From bbddf21f900a868072710fbc8b424cc387a390aa Mon Sep 17 00:00:00 2001 From: Chandler Carruth Date: Tue, 23 Apr 2019 01:42:07 +0000 Subject: Revert "Use const DebugLoc&" This reverts r358910 (git commit 2b744665308fc8d30a3baecb4947f2bd81aa7d30) While this patch *seems* trivial and safe and correct, it is not. The copies are actually load bearing copies. You can observe this with MSan or other ways of checking for use-after-destroy, but otherwise this may result in ... difficult to debug inexplicable behavior. I suspect the issue is that the debug location is used after the original reference to it is removed. The metadata backing it gets destroyed as its last references goes away, and then we reference it later through these const references. llvm-svn: 358940 --- llvm/lib/CodeGen/BranchRelaxation.cpp | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'llvm/lib/CodeGen/BranchRelaxation.cpp') diff --git a/llvm/lib/CodeGen/BranchRelaxation.cpp b/llvm/lib/CodeGen/BranchRelaxation.cpp index 15edc98c47f..3ad6266d4f3 100644 --- a/llvm/lib/CodeGen/BranchRelaxation.cpp +++ b/llvm/lib/CodeGen/BranchRelaxation.cpp @@ -300,7 +300,7 @@ bool BranchRelaxation::isBlockInRange( /// too far away to fit in its displacement field. It is converted to an inverse /// conditional branch + an unconditional branch to the destination. bool BranchRelaxation::fixupConditionalBranch(MachineInstr &MI) { - const DebugLoc &DL = MI.getDebugLoc(); + DebugLoc DL = MI.getDebugLoc(); MachineBasicBlock *MBB = MI.getParent(); MachineBasicBlock *TBB = nullptr, *FBB = nullptr; MachineBasicBlock *NewBB = nullptr; @@ -468,7 +468,7 @@ bool BranchRelaxation::fixupUnconditionalBranch(MachineInstr &MI) { MBB->replaceSuccessor(DestBB, BranchBB); } - const DebugLoc &DL = MI.getDebugLoc(); + DebugLoc DL = MI.getDebugLoc(); MI.eraseFromParent(); BlockInfo[BranchBB->getNumber()].Size += TII->insertIndirectBranch( *BranchBB, *DestBB, DL, DestOffset - SrcOffset, RS.get()); -- cgit v1.2.3