[c++2a] Improve diagnostic for use of declaration from another TU's
global module fragment.
We know that the declaration in question should have been introduced by
a '#include', so try to figure out which one and suggest it. Don't
suggest importing the global module fragment itself!
llvm-svn: 358631
diff --git a/clang/lib/Sema/SemaLookup.cpp b/clang/lib/Sema/SemaLookup.cpp
index c5d8c2f..874e561 100644
--- a/clang/lib/Sema/SemaLookup.cpp
+++ b/clang/lib/Sema/SemaLookup.cpp
@@ -5073,7 +5073,7 @@
auto Merged = Context.getModulesWithMergedDefinition(Def);
OwningModules.insert(OwningModules.end(), Merged.begin(), Merged.end());
- diagnoseMissingImport(Loc, Decl, Decl->getLocation(), OwningModules, MIK,
+ diagnoseMissingImport(Loc, Def, Def->getLocation(), OwningModules, MIK,
Recover);
}
@@ -5093,12 +5093,58 @@
MissingImportKind MIK, bool Recover) {
assert(!Modules.empty());
+ auto NotePrevious = [&] {
+ unsigned DiagID;
+ switch (MIK) {
+ case MissingImportKind::Declaration:
+ DiagID = diag::note_previous_declaration;
+ break;
+ case MissingImportKind::Definition:
+ DiagID = diag::note_previous_definition;
+ break;
+ case MissingImportKind::DefaultArgument:
+ DiagID = diag::note_default_argument_declared_here;
+ break;
+ case MissingImportKind::ExplicitSpecialization:
+ DiagID = diag::note_explicit_specialization_declared_here;
+ break;
+ case MissingImportKind::PartialSpecialization:
+ DiagID = diag::note_partial_specialization_declared_here;
+ break;
+ }
+ Diag(DeclLoc, DiagID);
+ };
+
// Weed out duplicates from module list.
llvm::SmallVector<Module*, 8> UniqueModules;
llvm::SmallDenseSet<Module*, 8> UniqueModuleSet;
- for (auto *M : Modules)
+ for (auto *M : Modules) {
+ if (M->Kind == Module::GlobalModuleFragment)
+ continue;
if (UniqueModuleSet.insert(M).second)
UniqueModules.push_back(M);
+ }
+
+ if (UniqueModules.empty()) {
+ // All candidates were global module fragments. Try to suggest a #include.
+ const FileEntry *E =
+ PP.getModuleHeaderToIncludeForDiagnostics(UseLoc, Modules[0], DeclLoc);
+ // FIXME: Find a smart place to suggest inserting a #include, and add
+ // a FixItHint there.
+ Diag(UseLoc, diag::err_module_unimported_use_global_module_fragment)
+ << (int)MIK << Decl << !!E
+ << (E ? getIncludeStringForHeader(PP, E) : "");
+ // Produce a "previous" note if it will point to a header rather than some
+ // random global module fragment.
+ // FIXME: Suppress the note backtrace even under
+ // -fdiagnostics-show-note-include-stack.
+ if (E)
+ NotePrevious();
+ if (Recover)
+ createImplicitModuleImportForErrorRecovery(UseLoc, Modules[0]);
+ return;
+ }
+
Modules = UniqueModules;
if (Modules.size() > 1) {
@@ -5131,25 +5177,7 @@
<< (int)MIK << Decl << Modules[0]->getFullModuleName();
}
- unsigned DiagID;
- switch (MIK) {
- case MissingImportKind::Declaration:
- DiagID = diag::note_previous_declaration;
- break;
- case MissingImportKind::Definition:
- DiagID = diag::note_previous_definition;
- break;
- case MissingImportKind::DefaultArgument:
- DiagID = diag::note_default_argument_declared_here;
- break;
- case MissingImportKind::ExplicitSpecialization:
- DiagID = diag::note_explicit_specialization_declared_here;
- break;
- case MissingImportKind::PartialSpecialization:
- DiagID = diag::note_partial_specialization_declared_here;
- break;
- }
- Diag(DeclLoc, DiagID);
+ NotePrevious();
// Try to recover by implicitly importing this module.
if (Recover)