[Sanitizer] sanitizer blacklist doesn't work

Hello, I have a question when using dfsan via clang. Blacklist doesn’t work.

clang -S -emit-llvm main.c
clang -S -emit-llvm -fsanitize=dataflow main.ll

DFsan changed the name of main function to dfs$main. In fact, main is in the blacklist, and the main function should not be changed.
But when I use -fsanitize=dataflow to main.c source file directly , blacklist works. The name of main function is ignored.

Clang - S - emit llvm - fsanitize = dataflow main.c
the blacklist works, and the main function is not modified.
It also works with opt .

Why doesn’t blacklist work when using [ clang -fsanitize=dataflow ] to IR file ?
Can you help me ? Thank you.