From 33149eb5aa291450612dc8070cd4b4e7f836253c Mon Sep 17 00:00:00 2001
From: NotAFile <notafile@gmail.com>
Date: Wed, 5 Jan 2022 00:13:56 +0100
Subject: [PATCH] reference strings, first error reporting

---
 src/frontend.rs | 37 +++++++++++++++++++++++++++++++++----
 src/main.rs     |  1 +
 src/parser.rs   | 44 ++++++++++++++++++++++----------------------
 3 files changed, 56 insertions(+), 26 deletions(-)

diff --git a/src/frontend.rs b/src/frontend.rs
index e1f20d4..8aeb19b 100644
--- a/src/frontend.rs
+++ b/src/frontend.rs
@@ -31,7 +31,36 @@ fn make_pubid(id: &str) -> String {
 }
 
 #[derive(Debug)]
-pub struct CompileError;
+pub enum CompileErrorKind {
+    UndefinedReference(String)
+}
+
+#[derive(Debug)]
+pub struct CompileError {
+    kind: CompileErrorKind,
+}
+
+impl CompileError {
+    fn new(kind: CompileErrorKind) -> Self {
+        Self {
+            kind
+        }
+    }
+}
+
+pub enum GenericParam<T> {
+    Unsolved,
+    Solved(T),
+}
+
+pub enum Type {
+    /// a wire of some width
+    Wire(GenericParam<u32>)
+}
+
+// module that can be instantiated like a function
+pub struct Callable {
+}
 
 fn lower_expression(module: &mut rtlil::Module, expr: &parser::Expression) -> Result<String, CompileError> {
     match expr {
@@ -43,7 +72,7 @@ fn lower_expression(module: &mut rtlil::Module, expr: &parser::Expression) -> Re
             let mut args_resolved = call.args.iter().map(|expr| lower_expression(module, expr));
 
             // TODO: make this sensible
-            let cell = match call.name.as_str() {
+            let cell = match *call.name.fragment() {
                 "and" => {
                     let arg_a = args_resolved.next().unwrap()?;
                     let arg_b = args_resolved.next().unwrap()?;
@@ -66,12 +95,12 @@ fn lower_expression(module: &mut rtlil::Module, expr: &parser::Expression) -> Re
                     let cell_id = module.make_genid("reduce_or");
                     builtin_unop_cell("$reduce_or", &cell_id, &arg_a, &output_gen_id)
                 }
-                _ => return Err(CompileError {}),
+                name => return Err(CompileError::new(CompileErrorKind::UndefinedReference(name.to_owned()))),
             };
             module.add_cell(cell);
             Ok(output_gen_id)
         }
-        parser::Expression::Operation(op) => todo!(),
+        parser::Expression::Operation(_op) => todo!(),
     }
 }
 
diff --git a/src/main.rs b/src/main.rs
index 03067b2..43512f8 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -2,6 +2,7 @@ mod literals;
 mod parser;
 mod rtlil;
 mod frontend;
+mod builtin_cells;
 
 use nom::error::convert_error;
 use std::fs::File;
diff --git a/src/parser.rs b/src/parser.rs
index c31b926..7f46583 100644
--- a/src/parser.rs
+++ b/src/parser.rs
@@ -43,8 +43,8 @@ fn intliteral(input: Span) -> IResult<Span, (u64, u64)> {
 }
 
 #[derive(Debug)]
-pub struct NetDecl {
-    pub name: String,
+pub struct NetDecl<'a> {
+    pub name: &'a str,
     pub width: Option<u64>,
     pub value: Option<(u64, u64)>,
 }
@@ -59,44 +59,44 @@ pub enum PortDirection {
 pub struct PortDecl<'a> {
     pub pos: Span<'a>,
     pub direction: PortDirection,
-    pub net: NetDecl,
+    pub net: NetDecl<'a>,
 }
 
 #[derive(Debug)]
 pub struct Module<'a> {
-    pub name: String,
+    pub name: &'a str,
     pub ports: Vec<PortDecl<'a>>,
-    pub statements: Vec<Statement>,
+    pub statements: Vec<Statement<'a>>,
 }
 
 #[derive(Debug)]
-pub enum Statement {
-    Assign(Assign),
+pub enum Statement<'a> {
+    Assign(Assign<'a>),
 }
 
 #[derive(Debug)]
-pub struct Assign {
-    pub lhs: String,
-    pub expr: Expression,
+pub struct Assign<'a> {
+    pub lhs: &'a str,
+    pub expr: Expression<'a>,
 }
 
 #[derive(Debug)]
-pub enum Operation {
-    And { a: String, b: Expression },
-    Or { a: String, b: Expression },
+pub enum Operation<'a> {
+    And { a: String, b: Expression<'a> },
+    Or { a: String, b: Expression<'a> },
 }
 
 #[derive(Debug)]
-pub struct Call {
-    pub name: String,
-    pub args: Vec<Expression>,
+pub struct Call<'a> {
+    pub name: Span<'a>,
+    pub args: Vec<Expression<'a>>,
 }
 
 #[derive(Debug)]
-pub enum Expression {
-    Ident(String),
-    Call(Box<Call>),
-    Operation(Box<Operation>),
+pub enum Expression<'a> {
+    Ident(&'a str),
+    Call(Box<Call<'a>>),
+    Operation(Box<Operation<'a>>),
 }
 
 fn declaration(i: Span) -> IResult<Span, NetDecl> {
@@ -108,7 +108,7 @@ fn declaration(i: Span) -> IResult<Span, NetDecl> {
             opt(preceded(ws0(char('=')), intliteral)),
         )),
         |(_, width, ident, value)| NetDecl {
-            name: (*ident.fragment()).into(),
+            name: ident.fragment(),
             width,
             value,
         },
@@ -167,7 +167,7 @@ fn call_item(input: Span) -> IResult<Span, Call> {
             ),
         )),
         |(name, args)| Call {
-            name: (*name.fragment()).into(),
+            name: name,
             args,
         },
     )(input)