How to add C++ compile in QEMU 10.0

[肖 嘉赫]

Hello,

I am using the latest QEMU 10.0.2. I want to add a C++ plugin in QEMU. But when 
I am compile the C++ file, it tells there is no host machine compiler. Then I 
tried to add the following codes in meson.build file:

all_langages += ['cpp']
cxx = meson.get_compiler('g++')


It still returns an error which "Tried to access compiler for language "g++", 
not specified for host machine."
How can I configure the meson environment?

Thanks,
Jiahe