[Lldb-commits] [PATCH] D153891: [lldb] Consider OP_addrx in DWARFExpression::Update_DW_OP_addr

[Felipe de Azevedo Piovezan via Phabricator via lldb-commits]

fdeazeve created this revision.
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This uses rewrites DW_OP_addrx as a DW_OP_addr so that we can update addresses
that are originally located in the debug_addr section.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D153891

Files:
  lldb/source/Expression/DWARFExpression.cpp


Index: lldb/source/Expression/DWARFExpression.cpp
===================================================================
--- lldb/source/Expression/DWARFExpression.cpp
+++ lldb/source/Expression/DWARFExpression.cpp
@@ -419,13 +419,32 @@
       // the heap data so "m_data" will now correctly manage the heap data.
       m_data.SetData(encoder.GetDataBuffer());
       return true;
-    } else {
-      const offset_t op_arg_size =
-          GetOpcodeDataSize(m_data, offset, op, dwarf_cu);
-      if (op_arg_size == LLDB_INVALID_OFFSET)
-        break;
-      offset += op_arg_size;
     }
+    if (op == DW_OP_addrx) {
+      // Replace DW_OP_addrx with DW_OP_addr, since we can't modify the
+      // read-only debug_addr table.
+      llvm::ArrayRef data_before_op = m_data.GetData().take_front(offset - 1);
+
+      // Read out the old index to determine how many bytes it needs.
+      const lldb::offset_t old_offset = offset;
+      m_data.GetULEB128(&offset);
+      if (old_offset == offset)
+        return false;
+      llvm::ArrayRef data_after_op = m_data.GetData().drop_front(offset);
+
+      DataEncoder encoder(m_data.GetByteOrder(), m_data.GetAddressByteSize());
+      encoder.AppendData(data_before_op);
+      encoder.AppendU8(DW_OP_addr);
+      encoder.AppendAddress(file_addr);
+      encoder.AppendData(data_after_op);
+      m_data.SetData(encoder.GetDataBuffer());
+      return true;
+    }
+    const offset_t op_arg_size =
+        GetOpcodeDataSize(m_data, offset, op, dwarf_cu);
+    if (op_arg_size == LLDB_INVALID_OFFSET)
+      break;
+    offset += op_arg_size;
   }
   return false;
 }


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