How to specify the dynamic extension directory when compiling PHP?

Question

1.How to specify the default dynamic expansion directory when compiling php?

2. If the default extension directory is specified during compilation, and then the extension_dir in php.ini is modified to specify another directory, what is the order in which extensions are loaded in the default directory and the specified directory?

Answer 1

./configure --help | grep extension

I just took a look, there should be no such option, that is, it can only be configured through the php.ini file