Introduce support for a simple module import declaration, which

loads the named module. The syntax itself is intentionally hideous and
will be replaced at some later point with something more
palatable. For now, we're focusing on the semantics:
  - Module imports are handled first by the preprocessor (to get macro
  definitions) and then the same tokens are also handled by the parser
  (to get declarations). If both happen (as in normal compilation),
  the second one is redundant, because we currently have no way to
  hide macros or declarations when loading a module. Chris gets credit
  for this mad-but-workable scheme.
  - The Preprocessor now holds on to a reference to a module loader,
  which is responsible for loading named modules. CompilerInstance is
  the only important module loader: it now knows how to create and
  wire up an AST reader on demand to actually perform the module load.
  - We search for modules in the include path, using the module name
  with the suffix ".pcm" (precompiled module) for the file name. This
  is a temporary hack; we hope to improve the situation in the
  future.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@138679 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 10 insertions, 0 deletions

diff --git a/include/clang/Lex/Preprocessor.h b/include/clang/Lex/Preprocessor.h
index a95645451e..1ab6411e98 100644
--- a/include/clang/Lex/Preprocessor.h
+++ b/include/clang/Lex/Preprocessor.h
@@ -49,6 +49,7 @@ class PPCallbacks;
 class CodeCompletionHandler;
 class DirectoryLookup;
 class PreprocessingRecord;
+class ModuleLoader;
   
 /// Preprocessor - This object engages in a tight little dance with the lexer to
 /// efficiently preprocess tokens.  Lexers know only about tokens within a
@@ -63,10 +64,12 @@ class Preprocessor : public llvm::RefCountedBase<Preprocessor> {
   SourceManager     &SourceMgr;
   ScratchBuffer     *ScratchBuf;
   HeaderSearch      &HeaderInfo;
+  ModuleLoader      &TheModuleLoader;
 
   /// \brief External source of macros.
   ExternalPreprocessorSource *ExternalSource;
 
+  
   /// PTH - An optional PTHManager object used for getting tokens from
   ///  a token cache rather than lexing the original source file.
   llvm::OwningPtr<PTHManager> PTH;
@@ -294,6 +297,7 @@ public:
   Preprocessor(Diagnostic &diags, const LangOptions &opts,
                const TargetInfo &target,
                SourceManager &SM, HeaderSearch &Headers,
+               ModuleLoader &TheModuleLoader,
                IdentifierInfoLookup *IILookup = 0,
                bool OwnsHeaderSearch = false);
 
@@ -325,6 +329,9 @@ public:
     return ExternalSource;
   }
 
+  /// \brief Retrieve the module loader associated with this preprocessor.
+  ModuleLoader &getModuleLoader() const { return TheModuleLoader; }
+  
   /// SetCommentRetentionState - Control whether or not the preprocessor retains
   /// comments in output.
   void SetCommentRetentionState(bool KeepComments, bool KeepMacroComments) {
@@ -1008,6 +1015,9 @@ private:
   /// the macro should not be expanded return true, otherwise return false.
   bool HandleMacroExpandedIdentifier(Token &Tok, MacroInfo *MI);
 
+  /// \brief Handle a module import directive.
+  void HandleModuleImport(Token &Import);
+  
   /// \brief Cache macro expanded tokens for TokenLexers.
   //
   /// Works like a stack; a TokenLexer adds the macro expanded tokens that is