Introduce EncodeMemoryReference & DecodeMemoryReference

Author: vogelsgesang

lldb/tools/lldb-dap/JSONUtils.cpp

@@ -112,6 +112,22 @@ bool ObjectContainsKey(const llvm::json::Object &obj, llvm::StringRef key) {
   return obj.find(key) != obj.end();
 }
 
+std::string EncodeMemoryReference(lldb::addr_t addr) {
+  return "0x" + llvm::utohexstr(addr);
+}
+
+std::optional<lldb::addr_t>
+DecodeMemoryReference(llvm::StringRef memoryReference) {
+  if (!memoryReference.starts_with("0x"))
+     return std::nullopt;
+
+  lldb::addr_t addr;
+  if (memoryReference.consumeInteger(0, addr))
+     return std::nullopt;
+
+  return addr;
+}
+
 std::vector<std::string> GetStrings(const llvm::json::Object *obj,
                                     llvm::StringRef key) {
   std::vector<std::string> strs;
@@ -1367,7 +1383,7 @@ llvm::json::Value CreateVariable(lldb::SBValue v, int64_t variablesReference,
     object.try_emplace("variablesReference", (int64_t)0);
 
   if (std::optional<lldb::addr_t> addr = GetMemoryReference(v))
-    object.try_emplace("memoryReference", "0x" + llvm::utohexstr(*addr));
+    object.try_emplace("memoryReference", EncodeMemoryReference(*addr));
 
   object.try_emplace("$__lldb_extensions", desc.GetVariableExtensionsJSON());
   return llvm::json::Value(std::move(object));

lldb/tools/lldb-dap/JSONUtils.h

@@ -131,6 +131,13 @@ int64_t GetSigned(const llvm::json::Object *obj, llvm::StringRef key,
 ///     \b True if the key exists in the \a obj, \b False otherwise.
 bool ObjectContainsKey(const llvm::json::Object &obj, llvm::StringRef key);
 
+/// Encodes a memory reference
+std::string EncodeMemoryReference(lldb::addr_t addr);
+
+/// Decodes a memory reference
+std::optional<lldb::addr_t>
+DecodeMemoryReference(llvm::StringRef memoryReference);
+
 /// Extract an array of strings for the specified key from an object.
 ///
 /// String values in the array will be extracted without any quotes

lldb/tools/lldb-dap/lldb-dap.cpp

@@ -1618,7 +1618,7 @@ void request_evaluate(const llvm::json::Object &request) {
         body.try_emplace("variablesReference", (int64_t)0);
       }
       if (std::optional<lldb::addr_t> addr = GetMemoryReference(value))
-        body.try_emplace("memoryReference", "0x" + llvm::utohexstr(*addr));
+        body.try_emplace("memoryReference", EncodeMemoryReference(*addr));
     }
   }
   response.try_emplace("body", std::move(body));
@@ -3793,7 +3793,7 @@ void request_setVariable(const llvm::json::Object &request) {
       body.try_emplace("variablesReference", newVariablesReference);
 
       if (std::optional<lldb::addr_t> addr = GetMemoryReference(variable))
-        body.try_emplace("memoryReference", "0x" + llvm::utohexstr(*addr));
+        body.try_emplace("memoryReference", EncodeMemoryReference(*addr));
     } else {
       EmplaceSafeString(body, "message", std::string(error.GetCString()));
     }
@@ -4090,17 +4090,18 @@ void request_variables(const llvm::json::Object &request) {
 void request_disassemble(const llvm::json::Object &request) {
   llvm::json::Object response;
   FillResponse(request, response);
-  auto arguments = request.getObject("arguments");
+  auto *arguments = request.getObject("arguments");
 
-  auto memoryReference = GetString(arguments, "memoryReference");
-  lldb::addr_t addr_ptr;
-  if (memoryReference.consumeInteger(0, addr_ptr)) {
+  llvm::StringRef memoryReference = GetString(arguments, "memoryReference");
+  auto addr_opt = DecodeMemoryReference(memoryReference);
+  if (!addr_opt.has_value()) {
     response["success"] = false;
     response["message"] =
         "Malformed memory reference: " + memoryReference.str();
     g_dap.SendJSON(llvm::json::Value(std::move(response)));
     return;
   }
+  lldb::addr_t addr_ptr = *addr_opt;
 
   addr_ptr += GetSigned(arguments, "instructionOffset", 0);
   lldb::SBAddress addr(addr_ptr, g_dap.target);
@@ -4299,7 +4300,7 @@ void request_disassemble(const llvm::json::Object &request) {
 void request_readMemory(const llvm::json::Object &request) {
   llvm::json::Object response;
   FillResponse(request, response);
-  auto arguments = request.getObject("arguments");
+  auto* arguments = request.getObject("arguments");
 
   lldb::SBProcess process = g_dap.target.GetProcess();
   if (!process.IsValid()) {
@@ -4309,15 +4310,16 @@ void request_readMemory(const llvm::json::Object &request) {
     return;
   }
 
-  auto memoryReference = GetString(arguments, "memoryReference");
-  lldb::addr_t addr;
-  if (memoryReference.consumeInteger(0, addr)) {
+  llvm::StringRef memoryReference = GetString(arguments, "memoryReference");
+  auto addr_opt = DecodeMemoryReference(memoryReference);
+  if (!addr_opt.has_value()) {
     response["success"] = false;
     response["message"] =
         "Malformed memory reference: " + memoryReference.str();
     g_dap.SendJSON(llvm::json::Value(std::move(response)));
     return;
   }
+  lldb::addr_t addr = *addr_opt;
 
   addr += GetSigned(arguments, "offset", 0);
   const uint64_t requested_count = GetUnsigned(arguments, "count", 0);