Clean up build logic for ASTGen library.

Only introduce it and its dependency when the new Swift parser is being
built, and rely more on existing logic to make sure we get the right
build/link flags.

Author: DougGregor

include/swift/AST/CASTBridging.h

@@ -155,4 +155,7 @@ void Stmt_dump(void *);
 
 SWIFT_END_NULLABILITY_ANNOTATIONS
 
-#endif // SWIFT_C_AST_ASTBRIDGING_H
+#undef SWIFT_BEGIN_NULLABILITY_ANNOTATIONS
+#undef SWIFT_END_NULLABILITY_ANNOTATIONS
+
+#endif // SWIFT_C_AST_ASTBRIDGING_H

lib/ASTGen/CMakeLists.txt

@@ -1,35 +1,34 @@
-# TODO: why do we need these on Linux?
-set(CMAKE_Swift_ARCHIVE_CREATE "<CMAKE_AR> crs <TARGET> <OBJECTS>")
-set(CMAKE_Swift_ARCHIVE_FINISH "")
-
 if (SWIFT_SWIFT_PARSER)
-    add_library(ASTGen
-            Sources/ASTGen/ASTGen.swift
-            Sources/ASTGen/Decls.swift
-            Sources/ASTGen/Exprs.swift
-            Sources/ASTGen/Literals.swift
-            Sources/ASTGen/Misc.swift
-            Sources/ASTGen/Stmts.swift)
+  add_swift_host_library(swiftASTGen STATIC
+    Sources/ASTGen/ASTGen.swift
+    Sources/ASTGen/Decls.swift
+    Sources/ASTGen/Exprs.swift
+    Sources/ASTGen/Literals.swift
+    Sources/ASTGen/Misc.swift
+    Sources/ASTGen/Stmts.swift
+  )
 
-    target_link_libraries(ASTGen PUBLIC
-            SwiftSyntax
-            SwiftParser
-            SwiftDiagnostics)
+  # Link against the SwiftSyntax parser and libraries it depends on. The actual
+  # formulation of this is a hack to work around a CMake bug in Ninja file
+  # generation that results in multiple Ninja targets producing the same file in
+  # a downstream SourceKit target. This should be expressed as:
+  #
+  #   target_link_libraries(swiftASTGen
+  #     PRIVATE
+  #     SwiftSyntax::SwiftCompilerSupport
+  #   )
+  target_link_libraries(swiftASTGen
+    PRIVATE
+    $<TARGET_OBJECTS:SwiftSyntax::SwiftBasicFormat>
+    $<TARGET_OBJECTS:SwiftSyntax::SwiftParser>
+    $<TARGET_OBJECTS:SwiftSyntax::SwiftDiagnostics>
+    $<TARGET_OBJECTS:SwiftSyntax::SwiftSyntax>
+    $<TARGET_OBJECTS:SwiftSyntax::SwiftOperators>
+    $<TARGET_OBJECTS:SwiftSyntax::SwiftCompilerSupport>
+  )
 
-    target_link_directories(ASTGen PUBLIC
-            "${SWIFT_PATH_TO_EARLYSWIFTSYNTAX_BUILD_DIR}/lib")
+  target_include_directories(swiftASTGen PUBLIC
+    "${SWIFT_PATH_TO_EARLYSWIFTSYNTAX_BUILD_DIR}/swift")
 
-    target_include_directories(ASTGen PUBLIC
-            "${SWIFT_PATH_TO_EARLYSWIFTSYNTAX_BUILD_DIR}/swift")
-else()
-    add_library(ASTGen
-            Sources/ASTGen/DummyASTGen.swift)
+  add_dependencies(swiftASTGen swiftAST)
 endif()
-
-set_target_properties(ASTGen PROPERTIES LINKER_LANGUAGE Swift)
-
-target_compile_options(ASTGen PUBLIC
-        "-emit-module-interface"
-        "-g")
-
-add_dependencies(ASTGen swiftAST)

lib/ASTGen/Sources/ASTGen/DummyASTGen.swift

@@ -45,6 +45,7 @@ if (SWIFT_SWIFT_PARSER)
   #   target_link_libraries(swiftParse
   #     PRIVATE
   #     SwiftSyntax::SwiftCompilerSupport
+  #     ...
   #   )
   target_link_libraries(swiftParse
     PRIVATE
@@ -54,6 +55,7 @@ if (SWIFT_SWIFT_PARSER)
     $<TARGET_OBJECTS:SwiftSyntax::SwiftSyntax>
     $<TARGET_OBJECTS:SwiftSyntax::SwiftOperators>
     $<TARGET_OBJECTS:SwiftSyntax::SwiftCompilerSupport>
+    $<TARGET_OBJECTS:swiftASTGen>
   )
 
   target_include_directories(swiftParse
@@ -67,7 +69,6 @@ if (SWIFT_SWIFT_PARSER)
   )
 endif()
 
-add_dependencies(swiftParse ASTGen)
 add_dependencies(swiftParse swift-parse-syntax-generated-headers)
 
 set_swift_llvm_is_available(swiftParse)

lib/Parse/CMakeLists.txt

@@ -251,6 +251,10 @@ macro(add_sourcekit_library name)
     add_llvm_symbol_exports(${name} ${EXPORTED_SYMBOL_FILE})
   endif()
 
+  # Once the new Swift parser is linked, everything has Swift modules.
+  if (SWIFT_SWIFT_PARSER AND SOURCEKITLIB_SHARED)
+    set(SOURCEKITLIB_HAS_SWIFT_MODULES ON)
+  endif()
 
   if(SOURCEKITLIB_SHARED)
     set(RPATH_LIST)
@@ -329,6 +333,16 @@ macro(add_sourcekit_executable name)
 
   set_target_properties(${name} PROPERTIES FOLDER "SourceKit executables")
   add_sourcekit_default_compiler_flags("${name}")
+
+  if(SWIFT_SWIFT_PARSER)
+    set(SKEXEC_HAS_SWIFT_MODULES TRUE)
+  else()
+    set(SKEXEC_HAS_SWIFT_MODULES FALSE)
+  endif()
+
+  set(RPATH_LIST)
+  add_sourcekit_swift_runtime_link_flags(${name} "../../../.." ${SKEXEC_HAS_SWIFT_MODULES})
+
 endmacro()
 
 # Add a new SourceKit framework.

tools/SourceKit/cmake/modules/AddSwiftSourceKit.cmake

@@ -14,7 +14,6 @@ if(${BOOTSTRAPPING_MODE} MATCHES "BOOTSTRAPPING.*")
   )
   target_link_libraries(swift-frontend-bootstrapping0
                         PRIVATE
-                          ASTGen
                           swiftCore
                           swiftDriverTool
                           swiftCompilerStub)
@@ -35,7 +34,6 @@ if(${BOOTSTRAPPING_MODE} MATCHES "BOOTSTRAPPING.*")
   )
   target_link_libraries(swift-frontend-bootstrapping1
                         PRIVATE
-                          ASTGen
                           swiftCore
                           swiftDriverTool
                           swiftCompilerModules-bootstrapping1)
@@ -53,7 +51,6 @@ add_swift_host_tool(swift-frontend
 )
 target_link_libraries(swift-frontend
                       PUBLIC
-                        ASTGen
                         swiftCore
                         swiftDriverTool
                         swiftCompilerModules)