Android: Drop support for NDK < r15

NDK r15c was released over two years ago (July 2017), and we
cannot build against r14b anyway as it seems to fail with our
setup to link the STL.

platform/android/SCsub

@@ -53,7 +53,6 @@ if lib_arch_dir != '':
 
     out_dir = '#platform/android/java/libs/' + lib_type_dir + '/' + lib_arch_dir
     env_android.Command(out_dir + '/libgodot_android.so', '#bin/libgodot' + env['SHLIBSUFFIX'], Move("$TARGET", "$SOURCE"))
-    ndk_version = get_ndk_version(env["ANDROID_NDK_ROOT"])
-    if ndk_version != None and LooseVersion(ndk_version) >= LooseVersion("15.0.4075724"):
-        stl_lib_path = str(env['ANDROID_NDK_ROOT']) + '/sources/cxx-stl/llvm-libc++/libs/' + lib_arch_dir + '/libc++_shared.so'
-        env_android.Command(out_dir + '/libc++_shared.so', stl_lib_path, Copy("$TARGET", "$SOURCE"))
+
+    stl_lib_path = str(env['ANDROID_NDK_ROOT']) + '/sources/cxx-stl/llvm-libc++/libs/' + lib_arch_dir + '/libc++_shared.so'
+    env_android.Command(out_dir + '/libc++_shared.so', stl_lib_path, Copy("$TARGET", "$SOURCE"))

platform/android/detect.py

@@ -205,9 +205,8 @@ def configure(env):
 
     common_opts = ['-fno-integrated-as', '-gcc-toolchain', gcc_toolchain_path]
 
-    lib_sysroot = env["ANDROID_NDK_ROOT"] + "/platforms/" + env['ndk_platform'] + "/" + env['ARCH']
-
     ## Compile flags
+
     # Disable exceptions and rtti on non-tools (template) builds
     if env['tools'] or env['android_stl']:
         env.Append(CPPFLAGS=["-isystem", env["ANDROID_NDK_ROOT"] + "/sources/cxx-stl/llvm-libc++/include"])
@@ -218,18 +217,15 @@ def configure(env):
         # Don't use dynamic_cast, necessary with no-rtti.
         env.Append(CPPDEFINES=['NO_SAFE_CAST'])
 
-    ndk_version = get_ndk_version(env["ANDROID_NDK_ROOT"])
-    if ndk_version != None and LooseVersion(ndk_version) >= LooseVersion("15.0.4075724"):
-        print("Using NDK unified headers")
-        sysroot = env["ANDROID_NDK_ROOT"] + "/sysroot"
-        env.Append(CPPFLAGS=["--sysroot=" + sysroot])
-        env.Append(CPPFLAGS=["-isystem", sysroot + "/usr/include/" + abi_subpath])
-        env.Append(CPPFLAGS=["-isystem", env["ANDROID_NDK_ROOT"] + "/sources/android/support/include"])
-        # For unified headers this define has to be set manually
-        env.Append(CPPDEFINES=[('__ANDROID_API__', str(get_platform(env['ndk_platform'])))])
-    else:
-        print("Using NDK deprecated headers")
-        env.Append(CPPFLAGS=["-isystem", lib_sysroot + "/usr/include"])
+    lib_sysroot = env["ANDROID_NDK_ROOT"] + "/platforms/" + env['ndk_platform'] + "/" + env['ARCH']
+
+    # Using NDK unified headers (NDK r15+)
+    sysroot = env["ANDROID_NDK_ROOT"] + "/sysroot"
+    env.Append(CPPFLAGS=["--sysroot=" + sysroot])
+    env.Append(CPPFLAGS=["-isystem", sysroot + "/usr/include/" + abi_subpath])
+    env.Append(CPPFLAGS=["-isystem", env["ANDROID_NDK_ROOT"] + "/sources/android/support/include"])
+    # For unified headers this define has to be set manually
+    env.Append(CPPDEFINES=[('__ANDROID_API__', str(get_platform(env['ndk_platform'])))])
 
     env.Append(CCFLAGS='-fpic -ffunction-sections -funwind-tables -fstack-protector-strong -fvisibility=hidden -fno-strict-aliasing'.split())
     env.Append(CPPDEFINES=['NO_STATVFS', 'GLES_ENABLED'])
@@ -263,18 +259,15 @@ def configure(env):
     env.Append(CCFLAGS=common_opts)
 
     ## Link flags
-    if ndk_version != None and LooseVersion(ndk_version) >= LooseVersion("15.0.4075724"):
-        if LooseVersion(ndk_version) >= LooseVersion("17.1.4828580"):
-            env.Append(LINKFLAGS=['-Wl,--exclude-libs,libgcc.a', '-Wl,--exclude-libs,libatomic.a', '-nostdlib++'])
-        else:
-            env.Append(LINKFLAGS=[env["ANDROID_NDK_ROOT"] + "/sources/cxx-stl/llvm-libc++/libs/" + arch_subpath + "/libandroid_support.a"])
-        env.Append(LINKFLAGS=['-shared', '--sysroot=' + lib_sysroot, '-Wl,--warn-shared-textrel'])
-        env.Append(LIBPATH=[env["ANDROID_NDK_ROOT"] + "/sources/cxx-stl/llvm-libc++/libs/" + arch_subpath + "/"])
-        env.Append(LINKFLAGS=[env["ANDROID_NDK_ROOT"] +"/sources/cxx-stl/llvm-libc++/libs/" + arch_subpath + "/libc++_shared.so"])
+
+    ndk_version = get_ndk_version(env["ANDROID_NDK_ROOT"])
+    if ndk_version != None and LooseVersion(ndk_version) >= LooseVersion("17.1.4828580"):
+        env.Append(LINKFLAGS=['-Wl,--exclude-libs,libgcc.a', '-Wl,--exclude-libs,libatomic.a', '-nostdlib++'])
     else:
-        env.Append(LINKFLAGS=['-shared', '--sysroot=' + lib_sysroot, '-Wl,--warn-shared-textrel'])
-        if mt_link:
-            env.Append(LINKFLAGS=['-Wl,--threads'])
+        env.Append(LINKFLAGS=[env["ANDROID_NDK_ROOT"] + "/sources/cxx-stl/llvm-libc++/libs/" + arch_subpath + "/libandroid_support.a"])
+    env.Append(LINKFLAGS=['-shared', '--sysroot=' + lib_sysroot, '-Wl,--warn-shared-textrel'])
+    env.Append(LIBPATH=[env["ANDROID_NDK_ROOT"] + "/sources/cxx-stl/llvm-libc++/libs/" + arch_subpath + "/"])
+    env.Append(LINKFLAGS=[env["ANDROID_NDK_ROOT"] +"/sources/cxx-stl/llvm-libc++/libs/" + arch_subpath + "/libc++_shared.so"])
 
     if env["android_arch"] == "armv7":
         env.Append(LINKFLAGS='-Wl,--fix-cortex-a8'.split())