[Lldb-commits] [lldb] 51aa6a4 - [lldb-dap] Use protocol types for ReadMemory request (#144552)
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Wed Jun 18 14:48:27 PDT 2025
Author: Ebuka Ezike
Date: 2025-06-18T22:48:24+01:00
New Revision: 51aa6a4993ea18c968a087352d1cf569c840c41f
URL: https://github.com/llvm/llvm-project/commit/51aa6a4993ea18c968a087352d1cf569c840c41f
DIFF: https://github.com/llvm/llvm-project/commit/51aa6a4993ea18c968a087352d1cf569c840c41f.diff
LOG: [lldb-dap] Use protocol types for ReadMemory request (#144552)
Read memory from process instead of target.
Added:
Modified:
lldb/test/API/tools/lldb-dap/memory/TestDAP_memory.py
lldb/tools/lldb-dap/Handler/ReadMemoryRequestHandler.cpp
lldb/tools/lldb-dap/Handler/RequestHandler.h
lldb/tools/lldb-dap/Protocol/ProtocolRequests.cpp
lldb/tools/lldb-dap/Protocol/ProtocolRequests.h
lldb/unittests/DAP/ProtocolTypesTest.cpp
Removed:
################################################################################
diff --git a/lldb/test/API/tools/lldb-dap/memory/TestDAP_memory.py b/lldb/test/API/tools/lldb-dap/memory/TestDAP_memory.py
index 74062f3ab2164..55fb4a961e783 100644
--- a/lldb/test/API/tools/lldb-dap/memory/TestDAP_memory.py
+++ b/lldb/test/API/tools/lldb-dap/memory/TestDAP_memory.py
@@ -111,8 +111,17 @@ def test_readMemory(self):
# VS Code sends those in order to check if a `memoryReference` can actually be dereferenced.
mem = self.dap_server.request_readMemory(memref, 0, 0)
self.assertEqual(mem["success"], True)
- self.assertEqual(mem["body"]["data"], "")
+ self.assertNotIn(
+ "data", mem["body"], f"expects no data key in response: {mem!r}"
+ )
+
+ # Reads at offset 0x0 return unreadable bytes
+ bytes_to_read = 6
+ mem = self.dap_server.request_readMemory("0x0", 0, bytes_to_read)
+ self.assertEqual(mem["body"]["unreadableBytes"], bytes_to_read)
+
+ # Reads with invalid address fails.
+ mem = self.dap_server.request_readMemory("-3204", 0, 10)
+ self.assertFalse(mem["success"], "expect fail on reading memory.")
- # Reads at offset 0x0 fail
- mem = self.dap_server.request_readMemory("0x0", 0, 6)
- self.assertEqual(mem["success"], False)
+ self.continue_to_exit()
diff --git a/lldb/tools/lldb-dap/Handler/ReadMemoryRequestHandler.cpp b/lldb/tools/lldb-dap/Handler/ReadMemoryRequestHandler.cpp
index 891c2af4f2f28..7065b6a24b554 100644
--- a/lldb/tools/lldb-dap/Handler/ReadMemoryRequestHandler.cpp
+++ b/lldb/tools/lldb-dap/Handler/ReadMemoryRequestHandler.cpp
@@ -7,136 +7,47 @@
//===----------------------------------------------------------------------===//
#include "DAP.h"
-#include "EventHelper.h"
#include "JSONUtils.h"
#include "RequestHandler.h"
#include "llvm/ADT/StringExtras.h"
-#include "llvm/Support/Base64.h"
namespace lldb_dap {
-// "ReadMemoryRequest": {
-// "allOf": [ { "$ref": "#/definitions/Request" }, {
-// "type": "object",
-// "description": "Reads bytes from memory at the provided location. Clients
-// should only call this request if the corresponding
-// capability `supportsReadMemoryRequest` is true.",
-// "properties": {
-// "command": {
-// "type": "string",
-// "enum": [ "readMemory" ]
-// },
-// "arguments": {
-// "$ref": "#/definitions/ReadMemoryArguments"
-// }
-// },
-// "required": [ "command", "arguments" ]
-// }]
-// },
-// "ReadMemoryArguments": {
-// "type": "object",
-// "description": "Arguments for `readMemory` request.",
-// "properties": {
-// "memoryReference": {
-// "type": "string",
-// "description": "Memory reference to the base location from which data
-// should be read."
-// },
-// "offset": {
-// "type": "integer",
-// "description": "Offset (in bytes) to be applied to the reference
-// location before reading data. Can be negative."
-// },
-// "count": {
-// "type": "integer",
-// "description": "Number of bytes to read at the specified location and
-// offset."
-// }
-// },
-// "required": [ "memoryReference", "count" ]
-// },
-// "ReadMemoryResponse": {
-// "allOf": [ { "$ref": "#/definitions/Response" }, {
-// "type": "object",
-// "description": "Response to `readMemory` request.",
-// "properties": {
-// "body": {
-// "type": "object",
-// "properties": {
-// "address": {
-// "type": "string",
-// "description": "The address of the first byte of data returned.
-// Treated as a hex value if prefixed with `0x`, or
-// as a decimal value otherwise."
-// },
-// "unreadableBytes": {
-// "type": "integer",
-// "description": "The number of unreadable bytes encountered after
-// the last successfully read byte.\nThis can be
-// used to determine the number of bytes that should
-// be skipped before a subsequent
-// `readMemory` request succeeds."
-// },
-// "data": {
-// "type": "string",
-// "description": "The bytes read from memory, encoded using base64.
-// If the decoded length of `data` is less than the
-// requested `count` in the original `readMemory`
-// request, and `unreadableBytes` is zero or
-// omitted, then the client should assume it's
-// reached the end of readable memory."
-// }
-// },
-// "required": [ "address" ]
-// }
-// }
-// }]
-// },
-void ReadMemoryRequestHandler::operator()(
- const llvm::json::Object &request) const {
- llvm::json::Object response;
- FillResponse(request, response);
- auto *arguments = request.getObject("arguments");
+// Reads bytes from memory at the provided location.
+//
+// Clients should only call this request if the corresponding capability
+// `supportsReadMemoryRequest` is true
+llvm::Expected<protocol::ReadMemoryResponseBody>
+ReadMemoryRequestHandler::Run(const protocol::ReadMemoryArguments &args) const {
+ const lldb::addr_t raw_address = args.memoryReference + args.offset;
- llvm::StringRef memoryReference =
- GetString(arguments, "memoryReference").value_or("");
- auto addr_opt = DecodeMemoryReference(memoryReference);
- if (!addr_opt.has_value()) {
- response["success"] = false;
- response["message"] =
- "Malformed memory reference: " + memoryReference.str();
- dap.SendJSON(llvm::json::Value(std::move(response)));
- return;
- }
- lldb::addr_t addr_int = *addr_opt;
- addr_int += GetInteger<uint64_t>(arguments, "offset").value_or(0);
- const uint64_t count_requested =
- GetInteger<uint64_t>(arguments, "count").value_or(0);
+ lldb::SBProcess process = dap.target.GetProcess();
+ if (!lldb::SBDebugger::StateIsStoppedState(process.GetState()))
+ return llvm::make_error<NotStoppedError>();
+ const uint64_t count_read = std::max<uint64_t>(args.count, 1);
// We also need support reading 0 bytes
// VS Code sends those requests to check if a `memoryReference`
// can be dereferenced.
- const uint64_t count_read = std::max<uint64_t>(count_requested, 1);
- std::vector<uint8_t> buf;
- buf.resize(count_read);
+ protocol::ReadMemoryResponseBody response;
+ std::vector<std::byte> &buffer = response.data;
+ buffer.resize(count_read);
+
lldb::SBError error;
- lldb::SBAddress addr{addr_int, dap.target};
- size_t count_result =
- dap.target.ReadMemory(addr, buf.data(), count_read, error);
- if (count_result == 0) {
- response["success"] = false;
- EmplaceSafeString(response, "message", error.GetCString());
- dap.SendJSON(llvm::json::Value(std::move(response)));
- return;
+ const size_t memory_count = dap.target.GetProcess().ReadMemory(
+ raw_address, buffer.data(), buffer.size(), error);
+
+ response.address = "0x" + llvm::utohexstr(raw_address);
+
+ // reading memory may fail for multiple reasons. memory not readable,
+ // reading out of memory range and gaps in memory. return from
+ // the last readable byte.
+ if (error.Fail() && (memory_count < count_read)) {
+ response.unreadableBytes = count_read - memory_count;
}
- buf.resize(std::min<size_t>(count_result, count_requested));
- llvm::json::Object body;
- std::string formatted_addr = "0x" + llvm::utohexstr(addr_int);
- body.try_emplace("address", formatted_addr);
- body.try_emplace("data", llvm::encodeBase64(buf));
- response.try_emplace("body", std::move(body));
- dap.SendJSON(llvm::json::Value(std::move(response)));
+ buffer.resize(std::min<size_t>(memory_count, args.count));
+ return response;
}
} // namespace lldb_dap
diff --git a/lldb/tools/lldb-dap/Handler/RequestHandler.h b/lldb/tools/lldb-dap/Handler/RequestHandler.h
index 054cc7a321316..e35b9830ab60f 100644
--- a/lldb/tools/lldb-dap/Handler/RequestHandler.h
+++ b/lldb/tools/lldb-dap/Handler/RequestHandler.h
@@ -564,14 +564,17 @@ class DisassembleRequestHandler final
Run(const protocol::DisassembleArguments &args) const override;
};
-class ReadMemoryRequestHandler : public LegacyRequestHandler {
+class ReadMemoryRequestHandler final
+ : public RequestHandler<protocol::ReadMemoryArguments,
+ llvm::Expected<protocol::ReadMemoryResponseBody>> {
public:
- using LegacyRequestHandler::LegacyRequestHandler;
+ using RequestHandler::RequestHandler;
static llvm::StringLiteral GetCommand() { return "readMemory"; }
FeatureSet GetSupportedFeatures() const override {
return {protocol::eAdapterFeatureReadMemoryRequest};
}
- void operator()(const llvm::json::Object &request) const override;
+ llvm::Expected<protocol::ReadMemoryResponseBody>
+ Run(const protocol::ReadMemoryArguments &args) const override;
};
class CancelRequestHandler : public RequestHandler<protocol::CancelArguments,
diff --git a/lldb/tools/lldb-dap/Protocol/ProtocolRequests.cpp b/lldb/tools/lldb-dap/Protocol/ProtocolRequests.cpp
index e6ba54ed4dcd6..9bd84a6c898f9 100644
--- a/lldb/tools/lldb-dap/Protocol/ProtocolRequests.cpp
+++ b/lldb/tools/lldb-dap/Protocol/ProtocolRequests.cpp
@@ -7,9 +7,11 @@
//===----------------------------------------------------------------------===//
#include "Protocol/ProtocolRequests.h"
+#include "JSONUtils.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/StringRef.h"
+#include "llvm/Support/Base64.h"
#include "llvm/Support/JSON.h"
#include <utility>
@@ -480,4 +482,39 @@ json::Value toJSON(const DisassembleResponseBody &DRB) {
return json::Object{{"instructions", DRB.instructions}};
}
+bool fromJSON(const json::Value &Params, ReadMemoryArguments &RMA,
+ json::Path P) {
+ json::ObjectMapper O(Params, P);
+
+ const json::Object *rma_obj = Params.getAsObject();
+ constexpr llvm::StringRef ref_key = "memoryReference";
+ const std::optional<llvm::StringRef> memory_ref = rma_obj->getString(ref_key);
+ if (!memory_ref) {
+ P.field(ref_key).report("missing value");
+ return false;
+ }
+
+ const std::optional<lldb::addr_t> addr_opt =
+ DecodeMemoryReference(*memory_ref);
+ if (!addr_opt) {
+ P.field(ref_key).report("Malformed memory reference");
+ return false;
+ }
+
+ RMA.memoryReference = *addr_opt;
+
+ return O && O.map("count", RMA.count) && O.mapOptional("offset", RMA.offset);
+}
+
+json::Value toJSON(const ReadMemoryResponseBody &RMR) {
+ json::Object result{{"address", RMR.address}};
+
+ if (RMR.unreadableBytes != 0)
+ result.insert({"unreadableBytes", RMR.unreadableBytes});
+ if (!RMR.data.empty())
+ result.insert({"data", llvm::encodeBase64(RMR.data)});
+
+ return result;
+}
+
} // namespace lldb_dap::protocol
diff --git a/lldb/tools/lldb-dap/Protocol/ProtocolRequests.h b/lldb/tools/lldb-dap/Protocol/ProtocolRequests.h
index 01b8f2445c9fa..7d9a99fdacce6 100644
--- a/lldb/tools/lldb-dap/Protocol/ProtocolRequests.h
+++ b/lldb/tools/lldb-dap/Protocol/ProtocolRequests.h
@@ -839,6 +839,42 @@ bool fromJSON(const llvm::json::Value &, DisassembleResponseBody &,
llvm::json::Path);
llvm::json::Value toJSON(const DisassembleResponseBody &);
+/// Arguments for `readMemory` request.
+struct ReadMemoryArguments {
+ /// Memory reference to the base location from which data should be read.
+ lldb::addr_t memoryReference;
+
+ /// Offset (in bytes) to be applied to the reference location before reading
+ /// data. Can be negative.
+ int64_t offset = 0;
+
+ /// Number of bytes to read at the specified location and offset.
+ uint64_t count;
+};
+bool fromJSON(const llvm::json::Value &, ReadMemoryArguments &,
+ llvm::json::Path);
+
+/// Response to `readMemory` request.
+struct ReadMemoryResponseBody {
+ /// The address of the first byte of data returned.
+ /// Treated as a hex value if prefixed with `0x`, or as a decimal value
+ /// otherwise.
+ std::string address;
+
+ /// The number of unreadable bytes encountered after the last successfully
+ /// read byte.
+ /// This can be used to determine the number of bytes that should be skipped
+ /// before a subsequent `readMemory` request succeeds.
+ uint64_t unreadableBytes = 0;
+
+ /// The bytes read from memory, encoded using base64. If the decoded length
+ /// of `data` is less than the requested `count` in the original `readMemory`
+ /// request, and `unreadableBytes` is zero or omitted, then the client should
+ /// assume it's reached the end of readable memory.
+ std::vector<std::byte> data;
+};
+llvm::json::Value toJSON(const ReadMemoryResponseBody &);
+
} // namespace lldb_dap::protocol
#endif
diff --git a/lldb/unittests/DAP/ProtocolTypesTest.cpp b/lldb/unittests/DAP/ProtocolTypesTest.cpp
index 46a09f090fea2..9c93eb8c94b05 100644
--- a/lldb/unittests/DAP/ProtocolTypesTest.cpp
+++ b/lldb/unittests/DAP/ProtocolTypesTest.cpp
@@ -765,3 +765,36 @@ TEST(ProtocolTypesTest, StepInTarget) {
EXPECT_EQ(target.endLine, deserialized_target->endLine);
EXPECT_EQ(target.endColumn, deserialized_target->endColumn);
}
+
+TEST(ProtocolTypesTest, ReadMemoryArguments) {
+ ReadMemoryArguments args;
+ args.count = 20;
+ args.memoryReference = 43962;
+ args.offset = 0;
+
+ llvm::Expected<ReadMemoryArguments> expected =
+ parse<ReadMemoryArguments>(R"({"memoryReference":"-4000", "count": 20})");
+ ASSERT_THAT_EXPECTED(expected, llvm::Failed());
+ expected = parse<ReadMemoryArguments>(
+ R"({"memoryReference":"0xabba", "count": 20})");
+ ASSERT_THAT_EXPECTED(expected, llvm::Succeeded());
+
+ EXPECT_EQ(args.count, expected->count);
+ EXPECT_EQ(args.memoryReference, expected->memoryReference);
+ EXPECT_EQ(args.offset, expected->offset);
+}
+
+TEST(ProtocolTypesTest, ReadMemoryResponseBody) {
+ ReadMemoryResponseBody response;
+ response.address = "0xdeadbeef";
+ const std::string data_str = "hello world!";
+ std::transform(data_str.begin(), data_str.end(),
+ std::back_inserter(response.data),
+ [](char letter) { return std::byte(letter); });
+ response.unreadableBytes = 1;
+
+ Expected<Value> expected = json::parse(
+ R"({ "address": "0xdeadbeef", "data": "aGVsbG8gd29ybGQh", "unreadableBytes": 1})");
+ ASSERT_THAT_EXPECTED(expected, llvm::Succeeded());
+ EXPECT_EQ(pp(*expected), pp(response));
+}
\ No newline at end of file
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