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

2 files changed, 14 insertions, 19 deletions

diff --git a/lldb/source/Plugins/JITLoader/GDB/CMakeLists.txt b/lldb/source/Plugins/JITLoader/GDB/CMakeLists.txt
index 774d85b16a2..ecdff2823d4 100644
--- a/lldb/source/Plugins/JITLoader/GDB/CMakeLists.txt
+++ b/lldb/source/Plugins/JITLoader/GDB/CMakeLists.txt
@@ -16,6 +16,7 @@ add_lldb_library(lldbPluginJITLoaderGDB PLUGIN
     lldbSymbol
     lldbTarget
     lldbUtility
+    lldbPluginObjectFileMachO
   LINK_COMPONENTS
     Support
   )
diff --git a/lldb/source/Plugins/JITLoader/GDB/JITLoaderGDB.cpp b/lldb/source/Plugins/JITLoader/GDB/JITLoaderGDB.cpp
index 0593af4caad..2aa284f2a5c 100644
--- a/lldb/source/Plugins/JITLoader/GDB/JITLoaderGDB.cpp
+++ b/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;