diff --git a/App/lib/core/Gen/ExprGenAttr.vp b/App/lib/core/Gen/ExprGenAttr.vp
index b5b025b..6d7834f 100644
--- a/App/lib/core/Gen/ExprGenAttr.vp
+++ b/App/lib/core/Gen/ExprGenAttr.vp
@@ -564,13 +564,18 @@ class ExprGenAttr(ExprGenBase.ExprGenBase):
                     # 此处返回 None，让上层嵌套属性访问路径处理
                     if string.strcmp(nm_ma.id, "t") == 0 and string.strcmp(at.attr, "ASM_DESCR") == 0:
                         return None
-                    # CDefine 未找到且属性名符合 ALL_CAPS 约定: fail-fast 终止编译
-                    # 不再创建未定义的外部全局变量引用（否则 llc 报 "use of undefined value"）
+                    # ALL_CAPS 模块属性但非 CDefine：先检查模块是否定义了同名全局
+                    # 变量（如 Phase1.PYI_BUF_SIZE: t.CSizeT = 262144 是 i64 全局、
+                    # 非宏，语义同 C 的 extern size_t PYI_BUF_SIZE）→ 按跨模块全局
+                    # 引用加载。仅当全局变量也不存在时才 fail-fast（防 llc
+                    # "use of undefined value"）。
                     if HandlesExpr._is_cdefine_name_pattern(at.attr) != 0:
-                        HandlesType.fatal_error(
-                            at,
-                            f"跨模块 CDefine 未找到: '{nm_ma.id}.{at.attr}'（CDefine cross-module lookup failed）",
-                            "TypeError")
+                        if self.find_global_in_module(mod, at.attr) is None:
+                            HandlesType.fatal_error(
+                                at,
+                                f"跨模块 CDefine 未找到: '{nm_ma.id}.{at.attr}'（CDefine cross-module lookup failed）",
+                                "TypeError")
+                        # 命中跨模块全局 → 落到下方跨模块全局加载路径
                     # 非 CDefine: 使用 i8* 作为类型提示 (模块级变量通常存储指针)
                     i8_ptr_hint: llvmlite.LLVMType | t.CPtr = llvmlite.Ptr(pool, llvmlite.Int8(pool))
                     mod_gv_ref: llvmlite.Value | t.CPtr = self._resolve_module_attribute_global(
diff --git a/App/lib/core/Gen/ExprGenName.vp b/App/lib/core/Gen/ExprGenName.vp
index 0aadd15..e9a01d4 100644
--- a/App/lib/core/Gen/ExprGenName.vp
+++ b/App/lib/core/Gen/ExprGenName.vp
@@ -99,6 +99,30 @@ class ExprGenName(ExprGenBase.ExprGenBase):
                         return llvmlite.ConstFloat(pool, llvmlite.Double(pool), dchk_nm)
                     return HandlesExpr._const_int_for_cdefine(pool, cdef_val)
 
+        # CDefine 查找失败：from-import 的模块级全局变量（如
+        # from Phase1 import PYI_BUF_SIZE；PYI_BUF_SIZE: t.CSizeT = 262144 是
+        # i64 全局、非宏，语义同 C 的 extern size_t PYI_BUF_SIZE）。from-import
+        # 确认名称确实来自某模块后，按后缀匹配查找该全局并加载。
+        if trans is not None and trans._from_imports is not None:
+            fi_mod_raw: str = HandlesImports.lookup_from_import(
+                trans._from_imports, nm_id, 0)
+            if fi_mod_raw is not None:
+                fi_gv: llvmlite.GlobalVariable | t.CPtr = HandlesExpr.find_global_in_module(
+                    trans.Module, nm_id)
+                if fi_gv is not None and fi_gv.Ty is not None:
+                    fi_ref: llvmlite.Value | t.CPtr = HandlesExpr.make_global_ref(
+                        pool, nm_id, fi_gv.Ty)
+                    if fi_ref is not None and fi_ref.Ty is not None:
+                        fi_pty: llvmlite.LLVMType | t.CPtr = fi_ref.Ty.Pointee
+                        if fi_pty is not None:
+                            match fi_pty:
+                                case llvmlite.LLVMType.Array(_, _):
+                                    # 数组全局按 C 语义退化为基址（对齐 L3383-3388）
+                                    return fi_ref
+                                case _:
+                                    pass
+                            return llvmlite.build_load(builder, fi_pty, fi_ref)
+
         # global 变量：从模块作用域查找（global 声明优先级最高）
         if trans is not None:
             if HT.is_global_name(trans, nm_id) != 0: