From 149aa7cce368a879e3ad20b2a6ec777e9441cdab Mon Sep 17 00:00:00 2001
From: Devang Patel <dpatel@apple.com>
Date: Fri, 16 Oct 2009 18:18:03 +0000
Subject: [PATCH] If there is not any llvm instruction associated with each
 lexical scope encoded in debug info then create such scope on demand for
 variable info.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84262 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/AsmPrinter/DwarfDebug.cpp | 12 ++++++++--
 test/DebugInfo/2009-11-16-Scope.ll    | 33 +++++++++++++++++++++++++++
 2 files changed, 43 insertions(+), 2 deletions(-)
 create mode 100644 test/DebugInfo/2009-11-16-Scope.ll

diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 29148510956..87e808ff9af 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -1811,10 +1811,18 @@ void DwarfDebug::CollectVariableInfo() {
     DIVariable DV (Var);
     if (DV.isNull()) continue;
     unsigned VSlot = VI->second;
+    DbgScope *Scope = NULL;
     DenseMap<MDNode *, DbgScope *>::iterator DSI = 
       DbgScopeMap.find(DV.getContext().getNode());
-    assert (DSI != DbgScopeMap.end() && "Unable to find variable scope!");
-    DbgScope *Scope = DSI->second;
+    if (DSI != DbgScopeMap.end()) 
+      Scope = DSI->second;
+    else 
+      // There is not any instruction assocated with this scope, so get
+      // a new scope.
+      Scope = getDbgScope(DV.getContext().getNode(), 
+                          NULL /* Not an instruction */,
+                          NULL /* Not inlined */);
+    assert (Scope && "Unable to find variable scope!");
     Scope->AddVariable(new DbgVariable(DV, VSlot, false));
   }
 }
diff --git a/test/DebugInfo/2009-11-16-Scope.ll b/test/DebugInfo/2009-11-16-Scope.ll
new file mode 100644
index 00000000000..ea43249668a
--- /dev/null
+++ b/test/DebugInfo/2009-11-16-Scope.ll
@@ -0,0 +1,33 @@
+; RUN: llc %s -O0 -o /dev/null
+; PR 5197
+; There is not any llvm instruction assocated with !5. The code generator
+; should be able to handle this.
+
+define void @bar() nounwind ssp {
+entry:
+  %count_ = alloca i32, align 4                   ; <i32*> [#uses=2]
+  br label %do.body, !dbg !0
+
+do.body:                                          ; preds = %entry
+  %0 = bitcast i32* %count_ to { }*               ; <{ }*> [#uses=1]
+  call void @llvm.dbg.declare({ }* %0, metadata !4)
+  %conv = ptrtoint i32* %count_ to i32, !dbg !0   ; <i32> [#uses=1]
+  %call = call i32 @foo(i32 %conv) ssp, !dbg !0   ; <i32> [#uses=0]
+  br label %do.end, !dbg !0
+
+do.end:                                           ; preds = %do.body
+  ret void, !dbg !7
+}
+
+declare void @llvm.dbg.declare({ }*, metadata) nounwind readnone
+
+declare i32 @foo(i32) ssp
+
+!0 = metadata !{i32 5, i32 2, metadata !1, null}
+!1 = metadata !{i32 458763, metadata !2}; [DW_TAG_lexical_block ]
+!2 = metadata !{i32 458798, i32 0, metadata !3, metadata !"bar", metadata !"bar", metadata !"bar", metadata !3, i32 4, null, i1 false, i1 true}; [DW_TAG_subprogram ]
+!3 = metadata !{i32 458769, i32 0, i32 12, metadata !"genmodes.i", metadata !"/Users/yash/Downloads", metadata !"clang 1.1", i1 true, i1 false, metadata !"", i32 0}; [DW_TAG_compile_unit ]
+!4 = metadata !{i32 459008, metadata !5, metadata !"count_", metadata !3, i32 5, metadata !6}; [ DW_TAG_auto_variable ]
+!5 = metadata !{i32 458763, metadata !1}; [DW_TAG_lexical_block ]
+!6 = metadata !{i32 458788, metadata !3, metadata !"int", metadata !3, i32 0, i64 32, i64 32, i64 0, i32 0, i32 5}; [DW_TAG_base_type ]
+!7 = metadata !{i32 6, i32 1, metadata !2, null}