Introduce an opt-in warning indicating when the compiler is treating

an #include/#import as a module import.

llvm-svn: 145500

clang/include/clang/Basic/DiagnosticGroups.td

@@ -25,6 +25,7 @@ def AmbigMemberTemplate : DiagGroup<"ambiguous-member-template">;
 def : DiagGroup<"attributes">;
 def : DiagGroup<"bad-function-cast">;
 def Availability : DiagGroup<"availability">;
+def AutoImport : DiagGroup<"auto-import">;
 def BoolConversions : DiagGroup<"bool-conversions">;
 def BuiltinRequiresHeader : DiagGroup<"builtin-requires-header">;
 def CXXCompat: DiagGroup<"c++-compat">;

clang/include/clang/Basic/DiagnosticLexKinds.td

@@ -400,4 +400,8 @@ def err_mmap_umbrella_header_submodule : Error<
 def err_mmap_umbrella_clash : Error<
   "umbrella header for module '%0' already covers this directory">;
 
+def warn_auto_module_import : Warning<
+  "treating #%select{include|import|include_next|__include_macros}0 as an "
+  "import of module '%1'">, InGroup<AutoImport>, DefaultIgnore;
+
 }

clang/lib/Lex/PPDirectives.cpp

@@ -22,6 +22,7 @@
 #include "clang/Basic/FileManager.h"
 #include "clang/Basic/SourceManager.h"
 #include "llvm/ADT/APInt.h"
+#include "llvm/Support/ErrorHandling.h"
 using namespace clang;
 
 //===----------------------------------------------------------------------===//
@@ -1208,6 +1209,7 @@ void Preprocessor::HandleIncludeDirective(SourceLocation HashLoc,
   llvm::SmallString<128> FilenameBuffer;
   StringRef Filename;
   SourceLocation End;
+  SourceLocation CharEnd; // the end of this directive, in characters
   
   switch (FilenameTok.getKind()) {
   case tok::eod:
@@ -1218,6 +1220,7 @@ void Preprocessor::HandleIncludeDirective(SourceLocation HashLoc,
   case tok::string_literal:
     Filename = getSpelling(FilenameTok, FilenameBuffer);
     End = FilenameTok.getLocation();
+    CharEnd = End.getLocWithOffset(Filename.size());
     break;
 
   case tok::less:
@@ -1227,6 +1230,7 @@ void Preprocessor::HandleIncludeDirective(SourceLocation HashLoc,
     if (ConcatenateIncludeName(FilenameBuffer, End))
       return;   // Found <eod> but no ">"?  Diagnostic already emitted.
     Filename = FilenameBuffer.str();
+    CharEnd = getLocForEndOfToken(End);
     break;
   default:
     Diag(FilenameTok.getLocation(), diag::err_pp_expects_filename);
@@ -1288,6 +1292,44 @@ void Preprocessor::HandleIncludeDirective(SourceLocation HashLoc,
                                     FilenameTok.getLocation()));
     std::reverse(Path.begin(), Path.end());
 
+    // Warn that we're replacing the include/import with a module import.
+    llvm::SmallString<128> PathString;
+    for (unsigned I = 0, N = Path.size(); I != N; ++I) {
+      if (I)
+        PathString += '.';
+      PathString += Path[I].first->getName();
+    }
+    int IncludeKind = 0;
+    
+    switch (IncludeTok.getIdentifierInfo()->getPPKeywordID()) {
+    case tok::pp_include:
+      IncludeKind = 0;
+      break;
+      
+    case tok::pp_import:
+      IncludeKind = 1;
+      break;        
+        
+      case tok::pp_include_next:
+        IncludeKind = 2;
+        break;
+        
+    case tok::pp___include_macros:
+      IncludeKind = 3;
+      break;
+        
+    default:
+      llvm_unreachable("unknown include directive kind");
+      break;
+    }
+
+    CharSourceRange ReplaceRange(SourceRange(HashLoc, CharEnd), 
+                                 /*IsTokenRange=*/false);
+    Diag(HashLoc, diag::warn_auto_module_import)
+      << IncludeKind << PathString 
+      << FixItHint::CreateReplacement(ReplaceRange,
+           "__import_module__ " + PathString.str().str() + ";");
+    
     // Load the module.
     TheModuleLoader.loadModule(IncludeTok.getLocation(), Path);
     return;

clang/test/Modules/Inputs/DependsOnModule.framework/Headers/DependsOnModule.h

@@ -1,4 +1,4 @@
-#include <Module/Module.h>
+#include <Module/Module.h> //expected-warning{{treating #include as an import of module 'Module'}}
 
 #define DEPENDS_ON_MODULE 1
 #__private_macro__ DEPENDS_ON_MODULE

clang/test/Modules/auto-module-import.c

@@ -1,8 +1,8 @@
 
 // RUN: rm -rf %t
-// RUN: %clang_cc1 -x objective-c -fmodule-cache-path %t -fauto-module-import -F %S/Inputs %s -verify
+// RUN: %clang_cc1 -x objective-c -Wauto-import -fmodule-cache-path %t -fauto-module-import -F %S/Inputs %s -verify
 
-#include <DependsOnModule/DependsOnModule.h>
+#include <DependsOnModule/DependsOnModule.h> // expected-warning{{treating #include as an import of module 'DependsOnModule'}}
 
 #ifdef MODULE_H_MACRO
 #  error MODULE_H_MACRO should have been hidden