[lldb] [llvm] DEBUGINFOD based DWP acquisition for LLDB (PR #70996)

[Alex Langford via llvm-commits]

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@@ -0,0 +1,142 @@
+//===-- SymbolLocatorDebuginfod.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 "SymbolLocatorDebuginfod.h"
+
+#include "lldb/Core/PluginManager.h"
+#include "lldb/Utility/Args.h"
+
+#include "llvm/Debuginfod/Debuginfod.h"
+#include "llvm/Debuginfod/HTTPClient.h"
+
+using namespace lldb;
+using namespace lldb_private;
+
+LLDB_PLUGIN_DEFINE(SymbolLocatorDebuginfod)
+
+namespace {
+
+#define LLDB_PROPERTIES_symbollocatordebuginfod
+#include "SymbolLocatorDebuginfodProperties.inc"
+
+enum {
+#define LLDB_PROPERTIES_symbollocatordebuginfod
+#include "SymbolLocatorDebuginfodPropertiesEnum.inc"
+};
+
+class PluginProperties : public Properties {
+public:
+  static llvm::StringRef GetSettingName() {
+    return SymbolLocatorDebuginfod::GetPluginNameStatic();
+  }
+
+  PluginProperties() {
+    m_collection_sp = std::make_shared<OptionValueProperties>(GetSettingName());
+    m_collection_sp->Initialize(g_symbollocatordebuginfod_properties);
+
+    // We need to read the default value first to read the environment variable.
+    llvm::SmallVector<llvm::StringRef> urls = llvm::getDefaultDebuginfodUrls();
+    Args arg_urls{urls};
+    m_collection_sp->SetPropertyAtIndexFromArgs(ePropertyServerURLs, arg_urls);
+
+    m_collection_sp->SetValueChangedCallback(
+        ePropertyServerURLs, [this] { ServerURLsChangedCallback(); });
+  }
+
+  Args GetDebugInfoDURLs() const {
+    Args urls;
+    m_collection_sp->GetPropertyAtIndexAsArgs(ePropertyServerURLs, urls);
+    return urls;
+  }
+
+private:
+  void ServerURLsChangedCallback() {
+    Args urls = GetDebugInfoDURLs();
+    llvm::SmallVector<llvm::StringRef> dbginfod_urls;
+    llvm::transform(urls, dbginfod_urls.end(),
+                    [](const auto &obj) { return obj.ref(); });
+    llvm::setDefaultDebuginfodUrls(dbginfod_urls);
+  }
+};
+
+} // namespace
+
+static PluginProperties &GetGlobalPluginProperties() {
+  static PluginProperties g_settings;
+  return g_settings;
+}
+
+SymbolLocatorDebuginfod::SymbolLocatorDebuginfod() : SymbolLocator() {}
+
+void SymbolLocatorDebuginfod::Initialize() {
+  static llvm::once_flag g_once_flag;
+
+  llvm::call_once(g_once_flag, []() {
+    PluginManager::RegisterPlugin(
+        GetPluginNameStatic(), GetPluginDescriptionStatic(), CreateInstance,
+        LocateExecutableObjectFile, LocateExecutableSymbolFile, nullptr,
+        nullptr, SymbolLocatorDebuginfod::DebuggerInitialize);
+    llvm::HTTPClient::initialize();
+  });
+}
+
+void SymbolLocatorDebuginfod::DebuggerInitialize(Debugger &debugger) {
+  if (!PluginManager::GetSettingForSymbolLocatorPlugin(
+          debugger, PluginProperties::GetSettingName())) {
+    const bool is_global_setting = true;
+    PluginManager::CreateSettingForSymbolLocatorPlugin(
+        debugger, GetGlobalPluginProperties().GetValueProperties(),
+        "Properties for the Debuginfod Symbol Locator plug-in.",
+        is_global_setting);
+  }
+}
+
+void SymbolLocatorDebuginfod::Terminate() {
+  PluginManager::UnregisterPlugin(CreateInstance);
+  llvm::HTTPClient::cleanup();
+}
+
+llvm::StringRef SymbolLocatorDebuginfod::GetPluginDescriptionStatic() {
+  return "Debuginfod symbol locator.";
+}
+
+SymbolLocator *SymbolLocatorDebuginfod::CreateInstance() {
+  return new SymbolLocatorDebuginfod();
----------------
bulbazord wrote:

You're calling `llvm::canUseDebuginfod` in the methods to actually locate the debug info. Would it not make sense to call that when creating an instance? What would the value be in having a `SymbolLocatorDebuginfod` instance if `llvm::canUseDebuginfod` returns false?

https://github.com/llvm/llvm-project/pull/70996