From c6f7a10c2f24852372318e6312ecc34f2a6d0183 Mon Sep 17 00:00:00 2001
From: Owen Voorhees <ovoorhees@apple.com>
Date: Mon, 29 Sep 2025 10:54:39 -0700
Subject: [PATCH 1/2] Correct -nostdlib handling when linking with swiftc

---
 Sources/SWBUniversalPlatform/Specs/Ld.xcspec | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/Sources/SWBUniversalPlatform/Specs/Ld.xcspec b/Sources/SWBUniversalPlatform/Specs/Ld.xcspec
index cb17257a..43082279 100644
--- a/Sources/SWBUniversalPlatform/Specs/Ld.xcspec
+++ b/Sources/SWBUniversalPlatform/Specs/Ld.xcspec
@@ -444,9 +444,24 @@
                 Name = "LINK_WITH_STANDARD_LIBRARIES";
                 Type = Boolean;
                 DefaultValue = YES;
+            },
+            {
+                Name = "CLANG_LINK_WITH_STANDARD_LIBRARIES";
+                Type = Boolean;
+                DefaultValue = "$(LINK_WITH_STANDARD_LIBRARIES)";
                 CommandLineArgs = {
                     NO = ("-nostdlib");
                 };
+                Condition = "$(LINKER_DRIVER) == clang";
+            },
+            {
+                Name = "SWIFTC_LINK_WITH_STANDARD_LIBRARIES";
+                Type = Boolean;
+                DefaultValue = "$(LINK_WITH_STANDARD_LIBRARIES)";
+                CommandLineArgs = {
+                    NO = ("-Xclang-linker", "-nostdlib");
+                };
+                Condition = "$(LINKER_DRIVER) == swiftc";
             },
             {
                 Name = "KEEP_PRIVATE_EXTERNS";

From 7cc3ae46a255eb1c8031dc331aa98215fc4c82e8 Mon Sep 17 00:00:00 2001
From: Owen Voorhees <ovoorhees@apple.com>
Date: Mon, 29 Sep 2025 11:35:39 -0700
Subject: [PATCH 2/2] Use clang to link relocatable objects when
 LINKER_DRIVER=auto

---
 .../SWBCore/SpecImplementations/Tools/LinkerTools.swift    | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/Sources/SWBCore/SpecImplementations/Tools/LinkerTools.swift b/Sources/SWBCore/SpecImplementations/Tools/LinkerTools.swift
index 3c3f5b7e..6a29a58f 100644
--- a/Sources/SWBCore/SpecImplementations/Tools/LinkerTools.swift
+++ b/Sources/SWBCore/SpecImplementations/Tools/LinkerTools.swift
@@ -362,6 +362,11 @@ public final class LdLinkerSpec : GenericLinkerSpec, SpecIdentifierType, @unchec
         return runpathSearchPaths
     }
 
+    private static func swiftcSupportsLinkingMachOType(_ type: String) -> Bool {
+        // swiftc does not currently support linking relocatable objects.
+        return type != "mh_object"
+    }
+
     static func resolveLinkerDriver(_ cbc: CommandBuildContext, usedTools: [CommandLineToolSpec: Set<FileTypeSpec>]) -> LinkerDriverChoice {
         switch cbc.scope.evaluate(BuiltinMacros.LINKER_DRIVER) {
         case .clang:
@@ -371,7 +376,7 @@ public final class LdLinkerSpec : GenericLinkerSpec, SpecIdentifierType, @unchec
         case .swiftc:
             return .swiftc
         case .auto:
-            if Self.isUsingSwift(usedTools) {
+            if Self.isUsingSwift(usedTools) && Self.swiftcSupportsLinkingMachOType(cbc.scope.evaluate(BuiltinMacros.MACH_O_TYPE)) {
                 return .swiftc
             } else {
                 return .clang