When an import statement fails to find a module in the module cache,

but there is a corresponding umbrella header in a framework, build the
module on-the-fly so it can be immediately loaded at the import
statement. This is very much proof-of-concept code, with details to be
fleshed out over time.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@139558 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 12 insertions, 1 deletions

diff --git a/include/clang/Basic/DiagnosticCommonKinds.td b/include/clang/Basic/DiagnosticCommonKinds.td
index 29bf270d11..25df8c9bd0 100644
--- a/include/clang/Basic/DiagnosticCommonKinds.td
+++ b/include/clang/Basic/DiagnosticCommonKinds.td
@@ -60,6 +60,7 @@ def err_friends_define_only_namespace_scope : Error<
 def err_deleted_non_function : Error<
   "only functions can have deleted definitions">;
 def err_module_not_found : Error<"module '%0' not found">, DefaultFatal;
+def err_module_not_built : Error<"could not build module '%0'">, DefaultFatal;
   
 // Sema && Lex
 def ext_longlong : Extension<
diff --git a/include/clang/Basic/FileManager.h b/include/clang/Basic/FileManager.h
index 83fb4e0c5a..826859fb50 100644
--- a/include/clang/Basic/FileManager.h
+++ b/include/clang/Basic/FileManager.h
@@ -187,6 +187,10 @@ public:
   /// \param openFile if true and the file exists, it will be opened.
   const FileEntry *getFile(StringRef Filename, bool openFile = false);
 
+  /// \brief Forget any information about the given file name, because (for 
+  /// example) something within this process has changed the file in some way.
+  void forgetFile(StringRef Filename);
+  
   /// \brief Returns the current file system options
   const FileSystemOptions &getFileSystemOptions() { return FileSystemOpts; }
 
diff --git a/include/clang/Lex/HeaderSearch.h b/include/clang/Lex/HeaderSearch.h
index f6552a4014..74c1080df8 100644
--- a/include/clang/Lex/HeaderSearch.h
+++ b/include/clang/Lex/HeaderSearch.h
@@ -319,9 +319,15 @@ public:
   /// \brief Search in the module cache path for a module with the given
   /// name.
   ///
+  /// \param UmbrellaHeader If non-NULL, and no module was found in the module
+  /// cache, this routine will search in the framework paths to determine
+  /// whether a module can be built from an umbrella header. If so, the pointee
+  /// will be set to the path of the umbrella header.
+  ///
   /// \returns A file describing the named module, if available, or NULL to
   /// indicate that the module could not be found.
-  const FileEntry *lookupModule(StringRef ModuleName);
+  const FileEntry *lookupModule(StringRef ModuleName,
+                                std::string *UmbrellaHeader = 0);
   
   void IncrementFrameworkLookupCount() { ++NumFrameworkLookups; }