[modules] Switch from inferring owning modules based on source location to

inferring based on the current module at the point of creation.

This should result in no functional change except when building a preprocessed
module (or more generally when using #pragma clang module begin/end to switch
module in the middle of a file), in which case it allows us to correctly track
the owning module for declarations. We can't map from FileID to module in the
preprocessed module case, since all modules would have the same FileID.

There are still a couple of remaining places that try to infer a module from a
source location; I'll clean those up in follow-up changes.

llvm-svn: 303322

1 files changed, 28 insertions, 37 deletions

diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index dca51b0e8c8..4928f3f35ae 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -2021,7 +2021,7 @@ bool Sema::isIncompatibleTypedef(TypeDecl *Old, TypedefNameDecl *New) {
     Diag(New->getLocation(), diag::err_redefinition_variably_modified_typedef)
       << Kind << NewType;
     if (Old->getLocation().isValid())
-      notePreviousDefinition(Old->getLocation(), New->getLocation());
+      notePreviousDefinition(Old, New->getLocation());
     New->setInvalidDecl();
     return true;
   }
@@ -2034,7 +2034,7 @@ bool Sema::isIncompatibleTypedef(TypeDecl *Old, TypedefNameDecl *New) {
     Diag(New->getLocation(), diag::err_redefinition_different_typedef)
       << Kind << NewType << OldType;
     if (Old->getLocation().isValid())
-      notePreviousDefinition(Old->getLocation(), New->getLocation());
+      notePreviousDefinition(Old, New->getLocation());
     New->setInvalidDecl();
     return true;
   }
@@ -2101,7 +2101,7 @@ void Sema::MergeTypedefNameDecl(Scope *S, TypedefNameDecl *New,
 
     NamedDecl *OldD = OldDecls.getRepresentativeDecl();
     if (OldD->getLocation().isValid())
-      notePreviousDefinition(OldD->getLocation(), New->getLocation());
+      notePreviousDefinition(OldD, New->getLocation());
 
     return New->setInvalidDecl();
   }
@@ -2193,7 +2193,7 @@ void Sema::MergeTypedefNameDecl(Scope *S, TypedefNameDecl *New,
 
     Diag(New->getLocation(), diag::err_redefinition)
       << New->getDeclName();
-    notePreviousDefinition(Old->getLocation(), New->getLocation());
+    notePreviousDefinition(Old, New->getLocation());
     return New->setInvalidDecl();
   }
 
@@ -2214,7 +2214,7 @@ void Sema::MergeTypedefNameDecl(Scope *S, TypedefNameDecl *New,
 
   Diag(New->getLocation(), diag::ext_redefinition_of_typedef)
     << New->getDeclName();
-  notePreviousDefinition(Old->getLocation(), New->getLocation());
+  notePreviousDefinition(Old, New->getLocation());
 }
 
 /// DeclhasAttr - returns true if decl Declaration already has the target
@@ -2448,7 +2448,7 @@ static bool mergeDeclAttribute(Sema &S, NamedDecl *D,
   return false;
 }
 
-static const Decl *getDefinition(const Decl *D) {
+static const NamedDecl *getDefinition(const Decl *D) {
   if (const TagDecl *TD = dyn_cast<TagDecl>(D))
     return TD->getDefinition();
   if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
@@ -2475,7 +2475,7 @@ static void checkNewAttributesAfterDef(Sema &S, Decl *New, const Decl *Old) {
   if (!New->hasAttrs())
     return;
 
-  const Decl *Def = getDefinition(Old);
+  const NamedDecl *Def = getDefinition(Old);
   if (!Def || Def == New)
     return;
 
@@ -2502,7 +2502,7 @@ static void checkNewAttributesAfterDef(Sema &S, Decl *New, const Decl *Old) {
                             : diag::err_redefinition;
         S.Diag(VD->getLocation(), Diag) << VD->getDeclName();
         if (Diag == diag::err_redefinition)
-          S.notePreviousDefinition(Def->getLocation(), VD->getLocation());
+          S.notePreviousDefinition(Def, VD->getLocation());
         else
           S.Diag(Def->getLocation(), diag::note_previous_definition);
         VD->setInvalidDecl();
@@ -2891,7 +2891,7 @@ bool Sema::MergeFunctionDecl(FunctionDecl *New, NamedDecl *&OldD,
     } else {
       Diag(New->getLocation(), diag::err_redefinition_different_kind)
         << New->getDeclName();
-      notePreviousDefinition(OldD->getLocation(), New->getLocation());
+      notePreviousDefinition(OldD, New->getLocation());
       return true;
     }
   }
@@ -2928,7 +2928,7 @@ bool Sema::MergeFunctionDecl(FunctionDecl *New, NamedDecl *&OldD,
       !Old->hasAttr<InternalLinkageAttr>()) {
     Diag(New->getLocation(), diag::err_internal_linkage_redeclaration)
         << New->getDeclName();
-    notePreviousDefinition(Old->getLocation(), New->getLocation());
+    notePreviousDefinition(Old, New->getLocation());
     New->dropAttr<InternalLinkageAttr>();
   }
 
@@ -3657,7 +3657,7 @@ void Sema::MergeVarDecl(VarDecl *New, LookupResult &Previous) {
   if (!Old) {
     Diag(New->getLocation(), diag::err_redefinition_different_kind)
         << New->getDeclName();
-    notePreviousDefinition(Previous.getRepresentativeDecl()->getLocation(),
+    notePreviousDefinition(Previous.getRepresentativeDecl(),
                            New->getLocation());
     return New->setInvalidDecl();
   }
@@ -3687,7 +3687,7 @@ void Sema::MergeVarDecl(VarDecl *New, LookupResult &Previous) {
       Old->getStorageClass() == SC_None &&
       !Old->hasAttr<WeakImportAttr>()) {
     Diag(New->getLocation(), diag::warn_weak_import) << New->getDeclName();
-    notePreviousDefinition(Old->getLocation(), New->getLocation());
+    notePreviousDefinition(Old, New->getLocation());
     // Remove weak_import attribute on new declaration.
     New->dropAttr<WeakImportAttr>();
   }
@@ -3696,7 +3696,7 @@ void Sema::MergeVarDecl(VarDecl *New, LookupResult &Previous) {
       !Old->hasAttr<InternalLinkageAttr>()) {
     Diag(New->getLocation(), diag::err_internal_linkage_redeclaration)
         << New->getDeclName();
-    notePreviousDefinition(Old->getLocation(), New->getLocation());
+    notePreviousDefinition(Old, New->getLocation());
     New->dropAttr<InternalLinkageAttr>();
   }
 
@@ -3853,29 +3853,22 @@ void Sema::MergeVarDecl(VarDecl *New, LookupResult &Previous) {
     New->setImplicitlyInline();
 }
 
-void Sema::notePreviousDefinition(SourceLocation Old, SourceLocation New) {
+void Sema::notePreviousDefinition(const NamedDecl *Old, SourceLocation New) {
   SourceManager &SrcMgr = getSourceManager();
   auto FNewDecLoc = SrcMgr.getDecomposedLoc(New);
-  auto FOldDecLoc = SrcMgr.getDecomposedLoc(Old);
+  auto FOldDecLoc = SrcMgr.getDecomposedLoc(Old->getLocation());
   auto *FNew = SrcMgr.getFileEntryForID(FNewDecLoc.first);
   auto *FOld = SrcMgr.getFileEntryForID(FOldDecLoc.first);
   auto &HSI = PP.getHeaderSearchInfo();
-  StringRef HdrFilename = SrcMgr.getFilename(SrcMgr.getSpellingLoc(Old));
+  StringRef HdrFilename =
+      SrcMgr.getFilename(SrcMgr.getSpellingLoc(Old->getLocation()));
 
-  auto noteFromModuleOrInclude = [&](SourceLocation &Loc,
-                                     SourceLocation &IncLoc) -> bool {
-    Module *Mod = nullptr;
+  auto noteFromModuleOrInclude = [&](Module *Mod,
+                                     SourceLocation IncLoc) -> bool {
     // Redefinition errors with modules are common with non modular mapped
     // headers, example: a non-modular header H in module A that also gets
     // included directly in a TU. Pointing twice to the same header/definition
     // is confusing, try to get better diagnostics when modules is on.
-    if (getLangOpts().Modules) {
-      auto ModLoc = SrcMgr.getModuleImportLoc(Old);
-      if (!ModLoc.first.isInvalid())
-        Mod = HSI.getModuleMap().inferModuleFromLocation(
-            FullSourceLoc(Loc, SrcMgr));
-    }
-
     if (IncLoc.isValid()) {
       if (Mod) {
         Diag(IncLoc, diag::note_redefinition_modules_same_file)
@@ -3899,19 +3892,19 @@ void Sema::notePreviousDefinition(SourceLocation Old, SourceLocation New) {
   if (FNew == FOld && FNewDecLoc.second == FOldDecLoc.second) {
     SourceLocation OldIncLoc = SrcMgr.getIncludeLoc(FOldDecLoc.first);
     SourceLocation NewIncLoc = SrcMgr.getIncludeLoc(FNewDecLoc.first);
-    EmittedDiag = noteFromModuleOrInclude(Old, OldIncLoc);
-    EmittedDiag |= noteFromModuleOrInclude(New, NewIncLoc);
+    EmittedDiag = noteFromModuleOrInclude(Old->getOwningModule(), OldIncLoc);
+    EmittedDiag |= noteFromModuleOrInclude(getCurrentModule(), NewIncLoc);
 
     // If the header has no guards, emit a note suggesting one.
     if (FOld && !HSI.isFileMultipleIncludeGuarded(FOld))
-      Diag(Old, diag::note_use_ifdef_guards);
+      Diag(Old->getLocation(), diag::note_use_ifdef_guards);
 
     if (EmittedDiag)
       return;
   }
 
   // Redefinition coming from different files or couldn't do better above.
-  Diag(Old, diag::note_previous_definition);
+  Diag(Old->getLocation(), diag::note_previous_definition);
 }
 
 /// We've just determined that \p Old and \p New both appear to be definitions
@@ -3934,7 +3927,7 @@ bool Sema::checkVarDeclRedefinition(VarDecl *Old, VarDecl *New) {
     return false;
   } else {
     Diag(New->getLocation(), diag::err_redefinition) << New;
-    notePreviousDefinition(Old->getLocation(), New->getLocation());
+    notePreviousDefinition(Old, New->getLocation());
     New->setInvalidDecl();
     return true;
   }
@@ -13503,9 +13496,7 @@ Decl *Sema::ActOnTag(Scope *S, unsigned TagSpec, TagUseKind TUK,
             } else if (TUK == TUK_Reference &&
                        (PrevTagDecl->getFriendObjectKind() ==
                             Decl::FOK_Undeclared ||
-                        PP.getModuleContainingLocation(
-                            PrevDecl->getLocation()) !=
-                            PP.getModuleContainingLocation(KWLoc)) &&
+                        PrevDecl->getOwningModule() != getCurrentModule()) &&
                        SS.isEmpty()) {
               // This declaration is a reference to an existing entity, but
               // has different visibility from that entity: it either makes
@@ -13561,7 +13552,7 @@ Decl *Sema::ActOnTag(Scope *S, unsigned TagSpec, TagUseKind TUK,
                   Diag(NameLoc, diag::warn_redefinition_in_param_list) << Name;
                 else
                   Diag(NameLoc, diag::err_redefinition) << Name;
-                notePreviousDefinition(Def->getLocation(),
+                notePreviousDefinition(Def,
                                        NameLoc.isValid() ? NameLoc : KWLoc);
                 // If this is a redefinition, recover by making this
                 // struct be anonymous, which will make any later
@@ -13652,7 +13643,7 @@ Decl *Sema::ActOnTag(Scope *S, unsigned TagSpec, TagUseKind TUK,
         // The tag name clashes with something else in the target scope,
         // issue an error and recover by making this tag be anonymous.
         Diag(NameLoc, diag::err_redefinition_different_kind) << Name;
-        notePreviousDefinition(PrevDecl->getLocation(), NameLoc);
+        notePreviousDefinition(PrevDecl, NameLoc);
         Name = nullptr;
         Invalid = true;
       }
@@ -15356,7 +15347,7 @@ Decl *Sema::ActOnEnumConstant(Scope *S, Decl *theEnumDecl, Decl *lastEnumConst,
         Diag(IdLoc, diag::err_redefinition_of_enumerator) << Id;
       else
         Diag(IdLoc, diag::err_redefinition) << Id;
-      notePreviousDefinition(PrevDecl->getLocation(), IdLoc);
+      notePreviousDefinition(PrevDecl, IdLoc);
       return nullptr;
     }
   }