fst: add small hack to deal with how NVC encodes bools

Cargo.toml

@@ -8,7 +8,7 @@ members = ["wellen"]
 default-members = ["wellen"]
 
 [workspace.package]
-version = "0.9.10"
+version = "0.9.11"
 edition = "2021"
 # we require the `div_ceil` method on integers
 rust-version = "1.73.0"

wellen/src/fst.rs

@@ -181,7 +181,25 @@ impl SignalWriter {
                 }
                 SignalType::BitVector(len, _) => {
                     let bits = len.get();
-                    debug_assert_eq!(value.len(), bits as usize);
+
+                    // nvc will declare boolean signals as 1-bit bit-vectors and then generate
+                    // the strings "true" and "false"
+                    let value = if value.len() > bits as usize && bits == 1 {
+                        match value {
+                            b"true" => b"1",
+                            b"false" => b"0",
+                            _ => value,
+                        }
+                    } else {
+                        value
+                    };
+
+                    debug_assert_eq!(
+                        value.len(),
+                        bits as usize,
+                        "{}",
+                        String::from_utf8_lossy(value)
+                    );
                     let local_encoding = check_states(value).unwrap_or_else(|| {
                         panic!(
                             "Unexpected signal value: {}",

wellen/tests/fst.rs

@@ -183,3 +183,23 @@ fn test_scope_merging() {
 fn test_nvc_xwb_fofb_shaper_filt_tb() {
     let _waves = read("inputs/nvc/xwb_fofb_shaper_filt_tb.fst").unwrap();
 }
+
+fn load_all_signals(waves: &mut Waveform) {
+    let all_signals = waves
+        .hierarchy()
+        .get_unique_signals_vars()
+        .iter()
+        .flatten()
+        .map(|v| v.signal_ref())
+        .collect::<Vec<_>>();
+    waves.load_signals(&all_signals);
+}
+
+/// This file was provided by Augusto Fraga Giachero in the following issue:
+/// https://github.com/ekiwi/wellen/issues/16
+#[test]
+fn test_nvc_vhdl_test_bool_issue_16() {
+    // turns out that NVC needs a little hack to deal with the way it encodes booleans
+    let mut waves = read("inputs/nvc/vhdl_test_bool_issue_16.fst").unwrap();
+    load_all_signals(&mut waves);
+}