Merge pull request #2020 from swiftwasm/main

[pull] swiftwasm from main

Author: pull[bot]

docs/HowToGuides/FAQ.md

@@ -42,7 +42,7 @@ built compiler to compile both packages and Xcode projects.
    Create a build setting `SWIFT_EXEC` with the value set to `/path/to/swiftc`.
    If you now do a clean build, your locally built compiler will be used.
 
-   At the time of writing, in the latest Xcode 12 beta, `SWIFT_EXEC` does not
+   At the time of writing, in the latest Xcode 12.2 beta 3, `SWIFT_EXEC` does not
    work for SwiftPM integration inside Xcode, so this will not work for Xcode
    projects that depend on SwiftPM packages.
 

docs/HowToGuides/GettingStarted.md

@@ -126,7 +126,7 @@ Double-check that running `pwd` prints a path ending with `swift`.
 
 ### macOS
 
-1. Install [Xcode 12 beta 3][Xcode] or newer:
+1. Install [Xcode 12.2 beta 3][Xcode] or newer:
    The required version of Xcode changes frequently and is often a beta release.
    Check this document or the host information on <https://ci.swift.org> for the
    current required version.

include/swift/Sema/ConstraintSystem.h

@@ -3160,8 +3160,7 @@ class ConstraintSystem {
   /// subsequent solution would be worse than the best known solution.
   bool recordFix(ConstraintFix *fix, unsigned impact = 1);
 
-  void recordPotentialHole(TypeVariableType *typeVar);
-  void recordPotentialHole(FunctionType *fnType);
+  void recordPotentialHole(Type type);
 
   void recordTrailingClosureMatch(
       ConstraintLocator *locator,

lib/Sema/CSSimplify.cpp

@@ -9913,16 +9913,11 @@ bool ConstraintSystem::recordFix(ConstraintFix *fix, unsigned impact) {
   return false;
 }
 
-void ConstraintSystem::recordPotentialHole(TypeVariableType *typeVar) {
-  assert(typeVar);
-  typeVar->getImpl().enableCanBindToHole(getSavedBindings());
-}
-
-void ConstraintSystem::recordPotentialHole(FunctionType *fnType) {
-  assert(fnType);
-  Type(fnType).visit([&](Type type) {
+void ConstraintSystem::recordPotentialHole(Type type) {
+  assert(type->hasTypeVariable());
+  type.visit([&](Type type) {
     if (auto *typeVar = type->getAs<TypeVariableType>())
-      recordPotentialHole(typeVar);
+      typeVar->getImpl().enableCanBindToHole(getSavedBindings());
   });
 }
 
@@ -10024,7 +10019,7 @@ ConstraintSystem::SolutionKind ConstraintSystem::simplifyFixConstraint(
           newTupleTypes.push_back(smallerElt);
       } else {
         if (largerElt.getType()->isTypeVariableOrMember())
-          recordPotentialHole(largerElt.getType()->getAs<TypeVariableType>());
+          recordPotentialHole(largerElt.getType());
       }
     }
     auto matchingType =

lib/Sema/TypeCheckEffects.cpp

@@ -878,6 +878,13 @@ class Context {
       HandlesErrors(handlesErrors), HandlesAsync(handlesAsync) { }
 
 public:
+  bool shouldDiagnoseErrorOnTry() const {
+    return DiagnoseErrorOnTry;
+  }
+  void setDiagnoseErrorOnTry(bool b) {
+    DiagnoseErrorOnTry = b;
+  }
+
   /// Whether this is a function that rethrows.
   bool isRethrows() const {
     if (!HandlesErrors)
@@ -1375,6 +1382,7 @@ class CheckEffectsCoverage : public EffectsHandlingWalker<CheckEffectsCoverage>
     DeclContext *OldRethrowsDC;
     ContextFlags OldFlags;
     ThrowingKind OldMaxThrowingKind;
+
   public:
     ContextScope(CheckEffectsCoverage &self, Optional<Context> newContext)
       : Self(self), OldContext(self.CurContext),
@@ -1468,7 +1476,15 @@ class CheckEffectsCoverage : public EffectsHandlingWalker<CheckEffectsCoverage>
     }
 
     ~ContextScope() {
+      // The "DiagnoseErrorOnTry" flag is a bit of mutable state
+      // in the Context itself, used to postpone diagnostic emission
+      // to a parent "try" expression. If something was diagnosed
+      // during this ContextScope, the flag may have been set, and
+      // we need to preseve its value when restoring the old Context.
+      bool DiagnoseErrorOnTry = Self.CurContext.shouldDiagnoseErrorOnTry();
       Self.CurContext = OldContext;
+      Self.CurContext.setDiagnoseErrorOnTry(DiagnoseErrorOnTry);
+
       Self.RethrowsDC = OldRethrowsDC;
       Self.Flags = OldFlags;
       Self.MaxThrowingKind = OldMaxThrowingKind;

test/Constraints/lvalues.swift

@@ -241,3 +241,28 @@ func wump<T>(to: T, _ body: (G<T>) -> ()) {}
 
 wump(to: 0, { $0[] = 0 })
 // expected-error@-1 {{missing argument for parameter #1 in call}}
+
+// SR-13732
+extension MutableCollection {
+  public mutating func writePrefix<I: IteratorProtocol>(from source: inout I)
+    -> (writtenCount: Int, afterLastWritten: Index)
+    where I.Element == Element
+  {
+    fatalError()
+  }
+  
+  public mutating func writePrefix<Source: Collection>(from source: Source)
+    -> (writtenCount: Int, afterLastWritten: Index, afterLastRead: Source.Index)
+    where Source.Element == Element
+  {
+    fatalError()
+  }
+
+}
+
+func testWritePrefixIterator() {
+  var a = Array(0..<10)
+  
+  var underflow = (1..<10).makeIterator()
+  var (writtenCount, afterLastWritten) = a.writePrefix(from: underflow) // expected-error {{passing value of type 'IndexingIterator<(Range<Int>)>' to an inout parameter requires explicit '&'}} {{62-62=&}}
+}

test/expr/unary/async_await.swift

@@ -133,3 +133,12 @@ func testStringInterpolation() async throws {
   _ = "Eventually produces \(await getInt())"
   _ = await "Eventually produces \(getInt())"
 }
+
+// Make sure try await works too
+func invalidAsyncFunction() async {
+  _ = try await throwingAndAsync() // expected-error {{errors thrown from here are not handled}}
+}
+
+func validAsyncFunction() async throws {
+  _ = try await throwingAndAsync()
+}

test/stmt/errors.swift

@@ -251,3 +251,16 @@ func sr_11402_func2(_ x: SR_11402_P) {
     print(y)
   }
 }
+
+// https://bugs.swift.org/browse/SR-13654
+
+func sr_13654_func() throws -> String {}
+
+func sr_13654_invalid_interpolation() {
+  _ = try "\(sr_13654_func())" // expected-error {{errors thrown from here are not handled}}
+  _ = "\(try sr_13654_func())" // expected-error {{errors thrown from here are not handled}}
+}
+func sr_13654_valid_interpolation() throws {
+  _ = try "\(sr_13654_func())"
+  _ = "\(try sr_13654_func())"
+}