[llvm-dev] [Instrumentation] Basic Block in function 'main' does not have terminator! (original) (raw)

Zhang via llvm-dev llvm-dev at lists.llvm.org
Fri Dec 28 16:59:09 PST 2018

First, you can't just call std::exit like that, you need to mangle its name first. Google "C++ name mangling"

wrt the second part, can you try to print out the function after your transform? I'm slightly lost in your code. blkBuilder.CreateCall does need a following-up terminator, however since you mentioned you added it and still had no luck, again, I suggest you print out the IR after your transform

Zhang ------------------ Original ------------------ From: "张雨姗(ZHANG Yushan)-11310380 via llvm-dev"<llvm-dev at lists.llvm.org>; Date: Sat, Dec 29, 2018 00:38 AM To: "llvm-dev"<llvm-dev at lists.llvm.org>;

Subject: [llvm-dev] [Instrumentation] Basic Block in function 'main' does not have terminator!

Hi all,

I want to add a new function to a module, which works as this: void cmpr(int l, int r) { if (i < l || i > r) std::exit(0); }

Here is my code: // if required, instrument this function BasicBlock * first = &func->getEntryBlock(); IRBuilder<> Builder(first); CallInst* v = Builder.CreateCall2(getTargetInst(), vl, vr);

Value * getTargetInst() {// insert a new function to program Constant *c = module->getOrInsertFunction("cmpr", FunctionType::getVoidTy(*context), Type::getInt64Ty(*context), Type::getInt64Ty(*context), NULL); f = &cast(*c);

// define arguments Function::arg_iterator args = f->arg_begin(); Value* l = args++; l->setName("l"); // lower bound Value* r = args++; r->setName("r"); // upper bound

BasicBlock *pb = BasicBlock::Create(*context, "entry", f); BasicBlock *blk = BasicBlock::Create(*context, "cond_true", f); BasicBlock *nblk = BasicBlock::Create(*context, "cond_false", f); IRBuilder<> Builder(pb);

// i < l Value *lower = Builder.CreateICmpSLT(vt, l); // i > r Value *upper = Builder.CreateICmpSGT(vt, r); // l - i || i - r (l > i or i > r) Value *both = Builder.CreateOr(lower, upper); // if (l > i || i > r), exit(0) BranchInst *br = Builder.CreateCondBr(both, blk, nblk); Builder.SetInsertPoint(ret);

// cond_true: call exit(0) IRBuilder<> blkBuilder(blk); Value *one = ConstantInt::get(Type::getInt64Ty(*context), 0, true); Value *blkv = module->getOrInsertFunction("std::exit", FunctionType::getVoidTy(*context), Type::getInt64Ty(*context), NULL);

blkBuilder.CreateCall(blkv, one); return f;​ } However, I get this error (I tried to fix with adding "CreateRetVoid" and other solutions from StackOverflow but didn't work ):Basic Block in function 'main' does not have terminator! label %entry LLVM ERROR: Broken function found, compilation aborted!

Could anyone help me to fix this? I appreciate any possible help. BTW, how could I call standard library in instrumented code?

Thanks, Yushan -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20181229/83b49a3f/attachment.html>

More information about the llvm-dev mailing list