android: Print error when trying to build on 32-bit host.

build/android/envsetup.sh

Index: build/android/envsetup.sh
diff --git a/build/android/envsetup.sh b/build/android/envsetup.sh
index 9d1b7e6fef8857b5d47afb3dd8288031ba1e1226..af7a6366e668cf7c788e26619a453fbc69fd836a 100755
--- a/build/android/envsetup.sh
+++ b/build/android/envsetup.sh
@@ -27,14 +27,38 @@ if [[ "${ANDROID_SDK_BUILD}" -eq 1 ]]; then
   echo "Using SDK build"
 fi
 
+# Get host architecture, and abort if it is 32-bit, unless --try-32
+# is also used.
+host_arch=$(uname -p)
+case "${host_arch}" in
+  "x86_64")  # pass

[Isaac (away), 2012/11/15 01:07:54]

nit: quotes unneeded here

[digit1, 2012/11/15 09:30:24]

Sure, will remove.

+    ;;
+  i?86)

[Isaac (away), 2012/11/15 01:07:54]

Assuming you made sure '?' works as intended

[digit1, 2012/11/15 09:30:24]

I've been using this for the NDK for a long time now, it seems to work :)

+    if [[ -z "${try_32bit_build}" ]]; then
+      echo "ERROR: Android build requires a 64-bit host."
+      echo "If you really want to try it on this machine, use the --try-32"
+      echo "flag. Be warned that this may fail horribly at link time, due"
+      echo "to some of the final binaries being too large."
+      return 1
+    else
+      echo "WARNING: 32-bit host build enabled. Here be dragons!"
+      host_arch=x86
+    fi
+    ;;
+  *)
+    echo "ERROR: Unsupported host architecture (${host_arch})."
+    echo "Try running this script on a Linux/x86_64 machine instead."
+    return 1
+esac
+
 host_os=$(uname -s | sed -e 's/Linux/linux/;s/Darwin/mac/')
 
 case "${host_os}" in
   "linux")
-    toolchain_dir="linux-x86_64"
+    toolchain_dir="linux-${host_arch}"
     ;;
   "mac")
-    toolchain_dir="darwin-x86"
+    toolchain_dir="darwin-${host_arch}"
     ;;
   *)
     echo "Host platform ${host_os} is not supported" >& 2