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use std::collections::{HashMap, HashSet};
#[derive(Debug)]
pub struct ActiveDependency
{
pub source: DepSource,
pub include_default_features: bool,
pub features: HashSet<String>,
}
#[derive(Debug)]
pub enum DepSource
{
Git {
url: String,
revision: GitRev,
},
Path(String),
CratesIo(String),
}
#[derive(Debug)]
pub enum GitRev
{
Master,
Branch(String),
Tag(String),
Revision(String),
}
pub fn enumerate() -> HashMap<String, ActiveDependency>
{
let manifest_path = {
let mut p = std::path::PathBuf::from(std::env::var_os("CARGO_MANIFEST_DIR").unwrap());
p.push("Cargo.toml");
p
};
let content = match std::fs::read(&manifest_path)
{
Ok(v) => v,
Err(e) => panic!("Unable to open {}: {:?}", manifest_path.display(), e),
};
let m = match cargo_toml::Manifest::from_slice(&content)
{
Ok(v) => v,
Err(e) => panic!("Unable to parse {}: {:?}", manifest_path.display(), e),
};
let mut dep_features = HashMap::<String, HashSet<String>>::new();
for (feat_name, subfeats) in m.features
{
if std::env::var_os(format!("CARGO_FEATURE_{}", feat_name)).is_some()
{
for subfeat_desc in subfeats
{
let (dep, f) = {
let mut it = subfeat_desc.split('/');
( it.next().unwrap(), it.next().unwrap(), )
};
dep_features.entry(dep.to_string()).or_default().insert(f.to_string());
}
}
}
let mut rv = HashMap::new();
for (depname, dep_info) in m.dependencies
{
if let Some(ad) = get_activedep(&dep_features, &depname, &dep_info)
{
rv.insert(depname.clone(), ad);
}
}
let current_target = std::env::var("TARGET").unwrap();
for (target_name, target_info) in m.target
{
let active =
if target_name.starts_with("cfg") {
let ml: syn::MetaList = match syn::parse_str(&target_name)
{
Ok(v) => v,
Err(e) => panic!("Failed to parse target cfg {:?} - {:?}", target_name, e),
};
match check_cfg_root(&ml)
{
Some(v) => v,
None => panic!("Failed to parse target cfg - {:?}", target_name),
}
}
else {
target_name == current_target
};
if active
{
for (depname, dep_info) in target_info.dependencies
{
if let Some(ad) = get_activedep(&dep_features, &depname, &dep_info)
{
rv.insert(depname.clone(), ad);
}
}
}
}
rv
}
fn get_activedep(dep_features: &HashMap<String, HashSet<String>>, depname: &str, dep_info: &cargo_toml::Dependency) -> Option<ActiveDependency>
{
Some(match dep_info
{
cargo_toml::Dependency::Simple(version_str) => {
ActiveDependency {
source: DepSource::CratesIo(version_str.clone()),
include_default_features: true,
features: dep_features.get(depname).cloned().unwrap_or(HashSet::new()),
}
},
cargo_toml::Dependency::Detailed(details) => {
if details.optional && std::env::var_os(format!("CARGO_FEATURE_{}", depname)).is_none() {
return None;
}
let source =
if let Some(ref version_str) = details.version {
DepSource::CratesIo(version_str.clone())
}
else if let Some(ref path) = details.path {
DepSource::Path(path.clone())
}
else if let Some(ref url) = details.git {
DepSource::Git {
url: url.clone(),
revision: if let Some(ref rev) = details.rev {
GitRev::Revision(rev.clone())
}
else if let Some(ref tag) = details.tag {
GitRev::Tag(tag.clone())
}
else if let Some(ref branch) = details.branch {
GitRev::Branch(branch.clone())
}
else {
GitRev::Master
},
}
}
else {
panic!("?");
};
let mut features = dep_features.get(depname).cloned().unwrap_or(HashSet::new());
for f in &details.features
{
features.insert(f.clone());
}
ActiveDependency {
source: source,
include_default_features: details.default_features.unwrap_or(true),
features: features,
}
},
})
}
fn check_cfg_root(ml: &syn::MetaList) -> Option<bool>
{
if ml.nested.len() != 1 {
eprintln!("Unexpected cfg(...) takes a single argument, {} provided", ml.nested.len());
return None;
}
check_cfg( ml.nested.first().unwrap() )
}
fn check_cfg(m: &syn::NestedMeta) -> Option<bool>
{
let m = match m
{
syn::NestedMeta::Meta(m) => m,
_ => return None,
};
Some(match m
{
syn::Meta::Path(_) => return None,
syn::Meta::List(ml) => {
let i = ml.path.get_ident()?;
if i == "any" {
for e in &ml.nested {
if check_cfg(e)? {
return Some(true);
}
}
false
}
else if i == "not" {
if ml.nested.len() != 1 {
eprintln!("Unexpected not(...) takes a single argument, {} provided", ml.nested.len());
return None;
}
let e = ml.nested.first().unwrap();
! check_cfg(e)?
}
else if i == "all" {
for e in &ml.nested {
if ! check_cfg(e)? {
return Some(false);
}
}
true
}
else {
eprintln!("Unexpected cfg fragment: {}", i);
return None;
}
},
syn::Meta::NameValue(nv) => {
let i = nv.path.get_ident()?;
let v = match &nv.lit
{
syn::Lit::Str(s) => s.value(),
_ => {
eprintln!("cfg options require strings, got {:?}", nv.lit);
return None;
},
};
let ev = std::env::var(format!("CARGO_CFG_{}", i));
ev == Ok(v)
},
})
}