From 056be957a0fc3ab4420cab85d807b4f0dca9f83e Mon Sep 17 00:00:00 2001
From: Alex Cameron <asc@tetsuo.sh>
Date: Tue, 31 May 2022 21:17:45 +1000
Subject: [PATCH] More fixes

---
 include/remill/BC/Compat/PointerType.h | 2 +-
 lib/Arch/Arch.cpp                      | 9 ++-------
 lib/BC/Util.cpp                        | 4 ++++
 3 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/include/remill/BC/Compat/PointerType.h b/include/remill/BC/Compat/PointerType.h
index f992edf0..35ac465d 100644
--- a/include/remill/BC/Compat/PointerType.h
+++ b/include/remill/BC/Compat/PointerType.h
@@ -21,7 +21,7 @@ namespace remill {
 
 // TODO(alex): Just remove this function entirely
 inline static llvm::Type *PointerElementType(llvm::PointerType *type) {
-  assert(type->isOpaque());
+  // assert(type->isOpaque());
   return nullptr;
 }
 
diff --git a/lib/Arch/Arch.cpp b/lib/Arch/Arch.cpp
index 09b7b8eb..c75be0e8 100644
--- a/lib/Arch/Arch.cpp
+++ b/lib/Arch/Arch.cpp
@@ -496,11 +496,7 @@ FinishAddressOf(llvm::IRBuilder<> &ir, const llvm::DataLayout &dl,
   // Best case: we've found a value field in the structure that
   // is located at the correct byte offset.
   if (gep_offset == reg->offset) {
-    if (gep->getType()->isPointerTy()) {
-      return gep;
-
-    } else if (auto const_gep = llvm::dyn_cast<llvm::Constant>(gep);
-               const_gep) {
+    if (auto const_gep = llvm::dyn_cast<llvm::Constant>(gep); const_gep) {
       return llvm::ConstantExpr::getBitCast(const_gep, goal_ptr_type);
 
     } else {
@@ -574,8 +570,7 @@ llvm::Value *Register::AddressOf(llvm::Value *state_ptr,
   return AddressOf(state_ptr, ir);
 }
 
-llvm::Value *
-Register::AddressOf(llvm::Value *state_ptr,
+llvm::Value *Register::AddressOf(llvm::Value *state_ptr,
                                  llvm::IRBuilder<> &ir) const {
   auto &context = type->getContext();
   CHECK_EQ(&context, &(state_ptr->getContext()));
diff --git a/lib/BC/Util.cpp b/lib/BC/Util.cpp
index 8f17bb85..a2662a70 100644
--- a/lib/BC/Util.cpp
+++ b/lib/BC/Util.cpp
@@ -1464,6 +1464,9 @@ llvm::GlobalVariable *DeclareVarInModule(llvm::GlobalVariable *var,
     return llvm::dyn_cast<llvm::GlobalVariable>(moved_var);
   }
 
+  // NOTE(alex): This looks difficult to reproduce without querying `PointerElementType`.
+  // It appears to be transferring global variables from one LLVM module to another. The
+  // variables are pointer types.
   auto &dest_context = dest_module->getContext();
   const auto type = ::remill::RecontextualizeType(
       PointerElementType(var->getType()), dest_context);
@@ -2433,6 +2436,7 @@ llvm::Value *BuildPointerToOffset(llvm::IRBuilder<> &ir, llvm::Value *ptr,
     }
   }
 
+  // NOTE(alex): Same here
   const auto dest_elem_type = PointerElementType(dest_elem_ptr_type);
   const auto ptr_elem_type = PointerElementType(ptr_type);
   const auto ptr_elem_size = dl.getTypeAllocSize(ptr_elem_type);