cmake: fix a wrong library search directory order when building swift-frontend with bootstrapping

Author: eeckstein

cmake/modules/AddSwift.cmake

@@ -800,16 +800,6 @@ macro(add_swift_lib_subdirectory name)
   add_llvm_subdirectory(SWIFT LIB ${name})
 endmacro()
 
-function(_link_built_compatibility_libs executable)
-  set(platform ${SWIFT_SDK_${SWIFT_HOST_VARIANT_SDK}_LIB_SUBDIR})
-  target_link_directories(${executable} PRIVATE
-    ${SWIFTLIB_DIR}/${platform})
-  add_dependencies(${executable}
-    "swiftCompatibility50-${platform}"
-    "swiftCompatibility51-${platform}"
-    "swiftCompatibilityDynamicReplacements-${platform}")
-endfunction()
-
 function(add_swift_host_tool executable)
   set(options HAS_LIBSWIFT)
   set(single_parameter_options SWIFT_COMPONENT BOOTSTRAPPING)
@@ -908,24 +898,26 @@ function(add_swift_host_tool executable)
         list(APPEND RPATH_LIST "/usr/lib/swift")
 
       elseif(LIBSWIFT_BUILD_MODE STREQUAL "BOOTSTRAPPING-WITH-HOSTLIBS")
-        # Pick up the built libswiftCompatibility<n>.a libraries
-        _link_built_compatibility_libs(${executable})
-
         # Add the SDK directory for the host platform.
         target_link_directories(${executable} PRIVATE "${sdk_dir}")
 
+        # A backup in case the toolchain doesn't have one of the compatibility libraries.
+        target_link_directories(${executable} PRIVATE
+          "${SWIFTLIB_DIR}/${SWIFT_SDK_${SWIFT_HOST_VARIANT_SDK}_LIB_SUBDIR}")
+
         # Include the abi stable system stdlib in our rpath.
         list(APPEND RPATH_LIST "/usr/lib/swift")
 
       elseif(LIBSWIFT_BUILD_MODE STREQUAL "BOOTSTRAPPING")
-        # Pick up the built libswiftCompatibility<n>.a libraries
-        _link_built_compatibility_libs(${executable})
-
         # At build time link against the built swift libraries from the
         # previous bootstrapping stage.
         get_bootstrapping_swift_lib_dir(bs_lib_dir "${ASHT_BOOTSTRAPPING}")
         target_link_directories(${executable} PRIVATE ${bs_lib_dir})
 
+        # Required to pick up the built libswiftCompatibility<n>.a libraries
+        target_link_directories(${executable} PRIVATE
+          "${SWIFTLIB_DIR}/${SWIFT_SDK_${SWIFT_HOST_VARIANT_SDK}_LIB_SUBDIR}")
+
         # At runtime link against the built swift libraries from the current
         # bootstrapping stage.
         list(APPEND RPATH_LIST "@executable_path/../lib/swift/${SWIFT_SDK_${SWIFT_HOST_VARIANT_SDK}_LIB_SUBDIR}")

libswift/CMakeLists.txt

@@ -34,28 +34,39 @@ else()
     set(b0_deps swift-frontend-bootstrapping0 symlink-headers-bootstrapping0)
     set(b1_deps swift-frontend-bootstrapping1 symlink-headers-bootstrapping1)
     if(${LIBSWIFT_BUILD_MODE} STREQUAL "BOOTSTRAPPING")
-      set(b0_deps ${b0_deps} swiftCore-bootstrapping0)
-      set(b1_deps ${b1_deps} swiftCore-bootstrapping1)
+      list(APPEND b0_deps swiftCore-bootstrapping0)
+      list(APPEND b1_deps swiftCore-bootstrapping1)
       if(CMAKE_BUILD_TYPE STREQUAL "Debug")
-        set(b0_deps ${b0_deps} swiftSwiftOnoneSupport-bootstrapping0)
-        set(b1_deps ${b1_deps} swiftSwiftOnoneSupport-bootstrapping1)
+        list(APPEND b0_deps swiftSwiftOnoneSupport-bootstrapping0)
+        list(APPEND b1_deps swiftSwiftOnoneSupport-bootstrapping1)
       endif()
       if(SWIFT_HOST_VARIANT_SDK IN_LIST SWIFT_DARWIN_PLATFORMS)
-        set(b0_deps ${b0_deps} swiftDarwin-bootstrapping0)
-        set(b1_deps ${b1_deps} swiftDarwin-bootstrapping1)
+        list(APPEND b0_deps swiftDarwin-bootstrapping0)
+        list(APPEND b1_deps swiftDarwin-bootstrapping1)
       endif()
     endif()
+    if(SWIFT_HOST_VARIANT_SDK IN_LIST SWIFT_DARWIN_PLATFORMS)
+      set(platform ${SWIFT_SDK_${SWIFT_HOST_VARIANT_SDK}_LIB_SUBDIR})
+      set(compatibility_libs
+          "swiftCompatibility50-${platform}"
+          "swiftCompatibility51-${platform}"
+          "swiftCompatibilityDynamicReplacements-${platform}")
+
+      list(APPEND b0_deps ${compatibility_libs})
+      list(APPEND b1_deps ${compatibility_libs})
+    endif()
+
 
     # Bootstrapping - stage 1, using the compiler from level 0
 
-    add_libswift("libswift-bootstrapping1"
+    add_libswift(libswift-bootstrapping1
       SWIFT_EXEC "${CMAKE_BINARY_DIR}/bootstrapping0/bin/swiftc"
       DEPENDS ${b0_deps}
       BOOTSTRAPPING 1)
 
     # The final build, using the compiler from stage 1
 
-    add_libswift("libswift"
+    add_libswift(libswift
         SWIFT_EXEC "${CMAKE_BINARY_DIR}/bootstrapping1/bin/swiftc"
         DEPENDS ${b1_deps})