Debug Info: Support fragmented variables in the MMI side table

This reapplies commit r309034 with a bugfix+test for inlined variables.

llvm-svn: 309057

1 files changed, 6 insertions, 1 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 036d1080a28..9533d61d08a 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -779,6 +779,7 @@ void DwarfDebug::ensureAbstractVariableIsCreatedIfScoped(DwarfCompileUnit &CU,
 // Collect variable information from side table maintained by MF.
 void DwarfDebug::collectVariableInfoFromMFTable(
     DwarfCompileUnit &TheCU, DenseSet<InlinedVariable> &Processed) {
+  SmallDenseMap<InlinedVariable, DbgVariable *> MFVars;
   for (const auto &VI : Asm->MF->getVariableDbgInfo()) {
     if (!VI.Var)
       continue;
@@ -796,8 +797,12 @@ void DwarfDebug::collectVariableInfoFromMFTable(
     ensureAbstractVariableIsCreatedIfScoped(TheCU, Var, Scope->getScopeNode());
     auto RegVar = make_unique<DbgVariable>(Var.first, Var.second);
     RegVar->initializeMMI(VI.Expr, VI.Slot);
-    if (InfoHolder.addScopeVariable(Scope, RegVar.get()))
+    if (DbgVariable *DbgVar = MFVars.lookup(Var))
+      DbgVar->addMMIEntry(*RegVar);
+    else if (InfoHolder.addScopeVariable(Scope, RegVar.get())) {
+      MFVars.insert({Var, RegVar.get()});
       ConcreteVariables.push_back(std::move(RegVar));
+    }
   }
 }