feat: add project & for_each_opengl_command macro

4 files changed, 617 insertions, 0 deletions

diff --git a/src/lib.rs b/src/lib.rs
new file mode 100644
index 0000000..35d975f
--- /dev/null
+++ b/src/lib.rs
@@ -0,0 +1,76 @@
+//! Macros utilizing the [OpenGL API and Extension Registry].
+//!
+//! [OpenGL API and Extension Registry]: https://github.com/KhronosGroup/OpenGL-Registry
+#![deny(clippy::all, clippy::pedantic, missing_docs)]
+use once_cell::sync::Lazy;
+use opengl_registry::Registry;
+use proc_macro::TokenStream;
+
+use crate::repeat::for_each_opengl_command_impl;
+
+mod repeat;
+mod str;
+mod token_stream;
+
+const OPENGL_CMD_IDENT_REPLACE: &str = "_gl_command_";
+const OPENGL_CMD_RET_TYPE_REPLACE: &str = "_gl_command_ret_type_";
+const OPENGL_CMD_ARGS_REPLACE: &str = "_gl_command_args_";
+const OPENGL_CMD_ARG_NAMES_REPLACE: &str = "_gl_command_arg_names_";
+const OPENGL_CMD_ARG_TYPES_REPLACE: &str = "_gl_command_arg_types_";
+
+static OPENGL_REGISTRY: Lazy<Registry> = Lazy::new(|| Registry::retrieve().unwrap());
+
+/// Repeats the input for each command in the [OpenGL API and Extension Registry].
+///
+/// # Replacements
+/// This macro will replace some specific identifiers. These identifiers are to be put
+/// between underscores.
+///
+/// ### The following identifiers will be replaced
+///
+/// **`gl_command`**<br>
+/// Will be replaced by the command name.
+///
+/// **`gl_command_ret_type`**<br>
+/// Will be replaced by the command return type.
+///
+/// **`gl_command_args`**<br>
+/// Will be replaced by the command arguments formatted as `name: type`.
+///
+/// **`gl_command_arg_names`**<br>
+/// Will be replaced by the command argument names.
+///
+/// **`gl_command_arg_types`**<br>
+/// Will be replaced by the command argument types.
+///
+/// # Examples
+/// ```
+/// # use opengl_registry_macros::for_each_opengl_command;
+/// for_each_opengl_command! {
+///     fn _gl_command_()
+///     {
+///         println!("Hello from {}", stringify!(_gl_command_));
+///     }
+/// }
+/// ```
+///
+/// Would expand to the following if the only OpenGL commands were `glCreateShader` and
+/// `glBindBuffer`.
+///
+/// ```
+/// fn glCreateShader()
+/// {
+///     println!("Hello from {}", stringify!(glCreateShader));
+/// }
+/// fn glBindBuffer()
+/// {
+///     println!("Hello from {}", stringify!(glBindBuffer));
+/// }
+/// ```
+///
+/// [OpenGL API and Extension Registry]: https://github.com/KhronosGroup/OpenGL-Registry
+#[proc_macro]
+pub fn for_each_opengl_command(input_stream: TokenStream) -> TokenStream
+{
+    for_each_opengl_command_impl(&input_stream.into(), &OPENGL_REGISTRY).into()
+}
diff --git a/src/repeat.rs b/src/repeat.rs
new file mode 100644
index 0000000..2f55ee8
--- /dev/null
+++ b/src/repeat.rs
@@ -0,0 +1,217 @@
+use std::str::FromStr;
+
+use convert_case::{Case, Casing};
+use opengl_registry::Registry;
+use proc_macro2::{Delimiter, Group, Ident, Span, TokenStream, TokenTree};
+
+use crate::str::c_ptr_to_rust_ptr;
+use crate::token_stream::TokenStreamExt;
+use crate::{
+    OPENGL_CMD_ARGS_REPLACE,
+    OPENGL_CMD_ARG_NAMES_REPLACE,
+    OPENGL_CMD_ARG_TYPES_REPLACE,
+    OPENGL_CMD_IDENT_REPLACE,
+    OPENGL_CMD_RET_TYPE_REPLACE,
+};
+
+pub fn for_each_opengl_command_impl(
+    input_stream: &TokenStream,
+    opengl_registry: &Registry,
+) -> TokenStream
+{
+    let gl_func_ident_index_paths = input_stream
+        .find_all_ident(&Ident::new(OPENGL_CMD_IDENT_REPLACE, Span::call_site()));
+
+    let gl_func_ret_type_index_paths = input_stream
+        .find_all_ident(&Ident::new(OPENGL_CMD_RET_TYPE_REPLACE, Span::call_site()));
+
+    let out: TokenStream = opengl_registry
+        .commands()
+        .iter()
+        .map(|gl_command| {
+            let stream = input_stream.replace_tokens(
+                &gl_func_ident_index_paths,
+                &TokenTree::Ident(Ident::new(
+                    gl_command.prototype().name(),
+                    Span::call_site(),
+                )),
+            );
+
+            let return_type = gl_command.prototype().return_type();
+
+            let stream = stream.replace_tokens(
+                &gl_func_ret_type_index_paths,
+                &TokenTree::Group(Group::new(
+                    Delimiter::None,
+                    TokenStream::from_str(&fix_type(return_type)).unwrap(),
+                )),
+            );
+
+            let gl_func_args_paths = stream
+                .find_all_ident(&Ident::new(OPENGL_CMD_ARGS_REPLACE, Span::call_site()));
+
+            let stream = stream.replace_tokens(
+                &gl_func_args_paths,
+                &TokenTree::Group(Group::new(
+                    Delimiter::None,
+                    TokenStream::from_str(
+                        &gl_command
+                            .parameters()
+                            .iter()
+                            .map(|param| {
+                                let param_name = clean_param_name(param.name());
+                                let param_type = fix_type(param.get_type());
+
+                                format!("{param_name}: {param_type}")
+                            })
+                            .collect::<Vec<_>>()
+                            .join(","),
+                    )
+                    .unwrap(),
+                )),
+            );
+
+            let gl_func_arg_names_paths = stream.find_all_ident(&Ident::new(
+                OPENGL_CMD_ARG_NAMES_REPLACE,
+                Span::call_site(),
+            ));
+
+            let stream = stream.replace_tokens(
+                &gl_func_arg_names_paths,
+                &TokenTree::Group(Group::new(
+                    Delimiter::None,
+                    TokenStream::from_str(
+                        &gl_command
+                            .parameters()
+                            .iter()
+                            .map(|param| clean_param_name(param.name()))
+                            .collect::<Vec<_>>()
+                            .join(","),
+                    )
+                    .unwrap(),
+                )),
+            );
+
+            let gl_func_arg_types_paths = stream.find_all_ident(&Ident::new(
+                OPENGL_CMD_ARG_TYPES_REPLACE,
+                Span::call_site(),
+            ));
+
+            stream.replace_tokens(
+                &gl_func_arg_types_paths,
+                &TokenTree::Group(Group::new(
+                    Delimiter::None,
+                    TokenStream::from_str(
+                        &gl_command
+                            .parameters()
+                            .iter()
+                            .map(|param| fix_type(param.get_type()))
+                            .collect::<Vec<_>>()
+                            .join(","),
+                    )
+                    .unwrap(),
+                )),
+            )
+        })
+        .collect();
+
+    out
+}
+
+fn clean_param_name(param_name: &str) -> String
+{
+    match param_name {
+        "ref" => "reference",
+        "type" => "ty",
+        "in" => "inside",
+        "box" => "a_box",
+        name => name,
+    }
+    .to_case(Case::Snake)
+}
+
+fn fix_type(ty: &str) -> String
+{
+    let ty = ty.replace("struct", "");
+
+    let ty = c_ptr_to_rust_ptr(&ty);
+
+    ty.replace("void", "std::ffi::c_void")
+}
+
+#[cfg(test)]
+mod tests
+{
+    use opengl_registry::command::{Command, Parameter, Prototype};
+    use pretty_assertions::assert_eq;
+    use quote::quote;
+
+    use super::*;
+
+    #[test]
+    fn for_each_opengl_command_impl_works()
+    {
+        let registry = Registry::new(vec![
+            Command::new(Prototype::new("glBindBuffer", "void"), vec![]),
+            Command::new(
+                Prototype::new("glActiveTexture", "void"),
+                vec![
+                    Parameter::new("abc", "GLuint"),
+                    Parameter::new("xyz", "GLshort"),
+                ],
+            ),
+            Command::new(
+                Prototype::new("glDrawArrays", "GLint"),
+                vec![Parameter::new("foo", "GLubyte")],
+            ),
+        ]);
+
+        assert_eq!(
+            for_each_opengl_command_impl(
+                &quote! {
+                    unsafe {
+                        functions::_gl_command_ = FunctionPtr::new_initialized(
+                            get_proc_addr(stringify!(_gl_command_))
+                        );
+                    }
+                },
+                &registry,
+            )
+            .to_string(),
+            quote! {
+                unsafe {
+                    functions::glBindBuffer = FunctionPtr::new_initialized(
+                        get_proc_addr(stringify!(glBindBuffer))
+                    );
+                }
+                unsafe {
+                    functions::glActiveTexture = FunctionPtr::new_initialized(
+                        get_proc_addr(stringify!(glActiveTexture))
+                    );
+                }
+                unsafe {
+                    functions::glDrawArrays = FunctionPtr::new_initialized(
+                        get_proc_addr(stringify!(glDrawArrays))
+                    );
+                }
+            }
+            .to_string()
+        );
+
+        assert_eq!(
+            for_each_opengl_command_impl(
+                &quote! {
+                    fn _gl_command_(_gl_command_args_) -> _gl_command_ret_type_ {}
+                },
+                &registry,
+            )
+            .to_string(),
+            quote! {
+                fn glBindBuffer() -> std::ffi::c_void {}
+                fn glActiveTexture(abc: GLuint, xyz: GLshort) -> std::ffi::c_void {}
+                fn glDrawArrays(foo: GLubyte) -> GLint {}
+            }
+            .to_string(),
+        );
+    }
+}
diff --git a/src/str.rs b/src/str.rs
new file mode 100644
index 0000000..90f3600
--- /dev/null
+++ b/src/str.rs
@@ -0,0 +1,61 @@
+use once_cell::sync::Lazy;
+use regex::{Captures, Regex};
+
+static C_PTR_RE: Lazy<Regex> =
+    Lazy::new(|| Regex::new(r"(const )?([a-zA-Z0-9_]+)\s?\*(.*)").unwrap());
+
+static REST_C_PTR_RE: Lazy<Regex> = Lazy::new(|| Regex::new(r"(const)?\s?\*").unwrap());
+
+pub fn c_ptr_to_rust_ptr(c_ptr: &str) -> String
+{
+    C_PTR_RE
+        .replace(c_ptr, |captures: &Captures| {
+            let const_or_mut = captures.get(1).map_or_else(|| "mut", |_| "const");
+
+            let type_name = captures.get(2).unwrap().as_str();
+
+            let rest = captures.get(3).unwrap();
+
+            let rest_ptr_matches = REST_C_PTR_RE.captures_iter(rest.as_str());
+
+            let rest_ptrs = rest_ptr_matches
+                .map(|capts| {
+                    let const_or_mut = capts.get(1).map_or_else(|| "mut", |_| "const");
+
+                    format!("*{const_or_mut} ")
+                })
+                .collect::<Vec<_>>();
+
+            format!("{}*{const_or_mut} {type_name}", rest_ptrs.join(" "))
+        })
+        .to_string()
+}
+
+#[cfg(test)]
+mod tests
+{
+    use pretty_assertions::assert_str_eq;
+
+    use super::*;
+
+    #[test]
+    fn c_ptr_to_rust_ptr_works()
+    {
+        assert_str_eq!(c_ptr_to_rust_ptr("void *"), "*mut void");
+        assert_str_eq!(c_ptr_to_rust_ptr("const void*"), "*const void");
+        assert_str_eq!(c_ptr_to_rust_ptr("GLint *"), "*mut GLint");
+        assert_str_eq!(c_ptr_to_rust_ptr("const GLint*"), "*const GLint");
+        assert_str_eq!(c_ptr_to_rust_ptr("const GLint *"), "*const GLint");
+        assert_str_eq!(c_ptr_to_rust_ptr("const GLint **"), "*mut *const GLint");
+        assert_str_eq!(c_ptr_to_rust_ptr("const GLint * *"), "*mut *const GLint");
+        assert_str_eq!(c_ptr_to_rust_ptr("GLint **"), "*mut *mut GLint");
+        assert_str_eq!(c_ptr_to_rust_ptr("GLuint * const*"), "*const *mut GLuint");
+
+        assert_str_eq!(
+            c_ptr_to_rust_ptr("const GLuint * const*"),
+            "*const *const GLuint"
+        );
+
+        assert_str_eq!(c_ptr_to_rust_ptr("GLchar"), "GLchar");
+    }
+}
diff --git a/src/token_stream.rs b/src/token_stream.rs
new file mode 100644
index 0000000..043de89
--- /dev/null
+++ b/src/token_stream.rs
@@ -0,0 +1,263 @@
+use proc_macro2::{Group, Ident, TokenStream, TokenTree};
+
+pub use self::index_path::IndexPath;
+
+#[allow(clippy::module_name_repetitions)]
+pub trait TokenStreamExt
+{
+    fn find_all_ident(&self, target_ident: &Ident) -> Vec<IndexPath>;
+
+    fn replace_tokens(
+        &self,
+        index_paths_to_replace: &[IndexPath],
+        substitution: &TokenTree,
+    ) -> TokenStream;
+}
+
+impl TokenStreamExt for TokenStream
+{
+    fn find_all_ident(&self, target_ident: &Ident) -> Vec<IndexPath>
+    {
+        let mut found_indices = Vec::new();
+
+        recurse_find_all_ident(
+            self.clone(),
+            target_ident,
+            &mut found_indices,
+            &IndexPath::new(),
+        );
+
+        found_indices
+    }
+
+    fn replace_tokens(
+        &self,
+        index_paths_to_replace: &[IndexPath],
+        substitution: &TokenTree,
+    ) -> TokenStream
+    {
+        self.clone()
+            .into_iter()
+            .enumerate()
+            .map(|(index, mut token_tree)| {
+                for index_path in index_paths_to_replace
+                    .iter()
+                    .filter(|path| path.indices()[0] == index)
+                {
+                    token_tree = match token_tree {
+                        TokenTree::Ident(_) => substitution.clone(),
+                        TokenTree::Group(group) => TokenTree::Group(Group::new(
+                            group.delimiter(),
+                            recurse_replace_tokens(
+                                group.stream(),
+                                substitution,
+                                &index_path.indices()[1..],
+                            ),
+                        )),
+                        tt => tt,
+                    }
+                }
+
+                token_tree
+            })
+            .collect()
+    }
+}
+
+fn recurse_find_all_ident(
+    input_stream: TokenStream,
+    target_ident: &Ident,
+    found_indices: &mut Vec<IndexPath>,
+    current_index_path: &IndexPath,
+)
+{
+    for (index, token_tree) in input_stream.into_iter().enumerate() {
+        match token_tree {
+            TokenTree::Ident(ident) if &ident == target_ident => {
+                let mut index_path = current_index_path.clone();
+
+                index_path.push_index(index);
+
+                found_indices.push(index_path);
+            }
+            TokenTree::Group(group) => {
+                let mut index_path = current_index_path.clone();
+
+                index_path.push_index(index);
+
+                recurse_find_all_ident(
+                    group.stream(),
+                    target_ident,
+                    found_indices,
+                    &index_path,
+                );
+            }
+            _ => {}
+        }
+    }
+}
+
+fn recurse_replace_tokens(
+    token_stream: TokenStream,
+    substitution: &TokenTree,
+    indices: &[usize],
+) -> TokenStream
+{
+    token_stream
+        .into_iter()
+        .enumerate()
+        .map(|(index, token_tree)| match token_tree {
+            TokenTree::Ident(_) if index == indices[0] => substitution.clone(),
+            TokenTree::Group(group) if index == indices[0] => {
+                TokenTree::Group(Group::new(
+                    group.delimiter(),
+                    recurse_replace_tokens(group.stream(), substitution, &indices[1..]),
+                ))
+            }
+            tt => tt,
+        })
+        .collect()
+}
+
+mod index_path
+{
+    #[derive(Debug, Clone, PartialEq, Eq)]
+    pub struct IndexPath
+    {
+        indices: Vec<usize>,
+    }
+
+    impl IndexPath
+    {
+        pub fn new() -> Self
+        {
+            Self {
+                indices: Vec::new(),
+            }
+        }
+
+        pub fn push_index(&mut self, index: usize)
+        {
+            self.indices.push(index);
+        }
+
+        pub fn indices(&self) -> &[usize]
+        {
+            &self.indices
+        }
+    }
+
+    impl<IntoIter> From<IntoIter> for IndexPath
+    where
+        IntoIter: IntoIterator<Item = usize>,
+    {
+        fn from(value: IntoIter) -> Self
+        {
+            Self {
+                indices: value.into_iter().collect(),
+            }
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests
+{
+    use proc_macro2::Span;
+    use quote::quote;
+
+    use super::*;
+
+    #[test]
+    fn find_all_ident_works()
+    {
+        assert_eq!(
+            quote! {
+                let abc = xyz;
+            }
+            .find_all_ident(&Ident::new("xyz", Span::call_site())),
+            vec![IndexPath::from([3])]
+        );
+
+        assert_eq!(
+            quote! {
+                let abc = (xyz, "123");
+            }
+            .find_all_ident(&Ident::new("xyz", Span::call_site())),
+            vec![IndexPath::from([3, 0])]
+        );
+
+        assert_eq!(
+            quote! {
+                return ("123", (yo, 180, xyz));
+            }
+            .find_all_ident(&Ident::new("xyz", Span::call_site())),
+            vec![IndexPath::from([1, 2, 4])]
+        );
+    }
+
+    #[test]
+    fn find_all_ident_works_with_multiple()
+    {
+        assert_eq!(
+            quote! {
+                unsafe {
+                    functions::xyz = FunctionPtr::new_initialized(
+                        get_proc_addr(stringify!(xyz))
+                    );
+                }
+            }
+            .find_all_ident(&Ident::new("xyz", Span::call_site()),),
+            vec![IndexPath::from([1, 3]), IndexPath::from([1, 9, 1, 2, 0])]
+        );
+    }
+
+    #[test]
+    fn recurse_replace_tokens_works()
+    {
+        assert_eq!(
+            recurse_replace_tokens(
+                quote! {
+                    let abc = xyz;
+                },
+                &TokenTree::Ident(Ident::new("foo", Span::call_site())),
+                &[3]
+            )
+            .to_string(),
+            quote! {
+                let abc = foo;
+            }
+            .to_string()
+        );
+
+        assert_eq!(
+            recurse_replace_tokens(
+                quote! {
+                    let abc = (xyz, "123");
+                },
+                &TokenTree::Ident(Ident::new("foo", Span::call_site())),
+                &[3, 0]
+            )
+            .to_string(),
+            quote! {
+                let abc = (foo, "123");
+            }
+            .to_string()
+        );
+
+        assert_eq!(
+            recurse_replace_tokens(
+                quote! {
+                    let abc = (hello, "123").iter_map(|_| xyz);
+                },
+                &TokenTree::Ident(Ident::new("foo", Span::call_site())),
+                &[6, 3]
+            )
+            .to_string(),
+            quote! {
+                let abc = (hello, "123").iter_map(|_| foo);
+            }
+            .to_string()
+        );
+    }
+}