Add llvm-style RTTI to ObjectFile hierarchy

Summary:
On the heels of D62934, this patch uses the same approach to introduce
llvm RTTI support to the ObjectFile hierarchy. It also replaces the
existing uses of GetPluginName doing run-time type checks with
llvm::dyn_cast and friends.

This formally introduces new dependencies from some other plugins to
ObjectFile plugins. However, I believe this is fine because:
- these dependencies were already kind of there, and the only reason
  we could get away with not modeling them explicitly was because the
  code was relying on magically knowing what will GetPluginName() return
  for a particular kind of object files.
- the dependencies themselves are logical (it makes sense for
  SymbolVendorELF to depend on ObjectFileELF), or at least don't
  actively get in the way (the JitLoaderGDB->MachO thing).
- they don't introduce any new dependency loops as ObjectFile plugins
  don't depend on any other plugins

Reviewers: xiaobai, JDevlieghere, espindola

Subscribers: emaste, mgorny, arichardson, MaskRay, lldb-commits

Differential Revision: https://reviews.llvm.org/D65450

llvm-svn: 367413

lldb/include/lldb/Symbol/ObjectFile.h

@@ -204,6 +204,10 @@ class ObjectFile : public std::enable_shared_from_this<ObjectFile>,
       const char *path_with_object, lldb_private::FileSpec &archive_file,
       lldb_private::ConstString &archive_object, bool must_exist);
 
+  // LLVM RTTI support
+  static char ID;
+  virtual bool isA(const void *ClassID) const { return ClassID == &ID; }
+
   /// Gets the address size in bytes for the current object file.
   ///
   /// \return

lldb/source/Plugins/JITLoader/GDB/CMakeLists.txt

@@ -16,6 +16,7 @@ add_lldb_library(lldbPluginJITLoaderGDB PLUGIN
     lldbSymbol
     lldbTarget
     lldbUtility
+    lldbPluginObjectFileMachO
   LINK_COMPONENTS
     Support
   )

lldb/source/Plugins/JITLoader/GDB/JITLoaderGDB.cpp

@@ -6,9 +6,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-
-#include "llvm/Support/MathExtras.h"
-
+#include "JITLoaderGDB.h"
+#include "Plugins/ObjectFile/Mach-O/ObjectFileMachO.h"
 #include "lldb/Breakpoint/Breakpoint.h"
 #include "lldb/Core/Module.h"
 #include "lldb/Core/ModuleSpec.h"
@@ -26,8 +25,7 @@
 #include "lldb/Utility/LLDBAssert.h"
 #include "lldb/Utility/Log.h"
 #include "lldb/Utility/StreamString.h"
-
-#include "JITLoaderGDB.h"
+#include "llvm/Support/MathExtras.h"
 
 #include <memory>
 
@@ -326,20 +324,16 @@ bool JITLoaderGDB::ReadJITDescriptorImpl(bool all_entries) {
         module_sp->GetObjectFile()->GetSymtab();
 
         m_jit_objects.insert(std::make_pair(symbolfile_addr, module_sp));
-        if (module_sp->GetObjectFile()->GetPluginName() ==
-            ConstString("mach-o")) {
-          ObjectFile *image_object_file = module_sp->GetObjectFile();
-          if (image_object_file) {
-            const SectionList *section_list =
-                image_object_file->GetSectionList();
-            if (section_list) {
-              uint64_t vmaddrheuristic = 0;
-              uint64_t lower = (uint64_t)-1;
-              uint64_t upper = 0;
-              updateSectionLoadAddress(*section_list, target, symbolfile_addr,
-                                       symbolfile_size, vmaddrheuristic, lower,
-                                       upper);
-            }
+        if (auto image_object_file =
+                llvm::dyn_cast<ObjectFileMachO>(module_sp->GetObjectFile())) {
+          const SectionList *section_list = image_object_file->GetSectionList();
+          if (section_list) {
+            uint64_t vmaddrheuristic = 0;
+            uint64_t lower = (uint64_t)-1;
+            uint64_t upper = 0;
+            updateSectionLoadAddress(*section_list, target, symbolfile_addr,
+                                     symbolfile_size, vmaddrheuristic, lower,
+                                     upper);
           }
         } else {
           bool changed = false;

lldb/source/Plugins/ObjectFile/Breakpad/ObjectFileBreakpad.cpp

@@ -42,6 +42,8 @@ llvm::Optional<Header> Header::parse(llvm::StringRef text) {
   return Header{ArchSpec(triple), std::move(uuid)};
 }
 
+char ObjectFileBreakpad::ID;
+
 void ObjectFileBreakpad::Initialize() {
   PluginManager::RegisterPlugin(GetPluginNameStatic(),
                                 GetPluginDescriptionStatic(), CreateInstance,

lldb/source/Plugins/ObjectFile/Breakpad/ObjectFileBreakpad.h

@@ -48,6 +48,13 @@ class ObjectFileBreakpad : public ObjectFile {
 
   uint32_t GetPluginVersion() override { return 1; }
 
+  // LLVM RTTI support
+  static char ID;
+  bool isA(const void *ClassID) const override {
+    return ClassID == &ID || ObjectFile::isA(ClassID);
+  }
+  static bool classof(const ObjectFile *obj) { return obj->isA(&ID); }
+
   // ObjectFile Protocol.
 
   bool ParseHeader() override;

lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp

@@ -333,6 +333,8 @@ static uint32_t subTypeFromElfHeader(const elf::ELFHeader &header) {
   return LLDB_INVALID_CPUTYPE;
 }
 
+char ObjectFileELF::ID;
+
 // Arbitrary constant used as UUID prefix for core files.
 const uint32_t ObjectFileELF::g_core_uuid_magic(0xE210C);
 

lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.h

@@ -89,6 +89,13 @@ class ObjectFileELF : public lldb_private::ObjectFile {
 
   uint32_t GetPluginVersion() override;
 
+  // LLVM RTTI support
+  static char ID;
+  bool isA(const void *ClassID) const override {
+    return ClassID == &ID || ObjectFile::isA(ClassID);
+  }
+  static bool classof(const ObjectFile *obj) { return obj->isA(&ID); }
+
   // ObjectFile Protocol.
   bool ParseHeader() override;
 

lldb/source/Plugins/ObjectFile/JIT/ObjectFileJIT.cpp

@@ -39,6 +39,8 @@
 using namespace lldb;
 using namespace lldb_private;
 
+char ObjectFileJIT::ID;
+
 void ObjectFileJIT::Initialize() {
   PluginManager::RegisterPlugin(GetPluginNameStatic(),
                                 GetPluginDescriptionStatic(), CreateInstance,

lldb/source/Plugins/ObjectFile/JIT/ObjectFileJIT.h

@@ -46,6 +46,13 @@ class ObjectFileJIT : public lldb_private::ObjectFile {
                                         lldb::offset_t length,
                                         lldb_private::ModuleSpecList &specs);
 
+  // LLVM RTTI support
+  static char ID;
+  bool isA(const void *ClassID) const override {
+    return ClassID == &ID || ObjectFile::isA(ClassID);
+  }
+  static bool classof(const ObjectFile *obj) { return obj->isA(&ID); }
+
   // Member Functions
   bool ParseHeader() override;
 

lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp

@@ -830,6 +830,8 @@ static uint32_t MachHeaderSizeFromMagic(uint32_t magic) {
 
 #define MACHO_NLIST_ARM_SYMBOL_IS_THUMB 0x0008
 
+char ObjectFileMachO::ID;
+
 void ObjectFileMachO::Initialize() {
   PluginManager::RegisterPlugin(
       GetPluginNameStatic(), GetPluginDescriptionStatic(), CreateInstance,

lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.h

@@ -63,6 +63,13 @@ class ObjectFileMachO : public lldb_private::ObjectFile {
   static bool MagicBytesMatch(lldb::DataBufferSP &data_sp, lldb::addr_t offset,
                               lldb::addr_t length);
 
+  // LLVM RTTI support
+  static char ID;
+  bool isA(const void *ClassID) const override {
+    return ClassID == &ID || ObjectFile::isA(ClassID);
+  }
+  static bool classof(const ObjectFile *obj) { return obj->isA(&ID); }
+
   // Member Functions
   bool ParseHeader() override;
 

lldb/source/Plugins/ObjectFile/PECOFF/ObjectFilePECOFF.cpp

@@ -88,6 +88,8 @@ static UUID GetCoffUUID(llvm::object::COFFObjectFile *coff_obj) {
   return UUID();
 }
 
+char ObjectFilePECOFF::ID;
+
 void ObjectFilePECOFF::Initialize() {
   PluginManager::RegisterPlugin(
       GetPluginNameStatic(), GetPluginDescriptionStatic(), CreateInstance,

lldb/source/Plugins/ObjectFile/PECOFF/ObjectFilePECOFF.h

@@ -85,6 +85,13 @@ class ObjectFilePECOFF : public lldb_private::ObjectFile {
 
   static lldb::SymbolType MapSymbolType(uint16_t coff_symbol_type);
 
+  // LLVM RTTI support
+  static char ID;
+  bool isA(const void *ClassID) const override {
+    return ClassID == &ID || ObjectFile::isA(ClassID);
+  }
+  static bool classof(const ObjectFile *obj) { return obj->isA(&ID); }
+
   bool ParseHeader() override;
 
   bool SetLoadAddress(lldb_private::Target &target, lldb::addr_t value,

lldb/source/Plugins/SymbolFile/Breakpad/SymbolFileBreakpad.cpp

@@ -179,10 +179,7 @@ ConstString SymbolFileBreakpad::GetPluginNameStatic() {
 }
 
 uint32_t SymbolFileBreakpad::CalculateAbilities() {
-  if (!m_objfile_sp)
-    return 0;
-  if (m_objfile_sp->GetPluginName() !=
-      ObjectFileBreakpad::GetPluginNameStatic())
+  if (!m_objfile_sp || !llvm::isa<ObjectFileBreakpad>(*m_objfile_sp))
     return 0;
 
   return CompileUnits | Functions | LineTables;

lldb/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.cpp

@@ -120,6 +120,8 @@ loadMatchingPDBFile(std::string exe_path, llvm::BumpPtrAllocator &allocator) {
   }
   OwningBinary<Binary> binary = std::move(*expected_binary);
 
+  // TODO: Avoid opening the PE/COFF binary twice by reading this information
+  // directly from the lldb_private::ObjectFile.
   auto *obj = llvm::dyn_cast<llvm::object::COFFObjectFile>(binary.getBinary());
   if (!obj)
     return nullptr;

lldb/source/Plugins/SymbolVendor/ELF/CMakeLists.txt

@@ -5,4 +5,5 @@ add_lldb_library(lldbPluginSymbolVendorELF PLUGIN
     lldbCore
     lldbHost
     lldbSymbol
+    lldbPluginObjectFileELF
   )

lldb/source/Plugins/SymbolVendor/ELF/SymbolVendorELF.cpp

@@ -10,6 +10,7 @@
 
 #include <string.h>
 
+#include "Plugins/ObjectFile/ELF/ObjectFileELF.h"
 #include "lldb/Core/Module.h"
 #include "lldb/Core/ModuleSpec.h"
 #include "lldb/Core/PluginManager.h"
@@ -61,15 +62,11 @@ SymbolVendorELF::CreateInstance(const lldb::ModuleSP &module_sp,
   if (!module_sp)
     return nullptr;
 
-  ObjectFile *obj_file = module_sp->GetObjectFile();
+  ObjectFileELF *obj_file =
+      llvm::dyn_cast_or_null<ObjectFileELF>(module_sp->GetObjectFile());
   if (!obj_file)
     return nullptr;
 
-  static ConstString obj_file_elf("elf");
-  ConstString obj_name = obj_file->GetPluginName();
-  if (obj_name != obj_file_elf)
-    return nullptr;
-
   lldb_private::UUID uuid = obj_file->GetUUID();
   if (!uuid)
     return nullptr;

lldb/source/Plugins/SymbolVendor/MacOSX/CMakeLists.txt

@@ -7,4 +7,5 @@ add_lldb_library(lldbPluginSymbolVendorMacOSX PLUGIN
     lldbCore
     lldbHost
     lldbSymbol
+    lldbPluginObjectFileMachO
   )

lldb/source/Plugins/SymbolVendor/MacOSX/SymbolVendorMacOSX.cpp

@@ -10,6 +10,7 @@
 
 #include <string.h>
 
+#include "Plugins/ObjectFile/Mach-O/ObjectFileMachO.h"
 #include "lldb/Core/Module.h"
 #include "lldb/Core/ModuleSpec.h"
 #include "lldb/Core/PluginManager.h"
@@ -97,15 +98,11 @@ SymbolVendorMacOSX::CreateInstance(const lldb::ModuleSP &module_sp,
   if (!module_sp)
     return NULL;
 
-  ObjectFile *obj_file = module_sp->GetObjectFile();
+  ObjectFile *obj_file =
+      llvm::dyn_cast_or_null<ObjectFileMachO>(module_sp->GetObjectFile());
   if (!obj_file)
     return NULL;
 
-  static ConstString obj_file_macho("mach-o");
-  ConstString obj_name = obj_file->GetPluginName();
-  if (obj_name != obj_file_macho)
-    return NULL;
-
   static Timer::Category func_cat(LLVM_PRETTY_FUNCTION);
   Timer scoped_timer(func_cat,
                      "SymbolVendorMacOSX::CreateInstance (module = %s)",

lldb/source/Symbol/ObjectFile.cpp

@@ -26,6 +26,8 @@
 using namespace lldb;
 using namespace lldb_private;
 
+char ObjectFile::ID;
+
 ObjectFileSP
 ObjectFile::FindPlugin(const lldb::ModuleSP &module_sp, const FileSpec *file,
                        lldb::offset_t file_offset, lldb::offset_t file_size,