This reverts r291628. As suggested by Richard, we can simply

filter out the implicilty imported modules at CodeGen instead of removing the
implicit ImportDecl when an implementation TU of a module imports a header of
that same module.

llvm-svn: 291688

clang/include/clang/Sema/Sema.h

@@ -1905,8 +1905,7 @@ public:
   /// \brief The parser has processed a module import translated from a
   /// #include or similar preprocessing directive.
   void ActOnModuleInclude(SourceLocation DirectiveLoc, Module *Mod);
-  void BuildModuleInclude(SourceLocation DirectiveLoc, Module *Mod,
+  void BuildModuleInclude(SourceLocation DirectiveLoc, Module *Mod);
-                          bool NoImport);
 
   /// \brief The parsed has entered a submodule.
   void ActOnModuleBegin(SourceLocation DirectiveLoc, Module *Mod);

clang/lib/Sema/SemaDecl.cpp

@@ -15652,11 +15652,10 @@ DeclResult Sema::ActOnModuleImport(SourceLocation StartLoc,
 
 void Sema::ActOnModuleInclude(SourceLocation DirectiveLoc, Module *Mod) {
   checkModuleImportContext(*this, Mod, DirectiveLoc, CurContext, true);
-  BuildModuleInclude(DirectiveLoc, Mod, false/*NoImport*/);
+  BuildModuleInclude(DirectiveLoc, Mod);
 }
 
-void Sema::BuildModuleInclude(SourceLocation DirectiveLoc, Module *Mod,
+void Sema::BuildModuleInclude(SourceLocation DirectiveLoc, Module *Mod) {
-                              bool NoImport) {
   // Determine whether we're in the #include buffer for a module. The #includes
   // in that buffer do not qualify as module imports; they're just an
   // implementation detail of us building the module.
@@ -15666,7 +15665,7 @@ void Sema::BuildModuleInclude(SourceLocation DirectiveLoc, Module *Mod,
       TUKind == TU_Module &&
       getSourceManager().isWrittenInMainFile(DirectiveLoc);
 
-  bool ShouldAddImport = !IsInModuleIncludes && !NoImport;
+  bool ShouldAddImport = !IsInModuleIncludes;
 
   // If this module import was due to an inclusion directive, create an
   // implicit import declaration to capture it in the AST.
@@ -15714,11 +15713,7 @@ void Sema::ActOnModuleEnd(SourceLocation EofLoc, Module *Mod) {
   assert(File != getSourceManager().getMainFileID() &&
          "end of submodule in main source file");
   SourceLocation DirectiveLoc = getSourceManager().getIncludeLoc(File);
-  // Do not create implicit ImportDecl if we are building the implementation
+  BuildModuleInclude(DirectiveLoc, Mod);
-  // of a module.
-  bool NoImport = Mod->getTopLevelModuleName() == getLangOpts().CurrentModule &&
-                  !getLangOpts().isCompilingModule();
-  BuildModuleInclude(DirectiveLoc, Mod, NoImport);
 }
 
 void Sema::createImplicitModuleImportForErrorRecovery(SourceLocation Loc,

clang/test/Modules/Inputs/module-impl-with-link/foo.h

@@ -1 +0,0 @@
-//empty

clang/test/Modules/Inputs/module-impl-with-link/module.modulemap

@@ -1,4 +0,0 @@
-module Clib {
-  header "foo.h"
-  link "Clib"
-}

clang/test/Modules/module-impl-with-link.c

@@ -1,7 +0,0 @@
-// RUN: rm -rf %t
-// RUN: %clang_cc1 -fmodules-cache-path=%t -fmodules -fimplicit-module-maps -fmodule-name=Clib %s -I %S/Inputs/module-impl-with-link -emit-llvm -o -
-#include "foo.h"
-// CHECK: !{{[0-9]+}} = !{i32 6, !"Linker Options", ![[LINK_OPTIONS:[0-9]+]]}
-// Make sure we don't generate linker option for module Clib since this TU is
-// an implementation of Clib.
-// CHECK: ![[LINK_OPTIONS]] = !{}