[Bug] something wrong

setting-json:
"code-runner.executorMap": {
"javascript": "node",
"java": "cd $dir && javac $fileName && java $fileNameWithoutExt",
**"c": "cd $dir && gcc $fileName -o $fileNameWithoutExt -lm && $dir$fileNameWithoutExt",**
"cpp": "cd $dir && g++ $fileName -o $fileNameWithoutExt && $dir$fileNameWithoutExt",
"objective-c": "cd $dir && gcc -framework Cocoa $fileName -o $fileNameWithoutExt && $dir$fileNameWithoutExt",
"..."
}

when i use code-runner, the compiler of "C" needs link "math.h", so, i use -lm to fix it in terminal;
but i get some wrong when I modify setting-json,
**In this settings.json, when use "-lm"(link math.h) args, return error:
aarch64-linux-gnu-gcc: error: /home/pi/test/12-structure/12-9p: No such file or directory
终端进程“/bin/bash '-c', '/usr/bin/aarch64-linux-gnu-gcc -g /home/pi/test/12-structure/12-9p.c -o -lm /home/pi/test/12-structure/12-9p'”启动失败(退出代码: 1)。**

**"-lm" ,it's just in wrong station!,even I can't debug it**