Add support for getting a dex pc.

Changes:
- Change the register type from int16_t to uint32_t for the location data
  and the Eval processing. This is because the special dex pc is > 65535.
- Add the ability for Dwarf register location information to point to a
  register that is itself a Dwarf location register.
- Add dex_pc to the frame information.
- Modify the unwind tool to print the dex pc if non-zero.

This does not implement the printing of the dex information in anything
but the unwind tool. It's not the final form of this printing.

Bug: 72070049

Test: Ran new unit tests.
Test: Dumped stack while in interpreter running 137-cfi art test and
Test: verified dex pc is set to non-zero.
Change-Id: I6ce8a6b577fb4f92abacbd433b1f68977e272542

2 files changed, 2 insertions, 0 deletions

diff --git a/libbacktrace/UnwindStack.cpp b/libbacktrace/UnwindStack.cpp
index b0345a140..b62ee1659 100644
--- a/libbacktrace/UnwindStack.cpp
+++ b/libbacktrace/UnwindStack.cpp
@@ -70,6 +70,7 @@ bool Backtrace::Unwind(unwindstack::Regs* regs, BacktraceMap* back_map,
     back_frame->rel_pc = frame->rel_pc;
     back_frame->pc = frame->pc;
     back_frame->sp = frame->sp;
+    back_frame->dex_pc = frame->dex_pc;
 
     back_frame->func_name = demangle(frame->function_name.c_str());
     back_frame->func_offset = frame->function_offset;
diff --git a/libbacktrace/include/backtrace/Backtrace.h b/libbacktrace/include/backtrace/Backtrace.h
index 592266429..f34fb2d5f 100644
--- a/libbacktrace/include/backtrace/Backtrace.h
+++ b/libbacktrace/include/backtrace/Backtrace.h
@@ -81,6 +81,7 @@ struct backtrace_frame_data_t {
   uintptr_t rel_pc;       // The relative pc.
   uintptr_t sp;           // The top of the stack.
   size_t stack_size;      // The size of the stack, zero indicate an unknown stack size.
+  uint64_t dex_pc;        // If non-zero, the Dex PC for the ART interpreter.
   backtrace_map_t map;    // The map associated with the given pc.
   std::string func_name;  // The function name associated with this pc, NULL if not found.
   uintptr_t func_offset;  // pc relative to the start of the function, only valid if func_name is not NULL.