Revert "Make the DWARF version emitted by the Swift compiler configurable."

Author: adrian-prantl

include/swift/ABI/ObjectFile.h

@@ -13,8 +13,7 @@
 
 namespace swift {
 
-/// Represents the nine reflection sections used by Swift + the Swift AST
-/// section used by the debugger.
+/// Represents the nine reflection sections used by Swift
 enum ReflectionSectionKind : uint8_t {
 #define HANDLE_SWIFT_SECTION(KIND, MACHO, ELF, COFF) KIND,
 #include "llvm/BinaryFormat/Swift.def"

include/swift/AST/IRGenOptions.h

@@ -237,7 +237,7 @@ class IRGenOptions {
   std::string DebugCompilationDir;
 
   /// The DWARF version of debug info.
-  uint8_t DWARFVersion = 4;
+  unsigned DWARFVersion;
 
   /// The command line string that is to be stored in the debug info.
   std::string DebugFlags;
@@ -512,7 +512,8 @@ class IRGenOptions {
   bool EmitCASIDFile;
 
   IRGenOptions()
-      : OutputKind(IRGenOutputKind::LLVMAssemblyAfterOptimization),
+      : DWARFVersion(2),
+        OutputKind(IRGenOutputKind::LLVMAssemblyAfterOptimization),
         Verify(true), OptMode(OptimizationMode::NotSet),
         Sanitizers(OptionSet<SanitizerKind>()),
         SanitizersWithRecoveryInstrumentation(OptionSet<SanitizerKind>()),

include/swift/Basic/Dwarf.h

@@ -0,0 +1,33 @@
+//===--- Dwarf.h - DWARF constants ------------------------------*- C++ -*-===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines several temporary Swift-specific DWARF constants.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SWIFT_BASIC_DWARF_H
+#define SWIFT_BASIC_DWARF_H
+
+#include "llvm/BinaryFormat/Dwarf.h"
+
+namespace swift {
+  /// The DWARF version emitted by the Swift compiler.
+  const unsigned DWARFVersion = 4;
+
+  static const char MachOASTSegmentName[] = "__DWARF";
+  static const char MachOASTSectionName[] = "__swift_ast";
+  static const char ELFASTSectionName[] = ".swift_ast";
+  static const char COFFASTSectionName[] = "swiftast";
+  static const char WasmASTSectionName[] = ".swift_ast";
+} // end namespace swift
+
+#endif // SWIFT_BASIC_DWARF_H

include/swift/Driver/Driver.h

@@ -125,9 +125,6 @@ class OutputInfo {
   /// What kind of debug info to generate.
   IRGenDebugInfoFormat DebugInfoFormat = IRGenDebugInfoFormat::None;
 
-  /// DWARF output format version number.
-  std::optional<uint8_t> DWARFVersion;
-
   /// Whether or not the driver should generate a module.
   bool ShouldGenerateModule = false;
 

include/swift/Option/Options.td

@@ -991,8 +991,8 @@ def gdwarf_types : Flag<["-"], "gdwarf-types">,
   Group<g_Group>, Flags<[FrontendOption]>,
   HelpText<"Emit full DWARF type info.">;
 def debug_prefix_map : Separate<["-"], "debug-prefix-map">,
-  Flags<[FrontendOption]>,
-  HelpText<"Remap source paths in debug info">, MetaVarName<"<prefix=replacement>">;
+    Flags<[FrontendOption]>,
+    HelpText<"Remap source paths in debug info">, MetaVarName<"<prefix=replacement>">;
 def coverage_prefix_map : Separate<["-"], "coverage-prefix-map">,
   Flags<[FrontendOption]>,
   HelpText<"Remap source paths in coverage info">, MetaVarName<"<prefix=replacement>">;
@@ -1007,10 +1007,6 @@ def file_compilation_dir : Separate<["-"], "file-compilation-dir">,
 def debug_info_format : Joined<["-"], "debug-info-format=">,
   Flags<[FrontendOption]>,
   HelpText<"Specify the debug info format type to either 'dwarf' or 'codeview'">;
-def dwarf_version : Joined<["-"], "dwarf-version=">,
-  Flags<[FrontendOption]>,
-  HelpText<"DWARF debug info version to produce if requested">,
-  MetaVarName<"<version>">;
 
 def prefix_serialized_debugging_options : Flag<["-"], "prefix-serialized-debugging-options">,
   Flags<[FrontendOption]>,

lib/ASTSectionImporter/ASTSectionImporter.cpp

@@ -18,6 +18,7 @@
 #include "swift/ASTSectionImporter/ASTSectionImporter.h"
 #include "../Serialization/ModuleFormat.h"
 #include "swift/AST/ASTContext.h"
+#include "swift/Basic/Dwarf.h"
 #include "swift/Serialization/SerializedModuleLoader.h"
 #include "swift/Serialization/Validation.h"
 #include "llvm/Support/Debug.h"

lib/Driver/DarwinToolChains.cpp

@@ -14,6 +14,7 @@
 
 #include "swift/AST/DiagnosticsDriver.h"
 #include "swift/AST/PlatformKind.h"
+#include "swift/Basic/Dwarf.h"
 #include "swift/Basic/LLVM.h"
 #include "swift/Basic/Platform.h"
 #include "swift/Basic/Range.h"
@@ -625,28 +626,6 @@ toolchains::Darwin::addDeploymentTargetArgs(ArgStringList &Arguments,
   }
 }
 
-static unsigned getDWARFVersionForTriple(const llvm::Triple &triple) {
-  llvm::VersionTuple osVersion;
-  const DarwinPlatformKind kind = getDarwinPlatformKind(triple);
-  switch (kind) {
-  case DarwinPlatformKind::MacOS:
-    triple.getMacOSXVersion(osVersion);
-    if (osVersion < llvm::VersionTuple(10, 11))
-      return 2;
-    return 4;
-  case DarwinPlatformKind::IPhoneOSSimulator:
-  case DarwinPlatformKind::IPhoneOS:
-  case DarwinPlatformKind::TvOS:
-  case DarwinPlatformKind::TvOSSimulator:
-    osVersion = triple.getiOSVersion();
-    if (osVersion < llvm::VersionTuple(9))
-      return 2;
-    return 4;
-  default:
-    return 4;
-  }
-}
-
 void toolchains::Darwin::addCommonFrontendArgs(
     const OutputInfo &OI, const CommandOutput &output,
     const llvm::opt::ArgList &inputArgs,
@@ -665,16 +644,6 @@ void toolchains::Darwin::addCommonFrontendArgs(
           inputArgs.MakeArgString(variantSDKVersion->getAsString()));
     }
   }
-  std::string dwarfVersion;
-  {
-    llvm::raw_string_ostream os(dwarfVersion);
-    os << "-dwarf-version=";
-    if (OI.DWARFVersion)
-      os << *OI.DWARFVersion;
-    else
-      os << getDWARFVersionForTriple(getTriple());
-  }
-  arguments.push_back(inputArgs.MakeArgString(dwarfVersion));
 }
 
 /// Add the frontend arguments needed to find external plugins in standard

lib/Driver/Driver.cpp

@@ -1685,16 +1685,6 @@ void Driver::buildOutputInfo(const ToolChain &TC, const DerivedArgList &Args,
                      : "-gdwarf_types");
   }
 
-  if (const Arg *A = Args.getLastArg(options::OPT_dwarf_version)) {
-    unsigned vers;
-    if (!StringRef(A->getValue()).getAsInteger(10, vers) && vers >= 2 &&
-        vers <= 5)
-      OI.DWARFVersion = vers;
-    else
-      Diags.diagnose(SourceLoc(), diag::error_invalid_arg_value,
-                     A->getAsString(Args), A->getValue());
-  }
-
   if (Args.hasArg(options::OPT_emit_module, options::OPT_emit_module_path)) {
     // The user has requested a module, so generate one and treat it as
     // top-level output.

lib/Driver/ToolChains.cpp

@@ -13,6 +13,7 @@
 #include "ToolChains.h"
 
 #include "swift/AST/DiagnosticsDriver.h"
+#include "swift/Basic/Dwarf.h"
 #include "swift/Basic/LLVM.h"
 #include "swift/Basic/Platform.h"
 #include "swift/Basic/Range.h"
@@ -261,7 +262,6 @@ void ToolChain::addCommonFrontendArgs(const OutputInfo &OI,
   inputArgs.AddLastArg(arguments, options::OPT_enable_private_imports);
   inputArgs.AddLastArg(arguments, options::OPT_g_Group);
   inputArgs.AddLastArg(arguments, options::OPT_debug_info_format);
-  inputArgs.AddLastArg(arguments, options::OPT_dwarf_version);
   inputArgs.AddLastArg(arguments, options::OPT_import_underlying_module);
   inputArgs.AddLastArg(arguments, options::OPT_module_cache_path);
   inputArgs.AddLastArg(arguments, options::OPT_module_link_name);

lib/Driver/UnixToolChains.cpp

@@ -12,6 +12,7 @@
 
 #include "ToolChains.h"
 
+#include "swift/Basic/Dwarf.h"
 #include "swift/Basic/LLVM.h"
 #include "swift/Basic/Platform.h"
 #include "swift/Basic/Range.h"