Merge pull request #14499 from DougGregor/solver-favor-more-specialized

[Constraint solver] Favor more-specialized overload among two generics.

Author: DougGregor

CMakeLists.txt

@@ -11,8 +11,6 @@ set_property(GLOBAL PROPERTY JOB_POOLS local_jobs=${localhost_logical_cores})
 # Put linking in that category
 set_property(GLOBAL PROPERTY JOB_POOL_LINK local_jobs)
 
-ENABLE_LANGUAGE(C)
-
 # First include general CMake utilities.
 include(SwiftUtils)
 include(CheckSymbolExists)
@@ -750,10 +748,10 @@ if(swift_build_android AND NOT "${SWIFT_ANDROID_NDK_PATH}" STREQUAL "")
 
   set(SWIFT_ANDROID_PREBUILT_PATH
       "${SWIFT_ANDROID_NDK_PATH}/toolchains/arm-linux-androideabi-${SWIFT_ANDROID_NDK_GCC_VERSION}/prebuilt/${_swift_android_prebuilt_suffix}")
-
+  
   # Resolve the correct linker based on the file name of CMAKE_LINKER (being 'ld' or 'ld.gold' the options)
   get_filename_component(SWIFT_ANDROID_LINKER_NAME "${CMAKE_LINKER}" NAME)
-  set(SWIFT_SDK_ANDROID_ARCH_armv7_LINKER
+  set(SWIFT_SDK_ANDROID_ARCH_armv7_LINKER 
       "${SWIFT_ANDROID_NDK_PATH}/toolchains/arm-linux-androideabi-${SWIFT_ANDROID_NDK_GCC_VERSION}/prebuilt/${_swift_android_prebuilt_suffix}/bin/arm-linux-androideabi-${SWIFT_ANDROID_LINKER_NAME}")
 
   configure_sdk_unix(ANDROID "Android" "android" "android" "armv7" "armv7-none-linux-androideabi" "${SWIFT_ANDROID_SDK_PATH}")
@@ -881,7 +879,7 @@ endif()
 ###############
 #
 # We have to include stdlib/ before tools/.
-# Do not move add_subdirectory(stdlib) after add_subdirectory(tools)!
+# Do not move add_subdirectory(stdlib) after add_subdirectory(tools)!                                             
 #
 # We must include stdlib/ before tools/ because stdlib/CMakeLists.txt
 # declares the swift-stdlib-* set of targets. These targets will then
@@ -900,7 +898,7 @@ add_subdirectory(stdlib)
 if(SWIFT_INCLUDE_TOOLS)
   add_subdirectory(include)
   add_subdirectory(lib)
-
+  
   # Always include this after including stdlib/!
   # Refer to the large comment above the add_subdirectory(stdlib) call.
   # https://bugs.swift.org/browse/SR-5975

cmake/modules/AddSwift.cmake

@@ -255,7 +255,7 @@ function(_add_variant_c_compile_flags)
   else()
     list(APPEND result "-DNDEBUG")
   endif()
-
+  
   if(SWIFT_ENABLE_RUNTIME_FUNCTION_COUNTERS)
     list(APPEND result "-DSWIFT_ENABLE_RUNTIME_FUNCTION_COUNTERS")
   endif()
@@ -320,7 +320,7 @@ function(_add_variant_swift_compile_flags
   if (SWIFT_ENABLE_GUARANTEED_NORMAL_ARGUMENTS)
     list(APPEND result "-Xfrontend" "-enable-guaranteed-normal-arguments")
   endif()
-
+  
   if(SWIFT_ENABLE_RUNTIME_FUNCTION_COUNTERS)
     list(APPEND result "-D" "SWIFT_ENABLE_RUNTIME_FUNCTION_COUNTERS")
   endif()
@@ -1605,7 +1605,7 @@ function(add_swift_library name)
         if(SWIFTLIB_IS_SDK_OVERLAY)
           list(APPEND swiftlib_swift_compile_flags_all "-Fsystem" "${SWIFT_SDK_${sdk}_PATH}/System/Library/PrivateFrameworks/")
         endif()
-
+       
        if("${sdk}" STREQUAL "IOS_SIMULATOR")
          if("${name}" STREQUAL "swiftMediaPlayer")
            message("DISABLING AUTOLINK FOR swiftMediaPlayer")
@@ -1854,7 +1854,7 @@ function(add_swift_library name)
           LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX}
           RUNTIME DESTINATION bin)
       swift_is_installing_component(dev is_installing)
-
+      
       if(NOT is_installing)
         set_property(GLOBAL APPEND PROPERTY SWIFT_BUILDTREE_EXPORTS ${name})
       else()
@@ -2177,7 +2177,7 @@ function(add_swift_host_tool executable)
 
     swift_is_installing_component(${ADDSWIFTHOSTTOOL_SWIFT_COMPONENT}
       is_installing)
-
+  
     if(NOT is_installing)
       set_property(GLOBAL APPEND PROPERTY SWIFT_BUILDTREE_EXPORTS ${executable})
     else()

lib/Sema/ConstraintSystem.cpp

@@ -1389,6 +1389,29 @@ void ConstraintSystem::addOverloadSet(Type boundType,
     return;
   }
 
+  // Performance hack: if there are two generic overloads, and one is
+  // more specialized than the other, prefer the more-specialized one.
+  if (!favoredChoice && choices.size() == 2 &&
+      choices[0].isDecl() && choices[1].isDecl() &&
+      isa<AbstractFunctionDecl>(choices[0].getDecl()) &&
+      cast<AbstractFunctionDecl>(choices[0].getDecl())->isGeneric() &&
+      isa<AbstractFunctionDecl>(choices[1].getDecl()) &&
+      cast<AbstractFunctionDecl>(choices[1].getDecl())->isGeneric()) {
+    switch (TC.compareDeclarations(DC, choices[0].getDecl(),
+                                   choices[1].getDecl())) {
+    case Comparison::Better:
+      favoredChoice = const_cast<OverloadChoice *>(&choices[0]);
+      break;
+
+    case Comparison::Worse:
+      favoredChoice = const_cast<OverloadChoice *>(&choices[1]);
+      break;
+
+    case Comparison::Unordered:
+      break;
+    }
+  }
+
   SmallVector<Constraint *, 4> overloads;
 
   // As we do for other favored constraints, if a favored overload has been

test/Compatibility/enum_cases.swift

@@ -19,13 +19,18 @@ enum G_E<T> {
 let arr: [String] = []
 let _ = arr.map(E.foo) // Ok
 let _ = arr.map(E.bar) // Ok
-let _ = arr.map(E.two) // expected-error {{cannot convert value of type '(Int, Int) -> E' to expected argument type '(String) -> _'}}
-let _ = arr.map(E.tuple) // expected-error {{cannot convert value of type '((x: Int, y: Int)) -> E' to expected argument type '(String) -> _'}}
+let _ = arr.map(E.two) // expected-error {{cannot invoke 'map' with an argument list of type '((Int, Int) -> E)'}}
+// expected-note@-1{{expected an argument list of type '((Self.Element) throws -> T)'}}
+let _ = arr.map(E.tuple) // expected-error {{cannot invoke 'map' with an argument list of type '(((x: Int, y: Int)) -> E)'}}
+// expected-note@-1{{expected an argument list of type '((Self.Element) throws -> T)'}}
 
 let _ = arr.map(G_E<String>.foo) // Ok
 let _ = arr.map(G_E<String>.bar) // Ok
-let _ = arr.map(G_E<String>.two) // expected-error {{cannot convert value of type '(String, String) -> G_E<String>' to expected argument type '(String) -> _'}}
-let _ = arr.map(G_E<Int>.tuple) // expected-error {{cannot convert value of type '((x: Int, y: Int)) -> G_E<Int>' to expected argument type '(String) -> _'}}
+let _ = arr.map(G_E<String>.two) // expected-error {{cannot invoke 'map' with an argument list of type '((String, String) -> G_E<String>)'}}
+// expected-note@-1{{expected an argument list of type '((Self.Element) throws -> T)'}}
+
+let _ = arr.map(G_E<Int>.tuple) // expected-error {{cannot invoke 'map' with an argument list of type '(((x: Int, y: Int)) -> G_E<Int>)'}}
+// expected-note@-1{{expected an argument list of type '((Self.Element) throws -> T)'}}
 
 let _ = E.foo("hello") // expected-error {{missing argument label 'bar:' in call}}
 let _ = E.bar("hello") // Ok

test/Constraints/enum_cases.swift

@@ -19,13 +19,18 @@ enum G_E<T> {
 let arr: [String] = []
 let _ = arr.map(E.foo) // Ok
 let _ = arr.map(E.bar) // Ok
-let _ = arr.map(E.two) // expected-error {{cannot convert value of type '(Int, Int) -> E' to expected argument type '(String) -> _'}}
-let _ = arr.map(E.tuple) // expected-error {{cannot convert value of type '((x: Int, y: Int)) -> E' to expected argument type '(String) -> _'}}
+let _ = arr.map(E.two) // expected-error {{cannot invoke 'map' with an argument list of type '((Int, Int) -> E)'}}
+// expected-note@-1{{expected an argument list of type '((Self.Element) throws -> T)'}}
+
+let _ = arr.map(E.tuple) // expected-error {{cannot invoke 'map' with an argument list of type '(((x: Int, y: Int)) -> E)'}}
+// expected-note@-1{{expected an argument list of type '((Self.Element) throws -> T)'}}
 
 let _ = arr.map(G_E<String>.foo) // Ok
 let _ = arr.map(G_E<String>.bar) // Ok
-let _ = arr.map(G_E<String>.two) // expected-error {{cannot convert value of type '(String, String) -> G_E<String>' to expected argument type '(String) -> _'}}
-let _ = arr.map(G_E<Int>.tuple) // expected-error {{cannot convert value of type '((x: Int, y: Int)) -> G_E<Int>' to expected argument type '(String) -> _'}}
+let _ = arr.map(G_E<String>.two) // expected-error {{cannot invoke 'map' with an argument list of type '((String, String) -> G_E<String>)'}}
+// expected-note@-1{{expected an argument list of type '((Self.Element) throws -> T)'}}
+let _ = arr.map(G_E<Int>.tuple) // expected-error {{cannot invoke 'map' with an argument list of type '(((x: Int, y: Int)) -> G_E<Int>)'}}
+// expected-note@-1{{expected an argument list of type '((Self.Element) throws -> T)'}}
 
 let _ = E.foo("hello") // expected-error {{missing argument label 'bar:' in call}}
 let _ = E.bar("hello") // Ok

test/Constraints/optional.swift

@@ -81,14 +81,22 @@ func test8(_ x : AnyObject?) {
 
 
 // Partial ordering with optionals
-func test9_helper<T>(_ x: T) -> Int { }
-func test9_helper<T>(_ x: T?) -> Double { }
+func test9_helper<T: P>(_ x: T) -> Int { }
+func test9_helper<T: P>(_ x: T?) -> Double { }
+
+func test9_helper2<T>(_ x: T) -> Int { }
+func test9_helper2<T>(_ x: T?) -> Double { }
 
 func test9(_ i: Int, io: Int?) {
   let result = test9_helper(i)
   var _: Int = result
   let result2 = test9_helper(io)
   let _: Double = result2
+
+  let result3 = test9_helper2(i)
+  var _: Double = result3
+  let result4 = test9_helper2(io)
+  let _: Double = result4
 }
 
 protocol P { }

test/SwiftSyntax/DeserializeFile.swift

@@ -6,7 +6,6 @@
 import StdlibUnittest
 import Foundation
 import SwiftSyntax
-import SwiftLang
 
 func getInput(_ file: String) -> URL {
   var result = URL(fileURLWithPath: #file)
@@ -20,7 +19,7 @@ var DecodeTests = TestSuite("DecodeSyntax")
 
 DecodeTests.test("Basic") {
   expectDoesNotThrow({
-    let content = try SwiftLang.parse(getInput("visitor.swift"))
+    let content = try SourceFileSyntax.encodeSourceFileSyntax(getInput("visitor.swift"))
     let source = try String(contentsOf: getInput("visitor.swift"))
     let parsed = try SourceFileSyntax.decodeSourceFileSyntax(content)
     expectEqual("\(parsed)", source)

test/SwiftSyntax/ParseFile.swift

@@ -2,11 +2,11 @@
 // REQUIRES: executable_test
 // REQUIRES: OS=macosx
 // REQUIRES: objc_interop
+// REQUIRES: rdar36740859
 
 import Foundation
 import StdlibUnittest
 import SwiftSyntax
-import SwiftLang
 
 var ParseFile = TestSuite("ParseFile")
 
@@ -31,8 +31,7 @@ ParseFile.test("ParseSingleFile") {
   let currentFile = URL(fileURLWithPath: #file)
   expectDoesNotThrow({
     let currentFileContents = try String(contentsOf: currentFile)
-    let parsed = try SourceFileSyntax.decodeSourceFileSyntax(try
-      SwiftLang.parse(currentFile))
+    let parsed = try SourceFileSyntax.parse(currentFile)
     expectEqual("\(parsed)", currentFileContents)
   })
 }

test/SwiftSyntax/VisitorTest.swift

@@ -3,10 +3,12 @@
 // REQUIRES: OS=macosx
 // REQUIRES: objc_interop
 
+// FIXME: This test fails occassionally in CI with invalid json.
+// REQUIRES: disabled
+
 import StdlibUnittest
 import Foundation
 import SwiftSyntax
-import SwiftLang
 
 func getInput(_ file: String) -> URL {
   var result = URL(fileURLWithPath: #file)
@@ -27,8 +29,7 @@ VisitorTests.test("Basic") {
     }
   }
   expectDoesNotThrow({
-    let parsed = try SourceFileSyntax.decodeSourceFileSyntax(try
-      SwiftLang.parse(getInput("visitor.swift")))
+    let parsed = try SourceFileSyntax.parse(getInput("visitor.swift"))
     let counter = FuncCounter()
     let hashBefore = parsed.hashValue
     counter.visit(parsed)

test/lit.cfg

@@ -286,7 +286,6 @@ else:
     test_resource_dir = os.path.join(config.swift_lib_dir, 'swift')
     resource_dir_opt = ""
 stdlib_resource_dir_opt = resource_dir_opt
-sourcekitd_framework_dir = config.swift_lib_dir
 lit_config.note('Using resource dir: ' + test_resource_dir)
 
 # Parse the variant triple.
@@ -671,13 +670,12 @@ if run_vendor == 'apple':
             (run_cpu, run_os, run_vers, clang_mcp_opt))
 
         config.target_build_swift = (
-            "%s %s %s -F %s -Xlinker -rpath -Xlinker %s %s %s %s %s -F %s -Xlinker -rpath -Xlinker %s"
+            "%s %s %s -F %s -Xlinker -rpath -Xlinker %s %s %s %s %s"
             % (xcrun_prefix, config.swiftc, target_options,
                extra_frameworks_dir, extra_frameworks_dir,
                sdk_overlay_linker_opt, config.swift_test_options,
                config.swift_driver_test_options,
-               swift_execution_tests_extra_flags, sourcekitd_framework_dir,
-               sourcekitd_framework_dir))
+               swift_execution_tests_extra_flags))
         config.target_run = ""
 
         if 'interpret' in lit_config.params:

tools/CMakeLists.txt

@@ -1,14 +1,3 @@
-include(CheckIncludeFiles)
-check_include_files("xpc/xpc.h" HAVE_XPC_H)
-
-swift_is_installing_component(sourcekit-inproc SOURCEKIT_INSTALLING_INPROC)
-
-if(HAVE_XPC_H AND SWIFT_BUILD_SOURCEKIT AND NOT SOURCEKIT_INSTALLING_INPROC)
-  set(BUILD_SOURCEKIT_XPC_SERVICE TRUE)
-else()
-  set(BUILD_SOURCEKIT_XPC_SERVICE FALSE)
-endif()
-
 # Add generated libSyntax headers to global dependencies.
 list(APPEND LLVM_COMMON_DEPENDS swift-syntax-generated-headers)
 
@@ -27,27 +16,19 @@ add_swift_tool_subdirectory(swift-api-digester)
 add_swift_tool_subdirectory(swift-syntax-test)
 add_swift_tool_subdirectory(swift-refactor)
 
-if(SWIFT_BUILD_STDLIB AND SWIFT_BUILD_SDK_OVERLAY)
-  set(BUILD_FOUNDATION TRUE)
-else()
-  set(BUILD_FOUNDATION FALSE)
-endif()
-
 if(SWIFT_BUILD_SOURCEKIT)
   add_swift_tool_subdirectory(SourceKit)
-  if(BUILD_SOURCEKIT_XPC_SERVICE AND BUILD_FOUNDATION)
-    add_subdirectory(SwiftSourceKitClient)
-  endif()
 endif()
 
+
 if(SWIFT_HOST_VARIANT STREQUAL "macosx")
   # Only build Darwin-specific tools when deploying to OS X.
   add_swift_tool_subdirectory(swift-stdlib-tool)
 
   # SwiftSyntax depends on both the standard library (because it's a
   # Swift module), and the SDK overlays (because it depends on Foundation).
   # Ensure we only build SwiftSyntax when we're building both.
-  if(BUILD_FOUNDATION)
+  if(SWIFT_BUILD_STDLIB AND SWIFT_BUILD_SDK_OVERLAY)
     add_subdirectory(SwiftSyntax)
   endif()
 endif()

tools/SourceKit/CMakeLists.txt

@@ -24,6 +24,8 @@ configure_file(
 set(SOURCEKIT_DEPLOYMENT_OS "${SWIFT_HOST_VARIANT}")
 set(SOURCEKIT_DEPLOYMENT_TARGET "${SWIFT_SDK_${SWIFT_HOST_VARIANT_SDK}_DEPLOYMENT_VERSION}")
 
+swift_is_installing_component(sourcekit-inproc SOURCEKIT_INSTALLING_INPROC)
+
 if("${CMAKE_SYSTEM_NAME}" STREQUAL "Darwin" AND NOT CMAKE_CROSSCOMPILING)
   set(CMAKE_OSX_SYSROOT "${SWIFT_SDK_${SWIFT_HOST_VARIANT_SDK}_PATH}")
   set(CMAKE_OSX_ARCHITECTURES "${SWIFT_HOST_VARIANT_ARCH}")

tools/SourceKit/tools/sourcekitd/bin/CMakeLists.txt

@@ -1,4 +1,4 @@
   add_subdirectory(InProc)
-if(HAVE_XPC_H)
+if (HAVE_XPC_H)
   add_subdirectory(XPC)
 endif()

tools/SourceKit/tools/sourcekitd/lib/API/CMakeLists.txt

@@ -1,3 +1,7 @@
+include(CheckIncludeFiles)
+
+check_include_files("xpc/xpc.h" HAVE_XPC_H)
+
 # If we were going to build for APPLE but don't have XPC, just build inproc.
 if(APPLE AND NOT HAVE_XPC_H)
   set(SWIFT_SOURCEKIT_USE_INPROC_LIBRARY TRUE)