From 8b15d74434dfde5ea9227b985c2c934f62bf03a7 Mon Sep 17 00:00:00 2001
From: Manman Ren <mren@apple.com>
Date: Thu, 31 Jan 2013 20:05:14 +0000
Subject: [PATCH] [Dwarf] early exit to avoid creating dangling DIEs
We used to create children DIEs for a scope, then check whether ScopeDIE is
null. If ScopeDIE is null, the children DIEs will be dangling. Other DIEs can
link to those dangling DIEs, which are not emitted at all, causing dwarf error.
The current testing case is 4k lines, from MultiSource/BenchMark/McCat/09-vor.
rdar://problem/13071959
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174084 91177308-0d34-0410-b5e6-96231b3b80d8
---
lib/CodeGen/AsmPrinter/DwarfDebug.cpp | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index f3c7a2afb39..13ad353be24 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -540,6 +540,12 @@ DIE *DwarfDebug::constructScopeDIE(CompileUnit *TheCU, LexicalScope *Scope) {
if (!Scope || !Scope->getScopeNode())
return NULL;
+ DIScope DS(Scope->getScopeNode());
+ // Early return to avoid creating dangling variable|scope DIEs.
+ if (!Scope->getInlinedAt() && DS.isSubprogram() && Scope->isAbstractScope() &&
+ !TheCU->getDIE(DS))
+ return NULL;
+
SmallVector<DIE *, 8> Children;
DIE *ObjectPointer = NULL;
@@ -565,7 +571,6 @@ DIE *DwarfDebug::constructScopeDIE(CompileUnit *TheCU, LexicalScope *Scope) {
for (unsigned j = 0, M = Scopes.size(); j < M; ++j)
if (DIE *Nested = constructScopeDIE(TheCU, Scopes[j]))
Children.push_back(Nested);
- DIScope DS(Scope->getScopeNode());
DIE *ScopeDIE = NULL;
if (Scope->getInlinedAt())
ScopeDIE = constructInlinedScopeDIE(TheCU, Scope);