Ignore "noescape" bit for all @convention(c) function pointers

Author: asl

include/swift/AST/ExtInfo.h

@@ -358,8 +358,6 @@ class ASTExtInfoBuilder {
 
   constexpr Representation getRepresentation() const {
     unsigned rawRep = bits & RepresentationMask;
-    assert(rawRep <= unsigned(Representation::Last) &&
-           "unexpected SIL representation");
     return Representation(rawRep);
   }
 

include/swift/AST/Types.h

@@ -3088,6 +3088,14 @@ class AnyFunctionType : public TypeBase {
       static_assert(
           ASTExtInfoBuilder::NumMaskBits == NumAFTExtInfoBits,
           "ExtInfo and AnyFunctionTypeBitfields must agree on bit size");
+
+      // Canonicalize all thin functions to be escaping (to keep compatibility
+      // with generic parameters).
+      Representation rep = Info.getValue().getRepresentation();
+      if (rep == FunctionTypeRepresentation::CFunctionPointer) {
+        auto extInfoBuilder = Info->intoBuilder().withNoEscape(false);
+        Bits.AnyFunctionType.ExtInfoBits = extInfoBuilder.bits;
+      }
     } else {
       Bits.AnyFunctionType.HasExtInfo = false;
       Bits.AnyFunctionType.HasClangTypeInfo = false;

lib/AST/ASTContext.cpp

@@ -24,6 +24,7 @@
 #include "swift/AST/DiagnosticsSema.h"
 #include "swift/AST/DistributedDecl.h"
 #include "swift/AST/ExistentialLayout.h"
+#include "swift/AST/ExtInfo.h"
 #include "swift/AST/FileUnit.h"
 #include "swift/AST/ForeignAsyncConvention.h"
 #include "swift/AST/ForeignErrorConvention.h"
@@ -3961,6 +3962,13 @@ SILFunctionType::SILFunctionType(
   if (!ext.getClangTypeInfo().empty())
     *getTrailingObjects<ClangTypeInfo>() = ext.getClangTypeInfo();
 
+  // Canonicalize all thin functions to be escaping (to keep compatibility
+  // with generic parameters)
+  if (ext.getRepresentation() == SILFunctionTypeRepresentation::CFunctionPointer) {
+    auto extInfoBuilder = ext.intoBuilder().withNoEscape(false);
+    Bits.SILFunctionType.ExtInfoBits = extInfoBuilder.bits;
+  }
+
 #ifndef NDEBUG
   if (ext.getRepresentation() == Representation::WitnessMethod)
     assert(!WitnessMethodConformance.isInvalid() &&

test/PrintAsObjC/blocks.swift

@@ -101,7 +101,7 @@ typealias MyBlockWithNoescapeParam = (() -> ()) -> Int
   ) {
   }
 
-  // CHECK-NEXT: - (void (* _Nonnull)(SWIFT_NOESCAPE NSInteger (* _Nonnull)(NSInteger, NSInteger)))returnsFunctionPointerThatTakesFunctionPointer SWIFT_WARN_UNUSED_RESULT;
+  // CHECK-NEXT: - (void (* _Nonnull)(NSInteger (* _Nonnull)(NSInteger, NSInteger)))returnsFunctionPointerThatTakesFunctionPointer SWIFT_WARN_UNUSED_RESULT;
   @objc func returnsFunctionPointerThatTakesFunctionPointer() ->
     @convention(c) (_ comparator: @convention(c) (_ x: Int, _ y: Int) -> Int) -> Void {
     fatalError()

test/PrintAsObjC/cdecl-imports.swift

@@ -18,7 +18,7 @@ import Foundation
 public func fwdDeclaresBee() -> Bee { fatalError() }
 
 // CHECK: @class Hive;
-// CHECK-LABEL: void fwd_declares_hive(SWIFT_NOESCAPE Hive * _Nonnull (* _Nonnull bzzz)(Bee * _Nonnull));
+// CHECK-LABEL: void fwd_declares_hive(Hive * _Nonnull (* _Nonnull bzzz)(Bee * _Nonnull));
 
 @_cdecl("fwd_declares_hive")
 public func fwdDeclaresHive(bzzz: @convention(c) (Bee) -> Hive) { fatalError() }

test/PrintAsObjC/cdecl.swift

@@ -26,12 +26,12 @@ public func block_recurring_nightmare(x: @escaping @convention(block) (@conventi
 @_cdecl("foo_bar")
 func foo(x: Int, bar y: Int) {}
 
-// CHECK-LABEL: SWIFT_EXTERN 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(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: 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;
+// CHECK-LABEL: SWIFT_EXTERN double (* _Nonnull function_pointer_recurring_nightmare(float (* _Nonnull x)(NSInteger (* _Nonnull)(double))))(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 {

test/SIL/clang-function-types-nonwindows.swift

@@ -7,6 +7,6 @@ import ctypes
 
 public func f(g: @convention(c, cType: "void (*)(size_t)") (Int) -> ()) { g(0) }
 
-// CHECK: sil @$s4main1f1gyySiXzC9_ZTSPFvmE_tF : $@convention(thin) (@convention(c, cType: "void (*)(unsigned long)") @noescape (Int) -> ()) -> () {
-// CHECK: bb0(%0 : $@convention(c, cType: "void (*)(unsigned long)") @noescape (Int) -> ()):
-// CHECK:   debug_value %0 : $@convention(c, cType: "void (*)(unsigned long)") @noescape (Int) -> (), let, name "g", argno 1 // id: %1
+// CHECK: sil @$s4main1f1gyySiXzC9_ZTSPFvmE_tF : $@convention(thin) (@convention(c, cType: "void (*)(unsigned long)") (Int) -> ()) -> () {
+// CHECK: bb0(%0 : $@convention(c, cType: "void (*)(unsigned long)") (Int) -> ()):
+// CHECK:   debug_value %0 : $@convention(c, cType: "void (*)(unsigned long)") (Int) -> (), let, name "g", argno 1 // id: %1

test/SILGen/c_function_pointers.swift

@@ -40,7 +40,7 @@ func calls(_ arg: @convention(c) (Int) -> Int, _ x: Int) -> Int {
   return arg(x)
 }
 // CHECK-LABEL: sil hidden [ossa] @$s19c_function_pointers5callsyS3iXC_SitF
-// CHECK:       bb0(%0 : $@convention(c) @noescape (Int) -> Int, %1 : $Int):
+// CHECK:       bb0(%0 : $@convention(c) (Int) -> Int, %1 : $Int):
 // CHECK:         [[RESULT:%.*]] = apply %0(%1)
 // CHECK:         return [[RESULT]]
 
@@ -60,24 +60,20 @@ func pointers_to_swift_functions(_ x: Int) {
   func local(_ y: Int) -> Int { return y }
 
   // CHECK:   [[GLOBAL_C:%.*]] = function_ref @$s19c_function_pointers6globalyS2iFTo
-  // CHECK:   [[CVT:%.*]] = convert_function [[GLOBAL_C]]
-  // CHECK:   apply {{.*}}([[CVT]], [[X]])
+  // CHECK:   apply {{.*}}([[GLOBAL_C]], [[X]])
   calls(global, x)
 
   // CHECK:   [[LOCAL_C:%.*]] = function_ref @$s19c_function_pointers0B19_to_swift_functionsyySiF5localL_yS2iFTo
-  // CHECK:   [[CVT:%.*]] = convert_function [[LOCAL_C]]
-  // CHECK:   apply {{.*}}([[CVT]], [[X]])
+  // CHECK:   apply {{.*}}([[LOCAL_C]], [[X]])
   calls(local, x)
 
-  // CHECK:   [[CLOSURE_C:%.*]] = function_ref @$s19c_function_pointers0B19_to_swift_functionsyySiFS2iXEfU_To
-  // CHECK:   [[CVT:%.*]] = convert_function [[CLOSURE_C]]
-  // CHECK:   apply {{.*}}([[CVT]], [[X]])
+  // CHECK:   [[CLOSURE_C:%.*]] = function_ref @$s19c_function_pointers0B19_to_swift_functionsyySiFS2icfU_To
+  // CHECK:   apply {{.*}}([[CLOSURE_C]], [[X]])
   calls({ $0 + 1 }, x)
 
   calls_no_args(no_args)
   // CHECK:   [[NO_ARGS_C:%.*]] = function_ref @$s19c_function_pointers7no_argsSiyFTo
-  // CHECK:   [[CVT:%.*]] = convert_function [[NO_ARGS_C]]
-  // CHECK:   apply {{.*}}([[CVT]])
+  // CHECK:   apply {{.*}}([[NO_ARGS_C]])
 }
 
 func unsupported(_ a: Any) -> Int { return 0 }

test/SILGen/objc_blocks_bridging.swift

@@ -66,7 +66,7 @@ import Foundation
   }
 
   // CHECK-LABEL: sil hidden [thunk] [ossa] @$s20objc_blocks_bridging3FooC16cFunctionPointer{{[_0-9a-zA-Z]*}}FTo
-  // CHECK:       bb0([[F:%.*]] : $@convention(c) @noescape (Int) -> Int, [[X:%.*]] : $Int, [[SELF:%.*]] : @unowned $Foo):
+  // CHECK:       bb0([[F:%.*]] : $@convention(c) (Int) -> Int, [[X:%.*]] : $Int, [[SELF:%.*]] : @unowned $Foo):
   // CHECK:         [[SELF_COPY:%.*]] = copy_value [[SELF]]
   // CHECK:         [[BORROWED_SELF_COPY:%.*]] = begin_borrow [[SELF_COPY]]
   // CHECK:         [[NATIVE:%.*]] = function_ref @$s20objc_blocks_bridging3FooC16cFunctionPointer{{[_0-9a-zA-Z]*}}F

test/SILGen/without_actually_escaping.swift

@@ -102,8 +102,8 @@ func withoutActuallyEscapingConflict() {
 }
 
 // CHECK-LABEL: sil [ossa] @$s25without_actually_escaping0A25ActuallyEscapingCFunction8functionyyyXC_tF
-// CHECK: bb0([[ARG:%.*]] : $@convention(c) @noescape () -> ()):
-// CHECK:   [[E:%.*]] = convert_function [[ARG]] : $@convention(c) @noescape () -> () to [without_actually_escaping] $@convention(c) () -> ()
+// CHECK: bb0([[ARG:%.*]] : $@convention(c) () -> ()):
+// CHECK:   [[E:%.*]] = convert_function [[ARG]] : $@convention(c) () -> () to [without_actually_escaping] $@convention(c) () -> ()
 // CHECK:   [[F:%.*]] = function_ref @$s25without_actually_escaping0A25ActuallyEscapingCFunction8functionyyyXC_tFyyyXCXEfU_ : $@convention(thin) (@convention(c) () -> ()) -> ()
 // CHECK:   apply [[F]]([[E]]) : $@convention(thin) (@convention(c) () -> ()) -> ()
 public func withoutActuallyEscapingCFunction(function: (@convention(c) () -> Void)) {