Adds a DW_OP_call_frame_cfa handler when evaluating DWARF 3/4 expressions
in LLDB that load the canonical frame address rather than a location list.
- Handles the simple case where a CFA can be pulled from the current stack frame.
- Fixes more than one hundred failing tests with gcc 4.8!
TODO: Use UnwindPlan::GetRowForFunctionOffset if the DWARFExpression needs
to be evaluated in a context analogous to a virtual unwind (perhaps using RegisterContextLLDB).
- Also adds some comments to DWARFCallFrameInfo whenever I got confused.
llvm-svn: 187361
diff --git a/lldb/source/Expression/DWARFExpression.cpp b/lldb/source/Expression/DWARFExpression.cpp
index 7797205..fc955c5 100644
--- a/lldb/source/Expression/DWARFExpression.cpp
+++ b/lldb/source/Expression/DWARFExpression.cpp
@@ -37,6 +37,7 @@
#include "lldb/Target/Process.h"
#include "lldb/Target/RegisterContext.h"
#include "lldb/Target/StackFrame.h"
+#include "lldb/Target/StackID.h"
using namespace lldb;
using namespace lldb_private;
@@ -2627,6 +2628,37 @@
case DW_OP_stack_value:
stack.back().SetValueType(Value::eValueTypeScalar);
break;
+
+ //----------------------------------------------------------------------
+ // OPCODE: DW_OP_call_frame_cfa
+ // OPERANDS: None
+ // DESCRIPTION: Specifies a DWARF expression that pushes the value of
+ // the canonical frame address consistent with the call frame information
+ // located in .debug_frame (or in the FDEs of the eh_frame section).
+ //----------------------------------------------------------------------
+ case DW_OP_call_frame_cfa:
+ if (frame)
+ {
+ // Note that we don't have to parse FDEs because this DWARF expression
+ // is commonly evaluated with a valid stack frame.
+ StackID id = frame->GetStackID();
+ addr_t cfa = id.GetCallFrameAddress();
+ if (cfa != LLDB_INVALID_ADDRESS)
+ {
+ stack.push_back(Scalar(cfa));
+ stack.back().SetValueType (Value::eValueTypeHostAddress);
+ }
+ else
+ if (error_ptr)
+ error_ptr->SetErrorString ("Stack frame does not include a canonical frame address for DW_OP_call_frame_cfa opcode.");
+ }
+ else
+ {
+ if (error_ptr)
+ error_ptr->SetErrorString ("Invalid stack frame in context for DW_OP_call_frame_cfa opcode.");
+ return false;
+ }
+ break;
}
}