[LLVMdev] MCJIT/interpreter and iostream

[Kaylor, Andrew]

Try using '-fno-use-cxa-atexit' with clang.  That should get rid of the use of '__dso_handle'.

Arguably, MCJIT and the interpreter should be able to handle this case, but they currently don't.  There's a very old bug against the interpreter regarding this (http://llvm.org/bugs/show_bug.cgi?id=7847).  If anyone needs this in MCJIT, we should probably open a bugzilla report for that too.

-Andy

-----Original Message-----
From: llvmdev-bounces at cs.uiuc.edu [mailto:llvmdev-bounces at cs.uiuc.edu] On Behalf Of Jaymie Strecker
Sent: Saturday, January 26, 2013 11:03 AM
To: LLVM Developers Mailing List
Subject: [LLVMdev] MCJIT/interpreter and iostream

As of LLVM 3.2, is it possible to use iostream with the MCJIT or interpreter execution engines? I'm getting some errors... 


Each of these commands correctly prints "hello": 

	echo -e '#include <stdio.h>\nint main(){ printf("hello"); }' | clang -cc1 -emit-llvm-bc -x c++ | lli -use-mcjit

	echo -e '#include <iostream>\nint main(){ std::cout << "hello" << std::endl; }' | clang -cc1 -emit-llvm-bc -x c++ | lli


Each of these commands results in "LLVM ERROR: Could not resolve external global address: __dso_handle": 

	echo -e '#include <iostream>\nint main(){ std::cout << "hello" << std::endl; }' | clang -cc1 -emit-llvm-bc -x c++ | lli -force-interpreter=true

	echo -e '#include <iostream>\nint main(){ std::cout << "hello" << std::endl; }' | clang -cc1 -emit-llvm-bc -x c++ | lli -use-mcjit


This command correctly prints "hello": 

	echo -e '#include <iostream>\nextern "C" {void *__dso_handle = NULL;} int main(){ std::cout << "hello" << std::endl; }' | clang -cc1 -emit-llvm-bc -x c++ | lli


This command results in "LLVM ERROR: Tried to execute an unknown external function: _ZNSt8ios_base4InitC1Ev"

	echo -e '#include <iostream>\nextern "C" {void *__dso_handle = NULL;} int main(){ std::cout << "hello" << std::endl; }' | clang -cc1 -emit-llvm-bc -x c++ | lli -force-interpreter=true


This command results in "Assertion failed: (FPtr && "Pointer to fn's code was null after getPointerToFunction"), function runFunction, file MCJIT.cpp, line 180."

	echo -e '#include <iostream>\nextern "C" {void *__dso_handle = NULL;} int main(){ std::cout << "hello" << std::endl; }' | clang -cc1 -emit-llvm-bc -x c++ | lli -use-mcjit


---
Jaymie Strecker
jstrecker at kosada.com




_______________________________________________
LLVM Developers mailing list
LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev