Consolidate definition of USE_WIN32API

I noticed that USE_WIN32API is defined separately by gdbserver and
gdb.  However, because it is used by code in gdbsupport, it should be
defined by common.m4.  This approach ensures that the code will
continue to work when it is moved to the top level.

gdb/ChangeLog
2020-01-14  Tom Tromey  <tom@tromey.com>

	* gdbsupport/common.m4 (GDB_AC_COMMON): Define WIN32APILIBS and
	USE_WIN32API when needed.
	* configure.ac (USE_WIN32API): Don't define.
	(WIN32LIBS): Use WIN32APILIBS.
	* configure: Rebuild.

gdb/gdbserver/ChangeLog
2020-01-14  Tom Tromey  <tom@tromey.com>

	* configure.ac (LIBS): Use WIN32APILIBS.
	(USE_WIN32API): Don't define.
	* configure: Rebuild.

Change-Id: I40d524d5445ebfb452b36f4d0e102f0b1e1089df

gdb/ChangeLog

@@ -1,3 +1,11 @@
+2020-01-14  Tom Tromey  <tom@tromey.com>
+
+	* gdbsupport/common.m4 (GDB_AC_COMMON): Define WIN32APILIBS and
+	USE_WIN32API when needed.
+	* configure.ac (USE_WIN32API): Don't define.
+	(WIN32LIBS): Use WIN32APILIBS.
+	* configure: Rebuild.
+
 2020-01-14  Tom Tromey  <tom@tromey.com>
 
 	* configure: Rebuild.

gdb/configure

@@ -688,12 +688,12 @@ TCL_BIN_DIR
 TCL_PATCH_LEVEL
 TCL_VERSION
 WIN32LDAPP
+WIN32LIBS
 GUI_CFLAGS_X
 LIBGUI
 LTLIBLZMA
 LIBLZMA
 HAVE_LIBLZMA
-WIN32LIBS
 SER_HARDWIRE
 WERROR_CFLAGS
 WARN_CFLAGS
@@ -13567,6 +13567,16 @@ _ACEOF
 fi
 
 
+  WIN32APILIBS=
+  case ${host} in
+    *mingw32*)
+
+$as_echo "#define USE_WIN32API 1" >>confdefs.h
+
+      WIN32APILIBS="-lws2_32"
+      ;;
+  esac
+
 
   { $as_echo "$as_me:${as_lineno-$LINENO}: checking for nl_langinfo and CODESET" >&5
 $as_echo_n "checking for nl_langinfo and CODESET... " >&6; }
@@ -16356,15 +16366,8 @@ if test x"$gdb_cv_os_cygwin" = xyes; then
 fi
 
 # The ser-tcp.c module requires sockets.
-case ${host} in
+# Note that WIN32APILIBS is set by GDB_AC_COMMON.
-  *mingw32*)
+WIN32LIBS="$WIN32LIBS $WIN32APILIBS"
-
-$as_echo "#define USE_WIN32API 1" >>confdefs.h
-
-    WIN32LIBS="$WIN32LIBS -lws2_32"
-    ;;
-esac
-
 
 # Add ELF support to GDB, but only if BFD includes ELF support.
 

gdb/configure.ac

@@ -1827,17 +1827,8 @@ if test x"$gdb_cv_os_cygwin" = xyes; then
 fi
 
 # The ser-tcp.c module requires sockets.
-case ${host} in
+# Note that WIN32APILIBS is set by GDB_AC_COMMON.
-  *mingw32*)
+WIN32LIBS="$WIN32LIBS $WIN32APILIBS"
-    AC_DEFINE(USE_WIN32API, 1,
-              [Define if we should use the Windows API, instead of the
-	       POSIX API.  On Windows, we use the Windows API when
-	       building for MinGW, but the POSIX API when building
-	       for Cygwin.])
-    WIN32LIBS="$WIN32LIBS -lws2_32"
-    ;;
-esac
-AC_SUBST(WIN32LIBS)
 
 # Add ELF support to GDB, but only if BFD includes ELF support.
 GDB_AC_CHECK_BFD([for ELF support in BFD], gdb_cv_var_elf,

gdb/gdbserver/ChangeLog

@@ -1,3 +1,9 @@
+2020-01-14  Tom Tromey  <tom@tromey.com>
+
+	* configure.ac (LIBS): Use WIN32APILIBS.
+	(USE_WIN32API): Don't define.
+	* configure: Rebuild.
+
 2020-01-14  Tom Tromey  <tom@tromey.com>
 
 	* configure: Rebuild.

gdb/gdbserver/configure

@@ -6959,6 +6959,16 @@ _ACEOF
 fi
 
 
+  WIN32APILIBS=
+  case ${host} in
+    *mingw32*)
+
+$as_echo "#define USE_WIN32API 1" >>confdefs.h
+
+      WIN32APILIBS="-lws2_32"
+      ;;
+  esac
+
 
   { $as_echo "$as_me:${as_lineno-$LINENO}: checking for nl_langinfo and CODESET" >&5
 $as_echo_n "checking for nl_langinfo and CODESET... " >&6; }
@@ -8705,19 +8715,14 @@ esac
 if test "${srv_mingwce}" = "yes"; then
   LIBS="$LIBS -lws2"
 elif test "${srv_mingw}" = "yes"; then
-  LIBS="$LIBS -lws2_32"
+  # WIN32APILIBS is set by GDB_AC_COMMON.
+  LIBS="$LIBS $WIN32APILIBS"
 elif test "${srv_qnx}" = "yes"; then
   LIBS="$LIBS -lsocket"
 elif test "${srv_lynxos}" = "yes"; then
   LIBS="$LIBS -lnetinet"
 fi
 
-if test "${srv_mingw}" = "yes"; then
-
-$as_echo "#define USE_WIN32API 1" >>confdefs.h
-
-fi
-
 if test "${srv_linux_usrregs}" = "yes"; then
 
 $as_echo "#define HAVE_LINUX_USRREGS 1" >>confdefs.h

gdb/gdbserver/configure.ac

@@ -248,21 +248,14 @@ esac
 if test "${srv_mingwce}" = "yes"; then
   LIBS="$LIBS -lws2"
 elif test "${srv_mingw}" = "yes"; then
-  LIBS="$LIBS -lws2_32"
+  # WIN32APILIBS is set by GDB_AC_COMMON.
+  LIBS="$LIBS $WIN32APILIBS"
 elif test "${srv_qnx}" = "yes"; then
   LIBS="$LIBS -lsocket"
 elif test "${srv_lynxos}" = "yes"; then
   LIBS="$LIBS -lnetinet"
 fi
 
-if test "${srv_mingw}" = "yes"; then
-  AC_DEFINE(USE_WIN32API, 1,
-	    [Define if we should use the Windows API, instead of the
-	     POSIX API.  On Windows, we use the Windows API when
-	     building for MinGW, but the POSIX API when building
-	     for Cygwin.])
-fi
-
 if test "${srv_linux_usrregs}" = "yes"; then
   AC_DEFINE(HAVE_LINUX_USRREGS, 1,
 	    [Define if the target supports PTRACE_PEEKUSR for register ]

gdb/gdbsupport/common.m4

@@ -21,6 +21,18 @@ AC_DEFUN([GDB_AC_COMMON], [
   AC_HEADER_STDC
   AC_FUNC_ALLOCA
 
+  WIN32APILIBS=
+  case ${host} in
+    *mingw32*)
+      AC_DEFINE(USE_WIN32API, 1,
+		[Define if we should use the Windows API, instead of the
+		 POSIX API.  On Windows, we use the Windows API when
+		 building for MinGW, but the POSIX API when building
+		 for Cygwin.])
+      WIN32APILIBS="-lws2_32"
+      ;;
+  esac
+
   dnl Note that this requires codeset.m4, which is included
   dnl by the users of common.m4.
   AM_LANGINFO_CODESET