Import `-A` flag doesn't pass flag arguments properly (suggested fix)

[technologeli]

Problem

I am trying to import a binary with a niche architecture that is not
auto-detected by Ghidra, in headless and in UI mode:

INFO  No load spec found for import file: main (ProgramLoader)
ERROR The ProgramLoader could not successfully load file://main with the provided import parameters. Please ensure that any specified processor/cspec arguments are compatible with the loader that is used during import and try again. (HeadlessAnalyzer)

The headless Ghidra script supports the -processor <language-id> flag, so I
wanted to pass that via CTADL's -A flag. However, I was not able to pass
the -processor properly.

Things I tried:

• -A -processor <my-language-id>
• -A -processor -A <my-language-id>
• -A "-processor" -A <my-language-id>
• -A "-processor,<my-language-id>
• Using --argument-passthrough instead of -A (just in case, but it
  shouldn't matter)
• -A "-processor <my-language-id>"

The first few result in this error:

ctadl import: error: argument -A/--argument-passthrough: expected one argument

The last one successfully passes the argument to analyzeHeadlessBigMem, but
it doesn't actually do anything, as it is surrounded in quotes and considered
one argument to the analyzeHeadlessBigMem script:

~/ghidra_12.0_DEV/support/launch.sh fg jdk Ghidra-Headless 40G '-XX:ParallelGCThreads=4 -XX:CICompilerCount=4 ' ghidra.app.util.headless.AnalyzeHeadless /tmp/ctadl-6aoindul/ghidra_headless headless -import main -deleteProject -postScript ExportPCodeForCTADL.java ctadl-output/facts -scriptPath ~/.venv/lib/python3.12/site-packages/ctadl/souffle-logic/pcode '-processor <my-language-id>'

Ultimately I hard-coded the argument in the analyzeHeadlessBigMem script,
which worked as expected.

Possible solution

A possible solution is to change the parser in the ctadl Python script to
collect the remainder of arguments for -A:

parser_add_argument_wrapper(
    parser,
    "-A",
    "--argument-passthrough",
    nargs=argparse.REMAINDER,
    metavar="<arg>",
    help="Passthrough args for the underlying fact generator. All subsequent args will be passed to the fact generator.",
)

This would allow a user to do something like this:

ctadl import -o ctadl-output pcode main -A -processor <my-language-id>

The change works for my use case, but in the event -A is in a script used in
its original way for multiple arguments (action="append") this would cause
issues.