DebugInfo: Emit only declarations (not whole definitions) of non-unit user defined types into type units

While this doesn't come up in reasonable cases currently (the only user
defined types not in type units are ones without linkage - which makes
for near-ODR violations, because it'd be a type with linkage referencing
a type without linkage - such a type can't be validly defined in more
than one TU, so arguably it shouldn't be in a type unit to begin with -
but it's a convenient way to demonstrate an issue that will become more
revalent with homed modular debug info type definitions - which also
don't need to be in type units but more legitimately so).

Precursor to the Clang change to de-type-unit (by omitting the
'identifier') types homed due to strong linkage vtables. (making that
change without this one would lead to major type duplication in type
units)

llvm-svn: 359122

1 files changed, 13 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
index a8cadaa60eb..2c2e6bf54c3 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
@@ -606,6 +606,19 @@ public:
   void addDwarfTypeUnitType(DwarfCompileUnit &CU, StringRef Identifier,
                             DIE &Die, const DICompositeType *CTy);
 
+  friend class NonTypeUnitContext;
+  class NonTypeUnitContext {
+    DwarfDebug *DD;
+    decltype(DwarfDebug::TypeUnitsUnderConstruction) TypeUnitsUnderConstruction;
+    friend class DwarfDebug;
+    NonTypeUnitContext(DwarfDebug *DD);
+  public:
+    NonTypeUnitContext(NonTypeUnitContext&&) = default;
+    ~NonTypeUnitContext();
+  };
+
+  NonTypeUnitContext enterNonTypeUnitContext();
+
   /// Add a label so that arange data can be generated for it.
   void addArangeLabel(SymbolCU SCU) { ArangeLabels.push_back(SCU); }