From 764287f1ad69469cc264bb094e8fcdcfdd0fcdfb Mon Sep 17 00:00:00 2001
From: Alex Langford <alangford@apple.com>
Date: Tue, 29 Aug 2023 14:11:41 -0700
Subject: [PATCH] [lldb] Add support for recognizing swift ast sections in
 object files

In Apple's downstream fork, there is support for understanding the swift
AST sections in various binaries. Even though the lldb on llvm.org does
not have support for debugging swift, I think it makes sense to move
support for recognizing swift ast sections upstream.

Differential Revision: https://reviews.llvm.org/D159142
---
 lldb/include/lldb/lldb-enumerations.h                      | 1 +
 lldb/source/Core/Section.cpp                               | 3 +++
 lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp       | 1 +
 lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp  | 4 ++++
 lldb/source/Plugins/ObjectFile/PECOFF/ObjectFilePECOFF.cpp | 1 +
 lldb/source/Symbol/ObjectFile.cpp                          | 1 +
 6 files changed, 11 insertions(+)

diff --git a/lldb/include/lldb/lldb-enumerations.h b/lldb/include/lldb/lldb-enumerations.h
index e2cda2a65eef..21e098481ce8 100644
--- a/lldb/include/lldb/lldb-enumerations.h
+++ b/lldb/include/lldb/lldb-enumerations.h
@@ -739,6 +739,7 @@ enum SectionType {
   eSectionTypeDWARFDebugLocListsDwo,
   eSectionTypeDWARFDebugTuIndex,
   eSectionTypeCTF,
+  eSectionTypeSwiftModules,
 };
 
 FLAGS_ENUM(EmulateInstructionOptions){
diff --git a/lldb/source/Core/Section.cpp b/lldb/source/Core/Section.cpp
index 212b3119894f..9e98b59deb03 100644
--- a/lldb/source/Core/Section.cpp
+++ b/lldb/source/Core/Section.cpp
@@ -149,6 +149,8 @@ const char *Section::GetTypeAsCString() const {
     return "ctf";
   case eSectionTypeOther:
     return "regular";
+  case eSectionTypeSwiftModules:
+    return "swift-modules";
   }
   return "unknown";
 }
@@ -455,6 +457,7 @@ bool Section::ContainsOnlyDebugInfo() const {
   case eSectionTypeDWARFAppleObjC:
   case eSectionTypeDWARFGNUDebugAltLink:
   case eSectionTypeCTF:
+  case eSectionTypeSwiftModules:
     return true;
   }
   return false;
diff --git a/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp b/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp
index 700af84a14c0..2da971dff895 100644
--- a/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp
+++ b/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp
@@ -1679,6 +1679,7 @@ static SectionType GetSectionTypeFromName(llvm::StringRef Name) {
       .Case(".gnu_debugaltlink", eSectionTypeDWARFGNUDebugAltLink)
       .Case(".gosymtab", eSectionTypeGoSymtab)
       .Case(".text", eSectionTypeCode)
+      .Case(".swift_ast", eSectionTypeSwiftModules)
       .Default(eSectionTypeOther);
 }
 
diff --git a/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp b/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
index 3e52c9e3c042..3ce2057d5372 100644
--- a/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
+++ b/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
@@ -1202,6 +1202,7 @@ AddressClass ObjectFileMachO::GetAddressClass(lldb::addr_t file_addr) {
         case eSectionTypeDWARFAppleObjC:
         case eSectionTypeDWARFGNUDebugAltLink:
         case eSectionTypeCTF:
+        case eSectionTypeSwiftModules:
           return AddressClass::eDebug;
 
         case eSectionTypeEHFrame:
@@ -1476,6 +1477,7 @@ static lldb::SectionType GetSectionType(uint32_t flags,
   static ConstString g_sect_name_data("__data");
   static ConstString g_sect_name_go_symtab("__gosymtab");
   static ConstString g_sect_name_ctf("__ctf");
+  static ConstString g_sect_name_swift_ast("__swift_ast");
 
   if (section_name == g_sect_name_dwarf_debug_abbrev)
     return eSectionTypeDWARFDebugAbbrev;
@@ -1555,6 +1557,8 @@ static lldb::SectionType GetSectionType(uint32_t flags,
     return eSectionTypeGoSymtab;
   if (section_name == g_sect_name_ctf)
     return eSectionTypeCTF;
+  if (section_name == g_sect_name_swift_ast)
+    return eSectionTypeSwiftModules;
   if (section_name == g_sect_name_objc_data ||
       section_name == g_sect_name_objc_classrefs ||
       section_name == g_sect_name_objc_superrefs ||
diff --git a/lldb/source/Plugins/ObjectFile/PECOFF/ObjectFilePECOFF.cpp b/lldb/source/Plugins/ObjectFile/PECOFF/ObjectFilePECOFF.cpp
index e89906a02e1b..7fb10a69391c 100644
--- a/lldb/source/Plugins/ObjectFile/PECOFF/ObjectFilePECOFF.cpp
+++ b/lldb/source/Plugins/ObjectFile/PECOFF/ObjectFilePECOFF.cpp
@@ -1009,6 +1009,7 @@ SectionType ObjectFilePECOFF::GetSectionType(llvm::StringRef sect_name,
           // .eh_frame can be truncated to 8 chars.
           .Cases(".eh_frame", ".eh_fram", eSectionTypeEHFrame)
           .Case(".gosymtab", eSectionTypeGoSymtab)
+          .Case("swiftast", eSectionTypeSwiftModules)
           .Default(eSectionTypeInvalid);
   if (section_type != eSectionTypeInvalid)
     return section_type;
diff --git a/lldb/source/Symbol/ObjectFile.cpp b/lldb/source/Symbol/ObjectFile.cpp
index 364cb850a28a..07f79aaedab8 100644
--- a/lldb/source/Symbol/ObjectFile.cpp
+++ b/lldb/source/Symbol/ObjectFile.cpp
@@ -357,6 +357,7 @@ AddressClass ObjectFile::GetAddressClass(addr_t file_addr) {
           case eSectionTypeDWARFAppleObjC:
           case eSectionTypeDWARFGNUDebugAltLink:
           case eSectionTypeCTF:
+          case eSectionTypeSwiftModules:
             return AddressClass::eDebug;
           case eSectionTypeEHFrame:
           case eSectionTypeARMexidx: