[CMake] config.h, part 2 - full compatibility with autoconf.

This commit makes the file config.h generated by CMake 100% compatible
with the one generated by autoconf/configure.

Fixes in this commit:
 - Set FLTK_DATADIR and FLTK_DOCDIR with the same default values.
   Note: needs some cleanup, option values are not clear, '/fltk'
   is currently appended in export.cmake (needs improvement).
 - Simulation of autoconf macro AC_HEADER_DIRENT for correct
   definition of only one 'dirent' header file.
 - Fix more function checks:
    - dlsym
    - png_get_valid
    - png_set_tRNS_to_alpha
 - Improve "Big Endian" check for __APPLE__ (mac_endianness.h).


git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3@10985 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

CMake/export.cmake

@@ -82,10 +82,28 @@ if(UNIX)
    )
 endif(UNIX)
 
+# prepare some variables for config.h
+
+if(IS_ABSOLUTE "${FLTK_DATADIR}")
+  set(PREFIX_DATA "${FLTK_DATADIR}/fltk")
+else(IS_ABSOLUTE "${FLTK_DATADIR}")
+  set(PREFIX_DATA "${CMAKE_INSTALL_PREFIX}/${FLTK_DATADIR}/fltk")
+endif(IS_ABSOLUTE "${FLTK_DATADIR}")
+
+if(IS_ABSOLUTE "${FLTK_DOCDIR}")
+  set(PREFIX_DOC "${FLTK_DOCDIR}/fltk")
+else(IS_ABSOLUTE "${FLTK_DOCDIR}")
+  set(PREFIX_DOC "${CMAKE_INSTALL_PREFIX}/${FLTK_DOCDIR}/fltk")
+endif(IS_ABSOLUTE "${FLTK_DOCDIR}")
+
+set(CONFIG_H_IN configh.cmake.in)
+set(CONFIG_H config.h)
+
 # generate config.h
+
 configure_file(
-   "${FLTK_SOURCE_DIR}/configh.cmake.in"
-   "${FLTK_BINARY_DIR}/config.h"
+   "${FLTK_SOURCE_DIR}/${CONFIG_H_IN}"
+   "${FLTK_BINARY_DIR}/${CONFIG_H}"
    @ONLY
 )
 

CMake/resources.cmake

@@ -22,26 +22,41 @@
 #######################################################################
 # headers
 find_file(HAVE_ALSA_ASOUNDLIB_H alsa/asoundlib.h)
-find_file(HAVE_DIRENT_H dirent.h)
 find_file(HAVE_DLFCN_H dlfcn.h)
 find_file(HAVE_FREETYPE_H freetype.h PATH_SUFFIXES freetype2 freetype2/freetype)
 find_file(HAVE_GL_GL_H GL/gl.h)
 find_file(HAVE_GL_GLU_H GL/glu.h)
 find_file(HAVE_LIBPNG_PNG_H libpng/png.h)
 find_file(HAVE_LOCALE_H locale.h)
-find_file(HAVE_NDIR_H ndir.h)
 find_file(HAVE_OPENGL_GLU_H OpenGL/glu.h)
 find_file(HAVE_PNG_H png.h)
 find_file(HAVE_PTHREAD_H pthread.h)
 find_file(HAVE_STDIO_H stdio.h)
 find_file(HAVE_STRINGS_H strings.h)
-find_file(HAVE_SYS_DIR_H sys/dir.h)
-find_file(HAVE_SYS_NDIR_H sys/ndir.h)
 find_file(HAVE_SYS_SELECT_H sys/select.h)
 find_file(HAVE_SYS_STDTYPES_H sys/stdtypes.h)
 find_file(HAVE_X11_XREGION_H X11/Xregion.h)
 find_path(HAVE_XDBE_H Xdbe.h PATH_SUFFIXES X11/extensions extensions)
 
+# Simulate the behavior of autoconf macro AC_HEADER_DIRENT, see:
+# https://www.gnu.org/software/autoconf/manual/autoconf-2.69/html_node/Particular-Headers.html
+# "Check for the following header files. For the first one that is found
+#  and defines ‘DIR’, define the listed C preprocessor macro ..."
+#
+# Note: we don't check if it really defines 'DIR', but we stop processing
+# once we found the first suitable header file.
+
+find_file(HAVE_DIRENT_H dirent.h)
+if(NOT HAVE_DIRENT_H)
+  find_file(HAVE_SYS_NDIR_H sys/ndir.h)
+  if(NOT HAVE_SYS_NDIR_H)
+    find_file(HAVE_SYS_DIR_H sys/dir.h)
+    if(NOT HAVE_SYS_DIR_H)
+      find_file(HAVE_NDIR_H ndir.h)
+    endif(NOT HAVE_SYS_DIR_H)
+  endif(NOT HAVE_SYS_NDIR_H)
+endif(NOT HAVE_DIRENT_H)
+
 mark_as_advanced(HAVE_ALSA_ASOUNDLIB_H HAVE_DIRENT_H HAVE_DLFCN_H)
 mark_as_advanced(HAVE_FREETYPE_H HAVE_GL_GL_H HAVE_GL_GLU_H)
 mark_as_advanced(HAVE_LIBPNG_PNG_H HAVE_LOCALE_H HAVE_NDIR_H)
@@ -79,15 +94,32 @@ mark_as_advanced(LIB_jpeg LIB_png LIB_zlib)
 # functions
 include(CheckFunctionExists)
 
+# save CMAKE_REQUIRED_LIBRARIES (is this really necessary ?)
+if(DEFINED CMAKE_REQUIRED_LIBRARIES)
+  set(SAVED_REQUIRED_LIBRARIES ${CMAKE_REQUIRED_LIBRARIES})
+else(DEFINED CMAKE_REQUIRED_LIBRARIES)
+  unset(SAVED_REQUIRED_LIBRARIES)
+endif(DEFINED CMAKE_REQUIRED_LIBRARIES)
+set(CMAKE_REQUIRED_LIBRARIES)
+
 if(HAVE_DLFCN_H)
    set(HAVE_DLFCN_H 1)
 endif(HAVE_DLFCN_H)
-CHECK_FUNCTION_EXISTS(dlsym                  HAVE_DLSYM)
 
-CHECK_FUNCTION_EXISTS(localeconv             HAVE_LOCALECONV)
+if(LIB_dl)
+  set(CMAKE_REQUIRED_LIBRARIES ${LIB_dl})
+  CHECK_FUNCTION_EXISTS(dlsym			HAVE_DLSYM)
+  set(CMAKE_REQUIRED_LIBRARIES)
+endif(LIB_dl)
 
-CHECK_FUNCTION_EXISTS(png_get_valid          HAVE_PNG_GET_VALID)
-CHECK_FUNCTION_EXISTS(png_set_tRNS_to_alpha  HAVE_PNG_SET_TRNS_TO_ALPHA)
+CHECK_FUNCTION_EXISTS(localeconv		HAVE_LOCALECONV)
+
+if(LIB_png)
+  set(CMAKE_REQUIRED_LIBRARIES ${LIB_png})
+  CHECK_FUNCTION_EXISTS(png_get_valid		HAVE_PNG_GET_VALID)
+  CHECK_FUNCTION_EXISTS(png_set_tRNS_to_alpha	HAVE_PNG_SET_TRNS_TO_ALPHA)
+  set(CMAKE_REQUIRED_LIBRARIES)
+endif(LIB_png)
 
 CHECK_FUNCTION_EXISTS(scandir                HAVE_SCANDIR)
 CHECK_FUNCTION_EXISTS(snprintf               HAVE_SNPRINTF)
@@ -120,6 +152,14 @@ if(HAVE_SCANDIR AND NOT HAVE_SCANDIR_POSIX)
 endif(HAVE_SCANDIR AND NOT HAVE_SCANDIR_POSIX)
 mark_as_advanced(HAVE_SCANDIR_POSIX)
 
+# restore CMAKE_REQUIRED_LIBRARIES (is this really necessary ?)
+if(DEFINED SAVED_REQUIRED_LIBRARIES)
+  set(CMAKE_REQUIRED_LIBRARIES ${CMAKE_REQUIRED_LIBRARIES})
+  unset(SAVED_REQUIRED_LIBRARIES)
+else(DEFINED SAVED_REQUIRED_LIBRARIES)
+  unset(CMAKE_REQUIRED_LIBRARIES)
+endif(DEFINED SAVED_REQUIRED_LIBRARIES)
+
 #######################################################################
 # packages
 

CMake/setup.cmake

@@ -60,6 +60,8 @@ set(FLTK_DATADIR ${CMAKE_INSTALL_DATADIR} CACHE PATH
     "Non-arch data install path relative to CMAKE_INSTALL_PREFIX unless set to an absolute path.")
 set(FLTK_MANDIR ${CMAKE_INSTALL_MANDIR} CACHE PATH
     "Manual install path relative to CMAKE_INSTALL_PREFIX unless set to an absolute path.")
+set(FLTK_DOCDIR ${CMAKE_INSTALL_DATADIR}/doc CACHE PATH
+    "Non-arch doc install path relative to CMAKE_INSTALL_PREFIX unless set to an absolute path.")
 
 
 #######################################################################

configh.cmake.in

@@ -1,8 +1,8 @@
+/* @CONFIG_H@.  Generated from @CONFIG_H_IN@ by CMake.  */
 /*
  * "$Id$"
  *
  * Configuration file for the Fast Light Tool Kit (FLTK).
- * @configure_input@
  *
  * Copyright 1998-2015 by Bill Spitzak and others.
  *
@@ -21,8 +21,8 @@
  * Where to find files...
  */
 
-#define FLTK_DATADIR	"@PREFIX_DATA@"
-#define FLTK_DOCDIR	"@PREFIX_DOC@"
+#define FLTK_DATADIR "@PREFIX_DATA@"
+#define FLTK_DOCDIR "@PREFIX_DOC@"
 
 /*
  * BORDER_WIDTH:
@@ -147,7 +147,7 @@
  * no meaning on operating systems other than Mac OS X.
  */
 
-#cmakedefine __APPLE_QUARTZ__ @__APPLE_QUARTZ__@
+#cmakedefine __APPLE_QUARTZ__ 1
 
 
 /*
@@ -185,7 +185,11 @@
  * Byte order of your machine: 1 = big-endian, 0 = little-endian.
  */
 
-#define WORDS_BIGENDIAN @WORDS_BIGENDIAN@
+#ifdef __APPLE__
+#include <mac_endianness.h>
+#else
+#cmakedefine01 WORDS_BIGENDIAN
+#endif
 
 /*
  * U16, U32, U64:

configh.in

@@ -2,7 +2,6 @@
  * "$Id$"
  *
  * Configuration file for the Fast Light Tool Kit (FLTK).
- * @configure_input@
  *
  * Copyright 1998-2015 by Bill Spitzak and others.
  *
@@ -21,8 +20,8 @@
  * Where to find files...
  */
 
-#define FLTK_DATADIR	""
-#define FLTK_DOCDIR	""
+#define FLTK_DATADIR ""
+#define FLTK_DOCDIR ""
 
 /*
  * BORDER_WIDTH:
@@ -184,7 +183,7 @@
  *
  * Byte order of your machine: 1 = big-endian, 0 = little-endian.
  */
- 
+
 #ifdef __APPLE__
 #include <mac_endianness.h>
 #else