DWARFExpression: Convert file addresses to load addresses early on.

This is a change that only affects Swift and is NFC for the language
plugins on llvm.org. In Swift, we can have global variables with a
location such as DW_OP_addr <addr> DW_OP_deref. The DWARF expression
evaluator doesn't know how to apply a DW_OP_deref to a file address,
but at the very end we convert the file address into a load address.

This patch moves the file->load address conversion to right after the
result of the DW_OP_addr is pushed onto the stack so that a subsequent
DW_OP_deref (and potentially other operations) can be interpreted.

rdar://problem/39767528

Differential revision: https://reviews.llvm.org/D46362

llvm-svn: 331492

1 files changed, 6 insertions, 0 deletions

diff --git a/lldb/source/Expression/DWARFExpression.cpp b/lldb/source/Expression/DWARFExpression.cpp
index 71495715e75..8f54bf37ea0 100644
--- a/lldb/source/Expression/DWARFExpression.cpp
+++ b/lldb/source/Expression/DWARFExpression.cpp
@@ -1374,6 +1374,7 @@ bool DWARFExpression::Evaluate(
       }
       log->Printf("0x%8.8" PRIx64 ": %s", op_offset, DW_OP_value_to_name(op));
     }
+
     switch (op) {
     //----------------------------------------------------------------------
     // The DW_OP_addr operation has a single operand that encodes a machine
@@ -1382,6 +1383,11 @@ bool DWARFExpression::Evaluate(
     case DW_OP_addr:
       stack.push_back(Scalar(opcodes.GetAddress(&offset)));
       stack.back().SetValueType(Value::eValueTypeFileAddress);
+      // Convert the file address to a load address, so subsequent
+      // DWARF operators can operate on it.
+      if (frame)
+        stack.back().ConvertToLoadAddress(module_sp.get(),
+                                          frame->CalculateTarget().get());
       break;
 
     //----------------------------------------------------------------------