add cli option to set verilog dialect

crates/fayalite/src/cli.rs

@@ -6,7 +6,7 @@ use crate::{
 };
 use clap::{
     builder::{OsStringValueParser, TypedValueParser},
-    Args, Parser, Subcommand, ValueHint,
+    Args, Parser, Subcommand, ValueEnum, ValueHint,
 };
 use eyre::{eyre, Report};
 use std::{error, ffi::OsString, fmt, io, path::PathBuf, process};
@@ -114,6 +114,35 @@ where
     }
 }
 
+/// based on https://circt.llvm.org/docs/VerilogGeneration/#recommended-loweringoptions-by-target
+#[derive(ValueEnum, Copy, Clone, Debug, PartialEq, Eq, Hash)]
+#[non_exhaustive]
+pub enum VerilogDialect {
+    Questa,
+    Spyglass,
+    Verilator,
+    Vivado,
+    Yosys,
+}
+
+impl VerilogDialect {
+    pub fn firtool_extra_args(self) -> &'static [&'static str] {
+        match self {
+            VerilogDialect::Questa => &["--lowering-options=emitWireInPorts"],
+            VerilogDialect::Spyglass => {
+                &["--lowering-options=explicitBitcast,disallowExpressionInliningInPorts"]
+            }
+            VerilogDialect::Verilator => &[
+                "--lowering-options=locationInfoStyle=wrapInAtSquareBracket,disallowLocalVariables",
+            ],
+            VerilogDialect::Vivado => &["--lowering-options=mitigateVivadoArrayIndexConstPropBug"],
+            VerilogDialect::Yosys => {
+                &["--lowering-options=disallowLocalVariables,disallowPackedArrays"]
+            }
+        }
+    }
+}
+
 #[derive(Args, Debug)]
 #[non_exhaustive]
 pub struct VerilogArgs {
@@ -129,6 +158,9 @@ pub struct VerilogArgs {
     pub firtool: PathBuf,
     #[arg(long)]
     pub firtool_extra_args: Vec<OsString>,
+    /// adapt the generated Verilog for a particular toolchain
+    #[arg(long)]
+    pub verilog_dialect: Option<VerilogDialect>,
 }
 
 #[derive(Debug)]
@@ -151,11 +183,14 @@ impl VerilogArgs {
             firrtl: firrtl_output,
         };
         let mut cmd = process::Command::new(&self.firtool);
-        cmd.arg(output.firrtl.firrtl_file(&self.firrtl))
-            .arg("-o")
-            .arg(output.verilog_file(self))
-            .args(&self.firtool_extra_args)
-            .current_dir(&self.firrtl.base.output);
+        cmd.arg(output.firrtl.firrtl_file(&self.firrtl));
+        cmd.arg("-o");
+        cmd.arg(output.verilog_file(self));
+        if let Some(dialect) = self.verilog_dialect {
+            cmd.args(dialect.firtool_extra_args());
+        }
+        cmd.args(&self.firtool_extra_args);
+        cmd.current_dir(&self.firrtl.base.output);
         let status = cmd.status()?;
         if status.success() {
             Ok(output)