1 files changed, 30 insertions, 14 deletions
diff --git a/src/google_breakpad/processor/stack_frame_cpu.h b/src/google_breakpad/processor/stack_frame_cpu.h
index c5bddffb..0996886f 100644
--- a/src/google_breakpad/processor/stack_frame_cpu.h
+++ b/src/google_breakpad/processor/stack_frame_cpu.h
@@ -139,28 +139,44 @@ struct StackFramePPC : public StackFrame {
 };
 
 struct StackFrameAMD64 : public StackFrame {
-  // ContextValidity has one entry for each relevant hardware pointer register
-  // (%rip and %rsp) and one entry for each nonvolatile (callee-save) register.
-  //FIXME: validate this list
+  // ContextValidity has one entry for each register that we might be able
+  // to recover.
   enum ContextValidity {
-    CONTEXT_VALID_NONE = 0,
-    CONTEXT_VALID_RIP  = 1 << 0,
-    CONTEXT_VALID_RSP  = 1 << 1,
-    CONTEXT_VALID_RBP  = 1 << 2,
+    CONTEXT_VALID_NONE  = 0,
+    CONTEXT_VALID_RAX   = 1 << 0,
+    CONTEXT_VALID_RDX   = 1 << 1,
+    CONTEXT_VALID_RCX   = 1 << 2,
+    CONTEXT_VALID_RBX   = 1 << 3,
+    CONTEXT_VALID_RSI   = 1 << 4,
+    CONTEXT_VALID_RDI   = 1 << 5,
+    CONTEXT_VALID_RBP   = 1 << 6,
+    CONTEXT_VALID_RSP   = 1 << 7,
+    CONTEXT_VALID_R8    = 1 << 8,
+    CONTEXT_VALID_R9    = 1 << 9,
+    CONTEXT_VALID_R10   = 1 << 10,
+    CONTEXT_VALID_R11   = 1 << 11,
+    CONTEXT_VALID_R12   = 1 << 12,
+    CONTEXT_VALID_R13   = 1 << 13,
+    CONTEXT_VALID_R14   = 1 << 14,
+    CONTEXT_VALID_R15   = 1 << 15,
+    CONTEXT_VALID_RIP   = 1 << 16,
     CONTEXT_VALID_ALL  = -1
   };
 
   StackFrameAMD64() : context(), context_validity(CONTEXT_VALID_NONE) {}
 
-  // Register state.  This is only fully valid for the topmost frame in a
-  // stack.  In other frames, the values of nonvolatile registers may be
-  // present, given sufficient debugging information.  Refer to
-  // context_validity.
+  // Register state. This is only fully valid for the topmost frame in a
+  // stack. In other frames, which registers are present depends on what
+  // debugging information we had available. Refer to context_validity.
   MDRawContextAMD64 context;
 
-  // context_validity is actually ContextValidity, but int is used because
-  // the OR operator doesn't work well with enumerated types.  This indicates
-  // which fields in context are valid.
+  // For each register in context whose value has been recovered, we set
+  // the corresponding CONTEXT_VALID_ bit in context_validity.
+  //
+  // context_validity's type should actually be ContextValidity, but
+  // we use int instead because the bitwise inclusive or operator
+  // yields an int when applied to enum values, and C++ doesn't
+  // silently convert from ints to enums.
   int context_validity;
 };