[llvm-branch-commits] [llvm] 6d1083b - Revert "[SelectionDAG] Fix null pointer dereference in resolveDanglingDebugIn…"

[via llvm-branch-commits]

Author: Nikita Popov
Date: 2025-12-29T22:27:43+01:00
New Revision: 6d1083b8f128c59ee03cf9441eb9343b1db281f9

URL: https://github.com/llvm/llvm-project/commit/6d1083b8f128c59ee03cf9441eb9343b1db281f9
DIFF: https://github.com/llvm/llvm-project/commit/6d1083b8f128c59ee03cf9441eb9343b1db281f9.diff

LOG: Revert "[SelectionDAG] Fix null pointer dereference in resolveDanglingDebugIn…"

This reverts commit 7a3bbf724dc65ca959714bfd66b5e7ebf8c4e091.

Added: 
    

Modified: 
    llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp

Removed: 
    llvm/test/CodeGen/Generic/selectiondag-dbgvalue-null-crash.ll


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diff  --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index d570581a8d608..c915cc058b4c5 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -1505,6 +1505,7 @@ void SelectionDAGBuilder::resolveDanglingDebugInfo(const Value *V,
   DanglingDebugInfoVector &DDIV = DanglingDbgInfoIt->second;
   for (auto &DDI : DDIV) {
     DebugLoc DL = DDI.getDebugLoc();
+    unsigned ValSDNodeOrder = Val.getNode()->getIROrder();
     unsigned DbgSDNodeOrder = DDI.getSDNodeOrder();
     DILocalVariable *Variable = DDI.getVariable();
     DIExpression *Expr = DDI.getExpression();
@@ -1518,7 +1519,6 @@ void SelectionDAGBuilder::resolveDanglingDebugInfo(const Value *V,
       // in the first place we should not be more successful here). Unless we
       // have some test case that prove this to be correct we should avoid
       // calling EmitFuncArgumentDbgValue here.
-      unsigned ValSDNodeOrder = Val.getNode()->getIROrder();
       if (!EmitFuncArgumentDbgValue(V, Variable, Expr, DL,
                                     FuncArgumentDbgValueKind::Value, Val)) {
         LLVM_DEBUG(dbgs() << "Resolve dangling debug info for "

diff  --git a/llvm/test/CodeGen/Generic/selectiondag-dbgvalue-null-crash.ll b/llvm/test/CodeGen/Generic/selectiondag-dbgvalue-null-crash.ll
deleted file mode 100644
index 3ae8eed1392a6..0000000000000
--- a/llvm/test/CodeGen/Generic/selectiondag-dbgvalue-null-crash.ll
+++ /dev/null
@@ -1,34 +0,0 @@
-; RUN: llc -O3 < %s
-;
-; Regression test for a null pointer dereference in 
-; SelectionDAG::resolveDanglingDebugInfo when Val.getNode() returns null
-; for aggregate types with nested empty structs.
-;
-; The crash occurred when:
-; 1. A dbg_value references an aggregate type containing empty structs {}
-; 2. An insertvalue operation on such types gets lowered by SelectionDAG
-; 3. The resulting SDValue has a null node, causing a crash when accessed
-
-define void @test() !dbg !4 {
-entry:
-  %tmp = alloca { { i1, {} }, ptr, { { {} }, { {} } }, i64 }, align 8
-    #dbg_value({ { {} }, { {} } } zeroinitializer, !5, !DIExpression(), !6)
-    #dbg_value(i64 2, !7, !DIExpression(), !6)
-  %0 = insertvalue { { i1, {} }, ptr, { { {} }, { {} } }, i64 } { { i1, {} } zeroinitializer, ptr null, { { {} }, { {} } } zeroinitializer, i64 2 }, ptr null, 1, !dbg !6
-  %1 = insertvalue { { i1, {} }, ptr, { { {} }, { {} } }, i64 } %0, { i1, {} } zeroinitializer, 0, !dbg !8
-  store { { i1, {} }, ptr, { { {} }, { {} } }, i64 } %1, ptr %tmp, align 8
-  ret void
-}
-
-!llvm.dbg.cu = !{!0}
-!llvm.module.flags = !{!2, !3}
-
-!0 = distinct !DICompileUnit(language: DW_LANG_C11, file: !1, isOptimized: false, runtimeVersion: 0, emissionKind: LineTablesOnly)
-!1 = !DIFile(filename: "test_selectiondag.cpp", directory: "/home/AnonTokyo/documents/llvm-project/temp")
-!2 = !{i32 2, !"Debug Info Version", i32 3}
-!3 = !{i32 2, !"Dwarf Version", i32 4}
-!4 = distinct !DISubprogram(name: "test", scope: !1, file: !1, line: 1, scopeLine: 1, spFlags: DISPFlagDefinition, unit: !0)
-!5 = !DILocalVariable(name: "v1", scope: !4, file: !1, line: 2)
-!6 = !DILocation(line: 2, column: 1, scope: !4)
-!7 = !DILocalVariable(name: "v2", scope: !4, file: !1, line: 3)
-!8 = !DILocation(line: 3, column: 1, scope: !4)