Address code review: preserve CO_FAST_HIDDEN, fix varint overflow

youknowone · youknowone · commit 11d2eaad2395 · 2026-03-22T17:34:14.000+09:00
- Use original localspluskinds from marshal data instead of
  rebuilding, preserving CO_FAST_HIDDEN and other flags
- Fix write_varint_be to handle values &gt;= 2^30 (add 6th chunk)
- Remove unused build_localspluskinds_from_split
diff --git a/crates/compiler-core/src/marshal.rs b/crates/compiler-core/src/marshal.rs
@@ -249,9 +249,8 @@ pub fn deserialize_code<R: Read, Bag: ConstantBag>(
     let instructions = CodeUnits::try_from(code_bytes.as_slice())?;
     let locations = linetable_to_locations(&linetable, first_line_raw, instructions.len());
 
-    // Build localspluskinds from split vars (matching CodeObject's merged layout)
-    let localspluskinds =
-        build_localspluskinds_from_split(&lp.varnames, &lp.cellvars, &lp.freevars);
+    // Use original localspluskinds from marshal data (preserves CO_FAST_HIDDEN etc.)
+    let localspluskinds = localspluskinds.into_boxed_slice();
 
     Ok(CodeObject {
         instructions,
@@ -1035,41 +1034,6 @@ pub struct LocalsPlusResult<S> {
     pub deref_map: Vec<u32>,
 }
 
-/// Build localspluskinds from split varnames/cellvars/freevars.
-/// This produces the merged layout matching CodeObject's localspluskinds field.
-fn build_localspluskinds_from_split<S: AsRef<str>>(
-    varnames: &[S],
-    cellvars: &[S],
-    freevars: &[S],
-) -> Box<[u8]> {
-    let nlocals = varnames.len();
-    let ncells = cellvars.len();
-    let nfrees = freevars.len();
-    let numdropped = cellvars
-        .iter()
-        .filter(|cv| varnames.iter().any(|v| v.as_ref() == cv.as_ref()))
-        .count();
-    let nlocalsplus = nlocals + ncells - numdropped + nfrees;
-    let mut kinds = alloc::vec![0u8; nlocalsplus];
-    for kind in kinds.iter_mut().take(nlocals) {
-        *kind = CO_FAST_LOCAL;
-    }
-    let mut cell_numdropped = 0usize;
-    for (i, cv) in cellvars.iter().enumerate() {
-        if let Some(local_idx) = varnames.iter().position(|v| v.as_ref() == cv.as_ref()) {
-            kinds[local_idx] |= CO_FAST_CELL;
-            cell_numdropped += 1;
-        } else {
-            kinds[nlocals + i - cell_numdropped] = CO_FAST_CELL;
-        }
-    }
-    let free_start = nlocals + ncells - numdropped;
-    for i in 0..nfrees {
-        kinds[free_start + i] = CO_FAST_FREE;
-    }
-    kinds.into_boxed_slice()
-}
-
 pub fn split_localplus<S: Clone>(
     names: &[S],
     kinds: &[u8],
diff --git a/crates/compiler-core/src/varint.rs b/crates/compiler-core/src/varint.rs
@@ -34,6 +34,9 @@ pub fn write_signed_varint(buf: &mut Vec<u8>, val: i32) -> usize {
 /// Write a big-endian varint (used by exception tables).
 pub fn write_varint_be(buf: &mut Vec<u8>, val: u32) -> usize {
     let start_len = buf.len();
+    if val >= 1 << 30 {
+        buf.push(0x40 | ((val >> 30) & 0x3f) as u8);
+    }
     if val >= 1 << 24 {
         buf.push(0x40 | ((val >> 24) & 0x3f) as u8);
     }
