[ExternalASTMerger] Import Objective-C classes

[spyffe]

Summary

This patch adds functionality and a test for importing Objective-C classes and their methods.

It also adds a flag to clang-import-test to set the language used for parsing. This takes the same argument format as the -x option to the driver.

[v.g.vassilev]

LGTM.

lib/AST/ExternalASTMerger.cpp

       ToTag->setMustBuildLookupTable();
     } else if (auto ToNamespace = dyn_cast<NamespaceDecl>(To)) {
       ToNamespace->setHasExternalVisibleStorage();
+    } else if (auto ToContainer = dyn_cast<ObjCContainerDecl>(To)) {
+      ToContainer->setHasExternalLexicalStorage();
+      ToContainer->setMustBuildLookupTable();
     }
     return ASTImporter::Imported(From, To);
   }

 }
 
 bool IsForwardDeclaration(Decl *D) {
-  assert(!isa<ObjCInterfaceDecl>(D)); // TODO handle this case
   if (auto TD = dyn_cast<TagDecl>(D)) {
     return !TD->isThisDeclarationADefinition();
   } else if (auto FD = dyn_cast<FunctionDecl>(D)) {
     return !FD->isThisDeclarationADefinition();
+  } else if (auto OID = dyn_cast<ObjCInterfaceDecl>(D)) {
+     return OID->isThisDeclarationADefinition();
   } else {
     return false;
   }

test/Import/objc-method/Inputs/S.m

-struct S {
-  int a;
-};
+@interface C {
+}
+-(int)m;
+@end

test/Import/objc-method/test.m

-// RUN: clang-import-test -import %S/Inputs/S.c -expression %s
+// RUN: clang-import-test -x objective-c++ -import %S/Inputs/S.m -expression %s
 void expr() {
-  struct S MyS;
-  MyS.a = 3;
+  C *c;
+  int i = [c m];
 }

tools/clang-import-test/clang-import-test.cpp

 #include "clang/Basic/TargetInfo.h"
 #include "clang/Basic/TargetOptions.h"
 #include "clang/CodeGen/ModuleBuilder.h"
+#include "clang/Driver/Types.h"
 #include "clang/Frontend/ASTConsumers.h"
 #include "clang/Frontend/CompilerInstance.h"
 #include "clang/Frontend/MultiplexConsumer.h"

               llvm::cl::desc("Argument to pass to the CompilerInvocation"),
               llvm::cl::CommaSeparated);
 
+static llvm::cl::opt<std::string>
+    Input("x", llvm::cl::Optional,
+          llvm::cl::desc("The language to parse (default: c++)"),
+          llvm::cl::init("c++"));
+
 static llvm::cl::opt<bool>
 DumpAST("dump-ast", llvm::cl::init(false),
         llvm::cl::desc("Dump combined AST"));

     llvm::errs() << LineString << '\n';
     llvm::errs().indent(LocColumn);
     llvm::errs() << '^';
+    llvm::errs() << '\n';
   }
 
   virtual void HandleDiagnostic(DiagnosticsEngine::Level DiagLevel,

 };
 
 std::unique_ptr<CompilerInstance>
-BuildCompilerInstance(ArrayRef<const char *> ClangArgv) {
+BuildCompilerInstance() {
   auto Ins = llvm::make_unique<CompilerInstance>();
   auto DC = llvm::make_unique<TestDiagnosticConsumer>();
   const bool ShouldOwnClient = true;

 
   auto Inv = llvm::make_unique<CompilerInvocation>();
 
+  std::vector<const char *> ClangArgv(ClangArgs.size());
+  std::transform(ClangArgs.begin(), ClangArgs.end(), ClangArgv.begin(),
+                 [](const std::string &s) -> const char * { return s.data(); });
   CompilerInvocation::CreateFromArgs(*Inv, ClangArgv.data(),
                                      &ClangArgv.data()[ClangArgv.size()],
                                      Ins->getDiagnostics());
 
-  Inv->getLangOpts()->CPlusPlus = true;
-  Inv->getLangOpts()->CPlusPlus11 = true;
-  Inv->getHeaderSearchOpts().UseLibcxx = true;
+  {
+    using namespace driver::types;
+    ID Id = lookupTypeForTypeSpecifier(Input.c_str());
+    assert(Id != TY_INVALID);
+    if (isCXX(Id)) {
+      Inv->getLangOpts()->CPlusPlus = true;
+      Inv->getLangOpts()->CPlusPlus11 = true;
+      Inv->getHeaderSearchOpts().UseLibcxx = true;
+    }
+    if (isObjC(Id)) {
+      Inv->getLangOpts()->ObjC1 = 1;
+      Inv->getLangOpts()->ObjC2 = 1;
+    }
+  }
   Inv->getLangOpts()->Bool = true;
   Inv->getLangOpts()->WChar = true;
   Inv->getLangOpts()->Blocks = true;

 }
 
 std::unique_ptr<CompilerInstance> BuildIndirect(std::unique_ptr<CompilerInstance> &CI) {
-  std::vector<const char *> ClangArgv(ClangArgs.size());
-  std::transform(ClangArgs.begin(), ClangArgs.end(), ClangArgv.begin(),
-                 [](const std::string &s) -> const char * { return s.data(); });
   std::unique_ptr<CompilerInstance> IndirectCI =
-      init_convenience::BuildCompilerInstance(ClangArgv);
+      init_convenience::BuildCompilerInstance();
   auto ST = llvm::make_unique<SelectorTable>();
   auto BC = llvm::make_unique<Builtin::Context>();
   std::unique_ptr<ASTContext> AST =

 Parse(const std::string &Path,
       llvm::ArrayRef<std::unique_ptr<CompilerInstance>> Imports,
       bool ShouldDumpAST) {
-  std::vector<const char *> ClangArgv(ClangArgs.size());
-  std::transform(ClangArgs.begin(), ClangArgs.end(), ClangArgv.begin(),
-                 [](const std::string &s) -> const char * { return s.data(); });
   std::unique_ptr<CompilerInstance> CI =
-      init_convenience::BuildCompilerInstance(ClangArgv);
+      init_convenience::BuildCompilerInstance();
   auto ST = llvm::make_unique<SelectorTable>();
   auto BC = llvm::make_unique<Builtin::Context>();
   std::unique_ptr<ASTContext> AST =