The second call of getFunctionAddress return NULL address. But the first call is ok

LLVM Project
#1

I have just write a simple case for llvm code generation. test-llvm/test_llvm.cpp at main · jiamo/test-llvm · GitHub .

	// B
	Function *addFunc = CreateAdd(context, module);
	AddFuncType addFuncAddr = (AddFuncType)exEngine->getFunctionAddress(addFunc->getName());
	printf("addFuncAddr=%lx %s \n", (unsigned long)addFuncAddr, addFunc->getName());

	// A
	Function *minFunc = CreateMin(context, module);
	MinFuncType minFuncAddr = (MinFuncType)exEngine->getFunctionAddress(minFunc->getName());
	printf("minFuncAddr=%lx %s \n", (unsigned long)minFuncAddr, minFunc->getName());

It is very strange. After I swap minFunc and addFunc position. The first call of getFunctionAddress is ok. The second still return NULL.

The dump of IR was almost same with function swap.

with ubuntu 20.04 + llvm-10 (default version).

#2

I find out I must call getFunctionAddress after all getOrInsertFunction was finished?

Do we have some document for this behavior?