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//! SPDX-License-Identifier: MIT
//!
//! Copyright (c) 2023, eunomia-bpf
//! All rights reserved.
//!
use anyhow::{bail, Result};
use clap::{Arg, ArgAction, Command};
use serde_json::Value;
use super::EunomiaObjectMeta;
const DEFAULT_DESCRIPTION: &str = "A simple eBPF program";
const DEFAULT_VERSION: &str = "0.1.0";
const DEFAULT_EPILOG: &str = "Built with eunomia-bpf framework.\nSee https://github.com/eunomia-bpf/eunomia-bpf for more information.";
impl EunomiaObjectMeta {
/// Build an argument parser use the `cmdarg` sections in .rodata/.bss variables.
///
/// Each variable in the `.bss` or `.rodata` sections will be mapped into a command line argument.
///
/// If a variable has it's default value, the default value will be used in the command line parser.
///
/// Variables with `bool` will have some special cases:
/// - If the variable has no default values, a switch named `--<NAME>` will be added, indicating to set the value to true or false
/// - If the default value if true, a switch named `--disable-<NAME>` will be added, means set the value to false
/// - If the default value if false, a switch named `--enable-<NAME>` will be added, means to set the value to true.
///
/// The first will be used to set the value of the variable to `true`, second one will be used to set `false`
///
/// Variables with other types will accept values. But values will be checked in `parse_arguments_and_fill_skeleton_variables`, so here the values input in the command line parser will be regarded as strings.
pub fn build_argument_parser(&self) -> Result<Command> {
let cmd = Command::new(self.bpf_skel.obj_name.to_string());
let cmd = if let Some(doc) = &self.bpf_skel.doc {
cmd.version(
doc.version
.to_owned()
.unwrap_or_else(|| DEFAULT_VERSION.to_string()),
)
.after_help(
doc.details
.to_owned()
.unwrap_or_else(|| DEFAULT_EPILOG.to_owned()),
)
.before_help(
doc.brief
.to_owned()
.or(doc.description.to_owned())
.unwrap_or_else(|| DEFAULT_DESCRIPTION.to_owned()),
)
} else {
cmd.version(DEFAULT_VERSION)
.after_help(DEFAULT_EPILOG)
.before_help(DEFAULT_DESCRIPTION)
};
// Add a switch to control whether to show debug information
let mut cmd = cmd.arg(
Arg::new("verbose")
.long("verbose")
.action(ArgAction::SetTrue)
.help("Whether to show libbpf debug information"),
);
// Add arguments for section vars
for section in self.bpf_skel.data_sections.iter() {
for variable in section.variables.iter() {
// Ignore useless variables
if variable.name.starts_with("__eunomia_dummy") {
continue;
}
let help = variable
.cmdarg
.help
.to_owned()
.or(variable.description.to_owned())
.unwrap_or_else(|| {
format!("Set value of `{}` variable {}", variable.ty, variable.name)
});
let long = variable
.cmdarg
.long
.to_owned()
.unwrap_or_else(|| variable.name.to_string());
if variable.ty == "bool" {
// If there is default values
let default = if let Some(val) = variable
.cmdarg
.default
.to_owned()
.or(variable.value.to_owned())
{
Some(match val {
Value::Bool(b) => b,
_ => bail!("Only expected bool values in bool variables"),
})
} else {
None
};
let arg = match default {
// without default values
None => Arg::new(variable.name.clone())
.help(help)
.long(long)
.action(ArgAction::SetTrue),
Some(true) => Arg::new(variable.name.clone())
.help(help)
.long(format!("disable-{long}"))
.default_value("true")
.action(ArgAction::SetFalse),
Some(false) => Arg::new(variable.name.clone())
.help(help)
.long(format!("enable-{long}"))
.action(ArgAction::SetTrue),
};
cmd = cmd.arg(arg);
} else {
let short = variable.cmdarg.short.to_owned();
let default = if let Some(default) = variable
.cmdarg
.default
.to_owned()
.or(variable.value.to_owned())
{
Some(match default {
Value::Number(v) => v.to_string(),
Value::String(v) => v,
_ => bail!(
"We only want to see integers or strings in default values for non-bool variables.."
),
})
} else {
None
};
let arg = Arg::new(variable.name.clone())
.action(ArgAction::Set)
.help(help)
.long(long);
let arg = if let Some(s) = short {
let chars = s.chars().collect::<Vec<char>>();
if chars.len() != 1 {
bail!(
"Short name for variable `{}` is expected to be just in 1 character",
variable.name
);
}
arg.short(chars[0])
} else {
arg
};
// For values with defaults, we set the default ones
// For other values, if they were not provided when parsing, we'll fill the corresponding memory with zero, or report error, based on what we need
let arg = if let Some(default) = default {
arg.default_value(default)
} else {
arg
};
cmd = cmd.arg(arg);
}
}
}
Ok(cmd)
}
}
#[cfg(test)]
mod tests {
use crate::{meta::EunomiaObjectMeta, tests::get_assets_dir};
#[test]
fn test_arg_builder() {
let skel = serde_json::from_str::<EunomiaObjectMeta>(
&std::fs::read_to_string(get_assets_dir().join("arg_builder_test").join("skel.json"))
.unwrap(),
)
.unwrap();
let cmd = skel.build_argument_parser().unwrap();
for p in cmd.get_arguments() {
println!("{:?}", p.get_long());
}
let cmd = cmd.color(clap::ColorChoice::Never);
let matches = cmd
.try_get_matches_from([
"myprog",
"--cv1",
"2333",
"--const_val_2",
"12345678",
"--const_val_3",
"abcdefg",
"--bss_val_1",
"111",
])
.unwrap();
assert_eq!(
matches.get_one::<String>("const_val_1"),
Some(&String::from("2333"))
);
assert_eq!(
matches.get_one::<String>("const_val_2"),
Some(&String::from("12345678"))
);
assert_eq!(
matches.get_one::<String>("const_val_3"),
Some(&String::from("abcdefg"))
);
assert_eq!(
matches.get_one::<String>("bss_val_1"),
Some(&String::from("111"))
);
assert_eq!(matches.get_one::<String>("bss_val_2"), None);
assert_eq!(matches.get_one::<String>("bss_val_3"), None);
}
#[test]
#[should_panic]
fn test_arg_builder_invalid_argument() {
let skel = serde_json::from_str::<EunomiaObjectMeta>(
&std::fs::read_to_string(get_assets_dir().join("arg_builder_test").join("skel.json"))
.unwrap(),
)
.unwrap();
let cmd = skel.build_argument_parser().unwrap();
cmd.try_get_matches_from(["prog", "-a", "123"]).unwrap();
}
#[test]
fn test_boolflag() {
let skel = serde_json::from_str::<EunomiaObjectMeta>(
&std::fs::read_to_string(get_assets_dir().join("arg_builder_test").join("skel.json"))
.unwrap(),
)
.unwrap();
let cmd = skel.build_argument_parser().unwrap();
let matches = cmd
.clone()
.try_get_matches_from([
"prog",
"--boolflag",
"--disable-boolflag-with-default-true",
"--enable-boolflag-with-default-false",
])
.unwrap();
assert!(matches.get_flag("boolflag"));
assert!(!matches.get_flag("boolflag-with-default-true"));
assert!(matches.get_flag("boolflag-with-default-false"));
let matches = cmd.clone().try_get_matches_from(["prog"]).unwrap();
assert!(!matches.get_flag("boolflag"));
assert!(matches.get_flag("boolflag-with-default-true"));
assert!(!matches.get_flag("boolflag-with-default-false"));
}
#[test]
#[should_panic]
fn test_boolflag_2() {
let skel = serde_json::from_str::<EunomiaObjectMeta>(
&std::fs::read_to_string(get_assets_dir().join("arg_builder_test").join("skel.json"))
.unwrap(),
)
.unwrap();
let cmd = skel.build_argument_parser().unwrap();
cmd.clone()
.try_get_matches_from(["prog", "--enable-boolflag-with-default-true"])
.unwrap();
}
#[test]
#[should_panic]
fn test_boolflag_3() {
let skel = serde_json::from_str::<EunomiaObjectMeta>(
&std::fs::read_to_string(get_assets_dir().join("arg_builder_test").join("skel.json"))
.unwrap(),
)
.unwrap();
let cmd = skel.build_argument_parser().unwrap();
cmd.clone()
.try_get_matches_from(["prog", "--disable-boolflag-with-default-false"])
.unwrap();
}
}