[modules] Start moving the module visibility information off the Module itself.

It has no place there; it's not a property of the Module, and it makes
restoring the visibility set when we leave a submodule more difficult.

llvm-svn: 236300

5 files changed, 36 insertions, 19 deletions

diff --git a/clang/lib/Lex/ModuleMap.cpp b/clang/lib/Lex/ModuleMap.cpp
index a4f1c05dc16..29594994ff6 100644
--- a/clang/lib/Lex/ModuleMap.cpp
+++ b/clang/lib/Lex/ModuleMap.cpp
@@ -89,7 +89,7 @@ ModuleMap::ModuleMap(SourceManager &SourceMgr, DiagnosticsEngine &Diags,
                      HeaderSearch &HeaderInfo)
     : SourceMgr(SourceMgr), Diags(Diags), LangOpts(LangOpts), Target(Target),
       HeaderInfo(HeaderInfo), BuiltinIncludeDir(nullptr),
-      CompilingModule(nullptr), SourceModule(nullptr) {
+      CompilingModule(nullptr), SourceModule(nullptr), NumCreatedModules(0) {
   MMapLangOpts.LineComment = true;
 }
 
@@ -563,7 +563,7 @@ ModuleMap::findOrCreateModule(StringRef Name, Module *Parent, bool IsFramework,
   
   // Create a new module with this name.
   Module *Result = new Module(Name, SourceLocation(), Parent,
-                              IsFramework, IsExplicit);
+                              IsFramework, IsExplicit, NumCreatedModules++);
   if (LangOpts.CurrentModule == Name) {
     SourceModule = Result;
     SourceModuleName = Name;
@@ -693,7 +693,8 @@ Module *ModuleMap::inferFrameworkModule(StringRef ModuleName,
     return nullptr;
 
   Module *Result = new Module(ModuleName, SourceLocation(), Parent,
-                              /*IsFramework=*/true, /*IsExplicit=*/false);
+                              /*IsFramework=*/true, /*IsExplicit=*/false,
+                              NumCreatedModules++);
   InferredModuleAllowedBy[Result] = ModuleMapFile;
   Result->IsInferred = true;
   if (LangOpts.CurrentModule == ModuleName) {
diff --git a/clang/lib/Lex/PPDirectives.cpp b/clang/lib/Lex/PPDirectives.cpp
index 1c66aac533b..7de6c14ef36 100644
--- a/clang/lib/Lex/PPDirectives.cpp
+++ b/clang/lib/Lex/PPDirectives.cpp
@@ -1686,7 +1686,8 @@ void Preprocessor::HandleIncludeDirective(SourceLocation HashLoc,
     ModuleLoadResult Imported
       = TheModuleLoader.loadModule(IncludeTok.getLocation(), Path, Visibility,
                                    /*IsIncludeDirective=*/true);
-    ++MacroVisibilityGeneration;
+    if (Imported)
+      makeModuleVisible(Imported, IncludeTok.getLocation());
     assert((Imported == nullptr || Imported == SuggestedModule.getModule()) &&
            "the imported module is different than the suggested one");
 
@@ -1766,6 +1767,9 @@ void Preprocessor::HandleIncludeDirective(SourceLocation HashLoc,
   assert(!FID.isInvalid() && "Expected valid file ID");
 
   // Determine if we're switching to building a new submodule, and which one.
+  //
+  // FIXME: If we've already processed this header, just make it visible rather
+  // than entering it again.
   ModuleMap::KnownHeader BuildingModule;
   if (getLangOpts().Modules && !getLangOpts().CurrentModule.empty()) {
     Module *RequestingModule = getModuleForLocation(FilenameLoc);
diff --git a/clang/lib/Lex/PPLexerChange.cpp b/clang/lib/Lex/PPLexerChange.cpp
index dc1b5bed049..6766fdfcd07 100644
--- a/clang/lib/Lex/PPLexerChange.cpp
+++ b/clang/lib/Lex/PPLexerChange.cpp
@@ -671,13 +671,7 @@ void Preprocessor::LeaveSubmodule() {
     Macro.second.setOverriddenMacros(SavedInfo.Overridden);
   }
 
-  if (Info.M->NameVisibility < Module::MacrosVisible) {
-    Info.M->NameVisibility = Module::MacrosVisible;
-    Info.M->MacroVisibilityLoc = Info.ImportLoc;
-    ++MacroVisibilityGeneration;
-    // FIXME: Also mark any exported modules as visible, and check for
-    // conflicts.
-  }
+  makeModuleVisible(Info.M, Info.ImportLoc);
 
   BuildingSubmoduleStack.pop_back();
 }
diff --git a/clang/lib/Lex/PPMacroExpansion.cpp b/clang/lib/Lex/PPMacroExpansion.cpp
index fca3f8b97ce..edeed42c17e 100644
--- a/clang/lib/Lex/PPMacroExpansion.cpp
+++ b/clang/lib/Lex/PPMacroExpansion.cpp
@@ -124,9 +124,9 @@ ModuleMacro *Preprocessor::getModuleMacro(Module *Mod, IdentifierInfo *II) {
 
 void Preprocessor::updateModuleMacroInfo(const IdentifierInfo *II,
                                          ModuleMacroInfo &Info) {
-  assert(Info.ActiveModuleMacrosGeneration != MacroVisibilityGeneration &&
+  assert(Info.ActiveModuleMacrosGeneration != VisibleModules.getGeneration() &&
          "don't need to update this macro name info");
-  Info.ActiveModuleMacrosGeneration = MacroVisibilityGeneration;
+  Info.ActiveModuleMacrosGeneration = VisibleModules.getGeneration();
 
   auto Leaf = LeafModuleMacros.find(II);
   if (Leaf == LeafModuleMacros.end()) {
@@ -146,7 +146,7 @@ void Preprocessor::updateModuleMacroInfo(const IdentifierInfo *II,
                                                 Leaf->second.end());
   while (!Worklist.empty()) {
     auto *MM = Worklist.pop_back_val();
-    if (MM->getOwningModule()->NameVisibility >= Module::MacrosVisible) {
+    if (VisibleModules.isVisible(MM->getOwningModule())) {
       // We only care about collecting definitions; undefinitions only act
       // to override other definitions.
       if (MM->getMacroInfo())
@@ -236,7 +236,7 @@ void Preprocessor::dumpMacroInfo(const IdentifierInfo *II) {
 
     if (Active.count(MM))
       llvm::errs() << " active";
-    else if (MM->getOwningModule()->NameVisibility < Module::MacrosVisible)
+    else if (!VisibleModules.isVisible(MM->getOwningModule()))
       llvm::errs() << " hidden";
     else
       llvm::errs() << " overridden";
diff --git a/clang/lib/Lex/Preprocessor.cpp b/clang/lib/Lex/Preprocessor.cpp
index 231720b8db1..2db109565af 100644
--- a/clang/lib/Lex/Preprocessor.cpp
+++ b/clang/lib/Lex/Preprocessor.cpp
@@ -107,9 +107,6 @@ Preprocessor::Preprocessor(IntrusiveRefCntPtr<PreprocessorOptions> PPOpts,
 
   // We haven't read anything from the external source.
   ReadMacrosFromExternalSource = false;
-  // We might already have some macros from an imported module (via a PCH or
-  // preamble) if modules is enabled.
-  MacroVisibilityGeneration = LangOpts.Modules ? 1 : 0;
   
   // "Poison" __VA_ARGS__, which can only appear in the expansion of a macro.
   // This gets unpoisoned where it is allowed.
@@ -757,13 +754,34 @@ void Preprocessor::LexAfterModuleImport(Token &Result) {
                                             ModuleImportPath,
                                             Module::MacrosVisible,
                                             /*IsIncludeDirective=*/false);
-      ++MacroVisibilityGeneration;
+      if (Imported)
+        makeModuleVisible(Imported, ModuleImportLoc);
     }
     if (Callbacks && (getLangOpts().Modules || getLangOpts().DebuggerSupport))
       Callbacks->moduleImport(ModuleImportLoc, ModuleImportPath, Imported);
   }
 }
 
+void Preprocessor::makeModuleVisible(Module *M, SourceLocation Loc) {
+  if (VisibleModules.isVisible(M))
+    return;
+
+  VisibleModules.setVisible(
+      M, Loc, [](Module *) {},
+      [&](ArrayRef<Module *> Path, Module *Conflict, StringRef Message) {
+        // FIXME: Include the path in the diagnostic.
+        // FIXME: Include the import location for the conflicting module.
+        Diag(ModuleImportLoc, diag::warn_module_conflict)
+            << Path[0]->getFullModuleName()
+            << Conflict->getFullModuleName()
+            << Message;
+      });
+
+  // Add this module to the imports list of the currently-built submodule.
+  if (!BuildingSubmoduleStack.empty())
+    BuildingSubmoduleStack.back().M->Imports.push_back(M);
+}
+
 bool Preprocessor::FinishLexStringLiteral(Token &Result, std::string &String,
                                           const char *DiagnosticTag,
                                           bool AllowMacroExpansion) {