Attempting to build from the trunk as of r102429 fails on Cygwin as follows:
gcc -c -Demacs -DHAVE_CONFIG_H -I. -I/d/downloads/emacs/test/src
-D_REENTRANT -I/usr/include/gtk-2.0 -I/usr/lib/gtk-2.0/include
-I/usr/include/atk-1.0 -I/usr/include/cairo -I/usr/include/pango-1.0
-I/usr/include/gio-unix-2.0/ -I/usr/include/glib-2.0
-I/usr/lib/glib-2.0/include -I/usr/include/pixman-1
-I/usr/include/freetype2 -I/usr/include/libpng12
-I/usr/include/freetype2 -fopenmp -I/usr/include/ImageMagick
-I/usr/include/libxml2 -I/usr/include/dbus-1.0
-I/usr/lib/dbus-1.0/include -MMD -MF deps/strftime.d
-Wimplicit-function-declaration -Wold-style-definition
-Wdeclaration-after-statement -Wno-pointer-sign -g -O2 strftime.c
strftime.c:58: warning: ‘_tzname’ redeclared without dllimport
attribute: previous dllimport ignored
strftime.c: In function ‘my_strftime_gmtime_r’:
strftime.c:187: warning: old-style function definition
strftime.c: In function ‘my_strftime_localtime_r’:
strftime.c:200: warning: old-style function definition
strftime.c: In function ‘ftime_tm_diff’:
strftime.c:388: warning: old-style function definition
strftime.c: In function ‘nstrftime’:
strftime.c:482: error: expected declaration specifiers before ‘,’ token
strftime.c:502: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’
before ‘{’ token
strftime.c:1454: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’
before ‘{’ token
strftime.c:1458: warning: old-style function definition
strftime.c:1456: error: expected ‘{’ at end of input