From a01a80fa6c0c6e9c92ecfa951e974b98c3ba1783 Mon Sep 17 00:00:00 2001 From: Dan Gohman Date: Thu, 27 Aug 2009 18:14:26 +0000 Subject: Adjust the MachineBasicBlock verifier rules to be more tolerant of blocks that end with "unreachable". git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80270 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/MachineVerifier.cpp | 25 ++++++++++++++----------- 1 file changed, 14 insertions(+), 11 deletions(-) (limited to 'lib/CodeGen/MachineVerifier.cpp') diff --git a/lib/CodeGen/MachineVerifier.cpp b/lib/CodeGen/MachineVerifier.cpp index a3b5937b29..f43a370345 100644 --- a/lib/CodeGen/MachineVerifier.cpp +++ b/lib/CodeGen/MachineVerifier.cpp @@ -312,14 +312,14 @@ MachineVerifier::visitMachineBasicBlockBefore(const MachineBasicBlock *MBB) if (MBB->empty()) { report("MBB doesn't fall through but is empty!", MBB); } - } else { - // Block falls through. - if (!MBB->empty() && MBB->back().getDesc().isBarrier()) { - report("MBB falls through but ends with a barrier instruction!", MBB); - } - if (TII->BlockHasNoFallThrough(*MBB)) { + } + if (TII->BlockHasNoFallThrough(*MBB)) { + if (MBB->empty()) { + report("TargetInstrInfo says the block has no fall through, but the " + "block is empty!", MBB); + } else if (!MBB->back().getDesc().isBarrier()) { report("TargetInstrInfo says the block has no fall through, but the " - "CFG has a fall-through edge!", MBB); + "block does not end in a barrier!", MBB); } } } else { @@ -341,10 +341,13 @@ MachineVerifier::visitMachineBasicBlockBefore(const MachineBasicBlock *MBB) MachineFunction::const_iterator MBBI = MBB; ++MBBI; if (MBBI == MF->end()) { - // TODO: This condition is sometimes reached for functions which - // make noreturn calls or contain unreachable. Should AnalyzeBranch - // be changed to handle such cases differently? - report("MBB falls through out of function!", MBB); + // It's possible that the block legitimately ends with a noreturn + // call or an unreachable, in which case it won't actually fall + // out the bottom of the function. + } else if (MBB->succ_empty()) { + // It's possible that the block legitimately ends with a noreturn + // call or an unreachable, in which case it won't actuall fall + // out of the block. } else if (MBB->succ_size() != 1) { report("MBB exits via unconditional fall-through but doesn't have " "exactly one CFG successor!", MBB); -- cgit v1.2.3-18-g5258