[libunwind] r317125 - [libunwind] Don't use dl_iterate_phdr if __ANDROID_API__ < 21

[Dan Albert via cfe-commits]

Author: danalbert
Date: Wed Nov  1 14:26:06 2017
New Revision: 317125

URL: http://llvm.org/viewvc/llvm-project?rev=317125&view=rev
Log:
[libunwind] Don't use dl_iterate_phdr if __ANDROID_API__ < 21

Summary:
On ARM, dl_iterate_phdr is only implemented in the Android NDK version 21 or later:
https://android.googlesource.com/platform/prebuilts/ndk/+/dev/platform/sysroot/usr/include/link.h#55

Reviewers: thakis, danalbert

Reviewed By: danalbert

Subscribers: dtzWill, aemerson, srhines, kristof.beyls

Differential Revision: https://reviews.llvm.org/D39468

Modified:
    libunwind/trunk/src/AddressSpace.hpp

Modified: libunwind/trunk/src/AddressSpace.hpp
URL: http://llvm.org/viewvc/llvm-project/libunwind/trunk/src/AddressSpace.hpp?rev=317125&r1=317124&r2=317125&view=diff
==============================================================================
--- libunwind/trunk/src/AddressSpace.hpp (original)
+++ libunwind/trunk/src/AddressSpace.hpp Wed Nov  1 14:26:06 2017
@@ -393,6 +393,14 @@ inline bool LocalAddressSpace::findUnwin
     }
   }
   return false;
+#elif defined(_LIBUNWIND_ARM_EHABI) && defined(__BIONIC__) &&                  \
+    (__ANDROID_API__ < 21)
+  int length = 0;
+  info.arm_section =
+      (uintptr_t)dl_unwind_find_exidx((_Unwind_Ptr)targetAddr, &length);
+  info.arm_section_length = (uintptr_t)length;
+  if (info.arm_section && info.arm_section_length)
+    return true;
 #elif defined(_LIBUNWIND_ARM_EHABI) || defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
   struct dl_iterate_cb_data {
     LocalAddressSpace *addressSpace;