From 59a1be3acf40663f078317cb0877def00a6cb673 Mon Sep 17 00:00:00 2001
From: Greg Clayton <gclayton@apple.com>
Date: Thu, 21 Jun 2018 17:58:06 +0000
Subject: [PATCH] Fix an issue where DW_OP_deref might be dereferencing a file
 address. Convert the file address to a load address so this works.

https://bugs.llvm.org/show_bug.cgi?id=36871

llvm-svn: 335263
---
 lldb/source/Expression/DWARFExpression.cpp | 28 ++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/lldb/source/Expression/DWARFExpression.cpp b/lldb/source/Expression/DWARFExpression.cpp
index c851e052a527..2837caafd045 100644
--- a/lldb/source/Expression/DWARFExpression.cpp
+++ b/lldb/source/Expression/DWARFExpression.cpp
@@ -15,6 +15,7 @@
 // C++ Includes
 #include <vector>
 
+#include "lldb/Core/Module.h"
 #include "lldb/Core/RegisterValue.h"
 #include "lldb/Core/Scalar.h"
 #include "lldb/Core/Value.h"
@@ -1452,6 +1453,33 @@ bool DWARFExpression::Evaluate(
         stack.back().GetScalar() = ptr;
         stack.back().ClearContext();
       } break;
+      case Value::eValueTypeFileAddress: {
+        auto file_addr = stack.back().GetScalar().ULongLong(
+            LLDB_INVALID_ADDRESS);
+        if (!module_sp) {
+          if (error_ptr)
+            error_ptr->SetErrorStringWithFormat(
+                "need module to resolve file address for DW_OP_deref");
+          return false;
+        }
+        Address so_addr;
+        if (!module_sp->ResolveFileAddress(file_addr, so_addr)) {
+          if (error_ptr)
+            error_ptr->SetErrorStringWithFormat(
+                "failed to resolve file address in module");
+          return false;
+        }
+        addr_t load_Addr = so_addr.GetLoadAddress(exe_ctx->GetTargetPtr());
+        if (load_Addr == LLDB_INVALID_ADDRESS) {
+          if (error_ptr)
+            error_ptr->SetErrorStringWithFormat(
+                "failed to resolve load address");
+          return false;
+        }
+        stack.back().GetScalar() = load_Addr;
+        stack.back().SetValueType(Value::eValueTypeLoadAddress);
+        // Fall through to load address code below...
+      } LLVM_FALLTHROUGH;
       case Value::eValueTypeLoadAddress:
         if (exe_ctx) {
           if (process) {