Method Pool in modules: we make sure that if a module contains an entry for

a selector, the entry should be complete, containing everything introduced by
that module and all modules it imports.

Before writing out the method pool of a module, we sync up the out of date
selectors by pulling in methods for the selectors, from all modules it imports.

In ReadMethodPool, after pulling in the method pool entry for module A, this
lets us skip the modules that module A imports.

rdar://problem/25900131

llvm-svn: 268091

5 files changed, 34 insertions, 0 deletions

diff --git a/clang/lib/Sema/MultiplexExternalSemaSource.cpp b/clang/lib/Sema/MultiplexExternalSemaSource.cpp
index 89eec242eb1..eee4c00324b 100644
--- a/clang/lib/Sema/MultiplexExternalSemaSource.cpp
+++ b/clang/lib/Sema/MultiplexExternalSemaSource.cpp
@@ -197,6 +197,11 @@ void MultiplexExternalSemaSource::ReadMethodPool(Selector Sel) {
     Sources[i]->ReadMethodPool(Sel);
 }
 
+void MultiplexExternalSemaSource::updateOutOfDateSelector(Selector Sel) {
+  for(size_t i = 0; i < Sources.size(); ++i)
+    Sources[i]->updateOutOfDateSelector(Sel);
+}
+
 void MultiplexExternalSemaSource::ReadKnownNamespaces(
                                    SmallVectorImpl<NamespaceDecl*> &Namespaces){
   for(size_t i = 0; i < Sources.size(); ++i)
diff --git a/clang/lib/Sema/Sema.cpp b/clang/lib/Sema/Sema.cpp
index 541b3180d8c..d8d10b637ec 100644
--- a/clang/lib/Sema/Sema.cpp
+++ b/clang/lib/Sema/Sema.cpp
@@ -1237,6 +1237,7 @@ void Sema::ActOnComment(SourceRange Comment) {
 ExternalSemaSource::~ExternalSemaSource() {}
 
 void ExternalSemaSource::ReadMethodPool(Selector Sel) { }
+void ExternalSemaSource::updateOutOfDateSelector(Selector Sel) { }
 
 void ExternalSemaSource::ReadKnownNamespaces(
                            SmallVectorImpl<NamespaceDecl *> &Namespaces) {
diff --git a/clang/lib/Sema/SemaDeclObjC.cpp b/clang/lib/Sema/SemaDeclObjC.cpp
index 8090bec4fab..400dc637754 100644
--- a/clang/lib/Sema/SemaDeclObjC.cpp
+++ b/clang/lib/Sema/SemaDeclObjC.cpp
@@ -3305,6 +3305,12 @@ void Sema::ReadMethodPool(Selector Sel) {
   ExternalSource->ReadMethodPool(Sel);
 }
 
+void Sema::updateOutOfDateSelector(Selector Sel) {
+  if (!ExternalSource)
+    return;
+  ExternalSource->updateOutOfDateSelector(Sel);
+}
+
 void Sema::AddMethodToGlobalPool(ObjCMethodDecl *Method, bool impl,
                                  bool instance) {
   // Ignore methods of invalid containers.
diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index 910f5dcf779..aa672b3a7ec 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -3606,6 +3606,9 @@ ASTReader::ASTReadResult ASTReader::ReadAST(StringRef FileName,
          Id != IdEnd; ++Id)
       Id->second->setOutOfDate(true);
   }
+  // Mark selectors as out of date.
+  for (auto Sel : SelectorGeneration)
+    SelectorOutOfDate[Sel.first] = true;
   
   // Resolve any unresolved module exports.
   for (unsigned I = 0, N = UnresolvedModuleRefs.size(); I != N; ++I) {
@@ -7139,6 +7142,7 @@ void ASTReader::ReadMethodPool(Selector Sel) {
   unsigned &Generation = SelectorGeneration[Sel];
   unsigned PriorGeneration = Generation;
   Generation = getGeneration();
+  SelectorOutOfDate[Sel] = false;
   
   // Search for methods defined with this selector.
   ++NumMethodPoolLookups;
@@ -7170,6 +7174,11 @@ void ASTReader::ReadMethodPool(Selector Sel) {
   addMethodsToPool(S, Visitor.getFactoryMethods(), Pos->second.second);
 }
 
+void ASTReader::updateOutOfDateSelector(Selector Sel) {
+  if (SelectorOutOfDate[Sel])
+    ReadMethodPool(Sel);
+}
+
 void ASTReader::ReadKnownNamespaces(
                           SmallVectorImpl<NamespaceDecl *> &Namespaces) {
   Namespaces.clear();
diff --git a/clang/lib/Serialization/ASTWriter.cpp b/clang/lib/Serialization/ASTWriter.cpp
index 32c9c4787c4..606228af753 100644
--- a/clang/lib/Serialization/ASTWriter.cpp
+++ b/clang/lib/Serialization/ASTWriter.cpp
@@ -4387,6 +4387,19 @@ uint64_t ASTWriter::WriteASTCore(Sema &SemaRef, StringRef isysroot,
     }
   }
 
+  // For method pool in the module, if it contains an entry for a selector,
+  // the entry should be complete, containing everything introduced by that
+  // module and all modules it imports. It's possible that the entry is out of
+  // date, so we need to pull in the new content here.
+
+  // It's possible that updateOutOfDateSelector can update SelectorIDs. To be
+  // safe, we copy all selectors out.
+  llvm::SmallVector<Selector, 256> AllSelectors;
+  for (auto &SelectorAndID : SelectorIDs)
+    AllSelectors.push_back(SelectorAndID.first);
+  for (auto &Selector : AllSelectors)
+    SemaRef.updateOutOfDateSelector(Selector);
+
   // Form the record of special types.
   RecordData SpecialTypes;
   AddTypeRef(Context.getRawCFConstantStringType(), SpecialTypes);