Support for OCaml native debugging

This introduces basic support for debugging OCaml binaries.
Use of the native compiler with DWARF emission support (see
https://github.com/ocaml/ocaml/pull/574) is required.

Available variables are considered as 64 bits unsigned integers,
their interpretation will be left to a OCaml-made debugging layer.

Differential revision: https://reviews.llvm.org/D22132

llvm-svn: 277443

3 files changed, 143 insertions, 0 deletions

diff --git a/lldb/source/Plugins/Language/OCaml/CMakeLists.txt b/lldb/source/Plugins/Language/OCaml/CMakeLists.txt
new file mode 100644
index 00000000000..e969618d5e0
--- /dev/null
+++ b/lldb/source/Plugins/Language/OCaml/CMakeLists.txt
@@ -0,0 +1,4 @@
+add_lldb_library(lldbPluginOCamlLanguage
+  OCamlLanguage.cpp
+)
+
diff --git a/lldb/source/Plugins/Language/OCaml/OCamlLanguage.cpp b/lldb/source/Plugins/Language/OCaml/OCamlLanguage.cpp
new file mode 100644
index 00000000000..abc6c8b53d7
--- /dev/null
+++ b/lldb/source/Plugins/Language/OCaml/OCamlLanguage.cpp
@@ -0,0 +1,78 @@
+//===-- OCamlLanguage.cpp ----------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// C Includes
+#include <string.h>
+// C++ Includes
+#include <functional>
+#include <mutex>
+
+// Other libraries and framework includes
+#include "llvm/ADT/StringRef.h"
+
+// Project includes
+#include "OCamlLanguage.h"
+#include "lldb/Core/ConstString.h"
+#include "lldb/Core/PluginManager.h"
+#include "lldb/DataFormatters/DataVisualization.h"
+#include "lldb/DataFormatters/FormattersHelpers.h"
+#include "lldb/Symbol/OCamlASTContext.h"
+
+using namespace lldb;
+using namespace lldb_private;
+
+void
+OCamlLanguage::Initialize()
+{
+    PluginManager::RegisterPlugin(GetPluginNameStatic(), "OCaml Language", CreateInstance);
+}
+
+void
+OCamlLanguage::Terminate()
+{
+    PluginManager::UnregisterPlugin(CreateInstance);
+}
+
+lldb_private::ConstString
+OCamlLanguage::GetPluginNameStatic()
+{
+    static ConstString g_name("OCaml");
+    return g_name;
+}
+
+lldb_private::ConstString
+OCamlLanguage::GetPluginName()
+{
+    return GetPluginNameStatic();
+}
+
+uint32_t
+OCamlLanguage::GetPluginVersion()
+{
+    return 1;
+}
+
+Language *
+OCamlLanguage::CreateInstance(lldb::LanguageType language)
+{
+    if (language == eLanguageTypeOCaml)
+        return new OCamlLanguage();
+    return nullptr;
+}
+
+bool
+OCamlLanguage::IsNilReference(ValueObject &valobj)
+{
+    if (!valobj.GetCompilerType().IsReferenceType())
+        return false;
+
+    // If we failed to read the value then it is not a nil reference.
+    return valobj.GetValueAsUnsigned(UINT64_MAX) == 0;
+}
+
diff --git a/lldb/source/Plugins/Language/OCaml/OCamlLanguage.h b/lldb/source/Plugins/Language/OCaml/OCamlLanguage.h
new file mode 100644
index 00000000000..33e3761e59a
--- /dev/null
+++ b/lldb/source/Plugins/Language/OCaml/OCamlLanguage.h
@@ -0,0 +1,61 @@
+//===-- OCamlLanguage.h ------------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef liblldb_OCamlLanguage_h_
+#define liblldb_OCamlLanguage_h_
+
+// C Includes
+// C++ Includes
+#include <vector>
+
+// Other libraries and framework includes
+#include "llvm/ADT/StringRef.h"
+
+// Project includes
+#include "lldb/Core/ConstString.h"
+#include "lldb/Target/Language.h"
+#include "lldb/lldb-private.h"
+
+namespace lldb_private
+{
+
+class OCamlLanguage : public Language
+{
+public:
+    lldb::LanguageType
+    GetLanguageType() const override
+    {
+        return lldb::eLanguageTypeOCaml;
+    }
+
+    static void
+    Initialize();
+
+    static void
+    Terminate();
+
+    static lldb_private::Language *
+    CreateInstance(lldb::LanguageType language);
+
+    static lldb_private::ConstString
+    GetPluginNameStatic();
+
+    ConstString
+    GetPluginName() override;
+
+    uint32_t
+    GetPluginVersion() override;
+
+    bool
+    IsNilReference(ValueObject &valobj) override;
+};
+
+} // namespace lldb_private
+
+#endif // liblldb_OCamlLanguage_h_