[lldb] Add minidump save-core functionality to ELF object files

This change adds save-core functionality into the ObjectFileELF that enables
saving minidump of a stopped process. This change is mainly targeting Linux
running on x86_64 machines. Minidump should contain basic information needed
to examine state of threads, local variables and stack traces. Full support
for other platforms is not so far implemented. API tests are using LLDB's
MinidumpParser.

This relands commit aafa05e, reverted in 1f986f6.
Failed tests were fixed.

Reviewed By: clayborg

Differential Revision: https://reviews.llvm.org/D108233

Author: Aj0SK

lldb/include/lldb/Core/PluginManager.h

@@ -192,7 +192,8 @@ class PluginManager {
 
   static Status SaveCore(const lldb::ProcessSP &process_sp,
                          const FileSpec &outfile,
-                         lldb::SaveCoreStyle &core_style);
+                         lldb::SaveCoreStyle &core_style,
+                         const ConstString plugin_name);
 
   // ObjectContainer
   static bool

lldb/source/API/SBProcess.cpp

@@ -1228,7 +1228,8 @@ lldb::SBError SBProcess::SaveCore(const char *file_name) {
 
   FileSpec core_file(file_name);
   SaveCoreStyle core_style = SaveCoreStyle::eSaveCoreFull;
-  error.ref() = PluginManager::SaveCore(process_sp, core_file, core_style);
+  error.ref() =
+      PluginManager::SaveCore(process_sp, core_file, core_style, ConstString());
   return LLDB_RECORD_RESULT(error);
 }
 

lldb/source/Commands/CommandObjectProcess.cpp

@@ -1180,12 +1180,13 @@ static constexpr OptionEnumValues SaveCoreStyles() {
 class CommandObjectProcessSaveCore : public CommandObjectParsed {
 public:
   CommandObjectProcessSaveCore(CommandInterpreter &interpreter)
-      : CommandObjectParsed(interpreter, "process save-core",
-                            "Save the current process as a core file using an "
-                            "appropriate file type.",
-                            "process save-core [-s corefile-style] FILE",
-                            eCommandRequiresProcess | eCommandTryTargetAPILock |
-                                eCommandProcessMustBeLaunched) {}
+      : CommandObjectParsed(
+            interpreter, "process save-core",
+            "Save the current process as a core file using an "
+            "appropriate file type.",
+            "process save-core [-s corefile-style -p plugin-name] FILE",
+            eCommandRequiresProcess | eCommandTryTargetAPILock |
+                eCommandProcessMustBeLaunched) {}
 
   ~CommandObjectProcessSaveCore() override = default;
 
@@ -1208,6 +1209,9 @@ class CommandObjectProcessSaveCore : public CommandObjectParsed {
       Status error;
 
       switch (short_option) {
+      case 'p':
+        m_requested_plugin_name.SetString(option_arg);
+        break;
       case 's':
         m_requested_save_core_style =
             (lldb::SaveCoreStyle)OptionArgParser::ToOptionEnum(
@@ -1223,10 +1227,12 @@ class CommandObjectProcessSaveCore : public CommandObjectParsed {
 
     void OptionParsingStarting(ExecutionContext *execution_context) override {
       m_requested_save_core_style = eSaveCoreUnspecified;
+      m_requested_plugin_name.Clear();
     }
 
     // Instance variables to hold the values for command options.
     SaveCoreStyle m_requested_save_core_style;
+    ConstString m_requested_plugin_name;
   };
 
 protected:
@@ -1237,7 +1243,8 @@ class CommandObjectProcessSaveCore : public CommandObjectParsed {
         FileSpec output_file(command.GetArgumentAtIndex(0));
         SaveCoreStyle corefile_style = m_options.m_requested_save_core_style;
         Status error =
-            PluginManager::SaveCore(process_sp, output_file, corefile_style);
+            PluginManager::SaveCore(process_sp, output_file, corefile_style,
+                                    m_options.m_requested_plugin_name);
         if (error.Success()) {
           if (corefile_style == SaveCoreStyle::eSaveCoreDirtyOnly ||
               corefile_style == SaveCoreStyle::eSaveCoreStackOnly) {

lldb/source/Commands/Options.td

@@ -749,6 +749,9 @@ let Command = "process save_core" in {
   def process_save_core_style : Option<"style", "s">, Group<1>,
     EnumArg<"SaveCoreStyle", "SaveCoreStyles()">, Desc<"Request a specific style "
     "of corefile to be saved.">;
+  def process_save_core_plugin_name : Option<"plugin-name", "p">,
+    OptionalArg<"Plugin">, Desc<"Specify a plugin name to create the core file."
+    "This allows core files to be saved in different formats.">;
 }
 
 let Command = "process trace save" in {

lldb/source/Core/PluginManager.cpp

@@ -685,10 +685,13 @@ PluginManager::GetObjectFileCreateMemoryCallbackForPluginName(
 
 Status PluginManager::SaveCore(const lldb::ProcessSP &process_sp,
                                const FileSpec &outfile,
-                               lldb::SaveCoreStyle &core_style) {
+                               lldb::SaveCoreStyle &core_style,
+                               const ConstString plugin_name) {
   Status error;
   auto &instances = GetObjectFileInstances().GetInstances();
   for (auto &instance : instances) {
+    if (plugin_name && instance.name != plugin_name)
+      continue;
     if (instance.save_core &&
         instance.save_core(process_sp, outfile, core_style, error))
       return error;

lldb/source/Plugins/ObjectFile/CMakeLists.txt

@@ -1,6 +1,7 @@
 add_subdirectory(Breakpad)
 add_subdirectory(ELF)
 add_subdirectory(Mach-O)
+add_subdirectory(Minidump)
 add_subdirectory(PDB)
 add_subdirectory(PECOFF)
 add_subdirectory(JIT)

lldb/source/Plugins/ObjectFile/Minidump/CMakeLists.txt

@@ -0,0 +1,14 @@
+add_lldb_library(lldbPluginObjectFileMinidump PLUGIN
+  ObjectFileMinidump.cpp
+  MinidumpFileBuilder.cpp
+
+  LINK_LIBS
+    lldbCore
+    lldbHost
+    lldbSymbol
+    lldbTarget
+    lldbUtility
+    lldbPluginProcessUtility
+  LINK_COMPONENTS
+    Support
+  )