add and use CanContainSwiftReflectionData

Author: kastiglione

lldb/include/lldb/Core/Section.h

@@ -201,6 +201,8 @@ class Section : public std::enable_shared_from_this<Section>,
   ObjectFile *GetObjectFile() { return m_obj_file; }
   const ObjectFile *GetObjectFile() const { return m_obj_file; }
 
+  bool CanContainSwiftReflectionData() const;
+
   /// Read the section data from the object file that the section
   /// resides in.
   ///

lldb/include/lldb/Symbol/ObjectFile.h

@@ -19,6 +19,7 @@
 #include "lldb/Utility/FileSpec.h"
 #include "lldb/Utility/UUID.h"
 #include "lldb/lldb-private.h"
+#include "llvm/ADT/StringRef.h"
 #include "llvm/Support/VersionTuple.h"
 
 namespace swift {
@@ -689,6 +690,8 @@ class ObjectFile : public std::enable_shared_from_this<ObjectFile>,
   virtual llvm::StringRef
   GetReflectionSectionIdentifier(swift::ReflectionSectionKind section);
 
+  virtual bool CanContainSwiftReflectionData(const Section &section);
+
   /// Load binaries listed in a corefile
   ///
   /// A corefile may have metadata listing binaries that can be loaded,

lldb/source/Core/Section.cpp

@@ -390,6 +390,10 @@ void Section::SetPermissions(uint32_t permissions) {
   m_executable = (permissions & ePermissionsExecutable) != 0;
 }
 
+bool Section::CanContainSwiftReflectionData() const {
+  return m_obj_file->CanContainSwiftReflectionData(*this);
+}
+
 lldb::offset_t Section::GetSectionData(void *dst, lldb::offset_t dst_len,
                                        lldb::offset_t offset) {
   if (m_obj_file)

lldb/source/Plugins/LanguageRuntime/Swift/LLDBMemoryReader.cpp

@@ -122,17 +122,6 @@ LLDBMemoryReader::getSymbolAddress(const std::string &name) {
 swift::remote::RemoteAbsolutePointer
 LLDBMemoryReader::resolvePointer(swift::remote::RemoteAddress address,
                                  uint64_t readValue) {
-  auto isEffectivelyReadOnly = [](SectionSP section) {
-    if ((section->GetPermissions() & ePermissionsWritable) == 0)
-      return true;
-    if (section->GetName() == "__const")
-      return true;
-    if (auto segment = section->GetParent())
-      if (segment->GetName() == "__DATA_CONST")
-        return true;
-    return false;
-  };
-
   // If an address has a symbol, that symbol provides additional useful data to
   // MetadataReader. Without the symbol, MetadataReader can derive the symbol
   // by loading other parts of reflection metadata, but that work has a cost.
@@ -141,7 +130,7 @@ LLDBMemoryReader::resolvePointer(swift::remote::RemoteAddress address,
   Address addr;
   auto &target = m_process.GetTarget();
   if (target.ResolveLoadAddress(address.getAddressData(), addr))
-    if (isEffectivelyReadOnly(addr.GetSection()))
+    if (addr.GetSection()->CanContainSwiftReflectionData())
       if (auto *symbol = addr.CalculateSymbolContextSymbol()) {
         auto mangledName = symbol->GetMangled().GetMangledName().GetStringRef();
         // MemoryReader requires any this to be a Swift symbol. LLDB can also be

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

@@ -3429,3 +3429,13 @@ llvm::StringRef ObjectFileELF::GetReflectionSectionIdentifier(
   llvm_unreachable("Swift support disabled");
 #endif //LLDB_ENABLE_SWIFT
 }
+
+bool ObjectFileELF::CanContainSwiftReflectionData(const Section &section) {
+#ifdef LLDB_ENABLE_SWIFT
+  swift::SwiftObjectFileFormatCOFF file_format;
+  return file_format.sectionContainsReflectionData(
+      section.GetName().GetStringRef());
+#else
+  llvm_unreachable("Swift support disabled");
+#endif // LLDB_ENABLE_SWIFT
+}

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

@@ -395,6 +395,9 @@ class ObjectFileELF : public lldb_private::ObjectFile {
 
   llvm::StringRef
   GetReflectionSectionIdentifier(swift::ReflectionSectionKind section) override;
+
+  bool
+  CanContainSwiftReflectionData(const lldb_private::Section &section) override;
 };
 
 #endif // LLDB_SOURCE_PLUGINS_OBJECTFILE_ELF_OBJECTFILEELF_H

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

@@ -7019,6 +7019,25 @@ llvm::StringRef ObjectFileMachO::GetReflectionSectionIdentifier(
 #endif //LLDB_ENABLE_SWIFT
 }
 
+bool ObjectFileMachO::CanContainSwiftReflectionData(const Section &section) {
+#ifdef LLDB_ENABLE_SWIFT
+  swift::SwiftObjectFileFormatMachO file_format;
+  if (file_format.sectionContainsReflectionData(
+          section.GetName().GetStringRef()))
+    return true;
+  // Some section names are not unique, such as `__const`, which could be in
+  // `__TEXT` or `__DATA`. For these, also check the segment,section name.
+  if (auto segment = section.GetParent()) {
+    std::string segmentSectionName =
+        llvm::formatv("{0},{1}", segment->GetName(), section.GetName()).str();
+    return file_format.sectionContainsReflectionData(segmentSectionName);
+  }
+  return false;
+#else
+  llvm_unreachable("Swift support disabled");
+#endif // LLDB_ENABLE_SWIFT
+}
+
 ObjectFileMachO::MachOCorefileAllImageInfos
 ObjectFileMachO::GetCorefileAllImageInfos() {
   MachOCorefileAllImageInfos image_infos;

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

@@ -220,6 +220,9 @@ class ObjectFileMachO : public lldb_private::ObjectFile {
   llvm::StringRef
   GetReflectionSectionIdentifier(swift::ReflectionSectionKind section) override;
 
+  bool
+  CanContainSwiftReflectionData(const lldb_private::Section &section) override;
+
   /// A corefile may include metadata about all of the binaries that were
   /// present in the process when the corefile was taken.  This is only
   /// implemented for Mach-O files for now; we'll generalize it when we

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

@@ -1217,3 +1217,12 @@ llvm::StringRef ObjectFilePECOFF::GetReflectionSectionIdentifier(
 #endif //LLDB_ENABLE_SWIFT
 }
 
+bool ObjectFilePECOFF::CanContainSwiftReflectionData(const Section &section) {
+#ifdef LLDB_ENABLE_SWIFT
+  swift::SwiftObjectFileFormatCOFF file_format;
+  return file_format.sectionContainsReflectionData(
+      section.GetName().GetStringRef());
+#else
+  llvm_unreachable("Swift support disabled");
+#endif // LLDB_ENABLE_SWIFT
+}

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

@@ -288,6 +288,9 @@ class ObjectFilePECOFF : public lldb_private::ObjectFile {
   llvm::StringRef
   GetReflectionSectionIdentifier(swift::ReflectionSectionKind section) override;
 
+  bool
+  CanContainSwiftReflectionData(const lldb_private::Section &section) override;
+
   typedef std::vector<section_header_t> SectionHeaderColl;
   typedef SectionHeaderColl::iterator SectionHeaderCollIter;
   typedef SectionHeaderColl::const_iterator SectionHeaderCollConstIter;

lldb/source/Symbol/ObjectFile.cpp

@@ -725,3 +725,9 @@ llvm::StringRef ObjectFile::GetReflectionSectionIdentifier(
          "Base class's GetReflectionSectionIdentifier should not be called");
   return "";
 }
+
+bool ObjectFile::CanContainSwiftReflectionData(const Section &section) {
+  assert(false &&
+         "Base class's CanContainSwiftReflectionData should not be called");
+  return false;
+}