1 files changed, 319 insertions, 0 deletions
diff --git a/rtic-macros/src/syntax/parse.rs b/rtic-macros/src/syntax/parse.rs
new file mode 100644
index 00000000..72eeeaf6
--- /dev/null
+++ b/rtic-macros/src/syntax/parse.rs
@@ -0,0 +1,319 @@
+mod app;
+mod hardware_task;
+mod idle;
+mod init;
+mod resource;
+mod software_task;
+mod util;
+
+use proc_macro2::TokenStream as TokenStream2;
+use syn::{
+    braced, parenthesized,
+    parse::{self, Parse, ParseStream, Parser},
+    token::Brace,
+    Ident, Item, LitInt, Token,
+};
+
+use crate::syntax::{
+    ast::{App, AppArgs, HardwareTaskArgs, IdleArgs, InitArgs, SoftwareTaskArgs, TaskLocal},
+    Either,
+};
+
+// Parse the app, both app arguments and body (input)
+pub fn app(args: TokenStream2, input: TokenStream2) -> parse::Result<App> {
+    let args = AppArgs::parse(args)?;
+    let input: Input = syn::parse2(input)?;
+
+    App::parse(args, input)
+}
+
+pub(crate) struct Input {
+    _mod_token: Token![mod],
+    pub ident: Ident,
+    _brace_token: Brace,
+    pub items: Vec<Item>,
+}
+
+impl Parse for Input {
+    fn parse(input: ParseStream<'_>) -> parse::Result<Self> {
+        fn parse_items(input: ParseStream<'_>) -> parse::Result<Vec<Item>> {
+            let mut items = vec![];
+
+            while !input.is_empty() {
+                items.push(input.parse()?);
+            }
+
+            Ok(items)
+        }
+
+        let content;
+
+        let _mod_token = input.parse()?;
+        let ident = input.parse()?;
+        let _brace_token = braced!(content in input);
+        let items = content.call(parse_items)?;
+
+        Ok(Input {
+            _mod_token,
+            ident,
+            _brace_token,
+            items,
+        })
+    }
+}
+
+fn init_args(tokens: TokenStream2) -> parse::Result<InitArgs> {
+    (|input: ParseStream<'_>| -> parse::Result<InitArgs> {
+        if input.is_empty() {
+            return Ok(InitArgs::default());
+        }
+
+        let mut local_resources = None;
+
+        let content;
+        parenthesized!(content in input);
+
+        if !content.is_empty() {
+            loop {
+                // Parse identifier name
+                let ident: Ident = content.parse()?;
+                // Handle equal sign
+                let _: Token![=] = content.parse()?;
+
+                match &*ident.to_string() {
+                    "local" => {
+                        if local_resources.is_some() {
+                            return Err(parse::Error::new(
+                                ident.span(),
+                                "argument appears more than once",
+                            ));
+                        }
+
+                        local_resources = Some(util::parse_local_resources(&content)?);
+                    }
+                    _ => {
+                        return Err(parse::Error::new(ident.span(), "unexpected argument"));
+                    }
+                }
+
+                if content.is_empty() {
+                    break;
+                }
+                // Handle comma: ,
+                let _: Token![,] = content.parse()?;
+            }
+        }
+
+        if let Some(locals) = &local_resources {
+            for (ident, task_local) in locals {
+                if let TaskLocal::External = task_local {
+                    return Err(parse::Error::new(
+                        ident.span(),
+                        "only declared local resources are allowed in init",
+                    ));
+                }
+            }
+        }
+
+        Ok(InitArgs {
+            local_resources: local_resources.unwrap_or_default(),
+        })
+    })
+    .parse2(tokens)
+}
+
+fn idle_args(tokens: TokenStream2) -> parse::Result<IdleArgs> {
+    (|input: ParseStream<'_>| -> parse::Result<IdleArgs> {
+        if input.is_empty() {
+            return Ok(IdleArgs::default());
+        }
+
+        let mut shared_resources = None;
+        let mut local_resources = None;
+
+        let content;
+        parenthesized!(content in input);
+        if !content.is_empty() {
+            loop {
+                // Parse identifier name
+                let ident: Ident = content.parse()?;
+                // Handle equal sign
+                let _: Token![=] = content.parse()?;
+
+                match &*ident.to_string() {
+                    "shared" => {
+                        if shared_resources.is_some() {
+                            return Err(parse::Error::new(
+                                ident.span(),
+                                "argument appears more than once",
+                            ));
+                        }
+
+                        shared_resources = Some(util::parse_shared_resources(&content)?);
+                    }
+
+                    "local" => {
+                        if local_resources.is_some() {
+                            return Err(parse::Error::new(
+                                ident.span(),
+                                "argument appears more than once",
+                            ));
+                        }
+
+                        local_resources = Some(util::parse_local_resources(&content)?);
+                    }
+
+                    _ => {
+                        return Err(parse::Error::new(ident.span(), "unexpected argument"));
+                    }
+                }
+                if content.is_empty() {
+                    break;
+                }
+
+                // Handle comma: ,
+                let _: Token![,] = content.parse()?;
+            }
+        }
+
+        Ok(IdleArgs {
+            shared_resources: shared_resources.unwrap_or_default(),
+            local_resources: local_resources.unwrap_or_default(),
+        })
+    })
+    .parse2(tokens)
+}
+
+fn task_args(tokens: TokenStream2) -> parse::Result<Either<HardwareTaskArgs, SoftwareTaskArgs>> {
+    (|input: ParseStream<'_>| -> parse::Result<Either<HardwareTaskArgs, SoftwareTaskArgs>> {
+        if input.is_empty() {
+            return Ok(Either::Right(SoftwareTaskArgs::default()));
+        }
+
+        let mut binds = None;
+        let mut priority = None;
+        let mut shared_resources = None;
+        let mut local_resources = None;
+        let mut prio_span = None;
+
+        let content;
+        parenthesized!(content in input);
+        loop {
+            if content.is_empty() {
+                break;
+            }
+
+            // Parse identifier name
+            let ident: Ident = content.parse()?;
+            let ident_s = ident.to_string();
+
+            // Handle equal sign
+            let _: Token![=] = content.parse()?;
+
+            match &*ident_s {
+                "binds" => {
+                    if binds.is_some() {
+                        return Err(parse::Error::new(
+                            ident.span(),
+                            "argument appears more than once",
+                        ));
+                    }
+
+                    // Parse identifier name
+                    let ident = content.parse()?;
+
+                    binds = Some(ident);
+                }
+
+                "priority" => {
+                    if priority.is_some() {
+                        return Err(parse::Error::new(
+                            ident.span(),
+                            "argument appears more than once",
+                        ));
+                    }
+
+                    // #lit
+                    let lit: LitInt = content.parse()?;
+
+                    if !lit.suffix().is_empty() {
+                        return Err(parse::Error::new(
+                            lit.span(),
+                            "this literal must be unsuffixed",
+                        ));
+                    }
+
+                    let value = lit.base10_parse::<u8>().ok();
+                    if value.is_none() {
+                        return Err(parse::Error::new(
+                            lit.span(),
+                            "this literal must be in the range 0...255",
+                        ));
+                    }
+
+                    prio_span = Some(lit.span());
+                    priority = Some(value.unwrap());
+                }
+
+                "shared" => {
+                    if shared_resources.is_some() {
+                        return Err(parse::Error::new(
+                            ident.span(),
+                            "argument appears more than once",
+                        ));
+                    }
+
+                    shared_resources = Some(util::parse_shared_resources(&content)?);
+                }
+
+                "local" => {
+                    if local_resources.is_some() {
+                        return Err(parse::Error::new(
+                            ident.span(),
+                            "argument appears more than once",
+                        ));
+                    }
+
+                    local_resources = Some(util::parse_local_resources(&content)?);
+                }
+
+                _ => {
+                    return Err(parse::Error::new(ident.span(), "unexpected argument"));
+                }
+            }
+
+            if content.is_empty() {
+                break;
+            }
+
+            // Handle comma: ,
+            let _: Token![,] = content.parse()?;
+        }
+        let priority = priority.unwrap_or(1);
+        let shared_resources = shared_resources.unwrap_or_default();
+        let local_resources = local_resources.unwrap_or_default();
+
+        Ok(if let Some(binds) = binds {
+            if priority == 0 {
+                return Err(parse::Error::new(
+                    prio_span.unwrap(),
+                    "hardware tasks are not allowed to be at priority 0",
+                ));
+            }
+
+            Either::Left(HardwareTaskArgs {
+                binds,
+                priority,
+                shared_resources,
+                local_resources,
+            })
+        } else {
+            Either::Right(SoftwareTaskArgs {
+                priority,
+                shared_resources,
+                local_resources,
+            })
+        })
+    })
+    .parse2(tokens)
+}