ClangImporter: Preserve CChar type (swiftlang#32692)

Addresses SR-466.

Author: dduan

include/swift/ClangImporter/BuiltinMappedTypes.def

@@ -21,23 +21,32 @@
 //  - CLANG_BUILTIN_KIND is the kind of builtin type, clang::BuiltinType
 //  - SWIFT_TYPE_NAME is the name of the corresponding stdlib type.
 //
+// MAP_BUILTIN_CCHAR_TYPE(CLANG_BUILTIN_KIND, SWIFT_TYPE_NAME)
+//  - CLANG_BUILTIN_KIND is the kind of builtin type, clang::BuiltinType
+//  - SWIFT_TYPE_NAME is the name of the corresponding stdlib type.
+//
 //===----------------------------------------------------------------------===//
 
 #ifndef MAP_BUILTIN_INTEGER_TYPE
 #define MAP_BUILTIN_INTEGER_TYPE(CLANG, SWIFT) MAP_BUILTIN_TYPE(CLANG, SWIFT)
 #endif
 
+#ifndef MAP_BUILTIN_CCHAR_TYPE
+#define MAP_BUILTIN_CCHAR_TYPE(CLANG, SWIFT) MAP_BUILTIN_TYPE(CLANG, SWIFT)
+#endif
+
+MAP_BUILTIN_CCHAR_TYPE(Char_U,    CChar)
+MAP_BUILTIN_CCHAR_TYPE(Char_S,    CChar)
+MAP_BUILTIN_CCHAR_TYPE(WChar_S,   CWideChar)
+MAP_BUILTIN_CCHAR_TYPE(WChar_U,   CWideChar)
+
 MAP_BUILTIN_TYPE(Bool,      CBool)
-MAP_BUILTIN_INTEGER_TYPE(Char_U,    CChar)
-MAP_BUILTIN_INTEGER_TYPE(Char_S,    CChar)
 MAP_BUILTIN_INTEGER_TYPE(UChar,     CUnsignedChar)
 MAP_BUILTIN_INTEGER_TYPE(UShort,    CUnsignedShort)
 MAP_BUILTIN_INTEGER_TYPE(UInt,      CUnsignedInt)
 MAP_BUILTIN_INTEGER_TYPE(ULong,     CUnsignedLong)
 MAP_BUILTIN_INTEGER_TYPE(ULongLong, CUnsignedLongLong)
 MAP_BUILTIN_INTEGER_TYPE(UInt128,   CUnsignedInt128)
-MAP_BUILTIN_INTEGER_TYPE(WChar_S,   CWideChar)
-MAP_BUILTIN_INTEGER_TYPE(WChar_U,   CWideChar)
 MAP_BUILTIN_INTEGER_TYPE(Char16,    CChar16)
 MAP_BUILTIN_INTEGER_TYPE(Char32,    CChar32)
 MAP_BUILTIN_INTEGER_TYPE(SChar,     CSignedChar)
@@ -54,4 +63,4 @@ MAP_BUILTIN_TYPE(LongDouble, CLongDouble)
 
 #undef MAP_BUILTIN_TYPE
 #undef MAP_BUILTIN_INTEGER_TYPE
-
+#undef MAP_BUILTIN_CCHAR_TYPE

lib/ClangImporter/ImportType.cpp

@@ -236,7 +236,9 @@ namespace {
       case clang::BuiltinType::CLANG_BUILTIN_KIND:                        \
         return unwrapCType(Impl.getNamedSwiftType(Impl.getStdlibModule(), \
                                         #SWIFT_TYPE_NAME));
-          
+#define MAP_BUILTIN_CCHAR_TYPE(CLANG_BUILTIN_KIND, SWIFT_TYPE_NAME)       \
+      case clang::BuiltinType::CLANG_BUILTIN_KIND:                        \
+        return Impl.getNamedSwiftType(Impl.getStdlibModule(), #SWIFT_TYPE_NAME);
 #include "swift/ClangImporter/BuiltinMappedTypes.def"
 
       // Types that cannot be mapped into Swift, and probably won't ever be.

test/ClangImporter/ctypes_parse.swift

@@ -223,7 +223,7 @@ func testStructDefaultInit() {
 
 func testArrays() {
   nonnullArrayParameters([], [], [])
-  nonnullArrayParameters(nil, [], []) // expected-error {{'nil' is not compatible with expected argument type 'UnsafePointer<Int8>'}}
+  nonnullArrayParameters(nil, [], []) // expected-error {{'nil' is not compatible with expected argument type 'UnsafePointer<CChar>'}}
   nonnullArrayParameters([], nil, []) // expected-error {{'nil' is not compatible with expected argument type 'UnsafePointer<UnsafeMutableRawPointer?>'}}
   nonnullArrayParameters([], [], nil) // expected-error {{'nil' is not compatible with expected argument type 'UnsafePointer<Int32>'}}
 
@@ -233,7 +233,7 @@ func testArrays() {
   // It would also be nice to warn here about the arrays being too short, but
   // that's probably beyond us for a while.
   staticBoundsArray([])
-  staticBoundsArray(nil) // expected-error {{'nil' is not compatible with expected argument type 'UnsafePointer<Int8>'}}
+  staticBoundsArray(nil) // expected-error {{'nil' is not compatible with expected argument type 'UnsafePointer<CChar>'}}
 }
 
 func testVaList() {

test/ClangImporter/ctypes_parse_swift4.swift

@@ -6,5 +6,5 @@ func testArrays() {
   // It would also be nice to warn here about the arrays being too short, but
   // that's probably beyond us for a while.
   staticBoundsArray([])
-  staticBoundsArray(nil) // expected-error {{'nil' is not compatible with expected argument type 'UnsafePointer<Int8>'}}
+  staticBoundsArray(nil) // expected-error {{'nil' is not compatible with expected argument type 'UnsafePointer<CChar>'}}
 }

test/IDE/infer_import_as_member.swift

@@ -89,7 +89,7 @@ let _ = mine.getCollisionNonProperty(1)
 // PRINT-NEXT:  }
 // PRINT-NEXT:  extension IAMMutableStruct1 {
 // PRINT-NEXT:    init(with withIAMStruct1: IAMStruct1)
-// PRINT-NEXT:    init(url url: UnsafePointer<Int8>!)
+// PRINT-NEXT:    init(url url: UnsafePointer<CChar>!)
 // PRINT-NEXT:    func doSomething()
 // PRINT-NEXT:  }
 //

test/IDE/print_omit_needless_words.swift

@@ -172,7 +172,7 @@
 // CHECK-FOUNDATION: var setShouldBeInfinite: Bool { get }
 
 // "UTF8" initialisms.
-// CHECK-FOUNDATION: init?(utf8String: UnsafePointer<Int8>!)
+// CHECK-FOUNDATION: init?(utf8String: UnsafePointer<CChar>!)
 
 // Don't strip prefixes from globals.
 // CHECK-FOUNDATION: let NSGlobalConstant: String

test/IDE/print_omit_needless_words_appkit.swift

@@ -18,7 +18,7 @@
 // CHECK-APPKIT: func same() -> Self
 
 // Note: Unsafe(Mutable)Pointers don't get defaulted to 'nil'
-// CHECK-APPKIT: func getRGBAComponents(_: UnsafeMutablePointer<Int8>?)
+// CHECK-APPKIT: func getRGBAComponents(_: UnsafeMutablePointer<CChar>?)
 
 // Note: Skipping over "3D"
 // CHECK-APPKIT: func drawInAir(at: Point3D)

test/Interop/C/chars/Inputs/import-cchar-types.h

@@ -0,0 +1,4 @@
+#include <stddef.h>
+
+extern char a_char;
+extern wchar_t a_wchar;

test/Interop/C/chars/Inputs/module.modulemap

@@ -0,0 +1,4 @@
+module ImportCCharTypes {
+  header "import-cchar-types.h"
+  export *
+}

test/Interop/C/chars/import-cchar-types.swift

@@ -0,0 +1,4 @@
+// RUN: %target-swift-ide-test -print-module -module-to-print=ImportCCharTypes -I %S/Inputs -source-filename=x | %FileCheck %s
+
+// CHECK: var a_char: CChar
+// CHECK: var a_wchar: wchar_t