[llvm-commits] [llvm] r86212 - in /llvm/trunk: lib/CodeGen/AsmPrinter/DwarfDebug.cpp test/DebugInfo/2009-11-05-DeadGlobalVariable.ll

[Devang Patel]

Author: dpatel
Date: Thu Nov  5 19:30:04 2009
New Revision: 86212

URL: http://llvm.org/viewvc/llvm-project?rev=86212&view=rev
Log:
Do not try to emit debug info entry for dead global variable.

Added:
    llvm/trunk/test/DebugInfo/2009-11-05-DeadGlobalVariable.ll
Modified:
    llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp

Modified: llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp?rev=86212&r1=86211&r2=86212&view=diff

==============================================================================
--- llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp (original)
+++ llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp Thu Nov  5 19:30:04 2009
@@ -1097,6 +1097,10 @@
 /// CreateGlobalVariableDIE - Create new DIE using GV.
 DIE *DwarfDebug::CreateGlobalVariableDIE(CompileUnit *DW_Unit,
                                          const DIGlobalVariable &GV) {
+  // If the global variable was optmized out then no need to create debug info entry.
+  if (!GV.getGlobal())
+    return NULL;
+
   DIE *GVDie = new DIE(dwarf::DW_TAG_variable);
   AddString(GVDie, dwarf::DW_AT_name, dwarf::DW_FORM_string, 
             GV.getDisplayName());
@@ -1518,7 +1522,8 @@
     DIGlobalVariable GV(N);
     if (GV.getContext().getNode() == RootScope->getDesc().getNode()) {
       DIE *ScopedGVDie = CreateGlobalVariableDIE(ModuleCU, GV);
-      SPDie->AddChild(ScopedGVDie);
+      if (ScopedGVDie)
+        SPDie->AddChild(ScopedGVDie);
     }
   }
 }

Added: llvm/trunk/test/DebugInfo/2009-11-05-DeadGlobalVariable.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/2009-11-05-DeadGlobalVariable.ll?rev=86212&view=auto

==============================================================================
--- llvm/trunk/test/DebugInfo/2009-11-05-DeadGlobalVariable.ll (added)
+++ llvm/trunk/test/DebugInfo/2009-11-05-DeadGlobalVariable.ll Thu Nov  5 19:30:04 2009
@@ -0,0 +1,17 @@
+; RUN: llc %s -o /dev/null
+; Here variable bar is optimzied away. Do not trip over while trying to generate debug info.
+
+define i32 @foo() nounwind readnone optsize ssp {
+entry:
+  ret i32 42, !dbg !6
+}
+
+!llvm.dbg.gv = !{!0}
+
+!0 = metadata !{i32 458804, i32 0, metadata !1, metadata !"foo.bar", metadata !"foo.bar", metadata !"foo.bar", metadata !2, i32 3, metadata !5, i1 true, i1 true, null}; [DW_TAG_variable ]
+!1 = metadata !{i32 458798, i32 0, metadata !2, metadata !"foo", metadata !"foo", metadata !"foo", metadata !2, i32 2, metadata !3, i1 false, i1 true}; [DW_TAG_subprogram ]
+!2 = metadata !{i32 458769, i32 0, i32 12, metadata !"st.c", metadata !"/private/tmp", metadata !"clang 1.1", i1 true, i1 true, metadata !"", i32 0}; [DW_TAG_compile_unit ]
+!3 = metadata !{i32 458773, metadata !2, metadata !"", null, i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !4, i32 0}; [DW_TAG_subroutine_type ]
+!4 = metadata !{metadata !5}
+!5 = metadata !{i32 458788, metadata !2, metadata !"int", metadata !2, i32 0, i64 32, i64 32, i64 0, i32 0, i32 5}; [DW_TAG_base_type ]
+!6 = metadata !{i32 5, i32 1, metadata !1, null}