[PATCH] D81631: Fix undefined behavior in Dwarf.

[zuojian lin via Phabricator via llvm-commits]

linzj created this revision.
Herald added subscribers: llvm-commits, hiraditya, kristof.beyls, aprantl.
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Caused by field PrevCU is not initialized.
llvm::DwarfCompileUnit::addRange () at ../lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp:276
llvm::DwarfDebug::endFunctionImpl () at ../lib/CodeGen/AsmPrinter/DwarfDebug.cpp:1586
llvm::DebugHandlerBase::endFunction () at ../lib/CodeGen/AsmPrinter/DebugHandlerBase.cpp:319
llvm::AsmPrinter::EmitFunctionBody () at ../lib/CodeGen/AsmPrinter/AsmPrinter.cpp:1230
llvm::ARMAsmPrinter::runOnMachineFunction () at ../lib/Target/ARM/ARMAsmPrinter.cpp:161


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D81631

Files:
  llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h


Index: llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
===================================================================
--- llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
+++ llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
@@ -325,7 +325,7 @@
   const MachineFunction *CurFn = nullptr;
 
   /// If nonnull, stores the CU in which the previous subprogram was contained.
-  const DwarfCompileUnit *PrevCU;
+  const DwarfCompileUnit *PrevCU = nullptr;
 
   /// As an optimization, there is no need to emit an entry in the directory
   /// table for the same directory as DW_AT_comp_dir.


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