Merge pull request #69824 from DougGregor/typed-throws-fixes

Yet more typed throws fixes

Author: DougGregor

lib/AST/Type.cpp

@@ -5065,6 +5065,28 @@ case TypeKind::Id:
         isUnchanged = false;
     }
 
+    llvm::Optional<ASTExtInfo> extInfo;
+    if (function->hasExtInfo()) {
+      extInfo = function->getExtInfo()
+                    .withGlobalActor(globalActorType)
+                    .withThrows(function->isThrowing(), thrownError);
+
+      // If there was a generic thrown error and it substituted with
+      // 'any Error' or 'Never', map to 'throws' or non-throwing rather than
+      // maintaining the sugar.
+      if (auto origThrownError = function->getThrownError()) {
+        if (origThrownError->isTypeParameter() ||
+            origThrownError->isTypeVariableOrMember()) {
+          // 'any Error'
+          if (thrownError->isEqual(
+                  thrownError->getASTContext().getErrorExistentialType()))
+            extInfo = extInfo->withThrows(true, Type());
+          else if (thrownError->isNever())
+            extInfo = extInfo->withThrows(false, Type());
+        }
+      }
+    }
+
     if (auto genericFnType = dyn_cast<GenericFunctionType>(base)) {
 #ifndef NDEBUG
       // Check that generic parameters won't be transformed.
@@ -5080,24 +5102,13 @@ case TypeKind::Id:
       if (isUnchanged) return *this;
 
       auto genericSig = genericFnType->getGenericSignature();
-      if (!function->hasExtInfo())
-        return GenericFunctionType::get(genericSig, substParams, resultTy);
       return GenericFunctionType::get(
-               genericSig, substParams, resultTy,
-               function->getExtInfo()
-                 .withGlobalActor(globalActorType)
-                 .withThrows(function->isThrowing(), thrownError));
+          genericSig, substParams, resultTy, extInfo);
     }
 
     if (isUnchanged) return *this;
 
-    if (!function->hasExtInfo())
-      return FunctionType::get(substParams, resultTy);
-    return FunctionType::get(
-             substParams, resultTy,
-             function->getExtInfo()
-               .withGlobalActor(globalActorType)
-               .withThrows(function->isThrowing(), thrownError));
+    return FunctionType::get(substParams, resultTy, extInfo);
   }
 
   case TypeKind::ArraySlice: {

lib/SILOptimizer/LoopTransforms/ForEachLoopUnroll.cpp

@@ -483,10 +483,11 @@ static void unrollForEach(ArrayInfo &arrayInfo, TryApplyInst *forEachCall,
   // targets must be taking a phi argument.
   SILBasicBlock *normalBB = forEachCall->getNormalBB();
   SILBasicBlock *errorBB = forEachCall->getErrorBB();
-  assert(errorBB->getSILPhiArguments().size() == 1 &&
-         normalBB->getSILPhiArguments().size() == 1);
+  assert(normalBB->getSILPhiArguments().size() == 1);
   SILPhiArgument *normalArgument = normalBB->getSILPhiArguments()[0];
-  SILPhiArgument *errorArgument = errorBB->getSILPhiArguments()[0];
+  SILPhiArgument *errorArgument = nullptr;
+  if (errorBB->getSILPhiArguments().size() == 1)
+    errorArgument = errorBB->getSILPhiArguments()[0];
 
   // A generator for creating a basic block for use as the target of the
   // "normal" branch of a try_apply.
@@ -503,8 +504,12 @@ static void unrollForEach(ArrayInfo &arrayInfo, TryApplyInst *forEachCall,
   auto errorTargetGenerator = [&](SILBasicBlock *insertionBlock,
                                   SILValue borrowedElem, SILValue storeBorrow) {
     SILBasicBlock *newErrorBB = fun->createBasicBlockBefore(insertionBlock);
-    SILValue argument = newErrorBB->createPhiArgument(
+    SILValue argument;
+    if (errorArgument) {
+      argument = newErrorBB->createPhiArgument(
         errorArgument->getType(), errorArgument->getOwnershipKind());
+    }
+
     // Make the errorBB jump to the error target of the original forEach.
     SILBuilderWithScope builder(newErrorBB, forEachCall);
     if (storeBorrow) {
@@ -513,7 +518,11 @@ static void unrollForEach(ArrayInfo &arrayInfo, TryApplyInst *forEachCall,
     if (borrowedElem) {
       builder.createEndBorrow(forEachLoc, borrowedElem);
     }
-    builder.createBranch(forEachLoc, errorBB, argument);
+
+    if (argument)
+      builder.createBranch(forEachLoc, errorBB, argument);
+    else
+      builder.createBranch(forEachLoc, errorBB);
     return newErrorBB;
   };
 

lib/SILOptimizer/Mandatory/TransferNonSendable.cpp

@@ -640,7 +640,8 @@ class PartitionOpTranslator {
 
     if (auto tryApplyInst = dyn_cast<TryApplyInst>(inst)) {
       foundResults.emplace_back(tryApplyInst->getNormalBB()->getArgument(0));
-      foundResults.emplace_back(tryApplyInst->getErrorBB()->getArgument(0));
+      if (tryApplyInst->getErrorBB()->getNumArguments() > 0)
+        foundResults.emplace_back(tryApplyInst->getErrorBB()->getArgument(0));
       return;
     }
 

lib/SILOptimizer/Transforms/SpeculativeDevirtualizer.cpp

@@ -239,11 +239,19 @@ static FullApplySite speculateMonomorphicTarget(FullApplySite AI,
   // Split critical edges resulting from VirtAI.
   if (auto *TAI = dyn_cast<TryApplyInst>(VirtAI)) {
     auto *ErrorBB = TAI->getFunction()->createBasicBlock();
-    ErrorBB->createPhiArgument(TAI->getErrorBB()->getArgument(0)->getType(),
-                               OwnershipKind::Owned);
+    SILArgument *ErrorArg = nullptr;
+    if (TAI->getErrorBB()->getNumArguments() == 1) {
+      ErrorArg = TAI->getErrorBB()->getArgument(0);
+      ErrorBB->createPhiArgument(ErrorArg->getType(), OwnershipKind::Owned);
+    }
     Builder.setInsertionPoint(ErrorBB);
-    Builder.createBranch(TAI->getLoc(), TAI->getErrorBB(),
-                         {ErrorBB->getArgument(0)});
+
+    if (ErrorArg) {
+      Builder.createBranch(TAI->getLoc(), TAI->getErrorBB(),
+                           {ErrorBB->getArgument(0)});
+    } else {
+      Builder.createBranch(TAI->getLoc(), TAI->getErrorBB());
+    }
 
     auto *NormalBB = TAI->getFunction()->createBasicBlock();
     NormalBB->createPhiArgument(TAI->getNormalBB()->getArgument(0)->getType(),

test/decl/func/typed_throws.swift

@@ -179,3 +179,14 @@ func fromRethrows(body: () throws -> Void) rethrows {
   try notRethrowsLike2(body) // expected-error{{call can throw, but the error is not handled; a function declared 'rethrows' may only throw if its parameter does}}
   try notRethrowsLike3(body) // expected-error{{call can throw, but the error is not handled; a function declared 'rethrows' may only throw if its parameter does}}
 }
+
+// Substitution involving 'any Error' or 'Never' thrown error types should
+// use untyped throws or be non-throwing.
+enum G_E<T> {
+  case tuple((x: T, y: T))
+}
+
+func testArrMap(arr: [String]) {
+  _ = mapArray(arr, body: G_E<Int>.tuple)
+  // expected-error@-1{{cannot convert value of type '((x: Int, y: Int)) -> G_E<Int>' to expected argument type '(String) -> G_E<Int>'}}
+}