Preparatory works for making Tk define its parameters via a config header.

2 files changed, 114 insertions, 75 deletions

diff --git a/unix/configure.in b/unix/configure.in
index a5cb663..249ec3d 100644
--- a/unix/configure.in
+++ b/unix/configure.in
@@ -3,7 +3,7 @@ dnl	This file is an input file used by the GNU "autoconf" program to
 dnl	generate the file "configure", which is run during Tk installation
 dnl	to configure the system for the local environment.
 #
-# RCS: @(#) $Id: configure.in,v 1.95 2004/07/16 23:40:29 hobbs Exp $
+# RCS: @(#) $Id: configure.in,v 1.96 2004/11/15 11:39:41 dkf Exp $
 
 AC_INIT(../generic/tk.h)
 AC_PREREQ(2.57)
@@ -138,7 +138,7 @@ AC_HEADER_EGREP(strtol, stdlib.h, tk_ok=yes, tk_ok=no)
 AC_HEADER_EGREP(strtoul, stdlib.h, , tk_ok=no)
 AC_HEADER_EGREP(strtod, stdlib.h, , tk_ok=no)
 if test $tk_ok = no; then
-    AC_DEFINE(NO_STDLIB_H)
+    AC_DEFINE(NO_STDLIB_H, 1, [Do we have a working <stdlib.h> to include?])
 fi
 AC_MSG_RESULT($tk_ok)
 
@@ -158,12 +158,12 @@ AC_TRY_COMPILE([#include <sys/types.h>],
 if test $tk_ok = no; then
     AC_HEADER_EGREP(fd_mask, sys/select.h, tk_ok=yes)
     if test $tk_ok = yes; then
-	AC_DEFINE(HAVE_SYS_SELECT_H)
+	AC_DEFINE(HAVE_SYS_SELECT_H, 1, [Should we include <sys/select.h>?])
     fi
 fi
 AC_MSG_RESULT($tk_ok)
 if test $tk_ok = no; then
-    AC_DEFINE(NO_FD_SET)
+    AC_DEFINE(NO_FD_SET, 1, [Do we have access to the fd_set type?])
 fi
 
 #--------------------------------------------------------------------
@@ -192,7 +192,7 @@ AC_TRY_COMPILE([#include <pwd.h>],
       [struct passwd pwd; pwd.pw_gecos;], tk_ok=yes, tk_ok=no)
 AC_MSG_RESULT($tk_ok)
 if test $tk_ok = yes; then
-    AC_DEFINE(HAVE_PW_GECOS)
+    AC_DEFINE(HAVE_PW_GECOS, 1, [Does struct password have a pw_gecos field?])
 fi
 
 #--------------------------------------------------------------------
@@ -307,7 +307,7 @@ if test "$enable_xft" = "yes" ; then
 fi
 if test $enable_xft = "yes" ; then
     UNIX_FONT_OBJS=tkUnixRFont.o
-    AC_DEFINE(HAVE_XFT)
+    AC_DEFINE(HAVE_XFT, 1, [Have we turned on XFT (antialiased fonts)?])
 else
     UNIX_FONT_OBJS=tkUnixFont.o
 fi
diff --git a/unix/tcl.m4 b/unix/tcl.m4
index 67e8984..4ef9b9e 100644
--- a/unix/tcl.m4
+++ b/unix/tcl.m4
@@ -346,7 +346,7 @@ AC_DEFUN(SC_ENABLE_SHARED, [
     else
 	AC_MSG_RESULT([static])
 	SHARED_BUILD=0
-	AC_DEFINE(STATIC_BUILD)
+	AC_DEFINE(STATIC_BUILD, 1, [Is this a static build?])
     fi
 ])
 
@@ -428,15 +428,17 @@ AC_DEFUN(SC_ENABLE_THREADS, [
 	    AC_MSG_RESULT([yes])
 	fi
 	TCL_THREADS=1
-	AC_DEFINE(TCL_THREADS)
+	AC_DEFINE(TCL_THREADS, 1, [Are we building with threads enabled?])
 	# USE_THREAD_ALLOC tells us to try the special thread-based
 	# allocator that significantly reduces lock contention
-	AC_DEFINE(USE_THREAD_ALLOC)
+	AC_DEFINE(USE_THREAD_ALLOC, 1,
+	    [Do we want to use the threaded memory allocator?])
 	# USE_THREAD_STORAGE tells us to use the new generic thread 
 	# storage subsystem. 
-	AC_DEFINE(USE_THREAD_STORAGE)
-	AC_DEFINE(_REENTRANT)
-	AC_DEFINE(_THREAD_SAFE)
+	AC_DEFINE(USE_THREAD_STORAGE, 1,
+	    [Use the generic thread storage subsystem?])
+	AC_DEFINE(_REENTRANT, 1, [Do we want the reentrant OS API?])
+	AC_DEFINE(_THREAD_SAFE, 1, [Do we want the thread-safe OS API?])
 	AC_CHECK_LIB(pthread,pthread_mutex_init,tcl_ok=yes,tcl_ok=no)
 	if test "$tcl_ok" = "no"; then
 	    # Check a little harder for __pthread_mutex_init in the same
@@ -476,15 +478,36 @@ AC_DEFUN(SC_ENABLE_THREADS, [
 	ac_saved_libs=$LIBS
 	LIBS="$LIBS $THREADS_LIBS"
 	AC_CHECK_FUNCS(pthread_attr_setstacksize)
-	AC_CHECK_FUNCS(pthread_attr_get_np pthread_getattr_np)
-	AC_MSG_CHECKING([for pthread_getattr_np declaration])
-	AC_CACHE_VAL(tcl_cv_grep_pthread_getattr_np,
-	    AC_EGREP_HEADER(pthread_getattr_np, pthread.h,
-		tcl_cv_grep_pthread_getattr_np=present,
-		tcl_cv_grep_pthread_getattr_np=missing))
-	AC_MSG_RESULT($tcl_cv_grep_pthread_getattr_np)
-	if test $tcl_cv_grep_pthread_getattr_np = missing ; then
-	    AC_DEFINE(GETATTRNP_NOT_DECLARED)
+	AC_CHECK_FUNC(pthread_attr_get_np,tcl_ok=yes,tcl_ok=no)
+	if test $tcl_ok = yes ; then
+	    AC_DEFINE(HAVE_PTHREAD_ATTR_GET_NP, 1,
+		[Do we want a BSD-like thread-attribute interface?])
+	    AC_MSG_CHECKING([for pthread_attr_get_np declaration])
+	    AC_CACHE_VAL(tcl_cv_grep_pthread_attr_get_np,
+		AC_EGREP_HEADER(pthread_attr_get_np, pthread.h,
+		    tcl_cv_grep_pthread_attr_get_np=present,
+		    tcl_cv_grep_pthread_attr_get_np=missing))
+	    AC_MSG_RESULT($tcl_cv_grep_pthread_attr_get_np)
+	    if test $tcl_cv_grep_pthread_attr_get_np = missing ; then
+		AC_DEFINE(ATTRGETNP_NOT_DECLARED, 1,
+		    [Is pthread_attr_get_np() declared in <pthread.h>?])
+	    fi
+	else
+	    AC_CHECK_FUNC(pthread_getattr_np,tcl_ok=yes,tcl_ok=no)
+	    if test $tcl_ok = yes ; then
+		AC_DEFINE(HAVE_PTHREAD_GETATTR_NP, 1,
+		    [Do we want a Linux-like thread-attribute interface?])
+		AC_MSG_CHECKING([for pthread_getattr_np declaration])
+		AC_CACHE_VAL(tcl_cv_grep_pthread_getattr_np,
+		    AC_EGREP_HEADER(pthread_getattr_np, pthread.h,
+			tcl_cv_grep_pthread_getattr_np=present,
+			tcl_cv_grep_pthread_getattr_np=missing))
+		AC_MSG_RESULT($tcl_cv_grep_pthread_getattr_np)
+		if test $tcl_cv_grep_pthread_getattr_np = missing ; then
+		    AC_DEFINE(GETATTRNP_NOT_DECLARED, 1,
+			[Is pthread_getattr_np declared in <pthread.h>?])
+		fi
+	    fi
 	fi
 	LIBS=$ac_saved_libs
 	AC_CHECK_FUNCS(readdir_r)
@@ -534,7 +557,7 @@ AC_DEFUN(SC_ENABLE_SYMBOLS, [
 	LDFLAGS_DEFAULT='$(LDFLAGS_OPTIMIZE)'
 	DBGX=""
 	AC_MSG_RESULT([no])
-	AC_DEFINE(TCL_CFG_OPTIMIZED)
+	AC_DEFINE(TCL_CFG_OPTIMIZED, 1, [Is this an optimized build?])
     else
 	CFLAGS_DEFAULT='$(CFLAGS_DEBUG)'
 	LDFLAGS_DEFAULT='$(LDFLAGS_DEBUG)'
@@ -545,15 +568,15 @@ AC_DEFUN(SC_ENABLE_SYMBOLS, [
     fi
     AC_SUBST(CFLAGS_DEFAULT)
     AC_SUBST(LDFLAGS_DEFAULT)
-    AC_DEFINE(TCL_CFG_DEBUG)
+    AC_DEFINE(TCL_CFG_DEBUG, 1, [Is debugging enabled?])
 
     if test "$tcl_ok" = "mem" -o "$tcl_ok" = "all"; then
-	AC_DEFINE(TCL_MEM_DEBUG)
+	AC_DEFINE(TCL_MEM_DEBUG, 1, [Is memory debugging enabled?])
     fi
 
     if test "$tcl_ok" = "compile" -o "$tcl_ok" = "all"; then
-	AC_DEFINE(TCL_COMPILE_DEBUG)
-	AC_DEFINE(TCL_COMPILE_STATS)
+	AC_DEFINE(TCL_COMPILE_DEBUG, 1, [Is bytecode debugging enabled?])
+	AC_DEFINE(TCL_COMPILE_STATS, 1, [Are bytecode statistics enabled?])
     fi
 
     if test "$tcl_ok" != "yes" -a "$tcl_ok" != "no"; then
@@ -604,7 +627,7 @@ AC_DEFUN(SC_ENABLE_LANGINFO, [
 	    langinfo_ok="no (could not compile with nl_langinfo)";
 	fi
 	if test "$langinfo_ok" = "yes"; then
-	    AC_DEFINE(HAVE_LANGINFO)
+	    AC_DEFINE(HAVE_LANGINFO, 1, [Do we have nl_langinfo()?])
 	fi
     fi
     AC_MSG_RESULT([$langinfo_ok])
@@ -953,7 +976,7 @@ dnl AC_CHECK_TOOL(AR, ar)
 	    AC_CHECK_LIB(bsd, gettimeofday, libbsd=yes, libbsd=no)
 	    if test $libbsd = yes; then
 	    	MATH_LIBS="$MATH_LIBS -lbsd"
-	    	AC_DEFINE(USE_DELTA_FOR_TZ)
+	    	AC_DEFINE(USE_DELTA_FOR_TZ, 1, [Do we need a special AIX hack for timezones?])
 	    fi
 	    ;;
 	BeOS*)
@@ -1004,8 +1027,8 @@ dnl AC_CHECK_TOOL(AR, ar)
 	    ;;
 	HP-UX-*.11.*)
 	    # Use updated header definitions where possible
-	    AC_DEFINE(_XOPEN_SOURCE)          # Use the XOPEN network library
-	    AC_DEFINE(_XOPEN_SOURCE_EXTENDED) # Use the XOPEN network library
+	    AC_DEFINE(_XOPEN_SOURCE, 1, [Do we want to use the XOPEN network library?])
+	    AC_DEFINE(_XOPEN_SOURCE_EXTENDED, 1, [Do we want to use the XOPEN network library?])
 	    LIBS="$LIBS -lxnet"               # Use the XOPEN network library
 
 	    SHLIB_SUFFIX=".sl"
@@ -1182,7 +1205,7 @@ dnl AC_CHECK_TOOL(AR, ar)
 	    fi
 
 	    # XIM peeking works under XFree86.
-	    AC_DEFINE(PEEK_XCLOSEIM)
+	    AC_DEFINE(PEEK_XCLOSEIM, 1, [May we use XIM peeking safely?])
 
 	    ;;
 	GNU*)
@@ -1335,10 +1358,11 @@ dnl AC_CHECK_TOOL(AR, ar)
 	    LD_SEARCH_FLAGS=""
 	    CFLAGS_OPTIMIZE="-Os"
 	    LD_LIBRARY_PATH_VAR="DYLD_LIBRARY_PATH"
-	    AC_DEFINE(MAC_OSX_TCL)
-	    AC_DEFINE(HAVE_CFBUNDLE)
-	    AC_DEFINE(USE_VFORK)
-	    AC_DEFINE(TCL_DEFAULT_ENCODING,"utf-8")
+	    AC_DEFINE(MAC_OSX_TCL, 1, ["Is this a Mac I see before me?"])
+	    AC_DEFINE(HAVE_CFBUNDLE, 1, [Do we have access to Mac bundles?])
+	    AC_DEFINE(USE_VFORK, 1, [Should we use vfork() instead of fork()?])
+	    AC_DEFINE(TCL_DEFAULT_ENCODING,"utf-8",
+		[Are we to override what our default encoding is?])
 	    LIBS="$LIBS -framework CoreFoundation"
 	    ;;
 	NEXTSTEP-*)
@@ -1352,8 +1376,9 @@ dnl AC_CHECK_TOOL(AR, ar)
 	    LD_SEARCH_FLAGS=""
 	    ;;
 	OS/390-*)
-	    CFLAGS_OPTIMIZE=""      # Optimizer is buggy
-	    AC_DEFINE(_OE_SOCKETS)  # needed in sys/socket.h
+	    CFLAGS_OPTIMIZE=""		# Optimizer is buggy
+	    AC_DEFINE(_OE_SOCKETS, 1,	# needed in sys/socket.h
+		[Should OS/390 do the right thing with sockets?])
 	    ;;      
 	OSF1-1.0|OSF1-1.1|OSF1-1.2)
 	    # OSF/1 1.[012] from OSF, and derivatives, including Paragon OSF/1
@@ -1492,8 +1517,9 @@ dnl AC_CHECK_TOOL(AR, ar)
 	    # Note: If _REENTRANT isn't defined, then Solaris
 	    # won't define thread-safe library routines.
 
-	    AC_DEFINE(_REENTRANT)
-	    AC_DEFINE(_POSIX_PTHREAD_SEMANTICS)
+	    AC_DEFINE(_REENTRANT, 1, [Do we want the reentrant OS API?])
+	    AC_DEFINE(_POSIX_PTHREAD_SEMANTICS, 1,
+		[Do we really want to follow the standard? Yes we do!])
 
 	    SHLIB_CFLAGS="-KPIC"
 
@@ -1519,8 +1545,9 @@ dnl AC_CHECK_TOOL(AR, ar)
 	    # Note: If _REENTRANT isn't defined, then Solaris
 	    # won't define thread-safe library routines.
 
-	    AC_DEFINE(_REENTRANT)
-	    AC_DEFINE(_POSIX_PTHREAD_SEMANTICS)
+	    AC_DEFINE(_REENTRANT, 1, [Do we want the reentrant OS API?])
+	    AC_DEFINE(_POSIX_PTHREAD_SEMANTICS, 1,
+		[Do we really want to follow the standard? Yes we do!])
 
 	    SHLIB_CFLAGS="-KPIC"
     
@@ -1597,11 +1624,11 @@ dnl AC_CHECK_TOOL(AR, ar)
     esac
 
     if test "$do64bit" = "yes" -a "$do64bit_ok" = "no" ; then
-    AC_MSG_WARN("64bit support being disabled -- don\'t know magic for this platform")
+	AC_MSG_WARN("64bit support being disabled -- don\'t know magic for this platform")
     fi
 
     if test "$do64bit" = "yes" -a "$do64bit_ok" = "yes" ; then
-	AC_DEFINE(TCL_CFG_DO64BIT)
+	AC_DEFINE(TCL_CFG_DO64BIT, 1, [Is this a 64-bit build?])
     fi
 
     # Step 4: If pseudo-static linking is in use (see K. B. Kenny, "Dynamic
@@ -1639,7 +1666,8 @@ dnl AC_CHECK_TOOL(AR, ar)
     ], tcl_ok=usable, tcl_ok=unusable)
 	AC_MSG_RESULT($tcl_ok)
 	if test $tcl_ok = usable; then
-	    AC_DEFINE(USE_SYS_EXEC_H)
+	    AC_DEFINE(USE_SYS_EXEC_H, 1,
+		[Should we use <sys/exec.h> when doing dynamic loading?])
 	else
 	    AC_MSG_CHECKING(a.out.h)
 	    AC_TRY_COMPILE([#include <a.out.h>],[
@@ -1656,7 +1684,8 @@ dnl AC_CHECK_TOOL(AR, ar)
 	    ], tcl_ok=usable, tcl_ok=unusable)
 	    AC_MSG_RESULT($tcl_ok)
 	    if test $tcl_ok = usable; then
-		AC_DEFINE(USE_A_OUT_H)
+		AC_DEFINE(USE_A_OUT_H, 1,
+		    [Should we use <a.out.h> when doing dynamic loading?])
 	    else
 		AC_MSG_CHECKING(sys/exec_aout.h)
 		AC_TRY_COMPILE([#include <sys/exec_aout.h>],[
@@ -1673,7 +1702,8 @@ dnl AC_CHECK_TOOL(AR, ar)
 		], tcl_ok=usable, tcl_ok=unusable)
 		AC_MSG_RESULT($tcl_ok)
 		if test $tcl_ok = usable; then
-		    AC_DEFINE(USE_SYS_EXEC_AOUT_H)
+		    AC_DEFINE(USE_SYS_EXEC_AOUT_H, 1,
+			[Should we use <sys/exec_aout.h> when doing dynamic loading?])
 		else
 		    DL_OBJS=""
 		fi
@@ -1938,9 +1968,9 @@ int main() {
 }], tcl_cv_api_serial=sgtty, tcl_cv_api_serial=none, tcl_cv_api_serial=none)
     fi])
     case $tcl_cv_api_serial in
-	termios) AC_DEFINE(USE_TERMIOS);;
-	termio)  AC_DEFINE(USE_TERMIO);;
-	sgtty)   AC_DEFINE(USE_SGTTY);;
+	termios) AC_DEFINE(USE_TERMIOS, 1, [Use the termios API for serial lines]);;
+	termio)  AC_DEFINE(USE_TERMIO, 1, [Use the termio API for serial lines]);;
+	sgtty)   AC_DEFINE(USE_SGTTY, 1, [Use the sgtty API for serial lines]);;
     esac
     AC_MSG_RESULT($tcl_cv_api_serial)
 ])
@@ -1999,21 +2029,22 @@ closedir(d);
 ], tcl_ok=yes, tcl_ok=no)
 
     if test $tcl_ok = no; then
-	AC_DEFINE(NO_DIRENT_H)
+	AC_DEFINE(NO_DIRENT_H, 1, [Do we have <dirent.h>?])
     fi
 
     AC_MSG_RESULT($tcl_ok)
-    AC_CHECK_HEADER(errno.h, , [AC_DEFINE(NO_ERRNO_H)])
-    AC_CHECK_HEADER(float.h, , [AC_DEFINE(NO_FLOAT_H)])
-    AC_CHECK_HEADER(values.h, , [AC_DEFINE(NO_VALUES_H)])
+    AC_CHECK_HEADER(errno.h, , [AC_DEFINE(NO_ERRNO_H, 1, [Do we have <errno.h>?])])
+    AC_CHECK_HEADER(float.h, , [AC_DEFINE(NO_FLOAT_H, 1, [Do we have <float.h>?])])
+    AC_CHECK_HEADER(values.h, , [AC_DEFINE(NO_VALUES_H, 1, [Do we have <values.h>?])])
     AC_CHECK_HEADER(limits.h,
-	[AC_DEFINE(HAVE_LIMITS_H)], [AC_DEFINE(NO_LIMITS_H)])
+	[AC_DEFINE(HAVE_LIMITS_H, 1, [Do we have <limits.h>?])],
+	[AC_DEFINE(NO_LIMITS_H, 1, [Do we have <limits.h>?])])
     AC_CHECK_HEADER(stdlib.h, tcl_ok=1, tcl_ok=0)
     AC_EGREP_HEADER(strtol, stdlib.h, , tcl_ok=0)
     AC_EGREP_HEADER(strtoul, stdlib.h, , tcl_ok=0)
     AC_EGREP_HEADER(strtod, stdlib.h, , tcl_ok=0)
     if test $tcl_ok = 0; then
-	AC_DEFINE(NO_STDLIB_H)
+	AC_DEFINE(NO_STDLIB_H, 1, [Do we have <stdlib.h>?])
     fi
     AC_CHECK_HEADER(string.h, tcl_ok=1, tcl_ok=0)
     AC_EGREP_HEADER(strstr, string.h, , tcl_ok=0)
@@ -2023,11 +2054,11 @@ closedir(d);
     # set and why.
 
     if test $tcl_ok = 0; then
-	AC_DEFINE(NO_STRING_H)
+	AC_DEFINE(NO_STRING_H, 1, [Do we have <string.h>?])
     fi
 
-    AC_CHECK_HEADER(sys/wait.h, , [AC_DEFINE(NO_SYS_WAIT_H)])
-    AC_CHECK_HEADER(dlfcn.h, , [AC_DEFINE(NO_DLFCN_H)])
+    AC_CHECK_HEADER(sys/wait.h, , [AC_DEFINE(NO_SYS_WAIT_H, 1, [Do we have <sys/wait.h>?])])
+    AC_CHECK_HEADER(dlfcn.h, , [AC_DEFINE(NO_DLFCN_H, 1, [Do we have <dlfcn.h>?])])
 
     # OS/390 lacks sys/param.h (and doesn't need it, by chance).
     AC_HAVE_HEADERS(sys/param.h)
@@ -2168,15 +2199,15 @@ AC_DEFUN(SC_BLOCKING_STYLE, [
 	# code (JO, 5/31/97).
 
 	OSF*)
-	    AC_DEFINE(USE_FIONBIO)
+	    AC_DEFINE(USE_FIONBIO, 1, [Should we use FIONBIO?])
 	    AC_MSG_RESULT(FIONBIO)
 	    ;;
 	SunOS-4*)
-	    AC_DEFINE(USE_FIONBIO)
+	    AC_DEFINE(USE_FIONBIO, 1, [Should we use FIONBIO?])
 	    AC_MSG_RESULT(FIONBIO)
 	    ;;
 	ULTRIX-4.*)
-	    AC_DEFINE(USE_FIONBIO)
+	    AC_DEFINE(USE_FIONBIO, 1, [Should we use FIONBIO?])
 	    AC_MSG_RESULT(FIONBIO)
 	    ;;
 	*)
@@ -2217,7 +2248,7 @@ AC_DEFUN(SC_TIME_HANDLER, [
 	    tcl_cv_member_tm_tzadj=yes, tcl_cv_member_tm_tzadj=no))
     AC_MSG_RESULT($tcl_cv_member_tm_tzadj)
     if test $tcl_cv_member_tm_tzadj = yes ; then
-	AC_DEFINE(HAVE_TM_TZADJ)
+	AC_DEFINE(HAVE_TM_TZADJ, 1, [Should we use the tm_tzadj field of struct tm?])
     fi
 
     AC_MSG_CHECKING([tm_gmtoff in struct tm])
@@ -2226,7 +2257,7 @@ AC_DEFUN(SC_TIME_HANDLER, [
 	    tcl_cv_member_tm_gmtoff=yes, tcl_cv_member_tm_gmtoff=no))
     AC_MSG_RESULT($tcl_cv_member_tm_gmtoff)
     if test $tcl_cv_member_tm_gmtoff = yes ; then
-	AC_DEFINE(HAVE_TM_GMTOFF)
+	AC_DEFINE(HAVE_TM_GMTOFF, 1, [Should we use the tm_gmtoff field of struct tm?])
     fi
 
     #
@@ -2242,7 +2273,7 @@ AC_DEFUN(SC_TIME_HANDLER, [
 	    tcl_cv_timezone_long=yes, tcl_cv_timezone_long=no))
     AC_MSG_RESULT($tcl_cv_timezone_long)
     if test $tcl_cv_timezone_long = yes ; then
-	AC_DEFINE(HAVE_TIMEZONE_VAR)
+	AC_DEFINE(HAVE_TIMEZONE_VAR, 1, [Should we use the global timezone variable?])
     else
 	#
 	# On some systems (eg IRIX 6.2), timezone is a time_t and not a long.
@@ -2256,7 +2287,7 @@ AC_DEFUN(SC_TIME_HANDLER, [
 		tcl_cv_timezone_time=yes, tcl_cv_timezone_time=no))
 	AC_MSG_RESULT($tcl_cv_timezone_time)
 	if test $tcl_cv_timezone_time = yes ; then
-	    AC_DEFINE(HAVE_TIMEZONE_VAR)
+	    AC_DEFINE(HAVE_TIMEZONE_VAR, 1, [Should we use the global timezone variable?])
 	fi
     fi
 ])
@@ -2312,7 +2343,7 @@ AC_DEFUN(SC_BUGGY_STRTOD, [
 	    AC_MSG_RESULT(buggy)
 	    AC_LIBOBJ([fixstrtod])
 	    USE_COMPAT=1
-	    AC_DEFINE(strtod, fixstrtod)
+	    AC_DEFINE(strtod, fixstrtod, [Do we want to use the strtod() in compat?])
 	fi
     fi
 ])
@@ -2355,7 +2386,8 @@ AC_DEFUN(SC_TCL_LINK_LIBS, [
     #--------------------------------------------------------------------
 
     AC_CHECK_LIB(inet, main, [LIBS="$LIBS -linet"])
-    AC_CHECK_HEADER(net/errno.h, [AC_DEFINE(HAVE_NET_ERRNO_H)])
+    AC_CHECK_HEADER(net/errno.h, [
+	AC_DEFINE(HAVE_NET_ERRNO_H, 1, [Do we have <net/errno.h>?])])
 
     #--------------------------------------------------------------------
     #	Check for the existence of the -lsocket and -lnsl libraries.
@@ -2415,7 +2447,7 @@ AC_DEFUN(SC_TCL_EARLY_FLAG,[
 		[tcl_cv_flag_]translit($1,[A-Z],[a-z])=yes,
 		[tcl_cv_flag_]translit($1,[A-Z],[a-z])=no)))
     if test ["x${tcl_cv_flag_]translit($1,[A-Z],[a-z])[}" = "xyes"] ; then
-	AC_DEFINE($1)
+	AC_DEFINE($1, 1, [Add the ]$1[ flag when building])
 	tcl_flags="$tcl_flags $1"
     fi])
 
@@ -2465,10 +2497,11 @@ AC_DEFUN(SC_TCL_64BIT_FLAGS, [
             case 1: case (sizeof(]${tcl_type_64bit}[)==sizeof(long)): ; 
         }],tcl_cv_type_64bit=${tcl_type_64bit})])
     if test "${tcl_cv_type_64bit}" = none ; then
-	AC_DEFINE(TCL_WIDE_INT_IS_LONG)
+	AC_DEFINE(TCL_WIDE_INT_IS_LONG, 1, [Are wide integers to be implemented with C 'long's?])
 	AC_MSG_RESULT(using long)
     else
-	AC_DEFINE_UNQUOTED(TCL_WIDE_INT_TYPE,${tcl_cv_type_64bit})
+	AC_DEFINE_UNQUOTED(TCL_WIDE_INT_TYPE,${tcl_cv_type_64bit},
+	    [What type should be used to define wide integers?])
 	AC_MSG_RESULT(${tcl_cv_type_64bit})
 
 	# Now check for auxiliary declarations
@@ -2478,7 +2511,7 @@ AC_DEFUN(SC_TCL_64BIT_FLAGS, [
 #include <sys/dirent.h>],[struct dirent64 p;],
 		tcl_cv_struct_dirent64=yes,tcl_cv_struct_dirent64=no)])
 	if test "x${tcl_cv_struct_dirent64}" = "xyes" ; then
-	    AC_DEFINE(HAVE_STRUCT_DIRENT64)
+	    AC_DEFINE(HAVE_STRUCT_DIRENT64, 1, [Is 'struct dirent64' in <sys/types.h>?])
 	fi
 	AC_MSG_RESULT(${tcl_cv_struct_dirent64})
 
@@ -2488,7 +2521,7 @@ AC_DEFUN(SC_TCL_64BIT_FLAGS, [
 ],
 		tcl_cv_struct_stat64=yes,tcl_cv_struct_stat64=no)])
 	if test "x${tcl_cv_struct_stat64}" = "xyes" ; then
-	    AC_DEFINE(HAVE_STRUCT_STAT64)
+	    AC_DEFINE(HAVE_STRUCT_STAT64, 1, [Is 'struct stat64' in <sys/stat.h>?])
 	fi
 	AC_MSG_RESULT(${tcl_cv_struct_stat64})
 
@@ -2498,7 +2531,7 @@ AC_DEFUN(SC_TCL_64BIT_FLAGS, [
 ],
 		tcl_cv_type_off64_t=yes,tcl_cv_type_off64_t=no)])
 	if test "x${tcl_cv_type_off64_t}" = "xyes" ; then
-	    AC_DEFINE(HAVE_TYPE_OFF64_T)
+	    AC_DEFINE(HAVE_TYPE_OFF64_T, 1, [Is off64_t in <sys/types.h>?])
 	fi
 	AC_MSG_RESULT(${tcl_cv_type_off64_t})
     fi])
@@ -2524,7 +2557,13 @@ AC_DEFUN(SC_TCL_CFG_ENCODING, [
     AC_ARG_WITH(encoding, [  --with-encoding              encoding for configuration values], with_tcencoding=${withval})
 
     if test x"${with_tcencoding}" != x ; then
-	AC_DEFINE_UNQUOTED(TCL_CFGVAL_ENCODING,"${with_tcencoding}")
+	AC_DEFINE_UNQUOTED(TCL_CFGVAL_ENCODING,"${with_tcencoding}",
+	    [What encoding should be used for embedded configuration info?])
     else
-	AC_DEFINE(TCL_CFGVAL_ENCODING,"iso8859-1")
+	AC_DEFINE(TCL_CFGVAL_ENCODING,"iso8859-1",
+	    [What encoding should be used for embedded configuration info?])
     fi])
+
+# Local Variables:
+# mode: autoconf
+# End: