r193850 - Simplify computation of visible module set.

[Richard Smith]

Author: rsmith
Date: Thu Oct 31 21:19:14 2013
New Revision: 193850

URL: http://llvm.org/viewvc/llvm-project?rev=193850&view=rev
Log:
Simplify computation of visible module set.

Modified:
    cfe/trunk/include/clang/Basic/Module.h
    cfe/trunk/lib/Basic/Module.cpp

Modified: cfe/trunk/include/clang/Basic/Module.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/Module.h?rev=193850&r1=193849&r2=193850&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/Module.h (original)
+++ cfe/trunk/include/clang/Basic/Module.h Thu Oct 31 21:19:14 2013
@@ -403,10 +403,10 @@ public:
   submodule_iterator submodule_end()   { return SubModules.end(); }
   submodule_const_iterator submodule_end() const { return SubModules.end(); }
 
-  /// \brief Returns the exported modules based on the wildcard restrictions.
+  /// \brief Appends this module's list of exported modules to \p Exported.
   ///
-  /// This returns a subset of immediately imported modules (the ones that are
-  /// exported), not the complete set of exported modules.
+  /// This provides a subset of immediately imported modules (the ones that are
+  /// directly exported), not the complete set of exported modules.
   void getExportedModules(SmallVectorImpl<Module *> &Exported) const;
 
   static StringRef getModuleInputBufferName() {

Modified: cfe/trunk/lib/Basic/Module.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Basic/Module.cpp?rev=193850&r1=193849&r2=193850&view=diff
==============================================================================
--- cfe/trunk/lib/Basic/Module.cpp (original)
+++ cfe/trunk/lib/Basic/Module.cpp Thu Oct 31 21:19:14 2013
@@ -253,22 +253,13 @@ void Module::buildVisibleModulesCache()
   VisibleModulesCache.insert(this);
 
   // Every imported module is visible.
-  // Every module exported by an imported module is visible.
-  llvm::SmallPtrSet<Module *, 4> Visited;
-  llvm::SmallVector<Module *, 4> Exports;
-  SmallVector<Module *, 4> Stack(Imports.begin(), Imports.end());
+  SmallVector<Module *, 16> Stack(Imports.begin(), Imports.end());
   while (!Stack.empty()) {
     Module *CurrModule = Stack.pop_back_val();
-    VisibleModulesCache.insert(CurrModule);
 
-    CurrModule->getExportedModules(Exports);
-    for (SmallVectorImpl<Module *>::iterator I = Exports.begin(),
-                                             E = Exports.end();
-         I != E; ++I) {
-      Module *Exported = *I;
-      if (Visited.insert(Exported))
-        Stack.push_back(Exported);
-    }
+    // Every module transitively exported by an imported module is visible.
+    if (VisibleModulesCache.insert(CurrModule).second)
+      CurrModule->getExportedModules(Stack);
   }
 }