CoreCommands: support -debug-info-format none for Windows

Windows does not have a reliable way to strip the binary as stripping is
not an operation that MSVC ever performs (PDBs are always externalised
and have support for private and public symbols).  This allows us to
have builds in release mode which do not embed debug information which
would then need to be extricated.

Author: compnerd

Sources/CoreCommands/Options.swift

@@ -510,6 +510,8 @@ public struct BuildOptions: ParsableArguments {
         case dwarf
         /// See `BuildParameters.DebugInfoFormat.codeview` for details.
         case codeview
+        /// See `BuildParameters.DebugInfoFormat.none` for details.
+        case none
     }
 }
 

Sources/CoreCommands/SwiftTool.swift

@@ -988,6 +988,8 @@ extension BuildOptions.DebugInfoFormat {
             return .dwarf
         case .codeview:
             return .codeview
+        case .none:
+            return .none
         }
     }
 }

Sources/SPMBuildCore/BuildParameters.swift

@@ -62,6 +62,8 @@ public struct BuildParameters: Encodable {
         case dwarf
         /// CodeView debug information format, used on Windows.
         case codeview
+        /// No debug information to be emitted.
+        case none
     }
 
     /// Represents the debugging strategy.
@@ -321,6 +323,13 @@ public struct BuildParameters: Encodable {
                 swiftCompilerFlags: ["-g", "-debug-info-format=codeview"],
                 linkerFlags: ["-debug"]
             ))
+        case .none:
+            var flags = flags
+            self.flags = flags.merging(BuildFlags(
+                cCompilerFlags: ["-g0"],
+                cxxCompilerFlags: ["-g0"],
+                swiftCompilerFlags: ["-gnone"]
+            ))
         }
         self.pkgConfigDirectories = pkgConfigDirectories
         self.architectures = architectures

Tests/CommandsTests/SwiftToolTests.swift

@@ -241,9 +241,6 @@ final class SwiftToolTests: CommandsTestCase {
             "/Pkg/Sources/exe/main.swift",
         ])
 
-        let explicitDwarfOptions = try GlobalOptions.parse(["--triple", "x86_64-unknown-windows-msvc", "-debug-info-format", "dwarf"])
-        let explicitDwarf = try SwiftTool.createSwiftToolForTest(options: explicitDwarfOptions)
-
         let observer = ObservabilitySystem.makeForTesting()
         let graph = try loadPackageGraph(fileSystem: fs, manifests: [
                 Manifest.createRootManifest(displayName: "Pkg",
@@ -253,6 +250,10 @@ final class SwiftToolTests: CommandsTestCase {
 
         var plan: BuildPlan
 
+
+        /* -debug-info-format dwarf */
+        let explicitDwarfOptions = try GlobalOptions.parse(["--triple", "x86_64-unknown-windows-msvc", "-debug-info-format", "dwarf"])
+        let explicitDwarf = try SwiftTool.createSwiftToolForTest(options: explicitDwarfOptions)
         plan = try BuildPlan(
             buildParameters: explicitDwarf.buildParameters(),
             graph: graph,
@@ -262,6 +263,8 @@ final class SwiftToolTests: CommandsTestCase {
         try XCTAssertMatch(plan.buildProducts.compactMap { $0 as? Build.ProductBuildDescription }.first?.linkArguments() ?? [],
                            [.anySequence, "-g", "-use-ld=lld", "-Xlinker", "-debug:dwarf"])
 
+
+        /* -debug-info-format codeview */
         let explicitCodeViewOptions = try GlobalOptions.parse(["--triple", "x86_64-unknown-windows-msvc", "-debug-info-format", "codeview"])
         let explicitCodeView = try SwiftTool.createSwiftToolForTest(options: explicitCodeViewOptions)
 
@@ -274,6 +277,17 @@ final class SwiftToolTests: CommandsTestCase {
         try XCTAssertMatch(plan.buildProducts.compactMap { $0 as?  Build.ProductBuildDescription }.first?.linkArguments() ?? [],
                            [.anySequence, "-g", "-debug-info-format=codeview", "-Xlinker", "-debug"])
 
+        // Explicitly pass Linux as when the SwiftTool tests are enabled on
+        // Windows, this would fail otherwise as CodeView is supported on the
+        // native host.
+        let unsupportedCodeViewOptions = try GlobalOptions.parse(["--triple", "x86_64-unknown-linux-gnu", "-debug-info-format", "codeview"])
+        let unsupportedCodeView = try SwiftTool.createSwiftToolForTest(options: unsupportedCodeViewOptions)
+
+        XCTAssertThrowsError(try unsupportedCodeView.buildParameters()) {
+            XCTAssertEqual($0 as? StringError, StringError("CodeView debug information is currently not supported on linux"))
+        }
+
+        /* <<null>> */
         let implicitDwarfOptions = try GlobalOptions.parse(["--triple", "x86_64-unknown-windows-msvc"])
         let implicitDwarf = try SwiftTool.createSwiftToolForTest(options: implicitDwarfOptions)
         plan = try BuildPlan(
@@ -285,15 +299,17 @@ final class SwiftToolTests: CommandsTestCase {
         try XCTAssertMatch(plan.buildProducts.compactMap { $0 as? Build.ProductBuildDescription }.first?.linkArguments() ?? [],
                            [.anySequence, "-g", "-use-ld=lld", "-Xlinker", "-debug:dwarf"])
 
-        // Explicitly pass Linux as when the SwiftTool tests are enabled on
-        // Windows, this would fail otherwise as CodeView is supported on the
-        // native host.
-        let unsupportedCodeViewOptions = try GlobalOptions.parse(["--triple", "x86_64-unknown-linux-gnu", "-debug-info-format", "codeview"])
-        let unsupportedCodeView = try SwiftTool.createSwiftToolForTest(options: unsupportedCodeViewOptions)
-
-        XCTAssertThrowsError(try unsupportedCodeView.buildParameters()) {
-            XCTAssertEqual($0 as? StringError, StringError("CodeView debug information is currently not supported on linux"))
-        }
+        /* -debug-info-format none */
+        let explicitNoDebugInfoOptions = try GlobalOptions.parse(["--triple", "x86_64-unknown-windows-msvc", "-debug-info-format", "none"])
+        let explicitNoDebugInfo = try SwiftTool.createSwiftToolForTest(options: explicitNoDebugInfoOptions)
+        plan = try BuildPlan(
+            buildParameters: explicitNoDebugInfo.buildParameters(),
+            graph: graph,
+            fileSystem: fs,
+            observabilityScope: observer.topScope
+        )
+        try XCTAssertMatch(plan.buildProducts.compactMap { $0 as? Build.ProductBuildDescription }.first?.linkArguments() ?? [],
+                           [.anySequence, "-gnone", .anySequence])
     }
 }