Appendix B: The cromo command

cromo is the only tool of Cromo: the compiler, the linker, the test runner, the formatter and the language server, in one executable.

cromo <command> [options] [file.cro] [-- arguments]

Without a file, the commands use main.cro of the current folder.

#Commands

Command	Does
`cromo build [file.cro]`	compiles the program into an executable
`cromo run [file.cro] [-- arguments]`	compiles the program into a temporary folder, runs it with the arguments that follow `--`, and ends with its exit code
`cromo test [file.cro] [names]`	runs the `[[test]]` functions of the program and of its modules; the names choose the tests that contain them
`cromo fmt [--check] [files and folders \| -]`	formats the code, by default of the current folder and its subfolders; `--check` only lists the files to format; `-` formats the standard input
`cromo lsp`	the language server, for editors, on the standard input and output
`cromo version`	prints the version of `cromo` and of LLVM
`cromo help`	prints the commands

Option	Meaning
`-o <file>`	the name of the executable; by default the name of the source, or of the folder without a file, with `.exe` for Windows
`--release`	integers wrap around on overflow, instead of stopping the program
`--target windows`, `--target linux`	the system of the executable; by default the one `cromo` runs on
`-O0` … `-O3`	the level of optimization; the default is `-O2`
`--emit-ir`	prints the LLVM IR of the program instead of writing the executable

	Debug (default)	`--release`
Optimization	`-O2`	`-O2`
Integer overflow	panic	wraps around
Bounds, division by zero, exclusivity	checked	checked
Stack traces	yes	yes
Information for a debugger	yes: PDB on Windows, DWARF on Linux	no

With -O0 a debugger shows every variable; with the optimizations, some can be optimized out.

Code	Meaning
0	the program ended normally, or `main` returned 0
1	an exception left `main`; or `cromo` found errors
101	a panic, or a stack overflow
other	the value returned by `main`, or given to `os.exit`

Path	Content
`~/.cromo/current/bin/cromo`	the active version, which the `PATH` reaches
`~/.cromo/versions/<version>`	the installed versions
`lib/` next to `bin/`	the standard library and the runtime, which `cromo` reads

On Windows, ~ is %USERPROFILE%.