[DebugInfo] Emit DWARF reference for DIVariable 'count' in DISubrange

Summary:
This patch implements the codegen of DWARF debug info for non-constant
'count' fields for DISubrange.

This is patch [2/3] in a series to extend LLVM's DISubrange Metadata
node to support debugging of C99 variable length arrays and vectors with
runtime length like the Scalable Vector Extension for AArch64. It is
also a first step towards representing more complex cases like arrays
in Fortran.

Reviewers: echristo, pcc, aprantl, dexonsmith, clayborg, kristof.beyls, dblaikie

Reviewed By: aprantl

Subscribers: fhahn, aemerson, rengolin, JDevlieghere, llvm-commits

Differential Revision: https://reviews.llvm.org/D41696

llvm-svn: 323323

1 files changed, 1 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
index e77e8d9b354..c009adc1e50 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
@@ -483,6 +483,7 @@ DIE *DwarfCompileUnit::constructVariableDIEImpl(const DbgVariable &DV,
                                                 bool Abstract) {
   // Define variable debug information entry.
   auto VariableDie = DIE::get(DIEValueAllocator, DV.getTag());
+  insertDIE(DV.getVariable(), VariableDie);
 
   if (Abstract) {
     applyVariableAttributes(DV, *VariableDie);