Merge pull request #59611 from gottesmm/moveonly-rebase

[no-implicit-copy] Update SILGen/move checker to work with new patterns from copyable_to_moveonly and friends.

Author: gottesmm

include/swift/SIL/SILValue.h

@@ -558,6 +558,19 @@ class ValueBase : public SILNode, public SILAllocated<ValueBase> {
 
   bool isLexical() const;
 
+  /// Unsafely eliminate moveonly from this value's type. Returns true if the
+  /// value's underlying type was move only and thus was changed. Returns false
+  /// otherwise.
+  ///
+  /// NOTE: Please do not use this directly! It is only meant to be used by the
+  /// optimizer pass: SILMoveOnlyTypeEliminator.
+  bool unsafelyEliminateMoveOnlyWrapper() {
+    if (!Type.isMoveOnlyWrapped())
+      return false;
+    Type = Type.removingMoveOnlyWrapper();
+    return true;
+  }
+
   static bool classof(SILNodePointer node) {
     return node->getKind() >= SILNodeKind::First_ValueBase &&
            node->getKind() <= SILNodeKind::Last_ValueBase;

include/swift/SILOptimizer/PassManager/Passes.def

@@ -440,6 +440,10 @@ PASS(MoveOnlyChecker, "sil-move-only-checker",
 PASS(MoveKillsCopyableValuesChecker, "sil-move-kills-copyable-values-checker",
      "Pass that checks that any copyable (non-move only) value that is passed "
      "to _move do not have any uses later than the _move")
+PASS(TrivialMoveOnlyTypeEliminator, "sil-trivial-move-only-type-eliminator",
+     "Pass that rewrites SIL to remove move only types from values of trivial type")
+PASS(MoveOnlyTypeEliminator, "sil-move-only-type-eliminator",
+     "Pass that rewrites SIL to remove move only types from all values")
 PASS(LexicalLifetimeEliminator, "sil-lexical-lifetime-eliminator",
      "Pass that removes lexical lifetime markers from borrows and alloc stack")
 PASS(MoveKillsCopyableAddressesChecker, "sil-move-kills-copyable-addresses-checker",

lib/SILGen/SILGenApply.cpp

@@ -1786,8 +1786,33 @@ static void emitRawApply(SILGenFunction &SGF,
 
   // Gather the arguments.
   for (auto i : indices(args)) {
-    auto argValue = (inputParams[i].isConsumed() ? args[i].forward(SGF)
-                                                 : args[i].getValue());
+    SILValue argValue;
+    if (inputParams[i].isConsumed()) {
+      argValue = args[i].forward(SGF);
+      if (argValue->getType().isMoveOnlyWrapped()) {
+        argValue =
+            SGF.B.createOwnedMoveOnlyWrapperToCopyableValue(loc, argValue);
+      }
+    } else {
+      ManagedValue arg = args[i];
+
+      // Move only is not represented in the Swift level type system, so if we
+      // have a move only value, convert it to a non-move only value. The
+      // move/is no escape checkers will ensure that it is legal to do this or
+      // will error. At this point we just want to make sure that the emitted
+      // types line up.
+      if (arg.getType().isMoveOnlyWrapped()) {
+        // We need to borrow so that we can convert from $@moveOnly T -> $T. Use
+        // a formal access borrow to ensure that we have tight scopes like we do
+        // when we borrow fn.
+        if (!arg.isPlusZero())
+          arg = arg.formalAccessBorrow(SGF, loc);
+        arg = SGF.B.createGuaranteedMoveOnlyWrapperToCopyableValue(loc, arg);
+      }
+
+      argValue = arg.getValue();
+    }
+
 #ifndef NDEBUG
     auto inputTy =
         substFnConv.getSILType(inputParams[i], SGF.getTypeExpansionContext());
@@ -3059,6 +3084,18 @@ class ArgEmitter {
 
       // If it's not already in memory, put it there.
       if (!result.getType().isAddress()) {
+        // If we have a move only wrapped type, we need to unwrap before we
+        // materialize. We will forward as appropriate so it will show up as a
+        // consuming use or a guaranteed use as appropriate.
+        if (result.getType().isMoveOnlyWrapped()) {
+          if (result.isPlusOne(SGF)) {
+            result =
+                SGF.B.createOwnedMoveOnlyWrapperToCopyableValue(loc, result);
+          } else {
+            result = SGF.B.createGuaranteedMoveOnlyWrapperToCopyableValue(
+                loc, result);
+          }
+        }
         result = result.materialize(SGF, loc);
       }
 

lib/SILGen/SILGenBuilder.cpp

@@ -12,6 +12,7 @@
 
 #include "SILGenBuilder.h"
 #include "ArgumentSource.h"
+#include "Cleanup.h"
 #include "RValue.h"
 #include "SILGenFunction.h"
 #include "Scope.h"
@@ -450,6 +451,9 @@ static ManagedValue createInputFunctionArgument(SILGenBuilder &B, SILType type,
   case SILArgumentConvention::Direct_Unowned:
     // Unowned parameters are only guaranteed at the instant of the call, so we
     // must retain them even if we're in a context that can accept a +0 value.
+    //
+    // NOTE: If we have a trivial value, the copy will do nothing, so this is
+    // just a convenient way to avoid writing conditional code.
     return ManagedValue::forUnmanaged(arg).copy(SGF, loc);
 
   case SILArgumentConvention::Direct_Owned:
@@ -882,3 +886,38 @@ ManagedValue SILGenBuilder::createMarkDependence(SILLocation loc,
                                    base.forward(getSILGenFunction()));
   return cloner.clone(mdi);
 }
+
+ManagedValue SILGenBuilder::createBeginBorrow(SILLocation loc,
+                                              ManagedValue value,
+                                              bool isLexical) {
+  auto *newValue =
+      SILBuilder::createBeginBorrow(loc, value.getValue(), isLexical);
+  SGF.emitManagedBorrowedRValueWithCleanup(newValue);
+  return ManagedValue::forUnmanaged(newValue);
+}
+
+ManagedValue SILGenBuilder::createMoveValue(SILLocation loc,
+                                            ManagedValue value) {
+  assert(value.isPlusOne(SGF) && "Must be +1 to be moved!");
+  CleanupCloner cloner(*this, value);
+  auto *mdi = createMoveValue(loc, value.forward(getSILGenFunction()));
+  return cloner.clone(mdi);
+}
+
+ManagedValue
+SILGenBuilder::createOwnedMoveOnlyWrapperToCopyableValue(SILLocation loc,
+                                                         ManagedValue value) {
+  assert(value.isPlusOne(SGF) && "Argument must be at +1!");
+  CleanupCloner cloner(*this, value);
+  auto *mdi = createOwnedMoveOnlyWrapperToCopyableValue(
+      loc, value.forward(getSILGenFunction()));
+  return cloner.clone(mdi);
+}
+
+ManagedValue SILGenBuilder::createGuaranteedMoveOnlyWrapperToCopyableValue(
+    SILLocation loc, ManagedValue value) {
+  auto *mdi =
+      createGuaranteedMoveOnlyWrapperToCopyableValue(loc, value.getValue());
+  assert(mdi->getOperand()->getType().isObject() && "Expected an object?!");
+  return ManagedValue::forUnmanaged(mdi);
+}

lib/SILGen/SILGenBuilder.h

@@ -26,8 +26,9 @@
 #include "JumpDest.h"
 #include "ManagedValue.h"
 #include "RValue.h"
-#include "swift/SIL/SILBuilder.h"
 #include "swift/Basic/ProfileCounter.h"
+#include "swift/SIL/SILBuilder.h"
+#include "swift/SIL/SILLocation.h"
 
 namespace swift {
 namespace Lowering {
@@ -362,7 +363,19 @@ class SILGenBuilder : public SILBuilder {
   BranchInst *createBranch(SILLocation Loc, SILBasicBlock *TargetBlock,
                            ArrayRef<ManagedValue> Args);
 
-  using SILBuilder::createReturn;
+  ReturnInst *createReturn(SILLocation Loc, SILValue ReturnValue) {
+    // If we have a move only type as our "result type", convert it back to
+    // being a copyable type. Move only types are never returned today and we
+    // will rely on the SIL level move only and no escape checker to validate
+    // that this is a correct usage. So just make the types line up.
+    if (ReturnValue->getType().isMoveOnlyWrapped()) {
+      auto cvtLoc = RegularLocation::getAutoGeneratedLocation();
+      ReturnValue =
+          createOwnedMoveOnlyWrapperToCopyableValue(cvtLoc, ReturnValue);
+    }
+    return SILBuilder::createReturn(Loc, ReturnValue);
+  }
+
   ReturnInst *createReturn(SILLocation Loc, ManagedValue ReturnValue);
 
   ReturnInst *createReturn(SILLocation Loc, SILValue ReturnValue,
@@ -385,6 +398,22 @@ class SILGenBuilder : public SILBuilder {
   using SILBuilder::createMarkDependence;
   ManagedValue createMarkDependence(SILLocation loc, ManagedValue value,
                                     ManagedValue base);
+
+  using SILBuilder::createBeginBorrow;
+  ManagedValue createBeginBorrow(SILLocation loc, ManagedValue value,
+                                 bool isLexical = false);
+
+  using SILBuilder::createMoveValue;
+  ManagedValue createMoveValue(SILLocation loc, ManagedValue value);
+
+  using SILBuilder::createOwnedMoveOnlyWrapperToCopyableValue;
+  ManagedValue createOwnedMoveOnlyWrapperToCopyableValue(SILLocation loc,
+                                                         ManagedValue value);
+
+  using SILBuilder::createGuaranteedMoveOnlyWrapperToCopyableValue;
+  ManagedValue
+  createGuaranteedMoveOnlyWrapperToCopyableValue(SILLocation loc,
+                                                 ManagedValue value);
 };
 
 } // namespace Lowering