Reinstate r284008 reverted in r284081, with two fixes:
1) Merge and demote variable definitions when we find a redefinition in
MergeVarDecls, not only when we find one in AddInitializerToDecl (we only reach
the second case if it's the addition of the initializer itself that converts an
existing declaration into a definition).
2) When rebuilding a redeclaration chain for a variable, if we merge two
definitions together, mark the definitions as merged so the retained definition
is made visible whenever the demoted definition would have been.
Original commit message (from r283882):
[modules] PR28752: Do not instantiate variable declarations which are not visible.
Original patch by Vassil Vassilev! Changes listed above are mine.
llvm-svn: 284284
diff --git a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
index 09068d7..911bc51 100644
--- a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -4068,6 +4068,10 @@
PrettyDeclStackTraceEntry CrashInfo(*this, Var, SourceLocation(),
"instantiating variable initializer");
+ // The instantiation is visible here, even if it was first declared in an
+ // unimported module.
+ Var->setHidden(false);
+
// If we're performing recursive template instantiation, create our own
// queue of pending implicit instantiations that we will instantiate
// later, while we're still within our own instantiation context.
@@ -4116,33 +4120,17 @@
Def = PatternDecl->getDefinition();
}
- // FIXME: Check that the definition is visible before trying to instantiate
- // it. This requires us to track the instantiation stack in order to know
- // which definitions should be visible.
+ TemplateSpecializationKind TSK = Var->getTemplateSpecializationKind();
// If we don't have a definition of the variable template, we won't perform
// any instantiation. Rather, we rely on the user to instantiate this
// definition (or provide a specialization for it) in another translation
// unit.
- if (!Def) {
- if (DefinitionRequired) {
- if (VarSpec) {
- Diag(PointOfInstantiation,
- diag::err_explicit_instantiation_undefined_var_template) << Var;
- Var->setInvalidDecl();
- }
- else
- Diag(PointOfInstantiation,
- diag::err_explicit_instantiation_undefined_member)
- << 2 << Var->getDeclName() << Var->getDeclContext();
- Diag(PatternDecl->getLocation(),
- diag::note_explicit_instantiation_here);
- } else if (Var->getTemplateSpecializationKind()
- == TSK_ExplicitInstantiationDefinition) {
+ if (!Def && !DefinitionRequired) {
+ if (TSK == TSK_ExplicitInstantiationDefinition) {
PendingInstantiations.push_back(
std::make_pair(Var, PointOfInstantiation));
- } else if (Var->getTemplateSpecializationKind()
- == TSK_ImplicitInstantiation) {
+ } else if (TSK == TSK_ImplicitInstantiation) {
// Warn about missing definition at the end of translation unit.
if (AtEndOfTU && !getDiagnostics().hasErrorOccurred()) {
Diag(PointOfInstantiation, diag::warn_var_template_missing)
@@ -4151,12 +4139,20 @@
if (getLangOpts().CPlusPlus11)
Diag(PointOfInstantiation, diag::note_inst_declaration_hint) << Var;
}
+ return;
}
- return;
}
- TemplateSpecializationKind TSK = Var->getTemplateSpecializationKind();
+ // FIXME: We need to track the instantiation stack in order to know which
+ // definitions should be visible within this instantiation.
+ // FIXME: Produce diagnostics when Var->getInstantiatedFromStaticDataMember().
+ if (DiagnoseUninstantiableTemplate(PointOfInstantiation, Var,
+ /*InstantiatedFromMember*/false,
+ PatternDecl, Def, TSK,
+ /*Complain*/DefinitionRequired))
+ return;
+
// Never instantiate an explicit specialization.
if (TSK == TSK_ExplicitSpecialization)