From: Leonard Mosescu <mosescu@google.com>
Date: Thu, 23 Aug 2018 21:34:33 +0000 (+0000)
Subject: Restrict the set of plugins used for ProcessMinidump
X-Git-Tag: llvmorg-8.0.0-rc1~10258
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=40b832ea084b04afca7c4ca10973f54a44eef083;p=platform%2Fupstream%2Fllvm.git

Restrict the set of plugins used for ProcessMinidump

1. The dynamic loaders should not be needed for loading minidumps
and they may create problems (ex. the macOS loader resets the list of
loaded sections, which for minidumps are already set up during minidump loading)

2. In general, the extra plugins can do extraneous work which hurts performance
(ex. trying to set up implicit symbolic breakpoints, which in turn will trigger
extra debug information loading)

Differential Revision: https://reviews.llvm.org/D51176

llvm-svn: 340578
---

diff --git a/lldb/source/Plugins/Process/minidump/ProcessMinidump.cpp b/lldb/source/Plugins/Process/minidump/ProcessMinidump.cpp
index 95229b9..7f8c49c 100644
--- a/lldb/source/Plugins/Process/minidump/ProcessMinidump.cpp
+++ b/lldb/source/Plugins/Process/minidump/ProcessMinidump.cpp
@@ -16,7 +16,7 @@
 #include "lldb/Core/ModuleSpec.h"
 #include "lldb/Core/PluginManager.h"
 #include "lldb/Core/Section.h"
-#include "lldb/Target/DynamicLoader.h"
+#include "lldb/Target/JITLoaderList.h"
 #include "lldb/Target/MemoryRegionInfo.h"
 #include "lldb/Target/SectionLoadList.h"
 #include "lldb/Target/Target.h"
@@ -201,12 +201,6 @@ Status ProcessMinidump::DoLoadCore() {
   return error;
 }
 
-DynamicLoader *ProcessMinidump::GetDynamicLoader() {
-  if (m_dyld_ap.get() == nullptr)
-    m_dyld_ap.reset(DynamicLoader::FindPlugin(this, nullptr));
-  return m_dyld_ap.get();
-}
-
 ConstString ProcessMinidump::GetPluginName() { return GetPluginNameStatic(); }
 
 uint32_t ProcessMinidump::GetPluginVersion() { return 1; }
@@ -401,3 +395,14 @@ bool ProcessMinidump::GetProcessInfo(ProcessInstanceInfo &info) {
   }
   return true;
 }
+
+// For minidumps there's no runtime generated code so we don't need JITLoader(s)
+// Avoiding them will also speed up minidump loading since JITLoaders normally
+// try to set up symbolic breakpoints, which in turn may force loading more
+// debug information than needed.
+JITLoaderList &ProcessMinidump::GetJITLoaders() {
+  if (!m_jit_loaders_ap) {
+    m_jit_loaders_ap = llvm::make_unique<JITLoaderList>();
+  }
+  return *m_jit_loaders_ap;
+}
diff --git a/lldb/source/Plugins/Process/minidump/ProcessMinidump.h b/lldb/source/Plugins/Process/minidump/ProcessMinidump.h
index d65ada9..b9e8d0f 100644
--- a/lldb/source/Plugins/Process/minidump/ProcessMinidump.h
+++ b/lldb/source/Plugins/Process/minidump/ProcessMinidump.h
@@ -55,7 +55,7 @@ public:
 
   Status DoLoadCore() override;
 
-  DynamicLoader *GetDynamicLoader() override;
+  DynamicLoader *GetDynamicLoader() override { return nullptr; }
 
   ConstString GetPluginName() override;
 
@@ -102,6 +102,8 @@ protected:
 
   void ReadModuleList();
 
+  JITLoaderList &GetJITLoaders() override;
+
 private:
   FileSpec m_core_file;
   llvm::ArrayRef<MinidumpThread> m_thread_list;