Revert "Make the DWARF version configurable."

Author: adrian-prantl

Sources/SwiftDriver/Driver/DebugInfo.swift

@@ -41,12 +41,9 @@
     }
   }
 
-  /// The format of debug information.
+  // The format of debug information.
   public let format: Format
 
-  /// The DWARF standard version to be produced.
-  public let dwarfVersion: UInt8
-
   /// The level of debug information.
   public let level: Level?
 

Sources/SwiftDriver/Driver/Driver.swift

@@ -2308,17 +2308,7 @@ extension Driver {
       diagnosticsEngine.emit(.error_argument_not_allowed_with(arg: fullNotAllowedOption, other: levelOption.spelling))
     }
 
-    // Determine the DWARF version.
-    var dwarfVersion: UInt8 = 4
-    if let versionArg = parsedOptions.getLastArgument(.dwarfVersion) {
-      if let parsedVersion = UInt8(versionArg.asSingle), parsedVersion >= 2 && parsedVersion <= 5 {
-        dwarfVersion = parsedVersion
-      } else {
-        diagnosticsEngine.emit(.error_invalid_arg_value(arg: .dwarfVersion, value: versionArg.asSingle))
-      }
-    }
-
-    return DebugInfo(format: format, dwarfVersion: dwarfVersion, level: level, shouldVerify: shouldVerify)
+    return DebugInfo(format: format, level: level, shouldVerify: shouldVerify)
   }
 
   /// Parses the set of `-sanitize={sanitizer}` arguments and returns all the

Sources/SwiftDriver/Jobs/FrontendJobHelpers.swift

@@ -193,7 +193,6 @@ extension Driver {
     try commandLine.appendLast(.enablePrivateImports, from: &parsedOptions)
     try commandLine.appendLast(in: .g, from: &parsedOptions)
     try commandLine.appendLast(.debugInfoFormat, from: &parsedOptions)
-    try commandLine.appendLast(.dwarfVersion, from: &parsedOptions)
     try commandLine.appendLast(.importUnderlyingModule, from: &parsedOptions)
     try commandLine.appendLast(.moduleCachePath, from: &parsedOptions)
     try commandLine.appendLast(.moduleLinkName, from: &parsedOptions)

Sources/SwiftOptions/Options.swift

@@ -111,7 +111,6 @@ extension Option {
   public static let debugForbidTypecheckPrefix: Option = Option("-debug-forbid-typecheck-prefix", .separate, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Triggers llvm fatal_error if typechecker tries to typecheck a decl with the provided prefix name")
   public static let debugGenericSignatures: Option = Option("-debug-generic-signatures", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Debug generic signatures")
   public static let debugInfoFormat: Option = Option("-debug-info-format=", .joined, attributes: [.frontend], helpText: "Specify the debug info format type to either 'dwarf' or 'codeview'")
-  public static let dwarfVersion: Option = Option("-dwarf-version=", .joined, attributes: [.frontend], helpText: "DWARF debug info version to produce if requested")
   public static let debugInfoStoreInvocation: Option = Option("-debug-info-store-invocation", .flag, attributes: [.frontend], helpText: "Emit the compiler invocation in the debug info.")
   public static let debugMapping: Option = Option("-debug-mapping", .flag, attributes: [.noDriver], helpText: "Dumping information for debug purposes")
   public static let debugMapping_: Option = Option("--debug-mapping", .flag, alias: Option.debugMapping, attributes: [.noDriver], helpText: "Dumping information for debug purposes")
@@ -929,7 +928,6 @@ extension Option {
       Option.debugForbidTypecheckPrefix,
       Option.debugGenericSignatures,
       Option.debugInfoFormat,
-      Option.dwarfVersion,
       Option.debugInfoStoreInvocation,
       Option.debugMapping,
       Option.debugMapping_,

Tests/SwiftDriverTests/SwiftDriverTests.swift

@@ -574,19 +574,6 @@ final class SwiftDriverTests: XCTestCase {
       $1.expect(.error("argument '-debug-info-format=codeview' is not allowed with '-gdwarf-types'"))
     }
 
-    try assertDriverDiagnostics(args: "swiftc", "foo.swift", "-emit-module", "-dwarf-version=0") {
-      $1.expect(.error("invalid value '0' in '-dwarf-version="))
-    }
-
-    try assertDriverDiagnostics(args: "swiftc", "foo.swift", "-emit-module", "-dwarf-version=6") {
-      $1.expect(.error("invalid value '6' in '-dwarf-version="))
-    }
-
-    try assertNoDriverDiagnostics(args: "swiftc", "foo.swift", "-emit-module", "-g", "-debug-info-format=dwarf", "-dwarf-version=4") { driver in
-        let jobs = try driver.planBuild()
-        XCTAssertTrue(jobs[0].commandLine.contains(.flag("-dwarf-version=4")))
-    }
-
     try assertNoDriverDiagnostics(args: "swiftc", "foo.swift", "-g", "-c", "-file-compilation-dir", ".") { driver in
       let jobs = try driver.planBuild()
       XCTAssertTrue(jobs[0].commandLine.contains(.flag("-file-compilation-dir")))