
+static void		TcpAccept(void *data, int mask);
+static int		TcpBlockModeProc(void *data, int mode);
+static int		TcpCloseProc(void *instanceData,
 			    Tcl_Interp *interp);
-static int		TcpClose2Proc(ClientData instanceData,
+static int		TcpClose2Proc(void *instanceData,
 			    Tcl_Interp *interp, int flags);
-static int		TcpGetHandleProc(ClientData instanceData,
-			    int direction, ClientData *handlePtr);
-static int		TcpGetOptionProc(ClientData instanceData,
+static int		TcpGetHandleProc(void *instanceData,
+			    int direction, void **handlePtr);
+static int		TcpGetOptionProc(void *instanceData,
 			    Tcl_Interp *interp, const char *optionName,
 			    Tcl_DString *dsPtr);
-static int		TcpInputProc(ClientData instanceData, char *buf,
+static int		TcpInputProc(void *instanceData, char *buf,
 			    int toRead, int *errorCode);
-static int		TcpOutputProc(ClientData instanceData,
+static int		TcpOutputProc(void *instanceData,
 			    const char *buf, int toWrite, int *errorCode);
-static void		TcpWatchProc(ClientData instanceData, int mask);
+static void		TcpWatchProc(void *instanceData, int mask);
 static int		WaitForConnect(TcpState *statePtr, int *errorCodePtr);
-static void		WrapNotify(ClientData clientData, int mask);
+static void		WrapNotify(void *clientData, int mask);
 
 /*
  * This structure describes the channel type structure for TCP socket
@@ -239,7 +239,7 @@ InitializeHostName(
 	    char *dot = strchr(u.nodename, '.');
 
 	    if (dot != NULL) {
-		char *node = Tcl_Alloc(dot - u.nodename + 1);
+		char *node = (char *)Tcl_Alloc(dot - u.nodename + 1);
 
 		memcpy(node, u.nodename, dot - u.nodename);
 		node[dot - u.nodename] = '\0';
@@ -283,11 +283,11 @@ InitializeHostName(
     *encodingPtr = Tcl_GetEncoding(NULL, NULL);
     if (native) {
 	*lengthPtr = strlen(native);
-	*valuePtr = Tcl_Alloc(*lengthPtr + 1);
+	*valuePtr = (char *)Tcl_Alloc(*lengthPtr + 1);
 	memcpy(*valuePtr, native, *lengthPtr + 1);
     } else {
 	*lengthPtr = 0;
-	*valuePtr = Tcl_Alloc(1);
+	*valuePtr = (char *)Tcl_Alloc(1);
 	*valuePtr[0] = '\0';
     }
 }
@@ -335,8 +335,10 @@ Tcl_GetHostName(void)
 
 int
 TclpHasSockets(
-    Tcl_Interp *interp)		/* Not used. */
+    Tcl_Interp *dummy)		/* Not used. */
 {
+    (void)dummy;
+
     return TCL_OK;
 }
 
@@ -382,12 +384,12 @@ TclpFinalizeSockets(void)
 	/* ARGSUSED */
 static int
 TcpBlockModeProc(
-    ClientData instanceData,	/* Socket state. */
+    void *instanceData,	/* Socket state. */
     int mode)			/* The mode to set. Can be one of
 				 * TCL_MODE_BLOCKING or
 				 * TCL_MODE_NONBLOCKING. */
 {
-    TcpState *statePtr = instanceData;
+    TcpState *statePtr = (TcpState *)instanceData;
 
     if (mode == TCL_MODE_BLOCKING) {
 	CLEAR_BITS(statePtr->flags, TCP_NONBLOCKING);
@@ -528,13 +530,13 @@ WaitForConnect(
 	/* ARGSUSED */
 static int
 TcpInputProc(
-    ClientData instanceData,	/* Socket state. */
+    void *instanceData,	/* Socket state. */
     char *buf,			/* Where to store data read. */
     int bufSize,		/* How much space is available in the
 				 * buffer? */
     int *errorCodePtr)		/* Where to store error code. */
 {
-    TcpState *statePtr = instanceData;
+    TcpState *statePtr = (TcpState *)instanceData;
     int bytesRead;
 
     *errorCodePtr = 0;
@@ -579,12 +581,12 @@ TcpInputProc(
 
 static int
 TcpOutputProc(
-    ClientData instanceData,	/* Socket state. */
+    void *instanceData,	/* Socket state. */
     const char *buf,		/* The data buffer. */
     int toWrite,		/* How many bytes to write? */
     int *errorCodePtr)		/* Where to store error code. */
 {
-    TcpState *statePtr = instanceData;
+    TcpState *statePtr = (TcpState *)instanceData;
     int written;
 
     *errorCodePtr = 0;
@@ -621,12 +623,13 @@ TcpOutputProc(
 	/* ARGSUSED */
 static int
 TcpCloseProc(
-    ClientData instanceData,	/* The socket to close. */
-    Tcl_Interp *interp)		/* For error reporting - unused. */
+    void *instanceData,	/* The socket to close. */
+    Tcl_Interp *dummy)		/* For error reporting - unused. */
 {
-    TcpState *statePtr = instanceData;
+    TcpState *statePtr = (TcpState *)instanceData;
     int errorCode = 0;
     TcpFdList *fds;
+    (void)dummy;
 
     /*
      * Delete a file handler that may be active for this socket if this is a
@@ -682,11 +685,11 @@ TcpCloseProc(
 
 static int
 TcpClose2Proc(
-    ClientData instanceData,	/* The socket to close. */
+    void *instanceData,	/* The socket to close. */
     Tcl_Interp *interp,		/* For error reporting. */
     int flags)			/* Flags that indicate which side to close. */
 {
-    TcpState *statePtr = instanceData;
+    TcpState *statePtr = (TcpState *)instanceData;
     int readError = 0;
     int writeError = 0;
 
@@ -833,7 +836,7 @@ TcpHostPortList(
 
 static int
 TcpGetOptionProc(
-    ClientData instanceData,	/* Socket state. */
+    void *instanceData,	/* Socket state. */
     Tcl_Interp *interp,		/* For error reporting - can be NULL. */
     const char *optionName,	/* Name of the option to retrieve the value
 				 * for, or NULL to get all options and their
@@ -841,7 +844,7 @@ TcpGetOptionProc(
     Tcl_DString *dsPtr)		/* Where to store the computed value;
 				 * initialized by caller. */
 {
-    TcpState *statePtr = instanceData;
+    TcpState *statePtr = (TcpState *)instanceData;
     size_t len = 0;
 
     WaitForConnect(statePtr, NULL);
@@ -999,7 +1002,7 @@ TcpGetOptionProc(
 
 static void
 WrapNotify(
-    ClientData clientData,
+    void *clientData,
     int mask)
 {
     TcpState *statePtr = (TcpState *) clientData;
@@ -1028,12 +1031,12 @@ WrapNotify(
 
 static void
 TcpWatchProc(
-    ClientData instanceData,	/* The socket state. */
+    void *instanceData,	/* The socket state. */
     int mask)			/* Events of interest; an OR-ed combination of
 				 * TCL_READABLE, TCL_WRITABLE and
 				 * TCL_EXCEPTION. */
 {
-    TcpState *statePtr = instanceData;
+    TcpState *statePtr = (TcpState *)instanceData;
 
     if (statePtr->acceptProc != NULL) {
         /*
@@ -1102,11 +1105,12 @@ TcpWatchProc(
 	/* ARGSUSED */
 static int
 TcpGetHandleProc(
-    ClientData instanceData,	/* The socket state. */
+    void *instanceData,	/* The socket state. */
     int direction,		/* Not used. */
-    ClientData *handlePtr)	/* Where to store the handle. */
+    void **handlePtr)	/* Where to store the handle. */
 {
-    TcpState *statePtr = instanceData;
+    TcpState *statePtr = (TcpState *)instanceData;
+    (void)direction;
 
     *handlePtr = INT2PTR(statePtr->fds.fd);
     return TCL_OK;
@@ -1126,12 +1130,14 @@ TcpGetHandleProc(
 
 static void
 TcpAsyncCallback(
-    ClientData clientData,	/* The socket state. */
+    void *clientData,	/* The socket state. */
     int mask)			/* Events of interest; an OR-ed combination of
 				 * TCL_READABLE, TCL_WRITABLE and
 				 * TCL_EXCEPTION. */
 {
-    TcpConnect(NULL, clientData);
+    (void)mask;
+
+    TcpConnect(NULL, (TcpState *)clientData);
 }
 
 /*
@@ -1173,6 +1179,7 @@ TcpConnect(
     int async_callback = GOT_BITS(statePtr->flags, TCP_ASYNC_PENDING);
     int ret = -1, error = EHOSTUNREACH;
     int async = GOT_BITS(statePtr->flags, TCP_ASYNC_CONNECT);
+    static const int reuseaddr = 1;
 
     if (async_callback) {
         goto reenter;
@@ -1183,7 +1190,6 @@ TcpConnect(
         for (statePtr->myaddr = statePtr->myaddrlist;
                 statePtr->myaddr != NULL;
                 statePtr->myaddr = statePtr->myaddr->ai_next) {
-            int reuseaddr = 1;
 
 	    /*
 	     * No need to try combinations of local and remote addresses of
@@ -1390,7 +1396,7 @@ Tcl_OpenTcpClient(
      * Allocate a new TcpState for this socket.
      */
 
-    statePtr = Tcl_Alloc(sizeof(TcpState));
+    statePtr = (TcpState *)Tcl_Alloc(sizeof(TcpState));
     memset(statePtr, 0, sizeof(TcpState));
     statePtr->flags = async ? TCP_ASYNC_CONNECT : 0;
     statePtr->cachedBlocking = TCL_MODE_BLOCKING;
@@ -1437,7 +1443,7 @@ Tcl_OpenTcpClient(
 
 Tcl_Channel
 Tcl_MakeTcpClientChannel(
-    ClientData sock)		/* The socket to wrap up into a channel. */
+    void *sock)		/* The socket to wrap up into a channel. */
 {
     return (Tcl_Channel) TclpMakeTcpClientChannelMode(sock,
             TCL_READABLE | TCL_WRITABLE);
@@ -1469,7 +1475,7 @@ TclpMakeTcpClientChannelMode(
     TcpState *statePtr;
     char channelName[SOCK_CHAN_LENGTH];
 
-    statePtr = Tcl_Alloc(sizeof(TcpState));
+    statePtr = (TcpState *)Tcl_Alloc(sizeof(TcpState));
     memset(statePtr, 0, sizeof(TcpState));
     statePtr->fds.fd = PTR2INT(sock);
     statePtr->flags = 0;
@@ -1512,7 +1518,7 @@ Tcl_OpenTcpServerEx(
     Tcl_TcpAcceptProc *acceptProc,
 				/* Callback for accepting connections from new
 				 * clients. */
-    ClientData acceptProcData)	/* Data for the callback. */
+    void *acceptProcData)	/* Data for the callback. */
 {
     int status = 0, sock = -1, optvalue, port, chosenport;
     struct addrinfo *addrlist = NULL, *addrPtr;	/* socket address */
@@ -1692,14 +1698,14 @@ Tcl_OpenTcpServerEx(
              * Allocate a new TcpState for this socket.
              */
 
-            statePtr = Tcl_Alloc(sizeof(TcpState));
+            statePtr = (TcpState *)Tcl_Alloc(sizeof(TcpState));
             memset(statePtr, 0, sizeof(TcpState));
             statePtr->acceptProc = acceptProc;
             statePtr->acceptProcData = acceptProcData;
             sprintf(channelName, SOCK_TEMPLATE, (long) statePtr);
             newfds = &statePtr->fds;
         } else {
-            newfds = Tcl_Alloc(sizeof(TcpFdList));
+            newfds = (TcpFdList *)Tcl_Alloc(sizeof(TcpFdList));
             memset(newfds, (int) 0, sizeof(TcpFdList));
             fds->next = newfds;
         }
@@ -1760,16 +1766,17 @@ Tcl_OpenTcpServerEx(
 	/* ARGSUSED */
 static void
 TcpAccept(
-    ClientData data,		/* Callback token. */
+    void *data,		/* Callback token. */
     int mask)			/* Not used. */
 {
-    TcpFdList *fds = data;	/* Client data of server socket. */
+    TcpFdList *fds = (TcpFdList *)data;	/* Client data of server socket. */
     int newsock;		/* The new client socket */
     TcpState *newSockState;	/* State for new socket. */
     address addr;		/* The remote address */
     socklen_t len;		/* For accept interface */
     char channelName[SOCK_CHAN_LENGTH];
     char host[NI_MAXHOST], port[NI_MAXSERV];
+    (void)mask;
 
     len = sizeof(addr);
     newsock = accept(fds->fd, &addr.sa, &len);
@@ -1784,7 +1791,7 @@ TcpAccept(
 
     (void) fcntl(newsock, F_SETFD, FD_CLOEXEC);
 
-    newSockState = Tcl_Alloc(sizeof(TcpState));
+    newSockState = (TcpState *)Tcl_Alloc(sizeof(TcpState));
     memset(newSockState, 0, sizeof(TcpState));
     newSockState->flags = 0;
     newSockState->fds.fd = newsock;
diff --git a/unix/tclUnixTest.c b/unix/tclUnixTest.c
index 75dccfa..8868bbe 100644
--- a/unix/tclUnixTest.c
+++ b/unix/tclUnixTest.c
@@ -129,7 +129,7 @@ TclplatformtestInit(
 
 static int
 TestfilehandlerCmd(
-    ClientData clientData,	/* Not used. */
+    ClientData dummy,	/* Not used. */
     Tcl_Interp *interp,		/* Current interpreter. */
     int objc,			/* Number of arguments. */
     Tcl_Obj *const *objv)	/* Argument strings. */
@@ -139,6 +139,7 @@ TestfilehandlerCmd(
     static int initialized = 0;
     char buffer[4000];
     TclFile file;
+    (void)dummy;
 
     /*
      * NOTE: When we make this code work on Windows also, the following
@@ -314,7 +315,7 @@ TestFileHandlerProc(
     int mask)			/* Indicates which events happened:
 				 * TCL_READABLE or TCL_WRITABLE. */
 {
-    Pipe *pipePtr = clientData;
+    Pipe *pipePtr = (Pipe *)clientData;
 
     if (mask & TCL_READABLE) {
 	pipePtr->readCount++;
@@ -343,7 +344,7 @@ TestFileHandlerProc(
 
 static int
 TestfilewaitCmd(
-    ClientData clientData,	/* Not used. */
+    ClientData dummy,	/* Not used. */
     Tcl_Interp *interp,		/* Current interpreter. */
     int objc,			/* Number of arguments. */
     Tcl_Obj *const *objv)	/* Argument strings. */
@@ -352,6 +353,7 @@ TestfilewaitCmd(
     Tcl_Channel channel;
     int fd;
     ClientData data;
+    (void)dummy;
 
     if (objc != 4) {
 	Tcl_WrongNumArgs(interp, 2, objv, "file readable|writable|both timeout");
@@ -411,12 +413,13 @@ TestfilewaitCmd(
 
 static int
 TestfindexecutableCmd(
-    ClientData clientData,	/* Not used. */
+    ClientData dummy,	/* Not used. */
     Tcl_Interp *interp,		/* Current interpreter. */
     int objc,			/* Number of arguments. */
     Tcl_Obj *const *objv)	/* Argument strings. */
 {
     Tcl_Obj *saveName;
+    (void)dummy;
 
     if (objc != 2) {
 	Tcl_WrongNumArgs(interp, 1, objv, "argv0");
@@ -453,12 +456,13 @@ TestfindexecutableCmd(
 
 static int
 TestforkCmd(
-    ClientData clientData,	/* Not used. */
+    ClientData dummy,	/* Not used. */
     Tcl_Interp *interp,		/* Current interpreter. */
     int objc,			/* Number of arguments. */
     Tcl_Obj *const *objv)	/* Argument strings. */
 {
     pid_t pid;
+    (void)dummy;
 
     if (objc != 1) {
         Tcl_WrongNumArgs(interp, 1, objv, "");
@@ -499,7 +503,7 @@ TestforkCmd(
 
 static int
 TestalarmCmd(
-    ClientData clientData,	/* Not used. */
+    ClientData dummy,	/* Not used. */
     Tcl_Interp *interp,		/* Current interpreter. */
     int objc,			/* Number of arguments. */
     Tcl_Obj *const *objv)	/* Argument strings. */
@@ -507,6 +511,7 @@ TestalarmCmd(
 #ifdef SA_RESTART
     unsigned int sec = 1;
     struct sigaction action;
+    (void)dummy;
 
     if (objc > 1) {
 	Tcl_GetIntFromObj(interp, objv[1], (int *)&sec);
@@ -528,6 +533,8 @@ TestalarmCmd(
     (void) alarm(sec);
     return TCL_OK;
 #else
+    (void)dummy;
+
     Tcl_AppendResult(interp,
 	    "warning: sigaction SA_RESTART not support on this platform",
 	    NULL);
@@ -555,6 +562,8 @@ static void
 AlarmHandler(
     int signum)
 {
+    (void)signum;
+
     gotsig = "1";
 }
 
@@ -576,11 +585,15 @@ AlarmHandler(
 
 static int
 TestgotsigCmd(
-    ClientData clientData,	/* Not used. */
+    ClientData dummy,	/* Not used. */
     Tcl_Interp *interp,		/* Current interpreter. */
     int objc,			/* Number of arguments. */
     Tcl_Obj *const *objv)		/* Argument strings. */
 {
+    (void)dummy;
+    (void)objc;
+    (void)objv;
+
     Tcl_AppendResult(interp, gotsig, NULL);
     gotsig = "0";
     return TCL_OK;
@@ -613,6 +626,7 @@ TestchmodCmd(
     Tcl_Obj *const *objv)		/* Argument strings. */
 {
     int i, mode;
+    (void)dummy;
 
     if (objc < 2) {
     Tcl_WrongNumArgs(interp, 1, objv, "mode file ?file ...?");
diff --git a/unix/tclUnixThrd.c b/unix/tclUnixThrd.c
index 7b1a4bb..302249a 100644
--- a/unix/tclUnixThrd.c
+++ b/unix/tclUnixThrd.c
@@ -569,7 +569,7 @@ Tcl_MutexLock(
 	     * Double inside master lock check to avoid a race condition.
 	     */
 
-	    pmutexPtr = Tcl_Alloc(sizeof(PMutex));
+	    pmutexPtr = (PMutex *)Tcl_Alloc(sizeof(PMutex));
 	    PMutexInit(pmutexPtr);
 	    *mutexPtr = (Tcl_Mutex) pmutexPtr;
 	    TclRememberMutex(mutexPtr);
@@ -679,7 +679,7 @@ Tcl_ConditionWait(
 	 */
 
 	if (*condPtr == NULL) {
-	    pcondPtr = Tcl_Alloc(sizeof(pthread_cond_t));
+	    pcondPtr = (pthread_cond_t *)Tcl_Alloc(sizeof(pthread_cond_t));
 	    pthread_cond_init(pcondPtr, NULL);
 	    *condPtr = (Tcl_Condition) pcondPtr;
 	    TclRememberCondition(condPtr);
@@ -790,7 +790,7 @@ TclpNewAllocMutex(void)
     AllocMutex *lockPtr;
     PMutex *plockPtr;
 
-    lockPtr = malloc(sizeof(AllocMutex));
+    lockPtr = (AllocMutex *)malloc(sizeof(AllocMutex));
     if (lockPtr == NULL) {
 	Tcl_Panic("could not allocate lock");
     }
@@ -861,7 +861,7 @@ TclpThreadCreateKey(void)
 {
     pthread_key_t *ptkeyPtr;
 
-    ptkeyPtr = TclpSysAlloc(sizeof(pthread_key_t));
+    ptkeyPtr = (pthread_key_t *)TclpSysAlloc(sizeof(pthread_key_t));
     if (NULL == ptkeyPtr) {
 	Tcl_Panic("unable to allocate thread key!");
     }
@@ -877,7 +877,7 @@ void
 TclpThreadDeleteKey(
     void *keyPtr)
 {
-    pthread_key_t *ptkeyPtr = keyPtr;
+    pthread_key_t *ptkeyPtr = (pthread_key_t *)keyPtr;
 
     if (pthread_key_delete(*ptkeyPtr)) {
 	Tcl_Panic("unable to delete key!");
@@ -891,7 +891,7 @@ TclpThreadSetMasterTSD(
     void *tsdKeyPtr,
     void *ptr)
 {
-    pthread_key_t *ptkeyPtr = tsdKeyPtr;
+    pthread_key_t *ptkeyPtr = (pthread_key_t *)tsdKeyPtr;
 
     if (pthread_setspecific(*ptkeyPtr, ptr)) {
 	Tcl_Panic("unable to set master TSD value");
@@ -902,7 +902,7 @@ void *
 TclpThreadGetMasterTSD(
     void *tsdKeyPtr)
 {
-    pthread_key_t *ptkeyPtr = tsdKeyPtr;
+    pthread_key_t *ptkeyPtr = (pthread_key_t*)tsdKeyPtr;
 
     return pthread_getspecific(*ptkeyPtr);
 }
diff --git a/unix/tclUnixTime.c b/unix/tclUnixTime.c
index 72de7a2..1ca0cbb 100644
--- a/unix/tclUnixTime.c
+++ b/unix/tclUnixTime.c
@@ -30,7 +30,7 @@ static void		NativeGetTime(Tcl_Time *timebuf,
 
 Tcl_GetTimeProc *tclGetTimeProcPtr = NativeGetTime;
 Tcl_ScaleTimeProc *tclScaleTimeProcPtr = NativeScaleTime;
-ClientData tclTimeClientData = NULL;
+void *tclTimeClientData = NULL;
 
 /*
  *----------------------------------------------------------------------
@@ -373,6 +373,8 @@ NativeScaleTime(
     Tcl_Time *timePtr,
     ClientData clientData)
 {
+    (void)timePtr;
+    (void)clientData;
     /* Native scale is 1:1. Nothing is done */
 }
 
@@ -396,9 +398,10 @@ NativeScaleTime(
 static void
 NativeGetTime(
     Tcl_Time *timePtr,
-    ClientData clientData)
+    ClientData dummy)
 {
     struct timeval tv;
+    (void)dummy;
 
     (void) gettimeofday(&tv, NULL);
     timePtr->sec = tv.tv_sec;
diff --git a/unix/tclXtNotify.c b/unix/tclXtNotify.c
index 56fe840..b2ec6e6 100644
--- a/unix/tclXtNotify.c
+++ b/unix/tclXtNotify.c
@@ -359,7 +359,7 @@ CreateFileHandler(
 	}
     }
     if (filePtr == NULL) {
-	filePtr = Tcl_Alloc(sizeof(FileHandler));
+	filePtr = (FileHandler *)Tcl_Alloc(sizeof(FileHandler));
 	filePtr->fd = fd;
 	filePtr->read = 0;
 	filePtr->write = 0;
@@ -525,7 +525,7 @@ FileProc(
      */
 
     filePtr->readyMask |= mask;
-    fileEvPtr = Tcl_Alloc(sizeof(FileHandlerEvent));
+    fileEvPtr = (FileHandlerEvent *)Tcl_Alloc(sizeof(FileHandlerEvent));
     fileEvPtr->header.proc = FileHandlerEventProc;
     fileEvPtr->fd = filePtr->fd;
     Tcl_QueueEvent((Tcl_Event *) fileEvPtr, TCL_QUEUE_TAIL);