提示词：

对标 LinuxCNC，分阶段完善 Web 版数控系统仿真的 WASM 程序，继续补齐 G 代码语法并严格测试。

总结：
- 对齐 LinuxCNC 对同一行重复非 G/M 字的拒绝行为，覆盖 G1 X1 X2 等重复轴字错误。
- 将 smoke parser 字母字归一为大写，补充 lowercase 普通字和命名 O-word 回归覆盖。
- 已通过 ./test-native.sh 和 ./test-linuxcnc-source-link.sh。

core/src/smoke_gcode_parser.cpp

@@ -354,13 +354,14 @@ bool looks_like_real_start(char ch) {
 
 bool parse_word_list_impl(const std::string &line, std::vector<Word> *words, std::string *error, bool strict) {
     words->clear();
+    std::array<bool, 26> seen_letters{};
     const char *text = line.c_str();
     for (size_t i = 0; text[i] != '\0';) {
         if (std::isspace(static_cast<unsigned char>(text[i]))) {
             ++i;
             continue;
         }
-        char letter = text[i];
+        char letter = static_cast<char>(std::toupper(static_cast<unsigned char>(text[i])));
         if (!std::isalpha(static_cast<unsigned char>(letter))) {
             ++i;
             continue;
@@ -391,6 +392,16 @@ bool parse_word_list_impl(const std::string &line, std::vector<Word> *words, std
             }
             return false;
         }
+        if (letter != 'G' && letter != 'M') {
+            const size_t letter_index = static_cast<size_t>(letter - 'A');
+            if (strict && seen_letters[letter_index]) {
+                if (error) {
+                    *error = "multiple " + std::string(1, letter) + " words on one line";
+                }
+                return false;
+            }
+            seen_letters[letter_index] = true;
+        }
         words->push_back({letter, value});
         i = next;
     }

core/tests/cnc_sim_api_smoke.cpp

@@ -242,6 +242,8 @@ int main() {
     bool saw_global_low_parameter_after_oword = false;
     bool saw_named_oword_call = false;
     bool saw_named_oword_return = false;
+    bool saw_lowercase_named_oword_call = false;
+    bool saw_lowercase_named_oword_return = false;
     bool saw_named_parameter_reference = false;
     bool saw_named_parameter_call_arg = false;
     bool saw_named_parameter_local = false;
@@ -274,6 +276,7 @@ int main() {
     bool saw_word_unary_function_motion = false;
     bool saw_word_atan_function_motion = false;
     bool saw_signed_word_unary_function_motion = false;
+    bool saw_lowercase_motion = false;
     bool saw_trig_function_motion = false;
     bool saw_inverse_trig_function_motion = false;
     bool saw_atan_function_motion = false;
@@ -3030,6 +3033,41 @@ int main() {
     ok &= expect(saw_named_oword_call, "expected named O-word subprogram call");
     ok &= expect(saw_named_oword_return, "expected named O-word return to caller");
 
+    const char lowercase_named_oword_subprogram[] =
+        "g21 g90\n"
+        "g0 x0 y0 z0\n"
+        "f100\n"
+        "o<lower_named> call [5]\n"
+        "g1 y3\n"
+        "m30\n"
+        "o<lower_named> sub\n"
+        "g1 x#1\n"
+        "o<lower_named> return\n"
+        "g1 x99\n"
+        "o<lower_named> endsub\n";
+    events.clear();
+    ok &= expect(cnc_sim_parse_program(sim,
+                                       lowercase_named_oword_subprogram,
+                                       sizeof(lowercase_named_oword_subprogram) - 1) == 0,
+                 cnc_sim_last_error(sim));
+    for (const auto &event : events) {
+        saw_lowercase_named_oword_call = saw_lowercase_named_oword_call ||
+                                         (event.type == CNC_SIM_EVENT_LINEAR_FEED &&
+                                          event.line == 8 &&
+                                          event.end.x == 5.0);
+        saw_lowercase_named_oword_return = saw_lowercase_named_oword_return ||
+                                           (event.type == CNC_SIM_EVENT_LINEAR_FEED &&
+                                            event.line == 5 &&
+                                            event.start.x == 5.0 &&
+                                            event.end.y == 3.0);
+        ok &= expect(!(event.type == CNC_SIM_EVENT_LINEAR_FEED &&
+                       event.line == 10 &&
+                       event.end.x == 99.0),
+                     "expected lowercase named O-word return to skip remaining subprogram body");
+    }
+    ok &= expect(saw_lowercase_named_oword_call, "expected lowercase named O-word subprogram call");
+    ok &= expect(saw_lowercase_named_oword_return, "expected lowercase named O-word return to caller");
+
     const char named_parameter_program[] =
         "#<target> = 5\n"
         "#<step> = [#<target> + 2]\n"
@@ -3524,6 +3562,16 @@ int main() {
                                        sizeof(g1_without_feed_program) - 1) != 0,
                  "expected LinuxCNC to reject G1 with zero feed rate");
 
+    const char duplicate_axis_word_program[] =
+        "G21 G90\n"
+        "F100\n"
+        "G1 X1 X2\n";
+    events.clear();
+    ok &= expect(cnc_sim_parse_program(sim,
+                                       duplicate_axis_word_program,
+                                       sizeof(duplicate_axis_word_program) - 1) != 0,
+                 "expected LinuxCNC to reject multiple X words on one line");
+
     const char scientific_notation_word_program[] =
         "G21 G90\n"
         "F100\n"
@@ -3597,6 +3645,23 @@ int main() {
     ok &= expect(saw_word_atan_function_motion, "expected LinuxCNC ATAN function as a word value");
     ok &= expect(saw_signed_word_unary_function_motion, "expected signed LinuxCNC unary function as a word value");
 
+    const char lowercase_word_program[] =
+        "g21 g90\n"
+        "f100\n"
+        "g1 x3\n";
+    events.clear();
+    ok &= expect(cnc_sim_parse_program(sim,
+                                       lowercase_word_program,
+                                       sizeof(lowercase_word_program) - 1) == 0,
+                 cnc_sim_last_error(sim));
+    for (const auto &event : events) {
+        saw_lowercase_motion = saw_lowercase_motion ||
+                               (event.type == CNC_SIM_EVENT_LINEAR_FEED &&
+                                event.line == 3 &&
+                                event.end.x == 3.0);
+    }
+    ok &= expect(saw_lowercase_motion, "expected LinuxCNC lowercase word parsing");
+
     const char additional_math_function_program[] =
         "#1 = [ASIN[0.5] + ACOS[0.5]]\n"
         "#2 = [FIX[1.9] + FUP[1.1] + ROUND[-1.5]]\n"