diff --git a/ext/bcmath/config.m4 b/ext/bcmath/config.m4
index 4dbeb6c3adc9d..2617ee0f13503 100644
--- a/ext/bcmath/config.m4
+++ b/ext/bcmath/config.m4
@@ -32,5 +32,6 @@ if test "$PHP_BCMATH" != "no"; then
     [$ext_shared],,
     [-DZEND_ENABLE_STATIC_TSRMLS_CACHE=1])
   PHP_ADD_BUILD_DIR([$ext_builddir/libbcmath/src])
-  AC_DEFINE(HAVE_BCMATH, 1, [Whether you have bcmath])
+  AC_DEFINE([HAVE_BCMATH], [1],
+    [Define to 1 if the PHP extension 'bcmath' is available.])
 fi
diff --git a/ext/bcmath/config.w32 b/ext/bcmath/config.w32
index bf5fc719a1077..f7346b1942692 100644
--- a/ext/bcmath/config.w32
+++ b/ext/bcmath/config.w32
@@ -10,5 +10,5 @@ if (PHP_BCMATH == "yes") {
 		floor_or_ceil.c nearzero.c num2str.c raise.c rmzero.c str2num.c \
 		round.c convert.c", "bcmath");
 
-	AC_DEFINE('HAVE_BCMATH', 1, 'Have BCMATH library');
+	AC_DEFINE('HAVE_BCMATH', 1, "Define to 1 if the PHP extension 'bcmath' is available.");
 }
diff --git a/ext/bz2/config.m4 b/ext/bz2/config.m4
index 3a41e9835a75b..afed141646b89 100644
--- a/ext/bz2/config.m4
+++ b/ext/bz2/config.m4
@@ -21,7 +21,8 @@ if test "$PHP_BZ2" != "no"; then
     PHP_ADD_LIBRARY_WITH_PATH([bz2],
       [$BZIP_DIR/$PHP_LIBDIR],
       [BZ2_SHARED_LIBADD])
-    AC_DEFINE([HAVE_BZ2], [1], [ ])
+    AC_DEFINE([HAVE_BZ2], [1],
+      [Define to 1 if the PHP extension 'bz2' is available.])
     ],
     [AC_MSG_ERROR([bz2 module requires libbz2 >= 1.0.0])],
     [-L$BZIP_DIR/$PHP_LIBDIR])
diff --git a/ext/bz2/config.w32 b/ext/bz2/config.w32
index 96214faf9c78d..afbb8c648cc5c 100644
--- a/ext/bz2/config.w32
+++ b/ext/bz2/config.w32
@@ -6,7 +6,7 @@ if (PHP_BZ2 != "no") {
 	if (CHECK_LIB("libbz2_a.lib;libbz2.lib", "bz2", PHP_BZ2) &&
 			CHECK_HEADER_ADD_INCLUDE("bzlib.h", "CFLAGS_BZ2")) {
 		EXTENSION("bz2", "bz2.c bz2_filter.c");
-		AC_DEFINE('HAVE_BZ2', 1, 'Have BZ2 library');
+		AC_DEFINE('HAVE_BZ2', 1, "Define to 1 if the PHP extension 'bz2' is available.");
 		// BZ2 extension does this slightly differently from others
 		if (PHP_BZ2_SHARED) {
 			ADD_FLAG("CFLAGS_BZ2", "/D PHP_BZ2_EXPORTS ");
diff --git a/ext/calendar/config.m4 b/ext/calendar/config.m4
index c2ffbf475e3f1..08ea6bb883fcd 100644
--- a/ext/calendar/config.m4
+++ b/ext/calendar/config.m4
@@ -4,7 +4,8 @@ PHP_ARG_ENABLE([calendar],
     [Enable support for calendar conversion])])
 
 if test "$PHP_CALENDAR" = "yes"; then
-  AC_DEFINE(HAVE_CALENDAR,1,[ ])
+  AC_DEFINE([HAVE_CALENDAR], [1],
+    [Define to 1 if the PHP extension 'calendar' is available.])
   PHP_NEW_EXTENSION([calendar],
     [calendar.c dow.c french.c gregor.c jewish.c julian.c easter.c cal_unix.c],
     [$ext_shared])
diff --git a/ext/calendar/config.w32 b/ext/calendar/config.w32
index 238c13eb16bee..00c65ab790560 100644
--- a/ext/calendar/config.w32
+++ b/ext/calendar/config.w32
@@ -5,5 +5,5 @@ ARG_ENABLE("calendar", "calendar conversion support", "yes");
 if (PHP_CALENDAR == "yes") {
 	EXTENSION("calendar", "calendar.c dow.c french.c gregor.c jewish.c \
 		julian.c easter.c cal_unix.c");
-	AC_DEFINE('HAVE_CALENDAR', 1, 'Have calendar');
+	AC_DEFINE('HAVE_CALENDAR', 1, "Define to 1 if the PHP extension 'calendar' is available.");
 }
diff --git a/ext/com_dotnet/config.w32 b/ext/com_dotnet/config.w32
index e1f20cba20db9..cc548ac48c777 100644
--- a/ext/com_dotnet/config.w32
+++ b/ext/com_dotnet/config.w32
@@ -8,6 +8,6 @@ if (PHP_COM_DOTNET == "yes") {
 		com_handlers.c com_iterator.c com_misc.c com_olechar.c \
 		com_typeinfo.c com_variant.c com_wrapper.c com_saproxy.c com_persist.c",
 		null, "/DZEND_ENABLE_STATIC_TSRMLS_CACHE=1");
-	AC_DEFINE('HAVE_COM_DOTNET', 1, 'Have COM_DOTNET support');
+	AC_DEFINE('HAVE_COM_DOTNET', 1, "Define to 1 if the PHP extension 'com_dotnet' is available.");
 	CHECK_HEADER_ADD_INCLUDE('mscoree.h', 'CFLAGS_COM_DOTNET');
 }
diff --git a/ext/ctype/config.m4 b/ext/ctype/config.m4
index 549cee6a867c1..4ac6614744d7e 100644
--- a/ext/ctype/config.m4
+++ b/ext/ctype/config.m4
@@ -5,6 +5,7 @@ PHP_ARG_ENABLE([ctype],
   [yes])
 
 if test "$PHP_CTYPE" != "no"; then
-  AC_DEFINE(HAVE_CTYPE, 1, [ ])
+  AC_DEFINE([HAVE_CTYPE], [1],
+    [Define to 1 if the PHP extension 'ctype' is available.])
   PHP_NEW_EXTENSION([ctype], [ctype.c], [$ext_shared])
 fi
diff --git a/ext/ctype/config.w32 b/ext/ctype/config.w32
index 552efada64ce3..7816ac667c5c9 100644
--- a/ext/ctype/config.w32
+++ b/ext/ctype/config.w32
@@ -4,5 +4,5 @@ ARG_ENABLE("ctype", "ctype", "yes");
 
 if (PHP_CTYPE == "yes") {
 	EXTENSION("ctype", "ctype.c");
-	AC_DEFINE('HAVE_CTYPE', 1, 'Have ctype');
+	AC_DEFINE('HAVE_CTYPE', 1, "Define to 1 if the PHP extension 'ctype' is available.");
 }
diff --git a/ext/curl/config.m4 b/ext/curl/config.m4
index d7d125f13726c..af4670c36de61 100644
--- a/ext/curl/config.m4
+++ b/ext/curl/config.m4
@@ -74,7 +74,7 @@ if test "$PHP_CURL" != "no"; then
   PHP_CHECK_LIBRARY([curl],
     [curl_easy_perform],
     [AC_DEFINE([HAVE_CURL], [1],
-      [Define to 1 if curl extension is available.])],
+      [Define to 1 if the PHP extension 'curl' is available.])],
     [AC_MSG_ERROR([The libcurl check failed. Please, check config.log for details.])],
     [$CURL_LIBS])
 
diff --git a/ext/curl/config.w32 b/ext/curl/config.w32
index e1851fbf3841b..82be5212e56b3 100644
--- a/ext/curl/config.w32
+++ b/ext/curl/config.w32
@@ -26,7 +26,7 @@ if (PHP_CURL != "no") {
 		 CHECK_LIB("nghttp2.lib", "curl", PHP_CURL))
 		) {
 		EXTENSION("curl", "interface.c multi.c share.c curl_file.c");
-		AC_DEFINE('HAVE_CURL', 1, 'Define to 1 if curl extension is available.');
+		AC_DEFINE('HAVE_CURL', 1, "Define to 1 if the PHP extension 'curl' is available.");
 		ADD_FLAG("CFLAGS_CURL", "/D CURL_STATICLIB /D PHP_CURL_EXPORTS=1");
 		PHP_INSTALL_HEADERS("ext/curl", "php_curl.h");
 	} else {
diff --git a/ext/dba/config.m4 b/ext/dba/config.m4
index 4d161fce32e34..7812ac23640f7 100644
--- a/ext/dba/config.m4
+++ b/ext/dba/config.m4
@@ -700,7 +700,8 @@ if test "$HAVE_DBA" = "1"; then
   else
     AC_MSG_RESULT([yes])
   fi
-  AC_DEFINE(HAVE_DBA, 1, [ ])
+  AC_DEFINE([HAVE_DBA], [1],
+    [Define to 1 if the PHP extension 'dba' is available.])
   PHP_NEW_EXTENSION([dba], m4_normalize([
       dba_cdb.c
       dba_db1.c
diff --git a/ext/dba/config.w32 b/ext/dba/config.w32
index ce1efe789abee..2ea340abca419 100644
--- a/ext/dba/config.w32
+++ b/ext/dba/config.w32
@@ -10,7 +10,7 @@ if (PHP_DBA != "no") {
 	ADD_SOURCES("ext/dba/libcdb", "cdb.c cdb_make.c uint32.c", "dba");
 	ADD_SOURCES("ext/dba/libflatfile", "flatfile.c", "dba");
 	ADD_SOURCES("ext/dba/libinifile", "inifile.c", "dba");
-	AC_DEFINE('HAVE_DBA', 1, 'DBA support');
+	AC_DEFINE('HAVE_DBA', 1, "Define to 1 if the PHP extension 'dba' is available.");
 	ADD_FLAG("CFLAGS_DBA", "/D DBA_FLATFILE=1 /D DBA_CDB=1 /D DBA_CDB_BUILTIN=1 /D DBA_INIFILE=1");
 
 	if (PHP_DB != "no") {
diff --git a/ext/dom/config.m4 b/ext/dom/config.m4
index f5d31337c7f49..2d130753ff042 100644
--- a/ext/dom/config.m4
+++ b/ext/dom/config.m4
@@ -11,7 +11,8 @@ if test "$PHP_DOM" != "no"; then
   fi
 
   PHP_SETUP_LIBXML([DOM_SHARED_LIBADD], [
-    AC_DEFINE([HAVE_DOM], [1], [Define to 1 if dom extension is available.])
+    AC_DEFINE([HAVE_DOM], [1],
+      [Define to 1 if the PHP extension 'dom' is available.])
     PHP_LEXBOR_CFLAGS="-I@ext_srcdir@/lexbor -DLEXBOR_STATIC"
     LEXBOR_DIR="lexbor/lexbor"
     LEXBOR_SOURCES=m4_normalize(["
diff --git a/ext/dom/config.w32 b/ext/dom/config.w32
index 0cdb0fc8d5d74..231f005895f56 100644
--- a/ext/dom/config.w32
+++ b/ext/dom/config.w32
@@ -38,7 +38,7 @@ if (PHP_DOM == "yes") {
 		ADD_SOURCES("ext/dom/lexbor/lexbor/tag", "tag.c", "dom");
 		ADD_FLAG("CFLAGS_DOM", "/D LEXBOR_STATIC ");
 
-		AC_DEFINE("HAVE_DOM", 1, "Define to 1 if dom extension is available.");
+		AC_DEFINE("HAVE_DOM", 1, "Define to 1 if the PHP extension 'dom' is available.");
 
 		if (!PHP_DOM_SHARED) {
 			ADD_FLAG("CFLAGS_DOM", "/D LIBXML_STATIC ");
diff --git a/ext/enchant/config.m4 b/ext/enchant/config.m4
index 0201f30153a51..9613c29297df4 100644
--- a/ext/enchant/config.m4
+++ b/ext/enchant/config.m4
@@ -33,7 +33,8 @@ if test "$PHP_ENCHANT" != "no"; then
       [$ENCHANT_LIBS])
   ])
 
-  AC_DEFINE(HAVE_ENCHANT, 1, [ ])
+  AC_DEFINE([HAVE_ENCHANT], [1],
+    [Define to 1 if the PHP extension 'enchant' is available.])
 
   PHP_NEW_EXTENSION([enchant], [enchant.c], [$ext_shared])
   PHP_SUBST([ENCHANT_SHARED_LIBADD])
diff --git a/ext/enchant/config.w32 b/ext/enchant/config.w32
index 25f088bba4726..167f06c11c535 100644
--- a/ext/enchant/config.w32
+++ b/ext/enchant/config.w32
@@ -16,7 +16,7 @@ if (PHP_ENCHANT == "yes") {
 		}
 		if (have_enchant) {
 			EXTENSION("enchant", "enchant.c");
-			AC_DEFINE('HAVE_ENCHANT', 1, 'Have Enchant support', false);
+			AC_DEFINE('HAVE_ENCHANT', 1, "Define to 1 if the PHP extension 'enchant' is available.");
 			AC_DEFINE('HAVE_ENCHANT_GET_VERSION', 1);
 		}
 	} else {
diff --git a/ext/exif/config.m4 b/ext/exif/config.m4
index f6f381288167e..5d096cb4c16b7 100644
--- a/ext/exif/config.m4
+++ b/ext/exif/config.m4
@@ -4,7 +4,8 @@ PHP_ARG_ENABLE([exif],
     [Enable EXIF (metadata from images) support])])
 
 if test "$PHP_EXIF" != "no"; then
-  AC_DEFINE(HAVE_EXIF, 1, [Whether you want EXIF (metadata from images) support])
+  AC_DEFINE([HAVE_EXIF], [1],
+    [Define to 1 if the PHP extension 'exif' is available.])
   PHP_NEW_EXTENSION([exif],
     [exif.c],
     [$ext_shared],,
diff --git a/ext/exif/config.w32 b/ext/exif/config.w32
index 0fe93cdb56221..52adaef5b12f7 100644
--- a/ext/exif/config.w32
+++ b/ext/exif/config.w32
@@ -6,7 +6,7 @@ if(PHP_EXIF != 'no')
 {
 	if(ADD_EXTENSION_DEP('exif', 'mbstring'))
 	{
-		AC_DEFINE('HAVE_EXIF', 1, 'Have EXIF Support');
+		AC_DEFINE('HAVE_EXIF', 1, "Define to 1 if the PHP extension 'exif' is available.");
 
 		EXTENSION('exif', 'exif.c', null, '/DZEND_ENABLE_STATIC_TSRMLS_CACHE=1');
 	}
diff --git a/ext/ffi/config.m4 b/ext/ffi/config.m4
index 4b15070469bd4..12940584cab39 100644
--- a/ext/ffi/config.m4
+++ b/ext/ffi/config.m4
@@ -9,7 +9,8 @@ if test "$PHP_FFI" != "no"; then
   PHP_EVAL_INCLINE([$FFI_CFLAGS])
   PHP_EVAL_LIBLINE([$FFI_LIBS], [FFI_SHARED_LIBADD])
 
-  AC_DEFINE(HAVE_FFI, 1, [Have ffi support])
+  AC_DEFINE([HAVE_FFI], [1],
+    [Define to 1 if the PHP extension 'ffi' is available.])
 
   AC_CHECK_TYPES([long double])
 
diff --git a/ext/ffi/config.w32 b/ext/ffi/config.w32
index 387113c8d57a7..536922eabadb1 100644
--- a/ext/ffi/config.w32
+++ b/ext/ffi/config.w32
@@ -3,7 +3,7 @@ ARG_WITH('ffi', 'ffi support', 'no');
 if (PHP_FFI != 'no') {
 	if (CHECK_HEADER_ADD_INCLUDE("ffi.h", "CFLAGS_FFI", PHP_FFI+ ";" + PHP_PHP_BUILD + "\\include") &&
 		CHECK_LIB("libffi.lib", "ffi", PHP_FFI)) {
-		AC_DEFINE('HAVE_FFI', 1, 'ffi support enabled');
+		AC_DEFINE('HAVE_FFI', 1, "Define to 1 if the PHP extension 'ffi' is available.");
 
 		if (!X64) {
 		    AC_DEFINE('HAVE_FFI_FASTCALL', 1 ,'libffi supports fastcall calling convention');
diff --git a/ext/ftp/config.m4 b/ext/ftp/config.m4
index 0837b8465041c..dccc904533ff2 100644
--- a/ext/ftp/config.m4
+++ b/ext/ftp/config.m4
@@ -13,7 +13,8 @@ PHP_ARG_WITH([ftp-ssl],
   [no])
 
 if test "$PHP_FTP" = "yes"; then
-  AC_DEFINE(HAVE_FTP,1,[Whether you want FTP support])
+  AC_DEFINE([HAVE_FTP], [1],
+    [Define to 1 if the PHP extension 'ftp' is available.])
   PHP_NEW_EXTENSION([ftp], [php_ftp.c ftp.c], [$ext_shared])
 
   dnl Empty variable means 'no' (for phpize builds).
diff --git a/ext/ftp/config.w32 b/ext/ftp/config.w32
index 2d6845ca5414a..410ce509f33fd 100644
--- a/ext/ftp/config.w32
+++ b/ext/ftp/config.w32
@@ -13,5 +13,5 @@ if (PHP_FTP != "no") {
 		AC_DEFINE('HAVE_FTP_SSL', 1, 'Have FTP over SSL support');
 	}
 
-	AC_DEFINE('HAVE_FTP', 1, 'Have FTP support');
+	AC_DEFINE('HAVE_FTP', 1, "Define to 1 if the PHP extension 'ftp' is available.");
 }
diff --git a/ext/gmp/config.m4 b/ext/gmp/config.m4
index db53d3df18cef..3af699abe505e 100644
--- a/ext/gmp/config.m4
+++ b/ext/gmp/config.m4
@@ -33,5 +33,6 @@ if test "$PHP_GMP" != "no"; then
     [$ext_shared],,
     [-DZEND_ENABLE_STATIC_TSRMLS_CACHE=1])
   PHP_SUBST([GMP_SHARED_LIBADD])
-  AC_DEFINE(HAVE_GMP, 1, [ ])
+  AC_DEFINE([HAVE_GMP], [1],
+    [Define to 1 if the PHP extension 'gmp' is available.])
 fi
diff --git a/ext/gmp/config.w32 b/ext/gmp/config.w32
index 13083d97b2806..2bb4aa63ad0f0 100644
--- a/ext/gmp/config.w32
+++ b/ext/gmp/config.w32
@@ -7,7 +7,7 @@ if (PHP_GMP != "no") {
 		CHECK_HEADER_ADD_INCLUDE("gmp.h", "CFLAGS_GMP", PHP_GMP +  ";" + PHP_PHP_BUILD + "\\include\\mpir")) {
 		EXTENSION("gmp", "gmp.c", null, "/DZEND_ENABLE_STATIC_TSRMLS_CACHE=1");
 		PHP_INSTALL_HEADERS("ext/gmp", "php_gmp_int.h");
-		AC_DEFINE('HAVE_GMP', 1, 'GMP support');
+		AC_DEFINE('HAVE_GMP', 1, "Define to 1 if the PHP extension 'gmp' is available.");
 	} else {
 		WARNING("GMP not enabled; libraries and headers not found");
 	}
diff --git a/ext/iconv/config.m4 b/ext/iconv/config.m4
index 6e052d0abe74a..d09e3dfde5d2d 100644
--- a/ext/iconv/config.m4
+++ b/ext/iconv/config.m4
@@ -128,7 +128,7 @@ int main(void) {
     CFLAGS="$save_CFLAGS"
 
     AC_DEFINE([HAVE_ICONV], [1],
-      [Define to 1 if PHP extension 'iconv' is available.])
+      [Define to 1 if the PHP extension 'iconv' is available.])
 
     PHP_NEW_EXTENSION([iconv],
       [iconv.c],
diff --git a/ext/iconv/config.w32 b/ext/iconv/config.w32
index bd44686182ef9..d99c53fb93634 100644
--- a/ext/iconv/config.w32
+++ b/ext/iconv/config.w32
@@ -9,7 +9,7 @@ if (PHP_ICONV != "no") {
 
 		EXTENSION("iconv", "iconv.c", PHP_ICONV_SHARED, "/DZEND_ENABLE_STATIC_TSRMLS_CACHE=1");
 
-		AC_DEFINE("HAVE_ICONV", 1, "Define to 1 if PHP extension 'iconv' is available.");
+		AC_DEFINE("HAVE_ICONV", 1, "Define to 1 if the PHP extension 'iconv' is available.");
 		AC_DEFINE("HAVE_LIBICONV", 1, "Define to 1 if you have the 'libiconv' function.");
 		AC_DEFINE("ICONV_ALIASED_LIBICONV", 1, "Define to 1 if 'iconv()' is aliased to 'libiconv()'.");
 		AC_DEFINE("PHP_ICONV_IMPL", "\"libiconv\"", "The iconv implementation.");
diff --git a/ext/ldap/config.m4 b/ext/ldap/config.m4
index 3de1471a128ac..1a70a3e78bfc3 100644
--- a/ext/ldap/config.m4
+++ b/ext/ldap/config.m4
@@ -96,7 +96,8 @@ if test "$PHP_LDAP" != "no"; then
 
   PHP_ADD_INCLUDE([$LDAP_INCDIR])
   PHP_SUBST([LDAP_SHARED_LIBADD])
-  AC_DEFINE(HAVE_LDAP,1,[ ])
+  AC_DEFINE([HAVE_LDAP], [1],
+    [Define to 1 if the PHP extension 'ldap' is available.])
 
   dnl Save original values
   _SAVE_CPPFLAGS=$CPPFLAGS
diff --git a/ext/ldap/config.w32 b/ext/ldap/config.w32
index e45d1c1f6a960..e131df2c70932 100644
--- a/ext/ldap/config.w32
+++ b/ext/ldap/config.w32
@@ -15,7 +15,7 @@ if (PHP_LDAP != "no") {
 		AC_DEFINE('HAVE_LDAP_PARSE_RESULT', 1);
 		AC_DEFINE('HAVE_LDAP_PARSE_REFERENCE', 1);
 		AC_DEFINE('HAVE_LDAP_START_TLS_S', 1);
-		AC_DEFINE('HAVE_LDAP', 1);
+		AC_DEFINE('HAVE_LDAP', 1, "Define to 1 if the PHP extension 'ldap' is available.");
 		AC_DEFINE('HAVE_LDAP_SASL', 1);
 		AC_DEFINE('HAVE_LDAP_CONTROL_FIND', 1);
 		AC_DEFINE('HAVE_LDAP_PARSE_EXTENDED_RESULT', 1);
diff --git a/ext/libxml/config.w32 b/ext/libxml/config.w32
index e20ae181be953..416ae1f136637 100644
--- a/ext/libxml/config.w32
+++ b/ext/libxml/config.w32
@@ -10,7 +10,7 @@ if (PHP_LIBXML == "yes") {
 			ADD_EXTENSION_DEP('libxml', 'iconv')) {
 
 		EXTENSION("libxml", "libxml.c mime_sniff.c", false /* never shared */, "/DZEND_ENABLE_STATIC_TSRMLS_CACHE=1");
-		AC_DEFINE("HAVE_LIBXML", 1, "Define to 1 if libxml extension is available.");
+		AC_DEFINE("HAVE_LIBXML", 1, "Define to 1 if the PHP extension 'libxml' is available.");
 		ADD_FLAG("CFLAGS_LIBXML", "/D LIBXML_STATIC /D LIBXML_STATIC_FOR_DLL /D HAVE_WIN32_THREADS ");
 		if (!PHP_LIBXML_SHARED) {
 			ADD_DEF_FILE("ext\\libxml\\php_libxml2.def");
diff --git a/ext/libxml/config0.m4 b/ext/libxml/config0.m4
index 780bc540587bf..a2f7c00ba55c6 100644
--- a/ext/libxml/config0.m4
+++ b/ext/libxml/config0.m4
@@ -11,7 +11,7 @@ if test "$PHP_LIBXML" != "no"; then
 
   PHP_SETUP_LIBXML([LIBXML_SHARED_LIBADD], [
     AC_DEFINE([HAVE_LIBXML], [1],
-      [Define to 1 if libxml extension is available.])
+      [Define to 1 if the PHP extension 'libxml' is available.])
     PHP_NEW_EXTENSION([libxml],
       [libxml.c mime_sniff.c],
       [$ext_shared],,
diff --git a/ext/mbstring/config.m4 b/ext/mbstring/config.m4
index ccc1d46e2a4bc..c2f1fe5fea7cf 100644
--- a/ext/mbstring/config.m4
+++ b/ext/mbstring/config.m4
@@ -167,7 +167,8 @@ PHP_ARG_ENABLE([mbregex],
   [no])
 
 if test "$PHP_MBSTRING" != "no"; then
-  AC_DEFINE([HAVE_MBSTRING],1,[whether to have multibyte string support])
+  AC_DEFINE([HAVE_MBSTRING], [1],
+    [Define to 1 if the PHP extension 'mbstring' is available.])
 
   PHP_MBSTRING_ADD_BASE_SOURCES([mbstring.c php_unicode.c mb_gpc.c])
 
diff --git a/ext/mbstring/config.w32 b/ext/mbstring/config.w32
index 28afe1153b3d3..dbfd1086488a3 100644
--- a/ext/mbstring/config.w32
+++ b/ext/mbstring/config.w32
@@ -38,7 +38,7 @@ if (PHP_MBSTRING != "no") {
 
 		PHP_INSTALL_HEADERS("ext/mbstring", "mbstring.h libmbfl/config.h libmbfl/mbfl/eaw_table.h libmbfl/mbfl/mbfilter.h libmbfl/mbfl/mbfilter_8bit.h libmbfl/mbfl/mbfilter_pass.h libmbfl/mbfl/mbfilter_wchar.h libmbfl/mbfl/mbfl_consts.h libmbfl/mbfl/mbfl_convert.h libmbfl/mbfl/mbfl_defs.h libmbfl/mbfl/mbfl_encoding.h libmbfl/mbfl/mbfl_filter_output.h libmbfl/mbfl/mbfl_language.h libmbfl/mbfl/mbfl_memory_device.h libmbfl/mbfl/mbfl_string.h");
 
-		AC_DEFINE('HAVE_MBSTRING', 1, 'Have mbstring support');
+		AC_DEFINE('HAVE_MBSTRING', 1, "Define to 1 if the PHP extension 'mbstring' is available.");
 
 		if (PHP_MBREGEX != "no") {
 			if (CHECK_HEADER_ADD_INCLUDE("oniguruma.h", "CFLAGS_MBSTRING", PHP_MBREGEX) &&
diff --git a/ext/odbc/config.m4 b/ext/odbc/config.m4
index 78d9df59f906d..ab19f1368d2ee 100644
--- a/ext/odbc/config.m4
+++ b/ext/odbc/config.m4
@@ -448,7 +448,8 @@ if test -n "$ODBC_TYPE"; then
     fi
   fi
 
-  AC_DEFINE(HAVE_UODBC,1,[ ])
+  AC_DEFINE([HAVE_UODBC], [1],
+    [Define to 1 if the PHP extension 'odbc' is available.])
   PHP_SUBST([ODBC_SHARED_LIBADD])
   AC_SUBST([ODBC_CFLAGS])
   AC_SUBST([ODBC_LIBS])
diff --git a/ext/odbc/config.w32 b/ext/odbc/config.w32
index 29d8a7673a6a5..a5740bdaa6cdc 100644
--- a/ext/odbc/config.w32
+++ b/ext/odbc/config.w32
@@ -8,7 +8,7 @@ if (PHP_ODBC == "yes") {
 	&& CHECK_HEADER_ADD_INCLUDE("sql.h", "CFLAGS_ODBC")
 	&& CHECK_HEADER_ADD_INCLUDE("sqlext.h", "CFLAGS_ODBC")) {
 		EXTENSION("odbc", "php_odbc.c odbc_utils.c", PHP_ODBC_SHARED, "/DZEND_ENABLE_STATIC_TSRMLS_CACHE=1");
-		AC_DEFINE("HAVE_UODBC", 1, "ODBC support");
+		AC_DEFINE("HAVE_UODBC", 1, "Define to 1 if the PHP extension 'odbc' is available.");
 		if ("no" == PHP_ODBCVER) {
 			AC_DEFINE("ODBCVER", "0x0350", "The highest supported ODBC version", false);
 		} else if ("0" != PHP_ODBCVER) {
diff --git a/ext/openssl/config.w32 b/ext/openssl/config.w32
index 535a4353f43ed..e71b86056bc95 100644
--- a/ext/openssl/config.w32
+++ b/ext/openssl/config.w32
@@ -7,6 +7,6 @@ if (PHP_OPENSSL != "no") {
 
 	if (ret >= 2) {
 		EXTENSION("openssl", "openssl.c xp_ssl.c");
-		AC_DEFINE("HAVE_OPENSSL_EXT", 1, "Define to 1 if the openssl extension is available.");
+		AC_DEFINE("HAVE_OPENSSL_EXT", 1, "Define to 1 if the PHP extension 'openssl' is available.");
 	}
 }
diff --git a/ext/openssl/config0.m4 b/ext/openssl/config0.m4
index 5d78dabe80078..213efc79572ba 100644
--- a/ext/openssl/config0.m4
+++ b/ext/openssl/config0.m4
@@ -22,7 +22,7 @@ if test "$PHP_OPENSSL" != "no"; then
   PHP_SUBST([OPENSSL_SHARED_LIBADD])
   PHP_SETUP_OPENSSL([OPENSSL_SHARED_LIBADD],
     [AC_DEFINE([HAVE_OPENSSL_EXT], [1],
-      [Define to 1 if the openssl extension is available.])])
+      [Define to 1 if the PHP extension 'openssl' is available.])])
 
   PHP_CHECK_LIBRARY([crypto], [RAND_egd],
     [AC_DEFINE([HAVE_RAND_EGD], [1],
diff --git a/ext/pdo_pgsql/config.m4 b/ext/pdo_pgsql/config.m4
index a8184140c9cc3..5a2b35dcce324 100644
--- a/ext/pdo_pgsql/config.m4
+++ b/ext/pdo_pgsql/config.m4
@@ -14,7 +14,8 @@ if test "$PHP_PDO_PGSQL" != "no"; then
   PHP_SETUP_PGSQL([PDO_PGSQL_SHARED_LIBADD],,, [$PHP_PDO_PGSQL])
   PHP_SUBST([PDO_PGSQL_SHARED_LIBADD])
 
-  AC_DEFINE(HAVE_PDO_PGSQL,1,[Whether to build PostgreSQL for PDO support or not])
+  AC_DEFINE([HAVE_PDO_PGSQL], [1],
+    [Define to 1 if the PHP extension 'pdo_pgsql' is available.])
 
   PHP_CHECK_LIBRARY([pq], [PQresultMemorySize],
     [AC_DEFINE([HAVE_PG_RESULT_MEMORY_SIZE], [1], [PostgreSQL 12 or later])],,
diff --git a/ext/pdo_pgsql/config.w32 b/ext/pdo_pgsql/config.w32
index 49c445f9902dc..aec5db508d077 100644
--- a/ext/pdo_pgsql/config.w32
+++ b/ext/pdo_pgsql/config.w32
@@ -7,7 +7,7 @@ if (PHP_PDO_PGSQL != "no") {
 			CHECK_HEADER_ADD_INCLUDE("libpq-fe.h", "CFLAGS_PDO_PGSQL", PHP_PDO_PGSQL + "\\include;" + PHP_PHP_BUILD + "\\include\\pgsql;" + PHP_PHP_BUILD + "\\include\\libpq;")) {
 		EXTENSION("pdo_pgsql", "pdo_pgsql.c pgsql_driver.c pgsql_statement.c pgsql_sql_parser.c");
 
-		AC_DEFINE('HAVE_PDO_PGSQL',		1, 'Have PostgreSQL library');
+		AC_DEFINE('HAVE_PDO_PGSQL', 1, "Define to 1 if the PHP extension 'pdo_pgsql' is available.");
 
 		ADD_EXTENSION_DEP('pdo_pgsql', 'pdo');
 		ADD_MAKEFILE_FRAGMENT();
diff --git a/ext/pgsql/config.m4 b/ext/pgsql/config.m4
index 6d5c4701a63f6..59b3f4c6a39d7 100644
--- a/ext/pgsql/config.m4
+++ b/ext/pgsql/config.m4
@@ -10,7 +10,8 @@ if test "$PHP_PGSQL" != "no"; then
   PHP_SETUP_PGSQL([PGSQL_SHARED_LIBADD],,, [$PHP_PGSQL])
   PHP_SUBST([PGSQL_SHARED_LIBADD])
 
-  AC_DEFINE(HAVE_PGSQL,1,[Whether to build PostgreSQL support or not])
+  AC_DEFINE([HAVE_PGSQL], [1],
+    [Define to 1 if the PHP extension 'pgsql' is available.])
 
   PHP_CHECK_LIBRARY([pq], [PQresultMemorySize],
     [AC_DEFINE([HAVE_PG_RESULT_MEMORY_SIZE], [1], [PostgreSQL 12 or later])],,
diff --git a/ext/pgsql/config.w32 b/ext/pgsql/config.w32
index 45f3200e0e0b6..3ca5fc2f16910 100644
--- a/ext/pgsql/config.w32
+++ b/ext/pgsql/config.w32
@@ -6,7 +6,7 @@ if (PHP_PGSQL != "no") {
 	if (CHECK_LIB("libpq.lib", "pgsql", PHP_PGSQL) &&
 		CHECK_HEADER_ADD_INCLUDE("libpq-fe.h", "CFLAGS_PGSQL", PHP_PGSQL + "\\include;" + PHP_PHP_BUILD + "\\include\\pgsql;" + PHP_PHP_BUILD + "\\include\\libpq;" + PHP_PGSQL)) {
 		EXTENSION("pgsql", "pgsql.c", PHP_PGSQL_SHARED, "/DZEND_ENABLE_STATIC_TSRMLS_CACHE=1");
-		AC_DEFINE('HAVE_PGSQL', 1, 'Have PostgreSQL library');
+		AC_DEFINE('HAVE_PGSQL', 1, "Define to 1 if the PHP extension 'pgsql' is available.");
 		ADD_FLAG("CFLAGS_PGSQL", "/D PGSQL_EXPORTS");
 		ADD_EXTENSION_DEP('pgsql', 'pcre');
 	} else {
diff --git a/ext/posix/config.m4 b/ext/posix/config.m4
index 1bdac1766763d..b5c45dd1c899e 100644
--- a/ext/posix/config.m4
+++ b/ext/posix/config.m4
@@ -5,7 +5,8 @@ PHP_ARG_ENABLE([posix],
   [yes])
 
 if test "$PHP_POSIX" = "yes"; then
-  AC_DEFINE(HAVE_POSIX, 1, [whether to include POSIX-like functions])
+  AC_DEFINE([HAVE_POSIX], [1],
+    [Define to 1 if the PHP extension 'posix' is available.])
   PHP_NEW_EXTENSION([posix],
     [posix.c],
     [$ext_shared],,
diff --git a/ext/session/config.m4 b/ext/session/config.m4
index 3ccbd117006eb..3bdab7de1c4c1 100644
--- a/ext/session/config.m4
+++ b/ext/session/config.m4
@@ -22,7 +22,8 @@ if test "$PHP_SESSION" != "no"; then
   PHP_ADD_EXTENSION_DEP(session, spl, true)
   PHP_SUBST([SESSION_SHARED_LIBADD])
   PHP_INSTALL_HEADERS([ext/session], [php_session.h mod_files.h mod_user.h])
-  AC_DEFINE(HAVE_PHP_SESSION,1,[ ])
+  AC_DEFINE([HAVE_PHP_SESSION], [1],
+    [Define to 1 if the PHP extension 'session' is available.])
 fi
 
 if test "$PHP_MM" != "no"; then
diff --git a/ext/session/config.w32 b/ext/session/config.w32
index e3163f9edb5f0..bd5065b599db0 100644
--- a/ext/session/config.w32
+++ b/ext/session/config.w32
@@ -6,6 +6,6 @@ if (PHP_SESSION == "yes") {
 	EXTENSION("session", "mod_user_class.c session.c mod_files.c mod_mm.c mod_user.c", false /* never shared */, "/DZEND_ENABLE_STATIC_TSRMLS_CACHE=1");
 	// https://bugs.php.net/53141
 	ADD_EXTENSION_DEP('session', 'spl', true);
-	AC_DEFINE("HAVE_PHP_SESSION", 1, "Session support");
+	AC_DEFINE("HAVE_PHP_SESSION", 1, "Define to 1 if the PHP extension 'session' is available.");
 	PHP_INSTALL_HEADERS("ext/session", "mod_mm.h php_session.h mod_files.h mod_user.h");
 }
diff --git a/ext/shmop/config.m4 b/ext/shmop/config.m4
index 55ae274c2e859..e3066965563b3 100644
--- a/ext/shmop/config.m4
+++ b/ext/shmop/config.m4
@@ -4,6 +4,7 @@ PHP_ARG_ENABLE([shmop],
     [Enable shmop support])])
 
 if test "$PHP_SHMOP" != "no"; then
-  AC_DEFINE(HAVE_SHMOP, 1, [ ])
+  AC_DEFINE([HAVE_SHMOP], [1],
+    [Define to 1 if the PHP extension 'shmop' is available.])
   PHP_NEW_EXTENSION([shmop], [shmop.c], [$ext_shared])
 fi
diff --git a/ext/shmop/config.w32 b/ext/shmop/config.w32
index f4b6885e781d5..efbbd56aa75d2 100644
--- a/ext/shmop/config.w32
+++ b/ext/shmop/config.w32
@@ -4,5 +4,5 @@ ARG_ENABLE("shmop", "shmop support", "no");
 
 if (PHP_SHMOP == "yes") {
 	EXTENSION("shmop", "shmop.c");
-	AC_DEFINE('HAVE_SHMOP', 1, 'Have SHMOP support');
+	AC_DEFINE('HAVE_SHMOP', 1, "Define to 1 if the PHP extension 'shmop' is available.");
 }
diff --git a/ext/simplexml/config.m4 b/ext/simplexml/config.m4
index a2eea474b7392..0e9dbd6ae957c 100644
--- a/ext/simplexml/config.m4
+++ b/ext/simplexml/config.m4
@@ -7,7 +7,7 @@ PHP_ARG_ENABLE([simplexml],
 if test "$PHP_SIMPLEXML" != "no"; then
   PHP_SETUP_LIBXML([SIMPLEXML_SHARED_LIBADD], [
     AC_DEFINE([HAVE_SIMPLEXML], [1],
-      [Define to 1 if simplexml extension is available.])
+      [Define to 1 if the PHP extension 'simplexml' is available.])
     PHP_NEW_EXTENSION([simplexml], [simplexml.c], [$ext_shared])
     PHP_ADD_EXTENSION_DEP(simplexml, libxml)
     PHP_ADD_EXTENSION_DEP(simplexml, spl)
diff --git a/ext/simplexml/config.w32 b/ext/simplexml/config.w32
index 9d734d1c93754..8942e6c93e3bf 100644
--- a/ext/simplexml/config.w32
+++ b/ext/simplexml/config.w32
@@ -9,7 +9,7 @@ if (PHP_SIMPLEXML == "yes") {
 		CHECK_HEADER_ADD_INCLUDE("libxml/tree.h", "CFLAGS_SIMPLEXML", PHP_PHP_BUILD + "\\include\\libxml2")
 	) {
 		EXTENSION("simplexml", "simplexml.c");
-		AC_DEFINE("HAVE_SIMPLEXML", 1, "Define to 1 if simplexml extension is available.");
+		AC_DEFINE("HAVE_SIMPLEXML", 1, "Define to 1 if the PHP extension 'simplexml' is available.");
 		if (!PHP_SIMPLEXML_SHARED) {
 			ADD_FLAG("CFLAGS_SIMPLEXML", "/D LIBXML_STATIC");
 		} else {
diff --git a/ext/skeleton/config.m4.in b/ext/skeleton/config.m4.in
index 48709bf6f3d29..d6fd14a0f830d 100644
--- a/ext/skeleton/config.m4.in
+++ b/ext/skeleton/config.m4.in
@@ -99,7 +99,7 @@ AS_VAR_IF([PHP_%EXTNAMECAPS%], [no],, [
   dnl Define a preprocessor macro to indicate that this PHP extension can
   dnl be dynamically loaded as a shared module or is statically built into PHP.
   AC_DEFINE([HAVE_%EXTNAMECAPS%], [1],
-    [Define to 1 if PHP extension '%EXTNAME%' is available.])
+    [Define to 1 if the PHP extension '%EXTNAME%' is available.])
 
   dnl Configure extension sources and compilation flags.
   PHP_NEW_EXTENSION([%EXTNAME%],
diff --git a/ext/skeleton/config.w32.in b/ext/skeleton/config.w32.in
index ea5064b7e2e3d..600a64d2ba2ed 100644
--- a/ext/skeleton/config.w32.in
+++ b/ext/skeleton/config.w32.in
@@ -1,7 +1,7 @@
 ARG_ENABLE('%EXTNAME%', '%EXTNAME% support', 'no');
 
 if (PHP_%EXTNAMECAPS% != 'no') {
-	AC_DEFINE('HAVE_%EXTNAMECAPS%', 1, '%EXTNAME% support enabled');
+	AC_DEFINE('HAVE_%EXTNAMECAPS%', 1, "Define to 1 if the PHP extension '%EXTNAME%' is available.");
 
 	EXTENSION('%EXTNAME%', '%EXTNAME%.c', null, '/DZEND_ENABLE_STATIC_TSRMLS_CACHE=1');
 }
diff --git a/ext/snmp/config.m4 b/ext/snmp/config.m4
index 3c95ff7ceeb8b..80430ba45bd0e 100644
--- a/ext/snmp/config.m4
+++ b/ext/snmp/config.m4
@@ -38,7 +38,8 @@ if test "$PHP_SNMP" != "no"; then
 
   dnl Test build.
   PHP_CHECK_LIBRARY([$SNMP_LIBNAME], [init_snmp],
-    [AC_DEFINE([HAVE_SNMP], [1], [ ])],
+    [AC_DEFINE([HAVE_SNMP], [1],
+      [Define to 1 if the PHP extension 'snmp' is available.])],
     [AC_MSG_ERROR([SNMP sanity check failed. Please check config.log for more information.])],
     [$SNMP_SHARED_LIBADD])
 
diff --git a/ext/snmp/config.w32 b/ext/snmp/config.w32
index 56a63b6e1ee81..07b9872883eab 100644
--- a/ext/snmp/config.w32
+++ b/ext/snmp/config.w32
@@ -7,7 +7,7 @@ if (PHP_SNMP != "no") {
 		SETUP_OPENSSL("snmp", PHP_SNMP) >= 2) {
 		if (CHECK_LIB("netsnmp.lib", "snmp", PHP_SNMP)) {
 			EXTENSION('snmp', 'snmp.c');
-			AC_DEFINE('HAVE_SNMP', 1);
+			AC_DEFINE('HAVE_SNMP', 1, "Define to 1 if the PHP extension 'snmp' is available.");
 		} else {
 			WARNING("snmp not enabled; libraries and headers not found");
 		}
diff --git a/ext/soap/config.m4 b/ext/soap/config.m4
index 08738d3051854..1f4370fdf8022 100644
--- a/ext/soap/config.m4
+++ b/ext/soap/config.m4
@@ -5,7 +5,8 @@ PHP_ARG_ENABLE([soap],
 
 if test "$PHP_SOAP" != "no"; then
   PHP_SETUP_LIBXML([SOAP_SHARED_LIBADD], [
-    AC_DEFINE([HAVE_SOAP], [1], [Define to 1 if soap extension is available.])
+    AC_DEFINE([HAVE_SOAP], [1],
+      [Define to 1 if the PHP extension 'soap' is available.])
     PHP_NEW_EXTENSION([soap], m4_normalize([
         php_encoding.c
         php_http.c
diff --git a/ext/soap/config.w32 b/ext/soap/config.w32
index 06eb618513d85..f30d108465fdc 100644
--- a/ext/soap/config.w32
+++ b/ext/soap/config.w32
@@ -9,7 +9,7 @@ if (PHP_SOAP != "no") {
 		CHECK_HEADER_ADD_INCLUDE("libxml/tree.h", "CFLAGS_SOAP", PHP_PHP_BUILD + "\\include\\libxml2")
 		) {
 		EXTENSION('soap', 'soap.c php_encoding.c php_http.c php_packet_soap.c php_schema.c php_sdl.c php_xml.c', null, "/DZEND_ENABLE_STATIC_TSRMLS_CACHE=1");
-		AC_DEFINE('HAVE_SOAP', 1, "Define to 1 if soap extension is available.");
+		AC_DEFINE('HAVE_SOAP', 1, "Define to 1 if the PHP extension 'soap' is available.");
 		ADD_EXTENSION_DEP('soap', 'session', true);
 
 		if (!PHP_SOAP_SHARED) {
diff --git a/ext/sockets/config.m4 b/ext/sockets/config.m4
index 417624382adf3..aed78416e8d16 100644
--- a/ext/sockets/config.m4
+++ b/ext/sockets/config.m4
@@ -6,7 +6,8 @@ PHP_ARG_ENABLE([sockets],
 if test "$PHP_SOCKETS" != "no"; then
   AC_CHECK_FUNCS([hstrerror if_nametoindex if_indextoname sockatmark])
   AC_CHECK_HEADERS([sys/sockio.h linux/filter.h])
-  AC_DEFINE([HAVE_SOCKETS], 1, [ ])
+  AC_DEFINE([HAVE_SOCKETS], [1],
+    [Define to 1 if the PHP extension 'sockets' is available.])
 
   dnl Check for field ss_family in sockaddr_storage (missing in AIX until 5.3)
   AC_CHECK_MEMBERS([struct sockaddr_storage.ss_family],,,[#include <sys/socket.h>])
diff --git a/ext/sockets/config.w32 b/ext/sockets/config.w32
index ad9becab2a170..10400985af5c8 100644
--- a/ext/sockets/config.w32
+++ b/ext/sockets/config.w32
@@ -7,7 +7,7 @@ if (PHP_SOCKETS != "no") {
 	&& CHECK_LIB("Iphlpapi.lib", "sockets", PHP_SOCKETS)
 	&& CHECK_HEADER_ADD_INCLUDE("winsock.h", "CFLAGS_SOCKETS")) {
 		EXTENSION('sockets', 'sockets.c multicast.c conversions.c sockaddr_conv.c sendrecvmsg.c', PHP_SOCKETS_SHARED, "/DZEND_ENABLE_STATIC_TSRMLS_CACHE=1");
-		AC_DEFINE('HAVE_SOCKETS', 1);
+		AC_DEFINE('HAVE_SOCKETS', 1, "Define to 1 if the PHP extension 'sockets' is available.");
 		PHP_INSTALL_HEADERS("ext/sockets", "php_sockets.h windows_common.h");
 		ADD_FLAG("CFLAGS_SOCKETS", "/D PHP_SOCKETS_EXPORTS=1");
 	} else {
diff --git a/ext/sqlite3/config.w32 b/ext/sqlite3/config.w32
index ab54989e1c403..bca565d5dbbad 100644
--- a/ext/sqlite3/config.w32
+++ b/ext/sqlite3/config.w32
@@ -6,7 +6,7 @@ if (PHP_SQLITE3 != "no") {
 	if (SETUP_SQLITE3("sqlite3", PHP_SQLITE3, PHP_SQLITE3_SHARED)) {
 		EXTENSION("sqlite3", "sqlite3.c", null, "/DZEND_ENABLE_STATIC_TSRMLS_CACHE=1");
 
-		AC_DEFINE("HAVE_SQLITE3", 1, "SQLite support");
+		AC_DEFINE("HAVE_SQLITE3", 1, "Define to 1 if the PHP extension 'sqlite3' is available.");
 		AC_DEFINE("HAVE_SQLITE3_ERRSTR", 1, "have sqlite3_errstr function");
 		AC_DEFINE("HAVE_SQLITE3_EXPANDED_SQL", 1, "have sqlite3_expanded_sql function");
 	} else {
diff --git a/ext/sqlite3/config0.m4 b/ext/sqlite3/config0.m4
index 308b9421d2658..08af7c1b371e1 100644
--- a/ext/sqlite3/config0.m4
+++ b/ext/sqlite3/config0.m4
@@ -6,7 +6,8 @@ PHP_ARG_WITH([sqlite3],
 
 if test $PHP_SQLITE3 != "no"; then
   PHP_SETUP_SQLITE([SQLITE3_SHARED_LIBADD])
-  AC_DEFINE(HAVE_SQLITE3, 1, [Define to 1 if you have the sqlite3 extension enabled.])
+  AC_DEFINE([HAVE_SQLITE3], [1],
+    [Define to 1 if the PHP extension 'sqlite3' is available.])
 
   PHP_CHECK_LIBRARY([sqlite3], [sqlite3_errstr],
     [AC_DEFINE([HAVE_SQLITE3_ERRSTR], [1], [have sqlite3_errstr function])],
diff --git a/ext/sysvmsg/config.m4 b/ext/sysvmsg/config.m4
index d5f5ef9d05379..13c54c93a5c9a 100644
--- a/ext/sysvmsg/config.m4
+++ b/ext/sysvmsg/config.m4
@@ -7,6 +7,7 @@ if test "$PHP_SYSVMSG" != "no"; then
   AC_CHECK_HEADER([sys/msg.h],,
     [AC_MSG_ERROR([Cannot enable System V IPC support, sys/msg.h is missing])])
 
-  AC_DEFINE(HAVE_SYSVMSG, 1, [ ])
+  AC_DEFINE([HAVE_SYSVMSG], [1],
+    [Define to 1 if the PHP extension 'sysvmsg' is available.])
   PHP_NEW_EXTENSION([sysvmsg], [sysvmsg.c], [$ext_shared])
 fi
diff --git a/ext/sysvsem/config.m4 b/ext/sysvsem/config.m4
index dbe3bd8e3bf45..0b9fa255ceb89 100644
--- a/ext/sysvsem/config.m4
+++ b/ext/sysvsem/config.m4
@@ -5,7 +5,8 @@ PHP_ARG_ENABLE([sysvsem],
 
 if test "$PHP_SYSVSEM" != "no"; then
   PHP_NEW_EXTENSION([sysvsem], [sysvsem.c], [$ext_shared])
-  AC_DEFINE(HAVE_SYSVSEM, 1, [ ])
+  AC_DEFINE([HAVE_SYSVSEM], [1],
+    [Define to 1 if the PHP extension 'sysvsem' is available.])
   AC_CHECK_TYPES([union semun],,,[#include <sys/types.h>
     #include <sys/ipc.h>
     #include <sys/sem.h>])
diff --git a/ext/sysvshm/config.m4 b/ext/sysvshm/config.m4
index 422f87e6beeb4..7a7c4c1ebe9b3 100644
--- a/ext/sysvshm/config.m4
+++ b/ext/sysvshm/config.m4
@@ -4,6 +4,7 @@ PHP_ARG_ENABLE([sysvshm],
     [Enable the System V shared memory support])])
 
 if test "$PHP_SYSVSHM" != "no"; then
-  AC_DEFINE(HAVE_SYSVSHM, 1, [ ])
+  AC_DEFINE([HAVE_SYSVSHM], [1],
+    [Define to 1 if the PHP extension 'sysvshm' is available.])
   PHP_NEW_EXTENSION([sysvshm], [sysvshm.c], [$ext_shared])
 fi
diff --git a/ext/sysvshm/config.w32 b/ext/sysvshm/config.w32
index 80fb28ee61f43..689c98681fdd2 100644
--- a/ext/sysvshm/config.w32
+++ b/ext/sysvshm/config.w32
@@ -3,6 +3,6 @@
 ARG_ENABLE('sysvshm', 'SysV Shared Memory support', 'no');
 
 if (PHP_SYSVSHM != 'no') {
-	AC_DEFINE('HAVE_SYSVSHM', 1);
+	AC_DEFINE('HAVE_SYSVSHM', 1, "Define to 1 if the PHP extension 'sysvshm' is available.");
 	EXTENSION('sysvshm', 'sysvshm.c');
 }
diff --git a/ext/tidy/config.m4 b/ext/tidy/config.m4
index 961ae0bbf1e51..bb9a779838119 100644
--- a/ext/tidy/config.m4
+++ b/ext/tidy/config.m4
@@ -64,5 +64,6 @@ if test "$PHP_TIDY" != "no"; then
   TIDY_COMPILER_FLAGS="$TIDY_CFLAGS -Wno-ignored-qualifiers -DZEND_ENABLE_STATIC_TSRMLS_CACHE=1"
   PHP_NEW_EXTENSION([tidy], [tidy.c], [$ext_shared],, [$TIDY_COMPILER_FLAGS])
   PHP_SUBST([TIDY_SHARED_LIBADD])
-  AC_DEFINE(HAVE_TIDY,1,[ ])
+  AC_DEFINE([HAVE_TIDY], [1],
+    [Define to 1 if the PHP extension 'tidy' is available.])
 fi
diff --git a/ext/tidy/config.w32 b/ext/tidy/config.w32
index d12302ac5e0e3..3221db8737abc 100644
--- a/ext/tidy/config.w32
+++ b/ext/tidy/config.w32
@@ -17,7 +17,7 @@ if (PHP_TIDY != "no") {
 		}
 
 		EXTENSION("tidy", "tidy.c");
-		AC_DEFINE('HAVE_TIDY', 1, 'Have TIDY library');
+		AC_DEFINE('HAVE_TIDY', 1, "Define to 1 if the PHP extension 'tidy' is available.");
 		AC_DEFINE('HAVE_TIDY_H', 1, "tidy include header")
 		AC_DEFINE('HAVE_TIDYOPTGETDOC', 1, "tidy_get_opt_doc function")
 		AC_DEFINE('HAVE_TIDYRELEASEDATE', 1, "tidy release date function")
diff --git a/ext/xml/config.m4 b/ext/xml/config.m4
index fbc63e19df205..65b2623042cb4 100644
--- a/ext/xml/config.m4
+++ b/ext/xml/config.m4
@@ -28,5 +28,6 @@ if test "$PHP_XML" != "no"; then
 
   PHP_SUBST([XML_SHARED_LIBADD])
   PHP_INSTALL_HEADERS([ext/xml], [expat_compat.h php_xml.h])
-  AC_DEFINE([HAVE_XML], [1], [Define to 1 if xml extension is available.])
+  AC_DEFINE([HAVE_XML], [1],
+    [Define to 1 if the PHP extension 'xml' is available.])
 fi
diff --git a/ext/xml/config.w32 b/ext/xml/config.w32
index 780c7b932f555..00ef36841c38d 100644
--- a/ext/xml/config.w32
+++ b/ext/xml/config.w32
@@ -9,7 +9,7 @@ if (PHP_XML == "yes") {
 		CHECK_HEADER_ADD_INCLUDE("libxml/tree.h", "CFLAGS_XML", PHP_PHP_BUILD + "\\include\\libxml2")
 	) {
 		EXTENSION("xml", "xml.c compat.c", null, "/DZEND_ENABLE_STATIC_TSRMLS_CACHE=1");
-		AC_DEFINE("HAVE_XML", 1, "Define to 1 if xml extension is available.");
+		AC_DEFINE("HAVE_XML", 1, "Define to 1 if the PHP extension 'xml' is available.");
 		if (!PHP_XML_SHARED) {
 			ADD_FLAG("CFLAGS_XML", "/D LIBXML_STATIC ");
 		}
diff --git a/ext/xmlreader/config.m4 b/ext/xmlreader/config.m4
index 365a3c1060d90..8a636f72b3dd5 100644
--- a/ext/xmlreader/config.m4
+++ b/ext/xmlreader/config.m4
@@ -7,7 +7,7 @@ PHP_ARG_ENABLE([xmlreader],
 if test "$PHP_XMLREADER" != "no"; then
   PHP_SETUP_LIBXML([XMLREADER_SHARED_LIBADD], [
     AC_DEFINE([HAVE_XMLREADER], [1],
-      [Define to 1 if xmlreader extension is available.])
+      [Define to 1 if the PHP extension 'xmlreader' is available.])
     PHP_NEW_EXTENSION([xmlreader], [php_xmlreader.c], [$ext_shared])
     PHP_ADD_EXTENSION_DEP(xmlreader, dom, true)
     PHP_ADD_EXTENSION_DEP(xmlreader, libxml)
diff --git a/ext/xmlreader/config.w32 b/ext/xmlreader/config.w32
index 9efed25337f08..d92672d427da7 100644
--- a/ext/xmlreader/config.w32
+++ b/ext/xmlreader/config.w32
@@ -8,7 +8,7 @@ if (PHP_XMLREADER == "yes" &&
 	CHECK_HEADER_ADD_INCLUDE("libxml/tree.h", "CFLAGS_XMLREADER", PHP_PHP_BUILD + "\\include\\libxml2")
 	) {
 	EXTENSION("xmlreader", "php_xmlreader.c");
-	AC_DEFINE("HAVE_XMLREADER", 1, "Define to 1 if xmlreader extension is available.");
+	AC_DEFINE("HAVE_XMLREADER", 1, "Define to 1 if the PHP extension 'xmlreader' is available.");
 	if (!PHP_XMLREADER_SHARED) {
 		ADD_FLAG("CFLAGS_XMLREADER", "/D LIBXML_STATIC");
 	}
diff --git a/ext/xmlwriter/config.m4 b/ext/xmlwriter/config.m4
index 38a71b91b2d78..345ae27e62186 100644
--- a/ext/xmlwriter/config.m4
+++ b/ext/xmlwriter/config.m4
@@ -7,7 +7,7 @@ PHP_ARG_ENABLE([xmlwriter],
 if test "$PHP_XMLWRITER" != "no"; then
   PHP_SETUP_LIBXML([XMLWRITER_SHARED_LIBADD], [
     AC_DEFINE([HAVE_XMLWRITER], [1],
-      [Define to 1 if xmlwriter extension is available.])
+      [Define to 1 if the PHP extension 'xmlwriter' is available.])
     PHP_NEW_EXTENSION([xmlwriter], [php_xmlwriter.c], [$ext_shared])
     PHP_ADD_EXTENSION_DEP(xmlwriter, libxml)
     PHP_SUBST([XMLWRITER_SHARED_LIBADD])
diff --git a/ext/xmlwriter/config.w32 b/ext/xmlwriter/config.w32
index ba0f18cc3a779..737e3fcd38c53 100644
--- a/ext/xmlwriter/config.w32
+++ b/ext/xmlwriter/config.w32
@@ -5,7 +5,7 @@ ARG_ENABLE("xmlwriter", "XMLWriter support", "yes");
 if (PHP_XMLWRITER == "yes" && PHP_LIBXML == "yes") {
 	if (CHECK_HEADER_ADD_INCLUDE('libxml/xmlwriter.h', 'CFLAGS_XMLWRITER', PHP_XMLWRITER + ";" + PHP_PHP_BUILD + "\\include\\libxml2")) {
 		EXTENSION("xmlwriter", "php_xmlwriter.c");
-		AC_DEFINE("HAVE_XMLWRITER", 1, "Define to 1 if xmlwriter extension is available.");
+		AC_DEFINE("HAVE_XMLWRITER", 1, "Define to 1 if the PHP extension 'xmlwriter' is available.");
 		if (!PHP_XMLWRITER_SHARED) {
 			ADD_FLAG("CFLAGS_XMLWRITER", "/D LIBXML_STATIC");
 		}
diff --git a/ext/xsl/config.m4 b/ext/xsl/config.m4
index 41bddea41bce4..9f0bbe021a2d9 100644
--- a/ext/xsl/config.m4
+++ b/ext/xsl/config.m4
@@ -26,7 +26,8 @@ if test "$PHP_XSL" != "no"; then
       [Define to 1 if system has the EXSLT extension library for XSLT.])
   ], [ ])
 
-  AC_DEFINE(HAVE_XSL,1,[ ])
+  AC_DEFINE([HAVE_XSL], [1],
+    [Define to 1 if the PHP extension 'xsl' is available.])
   PHP_NEW_EXTENSION([xsl], [php_xsl.c xsltprocessor.c], [$ext_shared])
   PHP_SUBST([XSL_SHARED_LIBADD])
   PHP_ADD_EXTENSION_DEP(xsl, libxml)
diff --git a/ext/xsl/config.w32 b/ext/xsl/config.w32
index add42ed15f9a5..fadf7ced01d7c 100644
--- a/ext/xsl/config.w32
+++ b/ext/xsl/config.w32
@@ -32,7 +32,7 @@ if (PHP_XSL != "no") {
 				}
 			}
 			EXTENSION("xsl", "php_xsl.c xsltprocessor.c", PHP_XSL_SHARED);
-			AC_DEFINE("HAVE_XSL", 1, "Define if xsl extension is enabled");
+			AC_DEFINE("HAVE_XSL", 1, "Define to 1 if the PHP extension 'xsl' is available.");
 			if (! PHP_XSL_SHARED) {
 				ADD_FLAG("CFLAGS_XSL", "/D DOM_EXPORTS /D LIBXML_STATIC");
 			} else {
diff --git a/ext/zip/config.m4 b/ext/zip/config.m4
index 1ced99eae7e62..4b97df9a18e94 100644
--- a/ext/zip/config.m4
+++ b/ext/zip/config.m4
@@ -45,7 +45,8 @@ if test "$PHP_ZIP" != "no"; then
     [],
     [$LIBZIP_LIBS])
 
-  AC_DEFINE(HAVE_ZIP,1,[ ])
+  AC_DEFINE([HAVE_ZIP], [1],
+    [Define to 1 if the PHP extension 'zip' is available.])
 
   PHP_NEW_EXTENSION([zip], [php_zip.c zip_stream.c], [$ext_shared])
   PHP_ADD_EXTENSION_DEP(zip, pcre)
diff --git a/ext/zip/config.w32 b/ext/zip/config.w32
index 0b5448c8e8958..c0226f8976460 100644
--- a/ext/zip/config.w32
+++ b/ext/zip/config.w32
@@ -16,7 +16,7 @@ if (PHP_ZIP != "no") {
 			AC_DEFINE("ZIP_STATIC", 1);
 		}
 
-		AC_DEFINE('HAVE_ZIP', 1);
+		AC_DEFINE('HAVE_ZIP', 1, "Define to 1 if the PHP extension 'zip' is available.");
 		ADD_FLAG("CFLAGS_ZIP", "/D HAVE_SET_MTIME /D HAVE_ENCRYPTION /D HAVE_LIBZIP_VERSION /D HAVE_PROGRESS_CALLBACK /D HAVE_CANCEL_CALLBACK /D HAVE_METHOD_SUPPORTED /D LZMA_API_STATIC");
 	} else {
 		WARNING("zip not enabled; libraries and headers not found");
diff --git a/ext/zlib/config.w32 b/ext/zlib/config.w32
index 80b7bb1766810..3bc24d88e1735 100644
--- a/ext/zlib/config.w32
+++ b/ext/zlib/config.w32
@@ -7,7 +7,7 @@ if (PHP_ZLIB == "yes") {
 		CHECK_HEADER_ADD_INCLUDE("zlib.h", "CFLAGS", "..\\zlib;" + php_usual_include_suspects)) {
 
 		EXTENSION("zlib", "zlib.c zlib_fopen_wrapper.c zlib_filter.c", PHP_ZLIB_SHARED, "/D ZLIB_EXPORTS /DZEND_ENABLE_STATIC_TSRMLS_CACHE=1");
-		AC_DEFINE("HAVE_ZLIB", 1, "Define to 1 if zlib extension is available.");
+		AC_DEFINE("HAVE_ZLIB", 1, "Define to 1 if the PHP extension 'zlib' is available.");
 
 		if (!PHP_ZLIB_SHARED) {
 			ADD_DEF_FILE("ext\\zlib\\php_zlib.def");
diff --git a/ext/zlib/config0.m4 b/ext/zlib/config0.m4
index 04949a4355bf2..93f5bd75ffd7f 100644
--- a/ext/zlib/config0.m4
+++ b/ext/zlib/config0.m4
@@ -5,7 +5,8 @@ PHP_ARG_WITH([zlib],
 
 if test "$PHP_ZLIB" != "no"; then
   PHP_SETUP_ZLIB([ZLIB_SHARED_LIBADD], [dnl
-    AC_DEFINE([HAVE_ZLIB], [1], [Define to 1 if zlib extension is available.])
+    AC_DEFINE([HAVE_ZLIB], [1],
+      [Define to 1 if the PHP extension 'zlib' is available.])
     PHP_NEW_EXTENSION([zlib],
       [zlib.c zlib_fopen_wrapper.c zlib_filter.c],
       [$ext_shared],,