build: Android support.

* Makefile (conftest.android): New helper target for testing
for Android toolchain, via presence of __ANDROID__
preprocessor symbol, similarly to how we detect Darwin.

* configure: New test for Android.  This is mutually exclusive
agains Darwin. On Android, we add some necessary feature
selection macros to the compiler command line.

1 files changed, 6 insertions, 0 deletions

diff --git a/Makefile b/Makefile
index dd7a2a11..6749a145 100644
--- a/Makefile
+++ b/Makefile
@@ -566,6 +566,12 @@ conftest.darwin:
 	  echo yes ; \
 	fi
 
+.PHONY: conftest.android
+conftest.android:
+	$(V)if echo | $(CC) -dM -E - | grep -s __ANDROID__ >  /dev/null 2>&1 ; then \
+	  echo yes ; \
+	fi
+
 .PHONY: conftest.clean
 conftest.clean:
 	$(V)rm -f conftest$(EXE) conftest.[co] \