Fix access to FP registers when visiting stack

Adds GetFPR and SetFPR to Context class so we can read from and write to
floating-point registers during stack visit. They return a boolean flag
indicating whether the read/write is successful. This allows the debugger to
return the JDWP error ABSENT_INFORMATION when we can't read/write a register.
We also update GetGPR and SetGPR for consistency. We keep a default GetGPR
implementation asserting the read was successful using a CHECK so we don't
silently fail.

Adds missing JDWP object tags for StackFrame.SetValues to avoid crash when
setting corresponding objects (thread, thread group, class object or class
loader). Also returns JDWP error INVALID_OBJECT (when the given object id is
invalid) instead of crashing with an unimplemented message.

Bug: 15433097
Change-Id: I70843c9280e694aec1eae5cf6f2dc155cb9ea10e

1 files changed, 15 insertions, 4 deletions

diff --git a/runtime/stack.h b/runtime/stack.h
index 1991115..9402cdd 100644
--- a/runtime/stack.h
+++ b/runtime/stack.h
@@ -561,15 +561,21 @@ class StackVisitor {
   bool GetNextMethodAndDexPc(mirror::ArtMethod** next_method, uint32_t* next_dex_pc)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
-  uint32_t GetVReg(mirror::ArtMethod* m, uint16_t vreg, VRegKind kind) const
+  bool GetVReg(mirror::ArtMethod* m, uint16_t vreg, VRegKind kind, uint32_t* val) const
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
-  void SetVReg(mirror::ArtMethod* m, uint16_t vreg, uint32_t new_value, VRegKind kind)
+  uint32_t GetVReg(mirror::ArtMethod* m, uint16_t vreg, VRegKind kind) const
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+    uint32_t val;
+    bool success = GetVReg(m, vreg, kind, &val);
+    CHECK(success) << "Failed to read vreg " << vreg << " of kind " << kind;
+    return val;
+  }
+
+  bool SetVReg(mirror::ArtMethod* m, uint16_t vreg, uint32_t new_value, VRegKind kind)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
   uintptr_t* GetGPRAddress(uint32_t reg) const;
-  uintptr_t GetGPR(uint32_t reg) const;
-  void SetGPR(uint32_t reg, uintptr_t value);
 
   // This is a fast-path for getting/setting values in a quick frame.
   uint32_t* GetVRegAddr(StackReference<mirror::ArtMethod>* cur_quick_frame,
@@ -700,6 +706,11 @@ class StackVisitor {
   StackVisitor(Thread* thread, Context* context, size_t num_frames)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
+  bool GetGPR(uint32_t reg, uintptr_t* val) const;
+  bool SetGPR(uint32_t reg, uintptr_t value);
+  bool GetFPR(uint32_t reg, uintptr_t* val) const;
+  bool SetFPR(uint32_t reg, uintptr_t value);
+
   instrumentation::InstrumentationStackFrame& GetInstrumentationStackFrame(uint32_t depth) const;
 
   void SanityCheckFrame() const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);