verifyStackFrame();
}
-// Does iterator point to a and b as the first two elements?
-static bool matchPair(MachineBasicBlock::const_succ_iterator i,
- const MachineBasicBlock *a, const MachineBasicBlock *b) {
- if (*i == a)
- return *++i == b;
- if (*i == b)
- return *++i == a;
- return false;
-}
-
void
MachineVerifier::visitMachineBasicBlockBefore(const MachineBasicBlock *MBB) {
FirstTerminator = nullptr;
}
}
- // Count the number of INLINEASM_BR indirect target successors.
- SmallPtrSet<const MachineBasicBlock*, 4> IndirectTargetSuccs;
- for (const auto *succ : MBB->successors()) {
- if (MBB->isInlineAsmBrIndirectTarget(succ))
- IndirectTargetSuccs.insert(succ);
- if (!FunctionBlocks.count(succ))
- report("MBB has successor that isn't part of the function.", MBB);
- if (!MBBInfoMap[succ].Preds.count(MBB)) {
- report("Inconsistent CFG", MBB);
- errs() << "MBB is not in the predecessor list of the successor "
- << printMBBReference(*succ) << ".\n";
- }
- }
-
// Check the predecessor list.
for (const MachineBasicBlock *Pred : MBB->predecessors()) {
if (!FunctionBlocks.count(Pred))
// check whether its answers match up with reality.
if (!TBB && !FBB) {
// Block falls through to its successor.
- MachineFunction::const_iterator MBBI = std::next(MBB->getIterator());
- if (MBBI == MF->end()) {
- // 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_size() == LandingPadSuccs.size() ||
- MBB->succ_size() == IndirectTargetSuccs.size()) {
- // It's possible that the block legitimately ends with a noreturn
- // call or an unreachable, in which case it won't actually fall
- // out of the block.
- } else if ((LandingPadSuccs.size() &&
- MBB->succ_size() != 1 + LandingPadSuccs.size()) ||
- (IndirectTargetSuccs.size() &&
- MBB->succ_size() != 1 + IndirectTargetSuccs.size())) {
- report("MBB exits via unconditional fall-through but doesn't have "
- "exactly one CFG successor!", MBB);
- } else if (!MBB->isSuccessor(&*MBBI)) {
- report("MBB exits via unconditional fall-through but its successor "
- "differs from its CFG successor!", MBB);
- }
if (!MBB->empty() && MBB->back().isBarrier() &&
!TII->isPredicated(MBB->back())) {
report("MBB exits via unconditional fall-through but ends with a "
}
} else if (TBB && !FBB && Cond.empty()) {
// Block unconditionally branches somewhere.
- // If the block has exactly one successor, that happens to be a
- // landingpad, accept it as valid control flow.
- if (MBB->succ_size() != 1+LandingPadSuccs.size() &&
- (MBB->succ_size() != 1 || LandingPadSuccs.size() != 1 ||
- *MBB->succ_begin() != *LandingPadSuccs.begin()) &&
- MBB->succ_size() != 1 + IndirectTargetSuccs.size() &&
- (MBB->succ_size() != 1 || IndirectTargetSuccs.size() != 1 ||
- *MBB->succ_begin() != *IndirectTargetSuccs.begin())) {
- report("MBB exits via unconditional branch but doesn't have "
- "exactly one CFG successor!", MBB);
- } else if (!MBB->isSuccessor(TBB)) {
- report("MBB exits via unconditional branch but the CFG "
- "successor doesn't match the actual successor!", MBB);
- }
if (MBB->empty()) {
report("MBB exits via unconditional branch but doesn't contain "
"any instructions!", MBB);
}
} else if (TBB && !FBB && !Cond.empty()) {
// Block conditionally branches somewhere, otherwise falls through.
- MachineFunction::const_iterator MBBI = std::next(MBB->getIterator());
- if (MBBI == MF->end()) {
- report("MBB conditionally falls through out of function!", MBB);
- } else if (MBB->succ_size() == 1) {
- // A conditional branch with only one successor is weird, but allowed.
- if (&*MBBI != TBB)
- report("MBB exits via conditional branch/fall-through but only has "
- "one CFG successor!", MBB);
- else if (TBB != *MBB->succ_begin())
- report("MBB exits via conditional branch/fall-through but the CFG "
- "successor don't match the actual successor!", MBB);
- } else if (MBB->succ_size() != 2) {
- report("MBB exits via conditional branch/fall-through but doesn't have "
- "exactly two CFG successors!", MBB);
- } else if (!matchPair(MBB->succ_begin(), TBB, &*MBBI)) {
- report("MBB exits via conditional branch/fall-through but the CFG "
- "successors don't match the actual successors!", MBB);
- }
if (MBB->empty()) {
report("MBB exits via conditional branch/fall-through but doesn't "
"contain any instructions!", MBB);
} else if (TBB && FBB) {
// Block conditionally branches somewhere, otherwise branches
// somewhere else.
- if (MBB->succ_size() == 1) {
- // A conditional branch with only one successor is weird, but allowed.
- if (FBB != TBB)
- report("MBB exits via conditional branch/branch through but only has "
- "one CFG successor!", MBB);
- else if (TBB != *MBB->succ_begin())
- report("MBB exits via conditional branch/branch through but the CFG "
- "successor don't match the actual successor!", MBB);
- } else if (MBB->succ_size() != 2) {
- report("MBB exits via conditional branch/branch but doesn't have "
- "exactly two CFG successors!", MBB);
- } else if (!matchPair(MBB->succ_begin(), TBB, FBB)) {
- report("MBB exits via conditional branch/branch but the CFG "
- "successors don't match the actual successors!", MBB);
- }
if (MBB->empty()) {
report("MBB exits via conditional branch/branch but doesn't "
"contain any instructions!", MBB);
} else {
report("analyzeBranch returned invalid data!", MBB);
}
+
+ // Now check that the successors match up with the answers reported by
+ // analyzeBranch.
+ if (TBB && !MBB->isSuccessor(TBB))
+ report("MBB exits via jump or conditional branch, but its target isn't a "
+ "CFG successor!",
+ MBB);
+ if (FBB && !MBB->isSuccessor(FBB))
+ report("MBB exits via conditional branch, but its target isn't a CFG "
+ "successor!",
+ MBB);
+
+ // There might be a fallthrough to the next block if there's either no
+ // unconditional true branch, or if there's a condition, and one of the
+ // branches is missing.
+ bool Fallthrough = !TBB || (!Cond.empty() && !FBB);
+
+ // A conditional fallthrough must be an actual CFG successor, not
+ // unreachable. (Conversely, an unconditional fallthrough might not really
+ // be a successor, because the block might end in unreachable.)
+ if (!Cond.empty() && !FBB) {
+ MachineFunction::const_iterator MBBI = std::next(MBB->getIterator());
+ if (MBBI == MF->end()) {
+ report("MBB conditionally falls through out of function!", MBB);
+ } else if (!MBB->isSuccessor(&*MBBI))
+ report("MBB exits via conditional branch/fall-through but the CFG "
+ "successors don't match the actual successors!",
+ MBB);
+ }
+
+ // Verify that there aren't any extra un-accounted-for successors.
+ for (const MachineBasicBlock *SuccMBB : MBB->successors()) {
+ // If this successor is one of the branch targets, it's okay.
+ if (SuccMBB == TBB || SuccMBB == FBB)
+ continue;
+ // If we might have a fallthrough, and the successor is the fallthrough
+ // block, that's also ok.
+ if (Fallthrough && SuccMBB == MBB->getNextNode())
+ continue;
+ // Also accept successors which are for exception-handling or might be
+ // inlineasm_br targets.
+ if (SuccMBB->isEHPad() || MBB->isInlineAsmBrIndirectTarget(SuccMBB))
+ continue;
+ report("MBB has unexpected successors which are not branch targets, "
+ "fallthrough, EHPads, or inlineasm_br targets.",
+ MBB);
+ }
}
regsLive.clear();
projects / platform / upstream / llvm.git / commitdiff