I have a native extension compiled as a dynamic library and loaded by the main
program.
In the native extension there is below code that causes SEGV while Nim is
running GC for data allocated. The same code would run fine if put in the main
program.
discard VM.eval("(ns N)")
Run
Traceback (most recent call last)
/Users/gcao/proj/gene/src/genex/http.nim(176) init
/Users/gcao/proj/gene/src/gene/interpreter_base.nim(167) eval
/Users/gcao/.choosenim/toolchains/nim-1.4.8/lib/system.nim(937) eval
/Users/gcao/.choosenim/toolchains/nim-1.4.8/lib/system/arc.nim(169)
nimDestroyAndDispose
/Users/gcao/.choosenim/toolchains/nim-1.4.8/lib/system/orc.nim(413)
nimDecRefIsLastCyclicDyn
/Users/gcao/.choosenim/toolchains/nim-1.4.8/lib/system/orc.nim(394)
rememberCycle
/Users/gcao/.choosenim/toolchains/nim-1.4.8/lib/system/orc.nim(128)
unregisterCycle
SIGSEGV: Illegal storage access. (Attempt to read from nil?)
Run
I'm trying to debug this issue. Based on the stack trace, there might be cyclic
references. My data type does allow cyclic references. However in the code
above, it probably will not create a real cyclic reference.
The first thing I want to figure out is which data/variable is being recycled.
I've enabled debugger but don't get much information out of the debugger other
than a stack with a lot of "optimized out".
I tried to pass a C flag "-O0" but it is ignored because the command has "-g3
-Og".
How should I approach fixing this issue?
Any help is much appreciated!
