CMake: Fix (Add?) Android support

Not sure if this ever worked, but now it at least compiles.

src/CMakeLists.txt

@@ -11,6 +11,7 @@ include("CMakeOptions.txt")
 include(BuildType)
 configure_file(config.h.in ${CMAKE_BINARY_DIR}/cmake/config.h)
 include_directories(${CMAKE_BINARY_DIR})
+include_directories(SYSTEM .)
 
 if(MACOS_FATLIB)
     if (CMAKE_OSX_ARCHITECTURES)
@@ -24,7 +25,7 @@ endif()
 file(GLOB raylib_sources *.c)
 list(REMOVE_ITEM raylib_sources ${CMAKE_CURRENT_SOURCE_DIR}/rglfw.c)
 
-if(NOT glfw3_FOUND)
+if(NOT glfw3_FOUND AND "${PLATFORM}" MATCHES "Desktop")
   set(GLFW_BUILD_DOCS OFF CACHE BOOL "" FORCE)
   set(GLFW_BUILD_TESTS OFF CACHE BOOL "" FORCE)
   set(GLFW_BUILD_EXAMPLES OFF CACHE BOOL "" FORCE)
@@ -53,6 +54,8 @@ else()
   set(sources ${raylib_sources})
 endif()
 
+include(AddIfFlagCompiles)
+
 ### Config options ###
 # Translate the config options to what raylib wants
 if(${PLATFORM} MATCHES "Desktop")
@@ -92,14 +95,27 @@ elseif(${PLATFORM} MATCHES "Web")
 elseif(${PLATFORM} MATCHES "Android")
   set(PLATFORM "PLATFORM_ANDROID")
   set(GRAPHICS "GRAPHICS_API_OPENGL_ES2")
+  add_if_flag_compiles(-ffunction-sections CMAKE_C_FLAGS)
+  add_if_flag_compiles(-funwind-tables CMAKE_C_FLAGS)
+  add_if_flag_compiles(-fstack-protector-strong CMAKE_C_FLAGS)
+  set(CMAKE_POSITION_INDEPENDENT_CODE ON)
+  add_if_flag_compiles(-Wa,--noexecstack CMAKE_C_FLAGS)
+  add_if_flag_compiles(-no-canonical-prefixes CMAKE_C_FLAGS)
+  add_definitions(-DANDROID -D__ANDROID_API__=21)
+  include_directories(external/android/native_app_glue )
+  set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -Wl,--exclude-libs,libatomic.a -Wl,--build-id -Wl,-z,noexecstack -Wl,-z,relro -Wl,-z,now -Wl,--warn-shared-textrel -Wl,--fatal-warnings -uANativeActivity_onCreate")
+
 elseif(${PLATFORM} MATCHES "Raspberry Pi")
   set(PLATFORM "PLATFORM_RPI")
   set(GRAPHICS "GRAPHICS_API_OPENGL_ES2")
 endif()
 
 # Which platform?
-if(${PLATFORM} MATCHES "PLATFORM_DESKTOP")
+if(${PLATFORM} MATCHES "PLATFORM_WEB")
+  # For the web.
+  add_executable(${RAYLIB} ${sources})
 
+else()
   if(${SHARED})
     add_library(${RAYLIB}_shared SHARED ${sources})
 
@@ -113,7 +129,10 @@ if(${PLATFORM} MATCHES "PLATFORM_DESKTOP")
     set(CMAKE_INSTALL_RPATH_USE_LINK_PATH TRUE)
     set(CMAKE_MACOSX_RPATH ON)
 
-    target_link_libraries(${RAYLIB}_shared ${LIBS_PRIVATE} glfw ${GLFW_LIBRARIES})
+    target_link_libraries(${RAYLIB}_shared ${LIBS_PRIVATE})
+    if (${PLATFORM} MATCHES "Desktop")
+      target_link_libraries(${RAYLIB}_shared glfw ${GLFW_LIBRARIES})
+    endif()
     if (UNIX AND ${FILESYSTEM_LACKS_SYMLINKS})
       MESSAGE(WARNING "Can't version UNIX shared library on file system without symlink support")
     else()
@@ -150,7 +169,9 @@ if(${PLATFORM} MATCHES "PLATFORM_DESKTOP")
     )
 
     set(PKG_CONFIG_LIBS_PRIVATE ${__PKG_CONFIG_LIBS_PRIVATE})
-    target_link_libraries(${RAYLIB} glfw ${GLFW_LIBRARIES})
+    if (${PLATFORM} MATCHES "Desktop")
+      target_link_libraries(${RAYLIB} glfw ${GLFW_LIBRARIES})
+    endif()
 
     if (WITH_PIC)
       set_property(TARGET ${RAYLIB} PROPERTY POSITION_INDEPENDENT_CODE ON)
@@ -171,9 +192,6 @@ if(${PLATFORM} MATCHES "PLATFORM_DESKTOP")
   file(COPY "physac.h" DESTINATION ".")
   file(COPY "raymath.h" DESTINATION ".")
   file(COPY "audio.h" DESTINATION ".")
-elseif(${PLATFORM} MATCHES "PLATFORM_WEB")
-  # For the web.
-  add_executable(${RAYLIB} ${sources})
 endif()
 
 # Print the flags for the user

src/utils.c

@@ -57,6 +57,12 @@
 #include <stdarg.h>                 // Required for: va_list, va_start(), vfprintf(), va_end()
 #include <string.h>                 // Required for: strlen(), strrchr(), strcmp()
 
+/* This should be in <stdio.h>, but Travis doesn't find it... */
+FILE *funopen(const void *cookie, int (*readfn)(void *, char *, int),
+              int (*writefn)(void *, const char *, int),
+              fpos_t (*seekfn)(void *, fpos_t, int), int (*closefn)(void *));
+
+
 #if defined(PLATFORM_DESKTOP) || defined(PLATFORM_RPI)
     #define STB_IMAGE_WRITE_IMPLEMENTATION
     #include "external/stb_image_write.h"   // Required for: stbi_write_bmp(), stbi_write_png()