From 120a3c59f41f25d25a85b1bcf56b574f6564bbc3 Mon Sep 17 00:00:00 2001
From: NotAFile <notafile@gmail.com>
Date: Tue, 18 Jan 2022 00:11:37 +0100
Subject: [PATCH] allow yosys to read il output

---
 src/frontend.rs   | 47 +++++++++++++++++++++++++++++++++--------------
 src/main.rs       | 17 ++++++++++++++---
 src/rtlil/sync.rs |  5 +++--
 3 files changed, 50 insertions(+), 19 deletions(-)

diff --git a/src/frontend.rs b/src/frontend.rs
index fb48b34..353dc27 100644
--- a/src/frontend.rs
+++ b/src/frontend.rs
@@ -76,6 +76,12 @@ impl Signal {
     }
 }
 
+/// context used when generating processes
+struct ProcContext {
+    updates: Vec<(rtlil::SigSpec, rtlil::SigSpec)>,
+    next_sigs: BTreeMap<String, rtlil::SigSpec>,
+}
+
 struct Context {
     /// map callable name to callable
     callables: BTreeMap<String, Callable>,
@@ -96,27 +102,36 @@ impl Context {
 
 fn lower_process_statement(
     ctx: &Context,
+    pctx: &mut ProcContext,
     module: &mut rtlil::Module,
-    updates: &mut Vec<(rtlil::SigSpec, rtlil::SigSpec)>,
     stmt: &parser::proc::ProcStatement,
 ) -> Result<rtlil::CaseRule, CompileError> {
     let rule = match stmt {
         parser::proc::ProcStatement::IfElse(_) => todo!("if/else unimplemented"),
         parser::proc::ProcStatement::Assign(assig) => {
             // FIXME: actually store this
-            let next_gen_id = format!("${}$next", assig.lhs);
-            module.add_wire(rtlil::Wire::new(&next_gen_id, TODO_WIDTH, None));
+            let next_sig;
+            if let Some(sig) = pctx.next_sigs.get(assig.lhs) {
+                next_sig = sig.clone();
+            }
+            else {
+                let next_gen_id = format!("${}$next", assig.lhs);
+                module.add_wire(rtlil::Wire::new(&next_gen_id, TODO_WIDTH, None));
+                next_sig = rtlil::SigSpec::Wire(next_gen_id);
 
-            let next_wire = rtlil::SigSpec::Wire(next_gen_id);
-            updates.push((
-                rtlil::SigSpec::Wire(assig.lhs.to_owned()),
-                next_wire.clone(),
-            ));
+                pctx.next_sigs.insert(assig.lhs.to_owned(), next_sig.clone());
+
+                // trigger the modified value to update
+                pctx.updates.push((
+                    ctx.try_get_signal(assig.lhs)?.sigspec(),
+                    next_sig.clone(),
+                ));
+            };
 
             let next_expr_wire = lower_expression(ctx, module, &assig.expr)?;
 
             rtlil::CaseRule {
-                assign: vec![(next_wire, next_expr_wire)],
+                assign: vec![(next_sig.clone(), next_expr_wire)],
                 switches: vec![],
             }
         }
@@ -124,7 +139,7 @@ fn lower_process_statement(
             let match_sig = lower_expression(ctx, module, &match_block.expr)?;
             let mut cases = vec![];
             for arm in &match_block.arms {
-                let case = lower_process_statement(ctx, module, updates, &arm.1)?;
+                let case = lower_process_statement(ctx, pctx, module, &arm.1)?;
                 let compare_sig = lower_expression(ctx, module, &arm.0)?;
                 cases.push((compare_sig, case));
             }
@@ -147,17 +162,21 @@ fn lower_process(
     module: &mut rtlil::Module,
     process: &parser::proc::ProcBlock,
 ) -> Result<(), CompileError> {
-    let mut updates = vec![];
+    let mut pctx = ProcContext {
+        updates: vec![],
+        next_sigs: BTreeMap::new(),
+    };
     let mut cases = vec![];
     for stmt in &process.items {
-        let case = lower_process_statement(ctx, module, &mut updates, stmt)?;
+        let case = lower_process_statement(ctx, &mut pctx, module, stmt)?;
         cases.push(case);
     }
 
-    let sync_cond = rtlil::SyncCond::Posedge((*process.net.fragment()).into());
+    let sync_sig = ctx.try_get_signal(process.net.fragment())?;
+    let sync_cond = rtlil::SyncCond::Posedge(sync_sig.sigspec());
     let sync_rule = rtlil::SyncRule {
         cond: sync_cond,
-        assign: updates,
+        assign: pctx.updates,
     };
     if cases.len() != 1 {
         panic!("only one expression per block, for now")
diff --git a/src/main.rs b/src/main.rs
index c9219d0..7228e9f 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -15,6 +15,12 @@ struct Opt {
     /// Input file
     #[structopt(parse(from_os_str))]
     input: PathBuf,
+    /// Debug AST
+    #[structopt(short)]
+    debug: bool,
+    /// Output file, stdout if not present
+    #[structopt(short, parse(from_os_str))]
+    output: Option<PathBuf>,
 }
 
 fn main() {
@@ -35,11 +41,16 @@ fn main() {
         }
         Err(_) => (),
         Ok(res) => {
-            println!("{:#?}", res);
+            if opt.debug {
+                println!("{:#?}", res);
+            }
             let lowered = crate::frontend::lower_module(res.1);
             match lowered {
-                Ok(res) => println!("{}", res),
-                Err(err) => println!("{:#?}", err),
+                Ok(res) => {
+                    let mut file = File::create(opt.output.unwrap_or("out.rtlil".into())).expect("could not open file");
+                    file.write_all(res.as_bytes()).expect("failed to write output file");
+                },
+                Err(err) => eprintln!("{:#?}", err),
             }
         }
     }
diff --git a/src/rtlil/sync.rs b/src/rtlil/sync.rs
index 2b71139..3d89e17 100644
--- a/src/rtlil/sync.rs
+++ b/src/rtlil/sync.rs
@@ -29,8 +29,8 @@ pub struct SyncRule {
 pub enum SyncCond {
     Always,
     Init,
-    Posedge(String),
-    Negedge(String),
+    Posedge(SigSpec),
+    Negedge(SigSpec),
 }
 
 impl RtlilWrite for Process {
@@ -64,6 +64,7 @@ impl RtlilWrite for SwitchRule {
             writer.dedent();
         }
         writer.dedent();
+        writer.write_line("end");
     }
 }