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Prefix @_cdecl functions with extern "C" in -Swift.h headers #38682

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Merged
merged 1 commit into from
Nov 12, 2021
Merged

Prefix @_cdecl functions with extern "C" in -Swift.h headers #38682

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2 changes: 2 additions & 0 deletions lib/PrintAsObjC/DeclAndTypePrinter.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -728,6 +728,8 @@ class DeclAndTypePrinter::Implementation
auto resultTy = getForeignResultType(
FD, funcTy, asyncConvention, errorConvention);

os << "SWIFT_EXTERN ";

// The result type may be a partial function type we need to close
// up later.
PrintMultiPartType multiPart(*this);
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7 changes: 7 additions & 0 deletions lib/PrintAsObjC/PrintAsObjC.cpp
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Expand Up @@ -243,6 +243,13 @@ static void writePrologue(raw_ostream &out, ASTContext &ctx,
"#if !defined(IBSegueAction)\n"
"# define IBSegueAction\n"
"#endif\n"
"#if !defined(SWIFT_EXTERN)\n"
"# if defined(__cplusplus)\n"
"# define SWIFT_EXTERN extern \"C\"\n"
"# else\n"
"# define SWIFT_EXTERN extern\n"
"# endif\n"
"#endif\n"
;
static_assert(SWIFT_MAX_IMPORTED_SIMD_ELEMENTS == 4,
"need to add SIMD typedefs here if max elements is increased");
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18 changes: 9 additions & 9 deletions test/PrintAsObjC/cdecl.swift
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Expand Up @@ -8,51 +8,51 @@
// REQUIRES: objc_interop

// CHECK: /// What a nightmare!
// CHECK-LABEL: double (^ _Nonnull block_nightmare(SWIFT_NOESCAPE float (^ _Nonnull x)(NSInteger)))(char) SWIFT_WARN_UNUSED_RESULT;
// CHECK-LABEL: SWIFT_EXTERN double (^ _Nonnull block_nightmare(SWIFT_NOESCAPE float (^ _Nonnull x)(NSInteger)))(char) SWIFT_WARN_UNUSED_RESULT;

/// What a nightmare!
@_cdecl("block_nightmare")
public func block_nightmare(x: @convention(block) (Int) -> Float)
-> @convention(block) (CChar) -> Double { return { _ in 0 } }

// CHECK-LABEL: double (^ _Nonnull block_recurring_nightmare(float (^ _Nonnull x)(SWIFT_NOESCAPE NSInteger (^ _Nonnull)(double))))(SWIFT_NOESCAPE char (^ _Nonnull)(unsigned char)) SWIFT_WARN_UNUSED_RESULT;
// CHECK-LABEL: SWIFT_EXTERN double (^ _Nonnull block_recurring_nightmare(float (^ _Nonnull x)(SWIFT_NOESCAPE NSInteger (^ _Nonnull)(double))))(SWIFT_NOESCAPE char (^ _Nonnull)(unsigned char)) SWIFT_WARN_UNUSED_RESULT;
@_cdecl("block_recurring_nightmare")
public func block_recurring_nightmare(x: @escaping @convention(block) (@convention(block) (Double) -> Int) -> Float)
-> @convention(block) (_ asdfasdf: @convention(block) (CUnsignedChar) -> CChar) -> Double {
fatalError()
}

// CHECK-LABEL: void foo_bar(NSInteger x, NSInteger y);
// CHECK-LABEL: SWIFT_EXTERN void foo_bar(NSInteger x, NSInteger y);
@_cdecl("foo_bar")
func foo(x: Int, bar y: Int) {}

// CHECK-LABEL: double (* _Nonnull function_pointer_nightmare(SWIFT_NOESCAPE float (* _Nonnull x)(NSInteger)))(char) SWIFT_WARN_UNUSED_RESULT;
// CHECK-LABEL: SWIFT_EXTERN double (* _Nonnull function_pointer_nightmare(SWIFT_NOESCAPE float (* _Nonnull x)(NSInteger)))(char) SWIFT_WARN_UNUSED_RESULT;
@_cdecl("function_pointer_nightmare")
func function_pointer_nightmare(x: @convention(c) (Int) -> Float)
-> @convention(c) (CChar) -> Double { return { _ in 0 } }

// CHECK-LABEL: double (* _Nonnull function_pointer_recurring_nightmare(float (* _Nonnull x)(SWIFT_NOESCAPE NSInteger (* _Nonnull)(double))))(SWIFT_NOESCAPE char (* _Nonnull)(unsigned char)) SWIFT_WARN_UNUSED_RESULT;
// CHECK-LABEL: SWIFT_EXTERN double (* _Nonnull function_pointer_recurring_nightmare(float (* _Nonnull x)(SWIFT_NOESCAPE NSInteger (* _Nonnull)(double))))(SWIFT_NOESCAPE char (* _Nonnull)(unsigned char)) SWIFT_WARN_UNUSED_RESULT;
@_cdecl("function_pointer_recurring_nightmare")
public func function_pointer_recurring_nightmare(x: @escaping @convention(c) (@convention(c) (Double) -> Int) -> Float)
-> @convention(c) (@convention(c) (CUnsignedChar) -> CChar) -> Double {
fatalError()
}

// CHECK-LABEL: void has_keyword_arg_names(NSInteger auto_, NSInteger union_);
// CHECK-LABEL: SWIFT_EXTERN void has_keyword_arg_names(NSInteger auto_, NSInteger union_);
@_cdecl("has_keyword_arg_names")
func keywordArgNames(auto: Int, union: Int) {}

@objc
class C {}

// CHECK-LABEL: C * _Null_unspecified return_iuo(void) SWIFT_WARN_UNUSED_RESULT;
// CHECK-LABEL: SWIFT_EXTERN C * _Null_unspecified return_iuo(void) SWIFT_WARN_UNUSED_RESULT;
@_cdecl("return_iuo")
func returnIUO() -> C! { return C() }

// CHECK-LABEL: void return_never(void) SWIFT_NORETURN;
// CHECK-LABEL: SWIFT_EXTERN void return_never(void) SWIFT_NORETURN;
@_cdecl("return_never")
func returnNever() -> Never { fatalError() }

// CHECK-LABEL: void takes_iuo(C * _Null_unspecified c);
// CHECK-LABEL: SWIFT_EXTERN void takes_iuo(C * _Null_unspecified c);
@_cdecl("takes_iuo")
func takesIUO(c: C!) {}