Bug: `ProcessCcArgs` mis-processes arguments containing `-fdebug-prefix-map`

Description

In ProcessCcArgs, when a -fdebug-prefix-map argument is detected, it is skipped, and the next argument is incorrectly also skipped. -fdebug-prefix-map does not take an additional argument, correct usage is something like -fdebug-prefix-map=a=b to map a to b. clang will not accept something like -fdebug-prefix-map a=b, so we should never skip the argument after -fdebug-prefix-map.

This will cause the arguments to get corrupted, in my case, an -iquote was getting skipped, causing the directory I included to be sent to the compiler as a compiler input file. This meant xcode got invalid command lines, making the "Indexing" step not succeed.

Code link.

Reproduction steps

In a cc_library, add

    copts = [
        "-fdebug-prefix-map=a=b",
        "-iquote",
        ".",
    ],

Then, bazel run //:xcodeproj, and open a source file in the modified library. The file will fail in the "Indexing" step since . will be passed as a compiler input (i.e., the iquote argument will not be provided to xcode)

Expected behavior

We expect -fdebug-prefix-m=a=b to be removed from the argument list, but no further arguments should be removed.

rules_xcodeproj version

8ba39d79ff79effb6c993ff0ac96e5cae4741095

Xcode version

15.4

Bazel version

7.2.1

rules_apple version

No response

rules_swift version

No response

Additional information

No response

Start in tools/generators/target_build_settings/src/Generator/ProcessCcArgs.swift at the linked ProcessCcArgs code. Reproduce with the provided cc_library copts and run bazel run //:xcodeproj, then inspect the generated Xcode indexing command. Done means only the -fdebug-prefix-map entry is removed and the -iquote arguments remain intact.