[Lldb-commits] [lldb] [lldb] Add PlatformEmscripten (PR #223200)
via lldb-commits
lldb-commits at lists.llvm.org
Sat Sep 12 20:02:51 PDT 2026
llvmorg-github-actions[bot] wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-lldb
Author: Anutosh Bhat (anutosh491)
<details>
<summary>Changes</summary>
This follows #<!-- -->223169, where I introduced `HostInfoEmscripten`.
While getting libLLDB and its SB API working in the browser, I initially used `PlatformLinux` as the host platform under Emscripten. That was enough for the first experiment, but Emscripten is not really Linux and we shouldn't keep inheriting Linux-specific behavior going forward.
This patch introduces a separate `PlatformEmscripten`, based on `PlatformPOSIX`, and makes it the host platform when LLDB itself is running under Emscripten.
For now, it:
- reports the Emscripten host architecture;
- supports `wasm32` and `wasm64` Emscripten targets;
- moves Emscripten host initialization out of `PlatformLinux`;
- does not claim that live process debugging works yet.
`PlatformWasm` remains separate. My understanding is that `PlatformEmscripten` describes the environment in which LLDB itself is running, while `PlatformWasm` describes the WebAssembly program being debugged.
I am keeping this patch small on purpose. Browser-specific launching, attachment and live execution can be added separately once we connect LLDB to an actual in-browser execution backend.
I added a small test confirming that an Emscripten triple selects this platform, and also compiled the new plugin source successfully with Emscripten 6.0.8.
---
Full diff: https://github.com/llvm/llvm-project/pull/223200.diff
10 Files Affected:
- (modified) lldb/include/lldb/Host/HostInfo.h (+4-1)
- (added) lldb/include/lldb/Host/emscripten/HostInfoEmscripten.h (+29)
- (modified) lldb/source/Host/CMakeLists.txt (+4-2)
- (added) lldb/source/Host/emscripten/HostInfoEmscripten.cpp (+17)
- (modified) lldb/source/Plugins/Platform/CMakeLists.txt (+1)
- (added) lldb/source/Plugins/Platform/Emscripten/CMakeLists.txt (+9)
- (added) lldb/source/Plugins/Platform/Emscripten/PlatformEmscripten.cpp (+82)
- (added) lldb/source/Plugins/Platform/Emscripten/PlatformEmscripten.h (+50)
- (modified) lldb/unittests/Platform/CMakeLists.txt (+2)
- (added) lldb/unittests/Platform/PlatformEmscriptenTest.cpp (+18)
``````````diff
diff --git a/lldb/include/lldb/Host/HostInfo.h b/lldb/include/lldb/Host/HostInfo.h
index 0f7ec0e0aa0d2..46973edaf8c75 100644
--- a/lldb/include/lldb/Host/HostInfo.h
+++ b/lldb/include/lldb/Host/HostInfo.h
@@ -35,7 +35,10 @@
#if defined(_WIN32)
#include "lldb/Host/windows/HostInfoWindows.h"
#define HOST_INFO_TYPE HostInfoWindows
-#elif defined(__linux__) || defined(__EMSCRIPTEN__)
+#elif defined(__EMSCRIPTEN__)
+#include "lldb/Host/emscripten/HostInfoEmscripten.h"
+#define HOST_INFO_TYPE HostInfoEmscripten
+#elif defined(__linux__)
#if defined(__ANDROID__)
#include "lldb/Host/android/HostInfoAndroid.h"
#define HOST_INFO_TYPE HostInfoAndroid
diff --git a/lldb/include/lldb/Host/emscripten/HostInfoEmscripten.h b/lldb/include/lldb/Host/emscripten/HostInfoEmscripten.h
new file mode 100644
index 0000000000000..8c1cdcf58765b
--- /dev/null
+++ b/lldb/include/lldb/Host/emscripten/HostInfoEmscripten.h
@@ -0,0 +1,29 @@
+//===-- HostInfoEmscripten.h -----------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLDB_HOST_EMSCRIPTEN_HOSTINFOEMSCRIPTEN_H
+#define LLDB_HOST_EMSCRIPTEN_HOSTINFOEMSCRIPTEN_H
+
+#include "lldb/Host/posix/HostInfoPosix.h"
+#include "lldb/Utility/FileSpec.h"
+
+namespace lldb_private {
+
+class HostInfoEmscripten : public HostInfoPosix {
+ friend class HostInfoBase;
+
+public:
+ static void Initialize();
+ static void Terminate();
+
+ static FileSpec GetProgramFileSpec();
+};
+
+} // namespace lldb_private
+
+#endif // LLDB_HOST_EMSCRIPTEN_HOSTINFOEMSCRIPTEN_H
diff --git a/lldb/source/Host/CMakeLists.txt b/lldb/source/Host/CMakeLists.txt
index ebcad8f63e4f3..ef99c79deab82 100644
--- a/lldb/source/Host/CMakeLists.txt
+++ b/lldb/source/Host/CMakeLists.txt
@@ -135,8 +135,10 @@ else()
set_property(SOURCE macosx/Host.mm APPEND PROPERTY
COMPILE_DEFINITIONS "NO_XPC_SERVICES=1")
endif()
-
-
+ elseif (CMAKE_SYSTEM_NAME MATCHES "Emscripten")
+ add_host_subdirectory(emscripten
+ emscripten/HostInfoEmscripten.cpp
+ )
elseif (CMAKE_SYSTEM_NAME MATCHES "Linux|Android")
add_host_subdirectory(linux
linux/AbstractSocket.cpp
diff --git a/lldb/source/Host/emscripten/HostInfoEmscripten.cpp b/lldb/source/Host/emscripten/HostInfoEmscripten.cpp
new file mode 100644
index 0000000000000..10f0e2fc1dc4a
--- /dev/null
+++ b/lldb/source/Host/emscripten/HostInfoEmscripten.cpp
@@ -0,0 +1,17 @@
+//===-- HostInfoEmscripten.cpp -------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "lldb/Host/emscripten/HostInfoEmscripten.h"
+
+using namespace lldb_private;
+
+void HostInfoEmscripten::Initialize() { HostInfoPosix::Initialize(); }
+
+void HostInfoEmscripten::Terminate() { HostInfoBase::Terminate(); }
+
+FileSpec HostInfoEmscripten::GetProgramFileSpec() { return {}; }
diff --git a/lldb/source/Plugins/Platform/CMakeLists.txt b/lldb/source/Plugins/Platform/CMakeLists.txt
index cc1432aa4754b..8ad1c4ef31218 100644
--- a/lldb/source/Plugins/Platform/CMakeLists.txt
+++ b/lldb/source/Plugins/Platform/CMakeLists.txt
@@ -7,6 +7,7 @@ set_property(DIRECTORY PROPERTY LLDB_TOLERATED_PLUGIN_DEPENDENCIES
add_subdirectory(AIX)
add_subdirectory(Android)
+add_subdirectory(Emscripten)
add_subdirectory(FreeBSD)
add_subdirectory(gdb-server)
add_subdirectory(Linux)
diff --git a/lldb/source/Plugins/Platform/Emscripten/CMakeLists.txt b/lldb/source/Plugins/Platform/Emscripten/CMakeLists.txt
new file mode 100644
index 0000000000000..3022c7692441a
--- /dev/null
+++ b/lldb/source/Plugins/Platform/Emscripten/CMakeLists.txt
@@ -0,0 +1,9 @@
+add_lldb_library(lldbPluginPlatformEmscripten PLUGIN
+ PlatformEmscripten.cpp
+
+ LINK_LIBS
+ lldbCore
+ lldbHost
+ lldbPluginPlatformPOSIX
+ lldbTarget
+ )
diff --git a/lldb/source/Plugins/Platform/Emscripten/PlatformEmscripten.cpp b/lldb/source/Plugins/Platform/Emscripten/PlatformEmscripten.cpp
new file mode 100644
index 0000000000000..01659e5556df4
--- /dev/null
+++ b/lldb/source/Plugins/Platform/Emscripten/PlatformEmscripten.cpp
@@ -0,0 +1,82 @@
+//===-- PlatformEmscripten.cpp -------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "PlatformEmscripten.h"
+
+#include "lldb/Core/PluginManager.h"
+#include "lldb/Host/HostInfo.h"
+#include "lldb/Utility/LLDBLog.h"
+#include "lldb/Utility/Log.h"
+
+using namespace lldb;
+using namespace lldb_private;
+using namespace lldb_private::platform_emscripten;
+
+LLDB_PLUGIN_DEFINE(PlatformEmscripten)
+
+static uint32_t g_initialize_count = 0;
+
+PlatformSP PlatformEmscripten::CreateInstance(bool force,
+ const ArchSpec *arch) {
+ Log *log = GetLog(LLDBLog::Platform);
+ LLDB_LOG(log, "force = {0}, arch=({1}, {2})", force,
+ arch ? arch->GetArchitectureName() : "<null>",
+ arch ? arch->GetTriple().getTriple() : "<null>");
+
+ bool create =
+ force || (arch && arch->IsValid() && arch->GetTriple().isOSEmscripten());
+ LLDB_LOG(log, "create = {0}", create);
+ return create ? PlatformSP(new PlatformEmscripten(false)) : PlatformSP();
+}
+
+llvm::StringRef PlatformEmscripten::GetPluginDescriptionStatic(bool is_host) {
+ if (is_host)
+ return "Local Emscripten user platform plug-in.";
+ return "Remote Emscripten user platform plug-in.";
+}
+
+void PlatformEmscripten::Initialize() {
+ PlatformPOSIX::Initialize();
+
+ if (g_initialize_count++ == 0) {
+#if defined(__EMSCRIPTEN__)
+ PlatformSP platform_sp(new PlatformEmscripten(true));
+ platform_sp->SetSystemArchitecture(HostInfo::GetArchitecture());
+ Platform::SetHostPlatform(platform_sp);
+#endif
+ PluginManager::RegisterPlugin(GetPluginNameStatic(false),
+ GetPluginDescriptionStatic(false),
+ PlatformEmscripten::CreateInstance, nullptr);
+ }
+}
+
+void PlatformEmscripten::Terminate() {
+ if (g_initialize_count > 0 && --g_initialize_count == 0)
+ PluginManager::UnregisterPlugin(PlatformEmscripten::CreateInstance);
+
+ PlatformPOSIX::Terminate();
+}
+
+PlatformEmscripten::PlatformEmscripten(bool is_host) : PlatformPOSIX(is_host) {
+ if (is_host)
+ m_supported_architectures.push_back(HostInfo::GetArchitecture());
+ else
+ m_supported_architectures = CreateArchList(
+ {llvm::Triple::wasm32, llvm::Triple::wasm64}, llvm::Triple::Emscripten);
+}
+
+std::vector<ArchSpec> PlatformEmscripten::GetSupportedArchitectures(
+ const ArchSpec &process_host_arch) {
+ if (m_remote_platform_sp)
+ return m_remote_platform_sp->GetSupportedArchitectures(process_host_arch);
+ return m_supported_architectures;
+}
+
+bool PlatformEmscripten::CanDebugProcess() {
+ return !IsHost() && IsConnected();
+}
diff --git a/lldb/source/Plugins/Platform/Emscripten/PlatformEmscripten.h b/lldb/source/Plugins/Platform/Emscripten/PlatformEmscripten.h
new file mode 100644
index 0000000000000..2b71001c2daf9
--- /dev/null
+++ b/lldb/source/Plugins/Platform/Emscripten/PlatformEmscripten.h
@@ -0,0 +1,50 @@
+//===-- PlatformEmscripten.h -----------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLDB_SOURCE_PLUGINS_PLATFORM_EMSCRIPTEN_PLATFORMEMSCRIPTEN_H
+#define LLDB_SOURCE_PLUGINS_PLATFORM_EMSCRIPTEN_PLATFORMEMSCRIPTEN_H
+
+#include "Plugins/Platform/POSIX/PlatformPOSIX.h"
+
+namespace lldb_private::platform_emscripten {
+
+class PlatformEmscripten : public PlatformPOSIX {
+public:
+ explicit PlatformEmscripten(bool is_host);
+
+ static void Initialize();
+ static void Terminate();
+
+ static lldb::PlatformSP CreateInstance(bool force, const ArchSpec *arch);
+
+ static llvm::StringRef GetPluginNameStatic(bool is_host) {
+ return is_host ? Platform::GetHostPlatformName() : "remote-emscripten";
+ }
+
+ static llvm::StringRef GetPluginDescriptionStatic(bool is_host);
+
+ llvm::StringRef GetPluginName() override {
+ return GetPluginNameStatic(IsHost());
+ }
+
+ llvm::StringRef GetDescription() override {
+ return GetPluginDescriptionStatic(IsHost());
+ }
+
+ std::vector<ArchSpec>
+ GetSupportedArchitectures(const ArchSpec &process_host_arch) override;
+
+ bool CanDebugProcess() override;
+
+private:
+ std::vector<ArchSpec> m_supported_architectures;
+};
+
+} // namespace lldb_private::platform_emscripten
+
+#endif // LLDB_SOURCE_PLUGINS_PLATFORM_EMSCRIPTEN_PLATFORMEMSCRIPTEN_H
diff --git a/lldb/unittests/Platform/CMakeLists.txt b/lldb/unittests/Platform/CMakeLists.txt
index 693faa07e53f8..f08d48ddfc203 100644
--- a/lldb/unittests/Platform/CMakeLists.txt
+++ b/lldb/unittests/Platform/CMakeLists.txt
@@ -2,6 +2,7 @@ add_lldb_unittest(LLDBPlatformTests
TestUtils.cpp
PlatformAppleSimulatorTest.cpp
PlatformDarwinTest.cpp
+ PlatformEmscriptenTest.cpp
PlatformMacOSXTest.cpp
PlatformSiginfoTest.cpp
PlatformTest.cpp
@@ -10,6 +11,7 @@ add_lldb_unittest(LLDBPlatformTests
LINK_COMPONENTS
Support
LINK_LIBS
+ lldbPluginPlatformEmscripten
lldbPluginPlatformFreeBSD
lldbPluginPlatformLinux
lldbPluginPlatformMacOSX
diff --git a/lldb/unittests/Platform/PlatformEmscriptenTest.cpp b/lldb/unittests/Platform/PlatformEmscriptenTest.cpp
new file mode 100644
index 0000000000000..e9c75ea9d4a97
--- /dev/null
+++ b/lldb/unittests/Platform/PlatformEmscriptenTest.cpp
@@ -0,0 +1,18 @@
+//===-- PlatformEmscriptenTest.cpp ---------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "Plugins/Platform/Emscripten/PlatformEmscripten.h"
+#include "gtest/gtest.h"
+
+using namespace lldb_private;
+using namespace lldb_private::platform_emscripten;
+
+TEST(PlatformEmscriptenTest, RecognizesEmscriptenTriple) {
+ ArchSpec emscripten_arch("wasm32-unknown-emscripten");
+ EXPECT_TRUE(PlatformEmscripten::CreateInstance(false, &emscripten_arch));
+}
``````````
</details>
https://github.com/llvm/llvm-project/pull/223200
More information about the lldb-commits
mailing list