• There are 18 files with units, with 7,882 lines of code.
• 0 very complex files (McCabe index sum 251+; 0 lines of code)
• 0 complex files (McCabe index sum 126-250; 0 lines of code)
• 4 medium complex files (McCabe index sum 51-125; 3,744 lines of code)
• 5 slightly complex files (McCabe index sum 26-50; 2,628 lines of code)
• 9 simple files (McCabe index sum 1-25; 1,510 lines of code)
• 11 main files have no units (e.g. languages without unit analysis, or files without functions) and are not classified.

The McCabe index of a file grows with its size: per 100 lines tells a large but plain file from a dense one, and most complex unit whether the complexity sits in one unit or is spread over many.

File	# lines	# units	McCabe index (sum)	per 100 lines	most complex unit
configure.rs in builder/src/build_rust_crate	1068	26	108	10	35
registry.rs in rust/src	871	36	77	9	8
manifest.rs in rust/src/lockfile_resolve	1013	22	61	6	11
resolve.rs in rust/src	792	25	59	7	12
mod.rs in rust/src/lockfile_resolve	1117	15	41	4	8
build.rs in builder/src/build_rust_crate	440	6	39	9	9
feature_resolve.rs in rust/src	533	17	31	6	14
cargo_config.rs in rust/src	314	18	29	9	8
install.rs in builder/src/build_rust_crate	224	8	28	13	7
cfg_eval.rs in rust/src	188	21	21	11	1
plugin.cc in cpp	92	5	17	18	10
doctest.rs in builder/src/build_rust_crate	178	7	15	8	5
ffi.rs in rust/src	220	5	9	4	5
rustc.rs in builder/src/build_rust_crate	232	2	8	3	7
lockfile.rs in rust/src	119	5	5	4	1
config.rs in builder/src/build_rust_crate	296	4	4	1	1
main.rs in builder/src	39	1	3	8	3
nextest.rs in builder/src/build_rust_crate	146	1	1	1	1

• File complexity is the sum of the McCabe indexes (conditional complexity) of the units (methods, functions...) in a file.
• Files are classified in five categories based on that sum: 1-25 (simple files), 26-50 (slightly complex files), 51-125 (medium complex files), 126-250 (complex files), 251+ (very complex files). The default bands are five times the unit complexity bands, as a file is a group of units.
• Only main code files with units are classified. Files without units (languages without unit analysis, or files without functions) have no complexity to measure and are left out rather than counted as simple.
• A very complex file holds many decisions, which often means it has too many responsibilities: a candidate to split, and a place where changes need more testing.