Add debug info for link-time generated thunks.

Add debug info for method call thunks (currently unused) and
Baker read barrier thunks. Refactor debug info generation
for trampolines and record their sizes; change their names
to start with upper-case letters, so that they can be easily
generated as `#fn_name`.

This improved debug info must be generated by `dex2oat -g`,
the debug info generated by `oatdump --symbolize` remains
the same as before, except for the renamed trampolines and
an adjustment for "code delta", i.e. the Thumb mode bit.

Cortex-A53 erratum 843419 workaround thunks are not covered
by this CL.

Test: Manual; run-test --gdb -Xcompiler-option -g 160, pull
      symbols for gdbclient, break in the introspection
      entrypoint, check that gdb knows the new symbols
      (and disassembles them) and `backtrace` works when
      setting $pc to an address in the thunk.
Bug: 36141117
Change-Id: Id224b72cfa7a0628799c7db65e66e24c8517aabf

1 files changed, 6 insertions, 0 deletions

diff --git a/compiler/linker/relative_patcher.cc b/compiler/linker/relative_patcher.cc
index ee49453938..dc15bb087e 100644
--- a/compiler/linker/relative_patcher.cc
+++ b/compiler/linker/relative_patcher.cc
@@ -16,6 +16,7 @@
 
 #include "linker/relative_patcher.h"
 
+#include "debug/method_debug_info.h"
 #ifdef ART_ENABLE_CODEGEN_arm
 #include "linker/arm/relative_patcher_thumb2.h"
 #endif
@@ -81,6 +82,11 @@ std::unique_ptr<RelativePatcher> RelativePatcher::Create(
       LOG(FATAL) << "Unexpected baker read barrier branch patch.";
     }
 
+    std::vector<debug::MethodDebugInfo> GenerateThunkDebugInfo(
+        uint32_t executable_offset ATTRIBUTE_UNUSED) OVERRIDE {
+      return std::vector<debug::MethodDebugInfo>();  // No thunks added.
+    }
+
    private:
     DISALLOW_COPY_AND_ASSIGN(RelativePatcherNone);
   };