Don't define |r_debug| and |link_map| on Android releases 21 and later

src/common/android/include/link.h

 // Copyright (c) 2012, Google Inc.
 // All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 // notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
@@ skipping 12 matching lines @@
 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #ifndef GOOGLE_BREAKPAD_ANDROID_INCLUDE_LINK_H
 #define GOOGLE_BREAKPAD_ANDROID_INCLUDE_LINK_H
 
-/* Android doesn't provide all the data-structures required in its <link.h>.
-   Provide custom version here. */
-#include_next <link.h>
-
 // TODO(rmcilroy): Remove this file once the ndk is updated for other
 // architectures - crbug.com/358831
 #if !defined(__aarch64__) && !defined(__x86_64__) && \
     !(defined(__mips__) && _MIPS_SIM == _ABI64)
 
 #ifdef __cplusplus
 extern "C" {
 #endif  // __cplusplus
 
+// Android doesn't provide all the data-structures required in
+// its <link.h> before release 21. Provide custom version here and
+// rename Bionic-provided structures to avoid conflicts.
+
+#define r_debug   __bionic_r_debug
+#define link_map  __bionic_link_map
+
+#include_next <link.h>
+
+#undef r_debug
+#undef link_map
+
 struct r_debug {
   int              r_version;
   struct link_map* r_map;
   ElfW(Addr)       r_brk;
   enum {
     RT_CONSISTENT,
     RT_ADD,
     RT_DELETE }    r_state;
   ElfW(Addr)       r_ldbase;
 };
 
 struct link_map {
   ElfW(Addr)       l_addr;
   char*            l_name;
   ElfW(Dyn)*       l_ld;
   struct link_map* l_next;
   struct link_map* l_prev;
 };
 
 #ifdef __cplusplus
 }  // extern "C"
 #endif  // __cplusplus
 
+#else
+
+#include_next <link.h>

[rmcilroy, 2016/07/21 15:04:21]

Instead of including this twice (and doing the one above inside a "extern "C" {"
which might change semantics), could you instead do the #ifdef check around the
#define / #undef code.

+
 #endif  // !defined(__aarch64__) && !defined(__x86_64__)
 
 #endif /* GOOGLE_BREAKPAD_ANDROID_INCLUDE_LINK_H */