Review feedback - Evaluate_DW_OP_deref_size cleanup

Author: dmpots

lldb/source/Expression/DWARFExpression.cpp

@@ -884,25 +884,23 @@ static llvm::Error Evaluate_DW_OP_deref_size(DWARFExpression::Stack &stack,
                                              lldb::ModuleSP module_sp,
                                              Process *process, Target *target,
                                              uint8_t size) {
-  if (stack.empty()) {
+  if (stack.empty())
     return llvm::createStringError(
         "expression stack empty for DW_OP_deref_size");
-  }
 
-  if (size > 8) {
+  if (size > 8)
     return llvm::createStringError(
         "Invalid address size for DW_OP_deref_size: %d\n", size);
-  }
+
   Value::ValueType value_type = stack.back().GetValueType();
   switch (value_type) {
   case Value::ValueType::HostAddress: {
     void *src = (void *)stack.back().GetScalar().ULongLong();
     intptr_t ptr;
     ::memcpy(&ptr, src, sizeof(void *));
     // I can't decide whether the size operand should apply to the bytes in
-    // their
-    // lldb-host endianness or the target endianness.. I doubt this'll ever
-    // come up but I'll opt for assuming big endian regardless.
+    // their lldb-host endianness or the target endianness.. I doubt this'll
+    // ever come up but I'll opt for assuming big endian regardless.
     switch (size) {
     case 1:
       ptr = ptr & 0xff;
@@ -916,10 +914,9 @@ static llvm::Error Evaluate_DW_OP_deref_size(DWARFExpression::Stack &stack,
     case 4:
       ptr = ptr & 0xffffffff;
       break;
-    // the casts are added to work around the case where intptr_t is a 32
-    // bit quantity;
-    // presumably we won't hit the 5..7 cases if (void*) is 32-bits in this
-    // program.
+    // The casts are added to work around the case where intptr_t is a 32-bit
+    // quantity. Presumably we won't hit the 5..7 cases if (void*) is 32-bits in
+    // this program.
     case 5:
       ptr = (intptr_t)ptr & 0xffffffffffULL;
       break;
@@ -951,20 +948,19 @@ static llvm::Error Evaluate_DW_OP_deref_size(DWARFExpression::Stack &stack,
       uint8_t addr_bytes[8];
       Status error;
 
-      if (target && target->ReadMemory(so_addr, &addr_bytes, size, error,
-                                       /*force_live_memory=*/false) == size) {
-        ObjectFile *objfile = module_sp->GetObjectFile();
-
-        stack.back().GetScalar() = DerefSizeExtractDataHelper(
-            addr_bytes, size, objfile->GetByteOrder(), size);
-        stack.back().ClearContext();
-        break;
-      } else {
+      if (!target || target->ReadMemory(so_addr, &addr_bytes, size, error,
+                                        /*force_live_memory=*/false) != size)
         return llvm::createStringError(
-            "Failed to dereference pointer for DW_OP_deref_size: "
+            "failed to dereference pointer for DW_OP_deref_size: "
             "%s\n",
             error.AsCString());
-      }
+
+      ObjectFile *objfile = module_sp->GetObjectFile();
+
+      stack.back().GetScalar() = DerefSizeExtractDataHelper(
+          addr_bytes, size, objfile->GetByteOrder(), size);
+      stack.back().ClearContext();
+      break;
     }
     stack.back().GetScalar() = load_addr;
     // Fall through to load address promotion code below.
@@ -975,37 +971,30 @@ static llvm::Error Evaluate_DW_OP_deref_size(DWARFExpression::Stack &stack,
     // Promote Scalar to LoadAddress and fall through.
     stack.back().SetValueType(Value::ValueType::LoadAddress);
     [[fallthrough]];
-  case Value::ValueType::LoadAddress:
-    if (exe_ctx) {
-      if (process) {
-        lldb::addr_t pointer_addr =
-            stack.back().GetScalar().ULongLong(LLDB_INVALID_ADDRESS);
-        uint8_t addr_bytes[sizeof(lldb::addr_t)];
-        Status error;
-        if (process->ReadMemory(pointer_addr, &addr_bytes, size, error) ==
-            size) {
-
-          stack.back().GetScalar() = DerefSizeExtractDataHelper(
-              addr_bytes, sizeof(addr_bytes), process->GetByteOrder(), size);
-          stack.back().ClearContext();
-        } else {
-          return llvm::createStringError(
-              "Failed to dereference pointer from 0x%" PRIx64
-              " for DW_OP_deref: %s\n",
-              pointer_addr, error.AsCString());
-        }
-      } else {
+  case Value::ValueType::LoadAddress: {
+    if (!exe_ctx)
+      return llvm::createStringError(
+          "no execution context for DW_OP_deref_size");
+    if (!process)
+      return llvm::createStringError("no process for DW_OP_deref_size");
 
-        return llvm::createStringError("NULL process for DW_OP_deref_size");
-      }
-    } else {
+    lldb::addr_t pointer_addr =
+        stack.back().GetScalar().ULongLong(LLDB_INVALID_ADDRESS);
+    uint8_t addr_bytes[sizeof(lldb::addr_t)];
+    Status error;
+
+    if (process->ReadMemory(pointer_addr, &addr_bytes, size, error) != size)
       return llvm::createStringError(
-          "NULL execution context for DW_OP_deref_size");
-    }
-    break;
+          "failed to dereference pointer from 0x%" PRIx64
+          " for DW_OP_deref_size: %s\n",
+          pointer_addr, error.AsCString());
 
-  case Value::ValueType::Invalid:
+    stack.back().GetScalar() = DerefSizeExtractDataHelper(
+        addr_bytes, sizeof(addr_bytes), process->GetByteOrder(), size);
+    stack.back().ClearContext();
+  } break;
 
+  case Value::ValueType::Invalid:
     return llvm::createStringError("invalid value for DW_OP_deref_size");
   }