Avoid compilation error due to 'mmap' on Android

[Bruno Haible]

Compiling for Android 4.3, I see a couple of compilation errors, such as

zerosize-ptr.h:59:13: error: call to 'mmap' declared with attribute error: mmap 
is not available with _FILE_OFFSET_BITS=64 when using GCC until android-21. 
Either raise your minSdkVersion, disable _FILE_OFFSET_BITS=64, or switch to 
Clang.

This patch avoids the errors.


2018-05-13  Bruno Haible  <br...@clisp.org>

        Avoid compilation error due to 'mmap' on Android.
        * lib/vma-iter.c (_FILE_OFFSET_BITS): Undefine on Android.
        * lib/get-rusage-as.c (_FILE_OFFSET_BITS): Likewise.
        * tests/zerosize-ptr.h (_FILE_OFFSET_BITS, __USE_FILE_OFFSET64):
        Undefine on Android.

diff --git a/lib/get-rusage-as.c b/lib/get-rusage-as.c
index 096d3d1..e3c3dfd 100644
--- a/lib/get-rusage-as.c
+++ b/lib/get-rusage-as.c
@@ -17,6 +17,18 @@
 
 #include <config.h>
 
+/* On Android, when targeting Android 4.4 or older with a GCC toolchain,
+   prevent a compilation error
+     "error: call to 'mmap' declared with attribute error: mmap is not
+      available with _FILE_OFFSET_BITS=64 when using GCC until android-21.
+      Either raise your minSdkVersion, disable _FILE_OFFSET_BITS=64, or
+      switch to Clang."
+   The files that we access in this compilation unit are less than 2 GB
+   large.  */
+#if defined __ANDROID__
+# undef _FILE_OFFSET_BITS
+#endif
+
 /* Specification.  */
 #include "resource-ext.h"
 
diff --git a/lib/vma-iter.c b/lib/vma-iter.c
index b98b041..30d19a5 100644
--- a/lib/vma-iter.c
+++ b/lib/vma-iter.c
@@ -20,9 +20,15 @@
 /* On Solaris in 32-bit mode, when gnulib module 'largefile' is in use,
    prevent a compilation error
      "Cannot use procfs in the large file compilation environment"
+   On Android, when targeting Android 4.4 or older with a GCC toolchain,
+   prevent a compilation error
+     "error: call to 'mmap' declared with attribute error: mmap is not
+      available with _FILE_OFFSET_BITS=64 when using GCC until android-21.
+      Either raise your minSdkVersion, disable _FILE_OFFSET_BITS=64, or
+      switch to Clang."
    The files that we access in this compilation unit are less than 2 GB
    large.  */
-#if defined __sun
+#if defined __sun || defined __ANDROID__
 # undef _FILE_OFFSET_BITS
 #endif
 
diff --git a/tests/zerosize-ptr.h b/tests/zerosize-ptr.h
index e4867e9..d5592c5 100644
--- a/tests/zerosize-ptr.h
+++ b/tests/zerosize-ptr.h
@@ -18,6 +18,19 @@
    argument.  Therefore this file produces a non-NULL pointer which cannot
    be dereferenced, if possible.  */
 
+/* On Android, when targeting Android 4.4 or older with a GCC toolchain,
+   prevent a compilation error
+     "error: call to 'mmap' declared with attribute error: mmap is not
+      available with _FILE_OFFSET_BITS=64 when using GCC until android-21.
+      Either raise your minSdkVersion, disable _FILE_OFFSET_BITS=64, or
+      switch to Clang."
+   The files that we access in this compilation unit are less than 2 GB
+   large.  */
+#if defined __ANDROID__
+# undef _FILE_OFFSET_BITS
+# undef __USE_FILE_OFFSET64
+#endif
+
 #include <stdlib.h>
 
 /* Test whether mmap() and mprotect() are available.