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Before writing out the method pool of a module, we sync up the out of date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

15 files changed, 94 insertions, 0 deletions

diff --git a/clang/include/clang/Sema/ExternalSemaSource.h b/clang/include/clang/Sema/ExternalSemaSource.h
index 2fdc42b1ac1..c2b13046d70 100644
--- a/clang/include/clang/Sema/ExternalSemaSource.h
+++ b/clang/include/clang/Sema/ExternalSemaSource.h
@@ -70,6 +70,10 @@ public:
   /// selector.
   virtual void ReadMethodPool(Selector Sel);
 
+  /// Load the contents of the global method pool for a given
+  /// selector if necessary.
+  virtual void updateOutOfDateSelector(Selector Sel);
+
   /// \brief Load the set of namespaces that are known to the external source,
   /// which will be used during typo correction.
   virtual void ReadKnownNamespaces(
diff --git a/clang/include/clang/Sema/MultiplexExternalSemaSource.h b/clang/include/clang/Sema/MultiplexExternalSemaSource.h
index 5f43f4051aa..9bf8cd3d925 100644
--- a/clang/include/clang/Sema/MultiplexExternalSemaSource.h
+++ b/clang/include/clang/Sema/MultiplexExternalSemaSource.h
@@ -203,6 +203,10 @@ public:
   /// selector.
   void ReadMethodPool(Selector Sel) override;
 
+  /// Load the contents of the global method pool for a given
+  /// selector if necessary.
+  void updateOutOfDateSelector(Selector Sel) override;
+
   /// \brief Load the set of namespaces that are known to the external source,
   /// which will be used during typo correction.
   void
diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
index a0dcd701df6..7731569fbce 100644
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -1017,6 +1017,7 @@ public:
   llvm::SmallSet<SpecialMemberDecl, 4> SpecialMembersBeingDeclared;
 
   void ReadMethodPool(Selector Sel);
+  void updateOutOfDateSelector(Selector Sel);
 
   /// Private Helper predicate to check for 'self'.
   bool isSelfExpr(Expr *RExpr);
diff --git a/clang/include/clang/Serialization/ASTReader.h b/clang/include/clang/Serialization/ASTReader.h
index a80989d8861..6e1cb0a916c 100644
--- a/clang/include/clang/Serialization/ASTReader.h
+++ b/clang/include/clang/Serialization/ASTReader.h
@@ -653,6 +653,10 @@ private:
   /// global method pool for this selector.
   llvm::DenseMap<Selector, unsigned> SelectorGeneration;
 
+  /// Whether a selector is out of date. We mark a selector as out of date
+  /// if we load another module after the method pool entry was pulled in.
+  llvm::DenseMap<Selector, bool> SelectorOutOfDate;
+
   struct PendingMacroInfo {
     ModuleFile *M;
     uint64_t MacroDirectivesOffset;
@@ -1781,6 +1785,10 @@ public:
   /// selector.
   void ReadMethodPool(Selector Sel) override;
 
+  /// Load the contents of the global method pool for a given
+  /// selector if necessary.
+  void updateOutOfDateSelector(Selector Sel) override;
+
   /// \brief Load the set of namespaces that are known to the external source,
   /// which will be used during typo correction.
   void ReadKnownNamespaces(
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);
diff --git a/clang/test/Modules/Inputs/MethodPoolCombined1.h b/clang/test/Modules/Inputs/MethodPoolCombined1.h
new file mode 100644
index 00000000000..057b7388b35
--- /dev/null
+++ b/clang/test/Modules/Inputs/MethodPoolCombined1.h
@@ -0,0 +1,6 @@
+
+@import MethodPoolString1;
+@interface A
+- (int)stringValue;
+@end
+
diff --git a/clang/test/Modules/Inputs/MethodPoolCombined2.h b/clang/test/Modules/Inputs/MethodPoolCombined2.h
new file mode 100644
index 00000000000..166906e32e3
--- /dev/null
+++ b/clang/test/Modules/Inputs/MethodPoolCombined2.h
@@ -0,0 +1 @@
+@import MethodPoolString2;
diff --git a/clang/test/Modules/Inputs/MethodPoolString1.h b/clang/test/Modules/Inputs/MethodPoolString1.h
new file mode 100644
index 00000000000..c64ad950033
--- /dev/null
+++ b/clang/test/Modules/Inputs/MethodPoolString1.h
@@ -0,0 +1,4 @@
+
+@interface S1
+- (int)stringValue;
+@end
diff --git a/clang/test/Modules/Inputs/MethodPoolString2.h b/clang/test/Modules/Inputs/MethodPoolString2.h
new file mode 100644
index 00000000000..30e9bfb0027
--- /dev/null
+++ b/clang/test/Modules/Inputs/MethodPoolString2.h
@@ -0,0 +1,4 @@
+
+@interface S2
+- (int)stringValue;
+@end
diff --git a/clang/test/Modules/Inputs/module.map b/clang/test/Modules/Inputs/module.map
index 632517dd363..1249387b9d9 100644
--- a/clang/test/Modules/Inputs/module.map
+++ b/clang/test/Modules/Inputs/module.map
@@ -393,3 +393,20 @@ module ElaboratedTypeStructs {
     header "elaborated-type-structs.h"
   }
 }
+
+// We import a module, then declare a method with selector stringValue in
+// MethodPoolCombined1.h. In MethodPoolCombined2.h, we import another module
+// that also contains a method for selector stringValue. We make sure that
+// the method pool entry for stringValue in this module is complete.
+module MethodPoolCombined {
+  header "MethodPoolCombined1.h"
+  header "MethodPoolCombined2.h"
+}
+
+module MethodPoolString1 {
+  header "MethodPoolString1.h"
+}
+
+module MethodPoolString2 {
+  header "MethodPoolString2.h"
+}
diff --git a/clang/test/Modules/method_pool_write.m b/clang/test/Modules/method_pool_write.m
new file mode 100644
index 00000000000..b7f8ac64b4d
--- /dev/null
+++ b/clang/test/Modules/method_pool_write.m
@@ -0,0 +1,11 @@
+// RUN: rm -rf %t
+// RUN: %clang_cc1 -fmodules-cache-path=%t -fmodules -fimplicit-module-maps -fsyntax-only -I %S/Inputs %s -verify
+// expected-no-diagnostics
+
+@import MethodPoolCombined;
+@import MethodPoolString2;
+
+void message_kindof_object(__kindof S2 *kindof_S2) {
+  [kindof_S2 stringValue];
+}
+