Support custom compiler arguments

[Pennycook]

Feature/behavior summary

CBI currently has very limited support for emulating the behaviors of other compilers. There are some hard-coded configurations in config.py, and users can provide unconditional definitions via the .cbi/config file.

We should provide a mechanism that allows users to define compiler behavior more precisely (e.g., by defining the behavior of specific flags). For example, a user could define that -std={something} defines a specific set of macros that are important to their application.

Request attributes

• Would this be a refactor of existing code?
• Does this proposal require new package dependencies?
• Would this change break backwards compatibility?

Related issues

• Implement common argument parsing with argparse #146
• Add custom argparse actions #155
• Add compiler customization schema #156

Solution description

Extend the .cbi/config schema to support the definition of additional compiler arguments.

One possibility would be to draw inspiration from argparse, supporting syntax like:

[[compiler."c++".parser]]
flags = ["-isystem", "-I"]
dest = "include_paths"
action = "append"

[[compiler."c++".parser]]
flags = ["-include"]
dest = "includes"
action = "append"

[[compiler."c++".parser]]
flags = ["-D"]
dest = "defines"
action = "append"

...but with a limited set of supported destination and action strings.

Additional notes

No response