1 files changed, 303 insertions, 0 deletions
diff --git a/src/bindgen/ir/generic_path.rs b/src/bindgen/ir/generic_path.rs
new file mode 100644
index 0000000..ef14890
--- /dev/null
+++ b/src/bindgen/ir/generic_path.rs
@@ -0,0 +1,303 @@
+use std::io::Write;
+use std::ops::Deref;
+
+use syn::ext::IdentExt;
+
+use crate::bindgen::cdecl;
+use crate::bindgen::config::{Config, Language};
+use crate::bindgen::declarationtyperesolver::{DeclarationType, DeclarationTypeResolver};
+use crate::bindgen::ir::{ConstExpr, Path, Type};
+use crate::bindgen::utilities::IterHelpers;
+use crate::bindgen::writer::{Source, SourceWriter};
+
+#[derive(Debug, Clone)]
+pub enum GenericParamType {
+    Type,
+    Const(Type),
+}
+
+#[derive(Debug, Clone)]
+pub struct GenericParam {
+    name: Path,
+    ty: GenericParamType,
+}
+
+impl GenericParam {
+    pub fn new_type_param(name: &str) -> Self {
+        GenericParam {
+            name: Path::new(name),
+            ty: GenericParamType::Type,
+        }
+    }
+
+    pub fn load(param: &syn::GenericParam) -> Result<Option<Self>, String> {
+        match *param {
+            syn::GenericParam::Type(syn::TypeParam { ref ident, .. }) => Ok(Some(GenericParam {
+                name: Path::new(ident.unraw().to_string()),
+                ty: GenericParamType::Type,
+            })),
+
+            syn::GenericParam::Lifetime(_) => Ok(None),
+
+            syn::GenericParam::Const(syn::ConstParam {
+                ref ident, ref ty, ..
+            }) => match Type::load(ty)? {
+                None => {
+                    // A type that evaporates, like PhantomData.
+                    Err(format!("unsupported const generic type: {:?}", ty))
+                }
+                Some(ty) => Ok(Some(GenericParam {
+                    name: Path::new(ident.unraw().to_string()),
+                    ty: GenericParamType::Const(ty),
+                })),
+            },
+        }
+    }
+
+    pub fn name(&self) -> &Path {
+        &self.name
+    }
+}
+
+#[derive(Default, Debug, Clone)]
+pub struct GenericParams(pub Vec<GenericParam>);
+
+impl GenericParams {
+    pub fn load(generics: &syn::Generics) -> Result<Self, String> {
+        let mut params = vec![];
+        for param in &generics.params {
+            if let Some(p) = GenericParam::load(param)? {
+                params.push(p);
+            }
+        }
+
+        Ok(GenericParams(params))
+    }
+
+    /// Associate each parameter with an argument.
+    pub fn call<'out>(
+        &'out self,
+        item_name: &str,
+        arguments: &'out [GenericArgument],
+    ) -> Vec<(&'out Path, &'out GenericArgument)> {
+        assert!(self.len() > 0, "{} is not generic", item_name);
+        assert!(
+            self.len() == arguments.len(),
+            "{} has {} params but is being instantiated with {} values",
+            item_name,
+            self.len(),
+            arguments.len(),
+        );
+        self.iter()
+            .map(|param| param.name())
+            .zip(arguments.iter())
+            .collect()
+    }
+
+    fn write_internal<F: Write>(
+        &self,
+        config: &Config,
+        out: &mut SourceWriter<F>,
+        with_default: bool,
+    ) {
+        if !self.0.is_empty() && config.language == Language::Cxx {
+            out.write("template<");
+            for (i, item) in self.0.iter().enumerate() {
+                if i != 0 {
+                    out.write(", ");
+                }
+                match item.ty {
+                    GenericParamType::Type => {
+                        write!(out, "typename {}", item.name);
+                        if with_default {
+                            write!(out, " = void");
+                        }
+                    }
+                    GenericParamType::Const(ref ty) => {
+                        cdecl::write_field(out, ty, item.name.name(), config);
+                        if with_default {
+                            write!(out, " = 0");
+                        }
+                    }
+                }
+            }
+            out.write(">");
+            out.new_line();
+        }
+    }
+
+    pub fn write_with_default<F: Write>(&self, config: &Config, out: &mut SourceWriter<F>) {
+        self.write_internal(config, out, true);
+    }
+}
+
+impl Deref for GenericParams {
+    type Target = [GenericParam];
+
+    fn deref(&self) -> &[GenericParam] {
+        &self.0
+    }
+}
+
+impl Source for GenericParams {
+    fn write<F: Write>(&self, config: &Config, out: &mut SourceWriter<F>) {
+        self.write_internal(config, out, false);
+    }
+}
+
+/// A (non-lifetime) argument passed to a generic, either a type or a constant expression.
+///
+/// Note: Both arguments in a type like `Array<T, N>` are represented as
+/// `GenericArgument::Type`s, even if `N` is actually the name of a const. This
+/// is a consequence of `syn::GenericArgument` doing the same thing.
+#[derive(Debug, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
+pub enum GenericArgument {
+    Type(Type),
+    Const(ConstExpr),
+}
+
+impl GenericArgument {
+    pub fn specialize(&self, mappings: &[(&Path, &GenericArgument)]) -> GenericArgument {
+        match *self {
+            GenericArgument::Type(ref ty) => {
+                if let Type::Path(ref path) = *ty {
+                    if path.is_single_identifier() {
+                        // See note on `GenericArgument` above: `ty` may
+                        // actually be the name of a const. Check for that now.
+                        for &(name, value) in mappings {
+                            if *name == path.path {
+                                return value.clone();
+                            }
+                        }
+                    }
+                }
+                GenericArgument::Type(ty.specialize(mappings))
+            }
+            GenericArgument::Const(ref expr) => GenericArgument::Const(expr.clone()),
+        }
+    }
+
+    pub fn rename_for_config(&mut self, config: &Config, generic_params: &GenericParams) {
+        match *self {
+            GenericArgument::Type(ref mut ty) => ty.rename_for_config(config, generic_params),
+            GenericArgument::Const(ref mut expr) => expr.rename_for_config(config),
+        }
+    }
+}
+
+impl Source for GenericArgument {
+    fn write<F: Write>(&self, config: &Config, out: &mut SourceWriter<F>) {
+        match *self {
+            GenericArgument::Type(ref ty) => ty.write(config, out),
+            GenericArgument::Const(ref expr) => expr.write(config, out),
+        }
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
+pub struct GenericPath {
+    path: Path,
+    export_name: String,
+    generics: Vec<GenericArgument>,
+    ctype: Option<DeclarationType>,
+}
+
+impl GenericPath {
+    pub fn new(path: Path, generics: Vec<GenericArgument>) -> Self {
+        let export_name = path.name().to_owned();
+        Self {
+            path,
+            export_name,
+            generics,
+            ctype: None,
+        }
+    }
+
+    pub fn self_path() -> Self {
+        Self::new(Path::new("Self"), vec![])
+    }
+
+    pub fn replace_self_with(&mut self, self_ty: &Path) {
+        if self.path.replace_self_with(self_ty) {
+            self.export_name = self_ty.name().to_owned();
+        }
+        // Caller deals with generics.
+    }
+
+    pub fn path(&self) -> &Path {
+        &self.path
+    }
+
+    pub fn generics(&self) -> &[GenericArgument] {
+        &self.generics
+    }
+
+    pub fn generics_mut(&mut self) -> &mut [GenericArgument] {
+        &mut self.generics
+    }
+
+    pub fn ctype(&self) -> Option<&DeclarationType> {
+        self.ctype.as_ref()
+    }
+
+    pub fn name(&self) -> &str {
+        self.path.name()
+    }
+
+    pub fn export_name(&self) -> &str {
+        &self.export_name
+    }
+
+    pub fn is_single_identifier(&self) -> bool {
+        self.generics.is_empty()
+    }
+
+    pub fn rename_for_config(&mut self, config: &Config, generic_params: &GenericParams) {
+        for generic in &mut self.generics {
+            generic.rename_for_config(config, generic_params);
+        }
+        if !generic_params.iter().any(|param| param.name == self.path) {
+            config.export.rename(&mut self.export_name);
+        }
+    }
+
+    pub fn resolve_declaration_types(&mut self, resolver: &DeclarationTypeResolver) {
+        self.ctype = resolver.type_for(&self.path);
+    }
+
+    pub fn load(path: &syn::Path) -> Result<Self, String> {
+        assert!(
+            !path.segments.is_empty(),
+            "{:?} doesn't have any segments",
+            path
+        );
+        let last_segment = path.segments.last().unwrap();
+        let name = last_segment.ident.unraw().to_string();
+
+        let path = Path::new(name);
+        let phantom_data_path = Path::new("PhantomData");
+        if path == phantom_data_path {
+            return Ok(Self::new(path, Vec::new()));
+        }
+
+        let generics = match last_segment.arguments {
+            syn::PathArguments::AngleBracketed(syn::AngleBracketedGenericArguments {
+                ref args,
+                ..
+            }) => args.iter().try_skip_map(|x| match *x {
+                syn::GenericArgument::Type(ref x) => Ok(Type::load(x)?.map(GenericArgument::Type)),
+                syn::GenericArgument::Lifetime(_) => Ok(None),
+                syn::GenericArgument::Const(ref x) => {
+                    Ok(Some(GenericArgument::Const(ConstExpr::load(x)?)))
+                }
+                _ => Err(format!("can't handle generic argument {:?}", x)),
+            })?,
+            syn::PathArguments::Parenthesized(_) => {
+                return Err("Path contains parentheses.".to_owned());
+            }
+            _ => Vec::new(),
+        };
+
+        Ok(Self::new(path, generics))
+    }
+}