It's possible for a global variable to be optimized out of a metadata object. So

we should allow a "null" with this dyn_cast.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@83573 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Analysis/DebugInfo.cpp b/lib/Analysis/DebugInfo.cpp
index 1436aa909e5960582c543a0a790d3cb709bad02e..81d0ddb6f5555da3366a48820f2487aafa32281f 100644 (file)
--- a/lib/Analysis/DebugInfo.cpp
+++ b/lib/Analysis/DebugInfo.cpp
@@ -116,7 +116,7 @@ GlobalVariable *DIDescriptor::getGlobalVariableField(unsigned Elt) const {
     return 0;
 
   if (Elt < DbgNode->getNumElements())
-      return dyn_cast<GlobalVariable>(DbgNode->getElement(Elt));
+      return dyn_cast_or_null<GlobalVariable>(DbgNode->getElement(Elt));
   return 0;
 }
 

diff --git a/test/DebugInfo/2009-10-08-DebugInfo-NullGlobalVariable.ll b/test/DebugInfo/2009-10-08-DebugInfo-NullGlobalVariable.ll
new file mode 100644 (file)
index 0000000..fc28107
--- /dev/null
+++ b/test/DebugInfo/2009-10-08-DebugInfo-NullGlobalVariable.ll
@@ -0,0 +1,72 @@
+; RUN: llc < %s
+
+%struct.TConstantDictionary = type { %struct.__CFDictionary* }
+%struct.TSharedGlobalSet_AS = type { [52 x i32], [20 x i32], [22 x i32], [8 x i32], [20 x i32], [146 x i32] }
+%struct.__CFDictionary = type opaque
+
+@llvm.used = appending global [1 x i8*] [i8* bitcast (void ()* @func to i8*)], section "llvm.metadata" ; <[1 x i8*]*> [#uses=0]
+
+define void @func() ssp {
+entry:
+  tail call void @llvm.dbg.func.start(metadata !13)
+  tail call void @llvm.dbg.stoppoint(i32 1001, i32 0, metadata !1)
+  %0 = tail call %struct.TSharedGlobalSet_AS* @g1() nounwind ; <%struct.TSharedGlobalSet_AS*> [#uses=1]
+  %1 = getelementptr inbounds %struct.TSharedGlobalSet_AS* %0, i32 0, i32 4, i32 4 ; <i32*> [#uses=1]
+  %2 = bitcast i32* %1 to %struct.TConstantDictionary* ; <%struct.TConstantDictionary*> [#uses=1]
+  tail call void @g2(%struct.TConstantDictionary* %2) ssp
+  tail call void @llvm.dbg.stoppoint(i32 1002, i32 0, metadata !1)
+  %3 = tail call %struct.TSharedGlobalSet_AS* @g1() nounwind ; <%struct.TSharedGlobalSet_AS*> [#uses=1]
+  %4 = getelementptr inbounds %struct.TSharedGlobalSet_AS* %3, i32 0, i32 4, i32 3 ; <i32*> [#uses=1]
+  %5 = bitcast i32* %4 to %struct.TConstantDictionary* ; <%struct.TConstantDictionary*> [#uses=1]
+  tail call void @g4(%struct.TConstantDictionary* %5) ssp
+  tail call void @llvm.dbg.stoppoint(i32 1003, i32 0, metadata !1)
+  %6 = tail call %struct.TSharedGlobalSet_AS* @g1() nounwind ; <%struct.TSharedGlobalSet_AS*> [#uses=1]
+  %7 = getelementptr inbounds %struct.TSharedGlobalSet_AS* %6, i32 0, i32 4, i32 2 ; <i32*> [#uses=1]
+  %8 = bitcast i32* %7 to %struct.TConstantDictionary* ; <%struct.TConstantDictionary*> [#uses=1]
+  tail call void @g3(%struct.TConstantDictionary* %8) ssp
+  tail call void @llvm.dbg.stoppoint(i32 1004, i32 0, metadata !1)
+  %9 = tail call %struct.TSharedGlobalSet_AS* @g1() nounwind ; <%struct.TSharedGlobalSet_AS*> [#uses=1]
+  %10 = getelementptr inbounds %struct.TSharedGlobalSet_AS* %9, i32 0, i32 4, i32 1 ; <i32*> [#uses=1]
+  %11 = bitcast i32* %10 to %struct.TConstantDictionary* ; <%struct.TConstantDictionary*> [#uses=1]
+  tail call void @g4(%struct.TConstantDictionary* %11) ssp
+  tail call void @llvm.dbg.stoppoint(i32 1005, i32 0, metadata !1)
+  tail call void @g5()
+  tail call void @llvm.dbg.stoppoint(i32 1006, i32 0, metadata !1)
+  tail call void @llvm.dbg.region.end(metadata !13)
+  ret void
+}
+
+declare void @llvm.dbg.func.start(metadata) nounwind readnone
+
+declare void @llvm.dbg.stoppoint(i32, i32, metadata) nounwind readnone
+
+declare void @llvm.dbg.region.end(metadata) nounwind readnone
+
+declare %struct.TSharedGlobalSet_AS* @g1() nounwind readonly ssp
+
+declare void @g2(%struct.TConstantDictionary* nocapture) ssp align 2
+
+declare void @g3(%struct.TConstantDictionary* nocapture) ssp align 2
+
+declare void @g4(%struct.TConstantDictionary* nocapture) ssp align 2
+
+declare void @g5()
+
+!llvm.dbg.gv = !{!0, !9, !10, !11, !12}
+
+!0 = metadata !{i32 458804, i32 0, metadata !1, metadata !"_ZZ7UASInitmmmmmmmmmE5C.408", metadata !"C.408", metadata !"_ZZ7UASInitmmmmmmmmmE5C.408", metadata !1, i32 874, metadata !2, i1 false, i1 true, null}; [DW_TAG_variable ]
+!1 = metadata !{i32 458769, i32 0, i32 4, metadata !"func.cp", metadata !"/tmp/func", metadata !"4.2.1 (Based on Apple Inc. build 5653) (LLVM build 2311)", i1 false, i1 false, metadata !"", i32 0}; [DW_TAG_compile_unit ]
+!2 = metadata !{i32 458753, metadata !3, metadata !"", metadata !3, i32 0, i64 16, i64 16, i64 0, i32 0, metadata !4, metadata !7, i32 0}; [DW_TAG_array_type ]
+!3 = metadata !{i32 458769, i32 0, i32 4, metadata !"testcase.ii", metadata !"/tmp/", metadata !"4.2.1 (Based on Apple Inc. build 5653) (LLVM build 2311)", i1 true, i1 false, metadata !"", i32 0}; [DW_TAG_compile_unit ]
+!4 = metadata !{i32 458774, metadata !3, metadata !"UniChar", metadata !5, i32 417, i64 0, i64 0, i64 0, i32 0, metadata !6}; [DW_TAG_typedef ]
+!5 = metadata !{i32 458769, i32 0, i32 4, metadata !"MacTypes.h", metadata !"/System/Library/Frameworks/CoreServices.framework/Headers/../Frameworks/CarbonCore.framework/Headers", metadata !"4.2.1 (Based on Apple Inc. build 5653) (LLVM build 2311)", i1 false, i1 true, metadata !"", i32 0}; [DW_TAG_compile_unit ]
+!6 = metadata !{i32 458788, metadata !3, metadata !"short unsigned int", metadata !3, i32 0, i64 16, i64 16, i64 0, i32 0, i32 7}; [DW_TAG_base_type ]
+!7 = metadata !{metadata !8}
+!8 = metadata !{i32 458785, i64 0, i64 0}; [DW_TAG_subrange_type ]
+!9 = metadata !{i32 458804, i32 0, metadata !1, metadata !"_ZZ7UASInitmmmmmmmmmE5C.409", metadata !"C.409", metadata !"_ZZ7UASInitmmmmmmmmmE5C.409", metadata !1, i32 877, metadata !2, i1 false, i1 true, null}; [DW_TAG_variable ]
+!10 = metadata !{i32 458804, i32 0, metadata !1, metadata !"_ZZ7UASInitmmmmmmmmmE5C.410", metadata !"C.410", metadata !"_ZZ7UASInitmmmmmmmmmE5C.410", metadata !1, i32 880, metadata !2, i1 false, i1 true, null}; [DW_TAG_variable ]
+!11 = metadata !{i32 458804, i32 0, metadata !1, metadata !"_ZZ7UASInitmmmmmmmmmE5C.411", metadata !"C.411", metadata !"_ZZ7UASInitmmmmmmmmmE5C.411", metadata !1, i32 924, metadata !2, i1 false, i1 true, null}; [DW_TAG_variable ]
+!12 = metadata !{i32 458804, i32 0, metadata !1, metadata !"_ZZ7UASInitmmmmmmmmmE5C.412", metadata !"C.412", metadata !"_ZZ7UASInitmmmmmmmmmE5C.412", metadata !1, i32 928, metadata !2, i1 false, i1 true, null}; [DW_TAG_variable ]
+!13 = metadata !{i32 458798, i32 0, metadata !3, metadata !"UASShutdown", metadata !"UASShutdown", metadata !"_Z11UASShutdownv", metadata !1, i32 999, metadata !14, i1 false, i1 true}; [DW_TAG_subprogram ]
+!14 = metadata !{i32 458773, metadata !3, metadata !"", metadata !3, i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !15, i32 0}; [DW_TAG_subroutine_type ]
+!15 = metadata !{null}