Update dyninst frontend (#701)

* cmake: Set c++ standard to c++17.

* dyninst: Properly set is_referenced_by_data if bb is target of data reference.

* dyninst: Always set some value to is_reference_by_data field.

Co-authored-by: Peter Goodman <[email protected]>

Author: Aiethel

tools/mcsema_disass/dyninst/CFGWriter.cpp

@@ -356,6 +356,7 @@ void CFGWriter::Write() {
   }
 
   module.set_name(FLAGS_binary);
+  ComputeBBAttributes();
 }
 
 void CFGWriter::WriteExternalVariables() {
@@ -1200,3 +1201,23 @@ bool CFGWriter::IsExternal(Address addr) const {
   return ctx.external_vars.find(addr) != ctx.external_vars.end() ||
          ctx.external_funcs.find(addr) != ctx.external_funcs.end();
 }
+
+// Set `is_referenced_by_data`. This is independent from the
+// actual xref resolution and is done as last step.
+// TODO(lukas): We may need mark offset tables entries as well.
+void CFGWriter::ComputeBBAttributes() {
+  std::unordered_map<uint64_t, mcsema::Block *> bbs;
+  for (auto &cfg_fn : *module.mutable_funcs()) {
+    for (auto &cfg_bb : *cfg_fn.mutable_blocks()) {
+      bbs.emplace(cfg_bb.ea(), &cfg_bb);
+      cfg_bb.set_is_referenced_by_data(false);
+    }
+  }
+
+  for (auto &[ea, cfg_dref] : ctx.data_xrefs) {
+    auto it = bbs.find(cfg_dref->target_ea());
+    if (it == bbs.end())
+      continue;
+    it->second->set_is_referenced_by_data(true);
+  }
+}

tools/mcsema_disass/dyninst/CFGWriter.h

@@ -96,6 +96,8 @@ class CFGWriter {
   void CheckDisplacement(Dyninst::InstructionAPI::Expression *,
                          mcsema::Instruction *);
   bool IsExternal(Dyninst::Address addr) const;
+  void ComputeBBAttributes();
+
 
   mcsema::Module &module;
 

tools/mcsema_disass/dyninst/CMakeLists.txt

@@ -16,9 +16,8 @@
 if (NOT UNIX)
   message (ERROR "The Dyninst frontend currently does not support this OS")
 else ()
-  add_compile_options(-frtti -std=c++14)
   set (CMAKE_CXX_FLAGS "-frtti")
-  set (CMAKE_CXX_FLAGS "-std=c++14")
+  set (CMAKE_CXX_STANDARD 17)
 endif ()
 
 set(CMAKE_INSTALL_RPATH_USE_LINK_PATH TRUE)