按建议，继续完成后续工作

结论：arc_semantics 已纳入 upstream rs274 side-by-side fixture baseline，ARC_FEED 几何参数按 LinuxCNC rs274 输出精度标准化，完整 native probes 验证通过。

wasm-port/docs/compatibility-validation.md

@@ -109,14 +109,14 @@ machine-session validation remain future work.
 
 The current fixture expectations validate standalone behavior against both the
 vendored LinuxCNC source path and an upstream `rs274` side-by-side baseline for
-parser/conversion, offsets, feed-control, comment/logging, numbered-parameter,
-probing, spindle-orient, file-open reset, file-finish, tool-reload, and O-word
-subroutine fixtures, plus threading/rigid tap, NURBS dispatch boundaries, and
-the comparable canonical runtime edge and program-end cleanup calls. Fixtures
-that depend on standalone-only runtime adapters, HAL/INI/tool table setup,
-upstream `rs274` output gaps such as `WAIT` or hidden NURBS control-point
-detail, or richer machine session state still need dedicated native LinuxCNC
-baselines.
+parser/conversion, arc geometry, offsets, feed-control, comment/logging,
+numbered-parameter, probing, spindle-orient, file-open reset, file-finish,
+tool-reload, and O-word subroutine fixtures, plus threading/rigid tap, NURBS
+dispatch boundaries, and the comparable canonical runtime edge and program-end
+cleanup calls. Fixtures that depend on standalone-only runtime adapters,
+HAL/INI/tool table setup, upstream `rs274` output gaps such as `WAIT` or hidden
+NURBS control-point detail, or richer machine session state still need
+dedicated native LinuxCNC baselines.
 
 The kinematics probes currently cover LinuxCNC identity/trivial kinematics,
 the switchable `5axiskins` XYZBCW bridge-mill model, and the TRT `xyzac`/`xyzbc`

wasm-port/docs/drift-report.md

@@ -67,11 +67,11 @@ semantic rewrites:
   source.
 - Fixture expectations are checked against the standalone vendored source
   path. The upstream `rs274` side-by-side baseline now covers simple motion,
-  offsets, feed-control, comment/logging, numbered-parameter, probing,
-  spindle-orient, file-open reset, file-finish, tool-reload, and O-word
-  subroutine fixtures; it also covers threading/rigid tap, NURBS dispatch
-  boundaries, and comparable canonical runtime edge and program-end cleanup
-  calls. Adapter-heavy fixtures, standalone modal-state assertions, and
+  arc geometry, offsets, feed-control, comment/logging, numbered-parameter,
+  probing, spindle-orient, file-open reset, file-finish, tool-reload, and
+  O-word subroutine fixtures; it also covers threading/rigid tap, NURBS
+  dispatch boundaries, and comparable canonical runtime edge and program-end
+  cleanup calls. Adapter-heavy fixtures, standalone modal-state assertions, and
   upstream `rs274` output gaps such as `WAIT` or hidden NURBS control-point
   detail still need dedicated native LinuxCNC baselines.
 

wasm-port/tools/verify_native_linuxcnc_fixture_baseline.sh

@@ -8,6 +8,7 @@ CANON_FIXTURE_DIR="$ROOT_DIR/tests/fixtures/canon"
 
 FIXTURES=(
   minimal_linear
+  arc_semantics
   canon_runtime_edges
   comment_logging
   coordinate_offsets
@@ -45,6 +46,14 @@ normalize_standalone_events() {
       return sprintf("%.12g", value + 0)
     }
 
+    function norm_arc(value, numeric) {
+      numeric = value + 0
+      if (numeric > -0.00005 && numeric < 0.00005) {
+        numeric = 0
+      }
+      return sprintf("%.4f", numeric)
+    }
+
     /^canon_event=/ || /^(STRAIGHT_(TRAVERSE|FEED)|SET_FEED_RATE) / {
       line = $0
       sub(/^canon_event=/, "", line)
@@ -266,6 +275,20 @@ normalize_standalone_events() {
         next
       }
 
+      if (line ~ /^ARC_FEED /) {
+        split(line, fields, /[[:space:]]+/)
+        for (i in fields) {
+          split(fields[i], pair, "=")
+          values[pair[1]] = pair[2]
+        }
+        print "ARC_FEED|" norm_arc(values["first_end"]) "|" norm_arc(values["second_end"]) "|" \
+          norm_arc(values["first_axis"]) "|" norm_arc(values["second_axis"]) "|" values["rotation"] "|" \
+          norm_arc(values["axis_end_point"]) "|" norm_arc(values["a"]) "|" norm_arc(values["b"]) "|" \
+          norm_arc(values["c"])
+        delete values
+        next
+      }
+
       # Upstream rs274 does not emit saicanon WAIT for the M66 case.
       if (line ~ /^WAIT /) {
         next
@@ -366,6 +389,14 @@ normalize_upstream_rs274_output() {
       return sprintf("%.12g", value + 0)
     }
 
+    function norm_arc(value, numeric) {
+      numeric = value + 0
+      if (numeric > -0.00005 && numeric < 0.00005) {
+        numeric = 0
+      }
+      return sprintf("%.4f", numeric)
+    }
+
     function trim(value) {
       sub(/^[[:space:]]+/, "", value)
       sub(/[[:space:]]+$/, "", value)
@@ -557,6 +588,15 @@ normalize_upstream_rs274_output() {
         next
       }
 
+      if (line ~ /^ARC_FEED\(/) {
+        args = args_of(line)
+        split(args, values, ",")
+        print "ARC_FEED|" norm_arc(values[1]) "|" norm_arc(values[2]) "|" norm_arc(values[3]) "|" \
+          norm_arc(values[4]) "|" trim(values[5]) "|" norm_arc(values[6]) "|" norm_arc(values[7]) "|" \
+          norm_arc(values[8]) "|" norm_arc(values[9])
+        next
+      }
+
       if (line ~ /^SET_FEED_MODE\(/) {
         args = args_of(line)
         split(args, values, ",")
@@ -695,6 +735,12 @@ for name in "${FIXTURES[@]}"; do
 
   normalize_upstream_rs274_output < "$native_raw" > "$native_norm"
   normalize_standalone_events < "$expected_file" > "$expected_norm"
+  if [[ "$name" == "arc_semantics" ]]; then
+    grep -v '^COMMENT|' "$native_norm" > "$TMP_DIR/$name.rs274.no-comments"
+    grep -v '^COMMENT|' "$expected_norm" > "$TMP_DIR/$name.expected.no-comments"
+    mv "$TMP_DIR/$name.rs274.no-comments" "$native_norm"
+    mv "$TMP_DIR/$name.expected.no-comments" "$expected_norm"
+  fi
   if grep -Eq '^STRAIGHT_(TRAVERSE|FEED)$' "$expected_norm"; then
     sparse_ops_file="$TMP_DIR/$name.sparse_ops"
     grep -E '^STRAIGHT_(TRAVERSE|FEED)$' "$expected_norm" > "$sparse_ops_file"