Fix windows NDK build - add runtime check for Cygwin 1.5

Change-Id: I73107f2f72ec3b3486e59f80b942f041cf65b02d

build/core/init.mk

@@ -147,6 +147,23 @@ else
 endif
 
 HOST_TAG := $(HOST_OS)-$(HOST_ARCH)
+
+# If we are on Windows, we need to check that we are not running
+# Cygwin 1.5, which is deprecated and won't run our toolchain
+# binaries properly.
+#
+ifeq ($(HOST_TAG),windows-x86)
+    # On cygwin, 'uname -r' returns something like 1.5.23(0.225/5/3)
+    # We recognize 1.5. as the prefix to look for then.
+    CYGWIN_VERSION := $(shell uname -r)
+    ifneq ($(filter XX1.5.%,XX$(CYGWIN_VERSION)),)
+        $(call __ndk_info,You seem to be running Cygwin 1.5, which is not supported.)
+        $(call __ndk_info,Please upgrade to Cygwin 1.7 or higher.)
+        $(call __ndk_error,Aborting.)
+    endif
+    # special-case the host-tag
+    HOST_TAG := windows
+endif
 $(call ndk_log,HOST_TAG set to $(HOST_TAG))
 
 #

docs/CHANGES.TXT

@@ -10,6 +10,10 @@ IMPORTANT BUG FIXES:
 
 IMPORTANT CHANGES:
 
+- On Windows, Cygwin 1.7 or higher is now required. The NDK will not
+  work properly with Cygwin 1.5 which is now officially obsolete
+  anyway.
+
 - Simplified build system: You no longer need to run build/host-setup.sh
   or modify anything under $NDK_ROOT/apps/. Instead, just invoke the
   new 'ndk-build' script from your application's project directory, or

docs/INSTALL.TXT

@@ -13,9 +13,7 @@ I. Requirements:
 The Android NDK currently requires a Linux, OS X or Windows host operating system.
 
 Windows users will need to install Cygwin 1.7 or later (http://www.cygwin.com) to
-use the NDK. Note that running it under MSys is not supported. Running under the
-now-obsolete Cygwin 1.5 has not been tested and might not work. Consider upgrading
-to 1.7 instead in case of problems.
+use the NDK. Note that running it under MSys or Cygwin 1.5 is not supported.
 
 You will need to have the Android SDK and its dependencies installed. The NDK
 cannot generate final application packages (.apk files), only the shared library