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Before writing out the method pool of a module, we sync up the out of date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

2 files changed, 22 insertions, 0 deletions

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+  // Mark selectors as out of date.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);