Don't represent mutate lifetime dependence separately

Author: meg-gupta

include/swift/AST/LifetimeDependence.h

@@ -132,7 +132,6 @@ class LifetimeDependenceSpecifier {
 class LifetimeDependenceInfo {
   IndexSubset *inheritLifetimeParamIndices;
   IndexSubset *borrowLifetimeParamIndices;
-  IndexSubset *mutateLifetimeParamIndices;
 
   static LifetimeDependenceInfo getForParamIndex(AbstractFunctionDecl *afd,
                                                  unsigned index,
@@ -147,21 +146,17 @@ class LifetimeDependenceInfo {
 public:
   LifetimeDependenceInfo()
       : inheritLifetimeParamIndices(nullptr),
-        borrowLifetimeParamIndices(nullptr),
-        mutateLifetimeParamIndices(nullptr) {}
+        borrowLifetimeParamIndices(nullptr) {}
   LifetimeDependenceInfo(IndexSubset *inheritLifetimeParamIndices,
-                         IndexSubset *borrowLifetimeParamIndices,
-                         IndexSubset *mutateLifetimeParamIndices)
+                         IndexSubset *borrowLifetimeParamIndices)
       : inheritLifetimeParamIndices(inheritLifetimeParamIndices),
-        borrowLifetimeParamIndices(borrowLifetimeParamIndices),
-        mutateLifetimeParamIndices(mutateLifetimeParamIndices) {}
+        borrowLifetimeParamIndices(borrowLifetimeParamIndices) {}
 
   operator bool() const { return !empty(); }
 
   bool empty() const {
     return inheritLifetimeParamIndices == nullptr &&
-           borrowLifetimeParamIndices == nullptr &&
-           mutateLifetimeParamIndices == nullptr;
+           borrowLifetimeParamIndices == nullptr;
   }
 
   bool hasInheritLifetimeParamIndices() const {
@@ -170,9 +165,6 @@ class LifetimeDependenceInfo {
   bool hasBorrowLifetimeParamIndices() const {
     return borrowLifetimeParamIndices != nullptr;
   }
-  bool hasMutateLifetimeParamIndices() const {
-    return mutateLifetimeParamIndices != nullptr;
-  }
 
   std::string getString() const;
   void Profile(llvm::FoldingSetNodeID &ID) const;

lib/Sema/LifetimeDependence.cpp

@@ -44,10 +44,6 @@ std::string LifetimeDependenceInfo::getString() const {
     lifetimeDependenceString +=
         "_borrow(" + getOnIndices(borrowLifetimeParamIndices) + ")";
   }
-  if (mutateLifetimeParamIndices && !mutateLifetimeParamIndices->isEmpty()) {
-    lifetimeDependenceString +=
-        "_mutate(" + getOnIndices(mutateLifetimeParamIndices) + ")";
-  }
   return lifetimeDependenceString;
 }
 
@@ -58,9 +54,6 @@ void LifetimeDependenceInfo::Profile(llvm::FoldingSetNodeID &ID) const {
   if (borrowLifetimeParamIndices) {
     borrowLifetimeParamIndices->Profile(ID);
   }
-  if (mutateLifetimeParamIndices) {
-    mutateLifetimeParamIndices->Profile(ID);
-  }
 }
 
 LifetimeDependenceInfo LifetimeDependenceInfo::getForParamIndex(
@@ -71,18 +64,12 @@ LifetimeDependenceInfo LifetimeDependenceInfo::getForParamIndex(
   auto indexSubset = IndexSubset::get(ctx, capacity, {index});
   if (ownership == ValueOwnership::Owned) {
     return LifetimeDependenceInfo{/*inheritLifetimeParamIndices*/ indexSubset,
-                                  /*borrowLifetimeParamIndices*/ nullptr,
-                                  /*mutateLifetimeParamIndices*/ nullptr};
-  }
-  if (ownership == ValueOwnership::Shared) {
-    return LifetimeDependenceInfo{/*inheritLifetimeParamIndices*/ nullptr,
-                                  /*borrowLifetimeParamIndices*/ indexSubset,
-                                  /*mutateLifetimeParamIndices*/ nullptr};
+                                  /*borrowLifetimeParamIndices*/ nullptr};
   }
-  assert(ownership == ValueOwnership::InOut);
+  assert(ownership == ValueOwnership::Shared ||
+         ownership == ValueOwnership::InOut);
   return LifetimeDependenceInfo{/*inheritLifetimeParamIndices*/ nullptr,
-                                /*borrowLifetimeParamIndices*/ nullptr,
-                                /*mutateLifetimeParamIndices*/ indexSubset};
+                                /*borrowLifetimeParamIndices*/ indexSubset};
 }
 
 void LifetimeDependenceInfo::getConcatenatedData(
@@ -107,9 +94,6 @@ void LifetimeDependenceInfo::getConcatenatedData(
   if (hasBorrowLifetimeParamIndices()) {
     pushData(borrowLifetimeParamIndices);
   }
-  if (hasMutateLifetimeParamIndices()) {
-    pushData(mutateLifetimeParamIndices);
-  }
 }
 
 llvm::Optional<LifetimeDependenceInfo>
@@ -124,7 +108,6 @@ LifetimeDependenceInfo::fromTypeRepr(AbstractFunctionDecl *afd, Type resultType,
 
   SmallBitVector inheritLifetimeParamIndices(capacity);
   SmallBitVector borrowLifetimeParamIndices(capacity);
-  SmallBitVector mutateLifetimeParamIndices(capacity);
 
   auto updateLifetimeDependenceInfo = [&](LifetimeDependenceSpecifier specifier,
                                           unsigned paramIndexToSet,
@@ -167,11 +150,10 @@ LifetimeDependenceInfo::fromTypeRepr(AbstractFunctionDecl *afd, Type resultType,
     if (kind == LifetimeDependenceKind::Copy ||
         kind == LifetimeDependenceKind::Consume) {
       inheritLifetimeParamIndices.set(paramIndexToSet);
-    } else if (kind == LifetimeDependenceKind::Borrow) {
-      borrowLifetimeParamIndices.set(paramIndexToSet);
     } else {
-      assert(kind == LifetimeDependenceKind::Mutate);
-      mutateLifetimeParamIndices.set(paramIndexToSet);
+      assert(kind == LifetimeDependenceKind::Borrow ||
+             kind == LifetimeDependenceKind::Mutate);
+      borrowLifetimeParamIndices.set(paramIndexToSet);
     }
     return false;
   };
@@ -247,9 +229,6 @@ LifetimeDependenceInfo::fromTypeRepr(AbstractFunctionDecl *afd, Type resultType,
           : nullptr,
       borrowLifetimeParamIndices.any()
           ? IndexSubset::get(ctx, borrowLifetimeParamIndices)
-          : nullptr,
-      mutateLifetimeParamIndices.any()
-          ? IndexSubset::get(ctx, mutateLifetimeParamIndices)
           : nullptr);
 }
 

lib/Serialization/Deserialization.cpp

@@ -8610,12 +8610,11 @@ bool ModuleFile::maybeReadLifetimeDependence(
     return false;
   }
 
-  bool hasInheritLifetimeParamIndices, hasBorrowLifetimeParamIndices,
-      hasMutateLifetimeParamIndices;
+  bool hasInheritLifetimeParamIndices, hasBorrowLifetimeParamIndices;
   ArrayRef<uint64_t> lifetimeDependenceData;
-  LifetimeDependenceLayout::readRecord(
-      scratch, hasInheritLifetimeParamIndices, hasBorrowLifetimeParamIndices,
-      hasMutateLifetimeParamIndices, lifetimeDependenceData);
+  LifetimeDependenceLayout::readRecord(scratch, hasInheritLifetimeParamIndices,
+                                       hasBorrowLifetimeParamIndices,
+                                       lifetimeDependenceData);
 
   unsigned startIndex = 0;
   auto pushData = [&](LifetimeDependenceKind kind) {
@@ -8635,8 +8634,5 @@ bool ModuleFile::maybeReadLifetimeDependence(
   if (hasBorrowLifetimeParamIndices) {
     pushData(LifetimeDependenceKind::Borrow);
   }
-  if (hasMutateLifetimeParamIndices) {
-    pushData(LifetimeDependenceKind::Mutate);
-  }
   return true;
 }

lib/Serialization/ModuleFormat.h

@@ -58,7 +58,7 @@ const uint16_t SWIFTMODULE_VERSION_MAJOR = 0;
 /// describe what change you made. The content of this comment isn't important;
 /// it just ensures a conflict if two people change the module format.
 /// Don't worry about adhering to the 80-column limit for this line.
-const uint16_t SWIFTMODULE_VERSION_MINOR = 848; // inroduced a package SIL linkage
+const uint16_t SWIFTMODULE_VERSION_MINOR = 849; // update LifetimeDependence
 
 /// A standard hash seed used for all string hashes in a serialized module.
 ///
@@ -2179,7 +2179,6 @@ namespace decls_block {
       BCRecordLayout<LIFETIME_DEPENDENCE,
                      BCFixed<1>,         // hasInheritLifetimeParamIndices
                      BCFixed<1>,         // hasBorrowLifetimeParamIndices
-                     BCFixed<1>,         // hasMutateLifetimeParamIndices
                      BCArray<BCFixed<1>> // concatenated param indices
                      >;
 

lib/Serialization/Serialization.cpp

@@ -3517,8 +3517,7 @@ class Serializer::DeclSerializer : public DeclVisitor<DeclSerializer> {
     LifetimeDependenceLayout::emitRecord(
         S.Out, S.ScratchRecord, abbrCode,
         lifetimeDependenceInfo.hasInheritLifetimeParamIndices(),
-        lifetimeDependenceInfo.hasBorrowLifetimeParamIndices(),
-        lifetimeDependenceInfo.hasMutateLifetimeParamIndices(), paramIndices);
+        lifetimeDependenceInfo.hasBorrowLifetimeParamIndices(), paramIndices);
   }
 
   void writeGenericParams(const GenericParamList *genericParams) {