1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169

use ::darling::FromDeriveInput;

impl crate::Module {
    /// Generate the `Module` (and all submodules) from the provided crate.
    pub fn from_crate(path: ::std::path::PathBuf) -> ::anyhow::Result<Self> {
        let manifest = ::cargo_toml::Manifest::from_path(&path.join("Cargo.toml"))?;
        let name = manifest.package.ok_or_else(|| {
            ::anyhow::Error::msg(format!("empty [package] section for {}", path.display()))
        })?.name.to_lowercase();
        Self::from_file(name.clone(), name, path.join("src/lib.rs"))
    }

    /// Generate the `Module` (and all submodules) from the provided file.
    pub fn from_file(
        name: String,
        crate_name: String,
        path: ::std::path::PathBuf
    ) -> ::anyhow::Result<Self> {
        Self::from_items(
            name,
            crate_name,
            path.clone(),
            ::syn::parse_file(&::std::fs::read_to_string(path)?)?.items,
        )
    }

    pub fn from_items(
        name: String,
        crate_name: String,
        path: ::std::path::PathBuf,
        items: Vec<::syn::Item>,
    ) -> ::anyhow::Result<Self> {
        let mut structs = vec![];
        let mut enums = vec![];
        let mut functions = vec![];
        let mut subs = vec![];

        for item in items {
            if let ::syn::Item::Mod(im) = item {
                let module = Self::from_itemmod(crate_name.clone(), path.clone(), im)?;
                if !module.is_empty() {
                    subs.push(module);
                }
            } else if let ::syn::Item::Struct(is) = item {
                if let Some(data) = filter_item_struct(is)? {
                    structs.push(data);
                }
            } else if let ::syn::Item::Enum(ie) = item {
                if let Some(data) = filter_item_enum(ie)? {
                    enums.push(data);
                }
            } else if let ::syn::Item::Fn(ifn) = item {
                if let Some(func) = filter_item_fn(ifn) {
                    functions.push(func);
                }
            }
        }

        Ok(Self{name, crate_name, structs, enums, functions, subs})
    }

    pub fn from_itemmod(
        crate_name: String,
        parent: ::std::path::PathBuf,
        im: ::syn::ItemMod,
    ) -> ::anyhow::Result<Self> {
        let name = im.ident.to_string();

        if let Some((_, items)) = im.content {
            Self::from_items(name, crate_name, parent, items)
        } else {
            let parent = parent.parent().ok_or_else(|| {
                ::anyhow::Error::msg(format!("cannot get parent of {}", parent.display()))
            })?;

            // TODO: not handled is when a submodule has name.rs and name/ for its submodules
            // we only handle the name/mod.rs for submodules with sub-submodule files.
            let mut file = parent.join(format!("{}.rs", name));
            if !file.exists() {
                file = parent.join(format!("{}/mod.rs", name));
            }

            Self::from_file(name, crate_name, file)
        }
    }

    fn is_empty(&self) -> bool {
        self.structs.is_empty() &&
            self.enums.is_empty() &&
            self.functions.is_empty() &&
            self.subs.is_empty()
    }
}

fn filter_item_struct(is: ::syn::ItemStruct) -> ::anyhow::Result<Option<::ffishim::Data>> {
    if derives_ffishim(&is.attrs) {
        let derive_input = ::syn::DeriveInput{
            attrs: is.attrs.clone(),
            vis: is.vis.clone(),
            ident: is.ident.clone(),
            generics: is.generics.clone(),
            data: ::syn::Data::Struct(::syn::DataStruct{
                struct_token: is.struct_token,
                fields: is.fields.clone(),
                semi_token: is.semi_token,
            }),
        };

        Ok(Some(::ffishim::Data::from_derive_input(&derive_input).map_err(|e| {
            ::anyhow::Error::msg(format!("{}", e)) // needed because darling error is not sync
        })?))
    } else {
        Ok(None)
    }
}

fn filter_item_enum(ie: ::syn::ItemEnum) -> ::anyhow::Result<Option<::ffishim::Data>> {
    if derives_ffishim(&ie.attrs) {
        let derive_input = ::syn::DeriveInput{
            attrs: ie.attrs.clone(),
            vis: ie.vis.clone(),
            ident: ie.ident.clone(),
            generics: ie.generics.clone(),
            data: ::syn::Data::Enum(::syn::DataEnum{
                enum_token: ie.enum_token,
                brace_token: ie.brace_token,
                variants: ie.variants.clone(),
            }),
        };

        Ok(Some(::ffishim::Data::from_derive_input(&derive_input).map_err(|e| {
            ::anyhow::Error::msg(format!("{}", e)) // needed because darling error is not sync
        })?))
    } else {
        Ok(None)
    }
}

fn filter_item_fn(ifn: ::syn::ItemFn) -> Option<::syn::ItemFn> {
    if derives_ffishim_function(&ifn.attrs) {
        Some(ifn)
    } else {
        None
    }
}

fn derives_ffishim(attrs: &Vec<::syn::Attribute>) -> bool {
    attrs.iter().any(|attr| if let Ok(::syn::Meta::List(list)) = attr.parse_meta() {
        if list.path.is_ident("derive") {
            list.nested.iter().any(|meta| if let ::syn::NestedMeta::Meta(m) = meta {
                if let ::syn::Meta::Path(p) = m {
                    p.is_ident("FFIShim")
                } else {
                    false
                }
            } else {
                false
            })
        } else {
            false
        }
    } else {
        false
    })
}

fn derives_ffishim_function(attrs: &Vec<::syn::Attribute>) -> bool {
    attrs.iter().any(|attr| attr.path.is_ident("ffishim_function"))
}