[llvm-branch-commits] [llvm] [BOLT][BTI] Add needed BTIs in LongJmp or refuse to optimize binary (PR #171149)

[Peter Waller via llvm-branch-commits]

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@@ -483,11 +483,54 @@ Error LongJmpPass::relaxStub(BinaryBasicBlock &StubBB, bool &Modified) {
       ~((1ULL << (RangeSingleInstr - 1)) - 1);
 
   const MCSymbol *RealTargetSym = BC.MIB->getTargetSymbol(*StubBB.begin());
-  const BinaryBasicBlock *TgtBB = Func.getBasicBlockForLabel(RealTargetSym);
+  BinaryBasicBlock *TgtBB = Func.getBasicBlockForLabel(RealTargetSym);
+  BinaryFunction *TargetFunction = BC.getFunctionForSymbol(RealTargetSym);
   uint64_t TgtAddress = getSymbolAddress(BC, RealTargetSym, TgtBB);
   uint64_t DotAddress = BBAddresses[&StubBB];
   uint64_t PCRelTgtAddress = DotAddress > TgtAddress ? DotAddress - TgtAddress
                                                      : TgtAddress - DotAddress;
+
+  auto applyBTIFixup = [&](BinaryFunction *TargetFunction,
+                           BinaryBasicBlock *RealTgtBB) {
+    // TODO: add support for editing each type, and remove errors.
+    if (!TargetFunction && !RealTgtBB) {
+      BC.errs() << "BOLT-ERROR: Cannot add BTI to function with symbol "
+                << RealTargetSym->getName() << "\n";
+      exit(1);
+    }
+    if (TargetFunction && TargetFunction->isIgnored()) {
+      BC.errs() << "BOLT-ERROR: Cannot add BTI landing pad to ignored function "
+                << TargetFunction->getPrintName() << "\n";
+      exit(1);
+    }
+    if (TargetFunction && !TargetFunction->hasCFG()) {
+      auto FirstII = TargetFunction->instrs().begin();
+      MCInst FirstInst = FirstII->second;
+      if (BC.MIB->isBTIVariantCoveringCall(FirstInst,
+                                           *StubBB.getLastNonPseudoInstr()))
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peterwaller-arm wrote:

Are these parameters the wrong way around?

https://github.com/llvm/llvm-project/pull/171149