refactor: 拆分 counter statement 计数分发

crates/oxide_compiler/src/counter/stmt/exception.rs

@@ -0,0 +1,68 @@
+use super::*;
+
+impl Compiler {
+    pub(in crate::counter) fn count_throw_statement(
+        &self, stmt: &oxide_parser::ThrowStatement<'_>, ctx: &mut CompileCtx,
+    ) {
+        self.count_expression(&stmt.argument, ctx);
+        ctx.projected_pc += 1; // THROW
+    }
+
+    pub(in crate::counter) fn count_try_statement(&self, stmt: &oxide_parser::TryStatement<'_>, ctx: &mut CompileCtx) {
+        let id = ctx.next_label_id();
+        let catch_label = Label::CatchBody(id);
+        let try_end_label = Label::TryEnd(id);
+        let has_catch = stmt.handler.is_some();
+        let has_finally = stmt.finalizer.is_some();
+
+        ctx.alloc_reg(); // result_reg
+
+        if has_finally {
+            ctx.projected_pc += 1; // TRY_FINALLY_BEGIN (before try body)
+        }
+
+        if has_catch {
+            ctx.projected_pc += 1; // TRY_BEGIN (before try body)
+        }
+
+        for s in &stmt.block.body {
+            self.count_statement(s, ctx);
+        }
+        ctx.projected_pc += 1; // LOAD_VAR result_reg (if try body has result)
+
+        if has_catch {
+            ctx.projected_pc += 1; // TRY_END
+        }
+
+        let jmp_needed = has_catch || has_finally;
+        if jmp_needed {
+            ctx.projected_pc += 1; // JMP
+        }
+
+        ctx.label_map.insert(catch_label, ctx.projected_pc);
+        if let Some(catch) = &stmt.handler {
+            ctx.push_scope();
+            if let Some(_param) = &catch.param {
+                ctx.alloc_reg();
+                ctx.projected_pc += 1; // STORE_VAR
+            }
+            for cs in &catch.body.body {
+                self.count_statement(cs, ctx);
+            }
+            ctx.projected_pc += 1; // LOAD_VAR result_reg (if catch body has result)
+            ctx.pop_scope();
+        }
+
+        if let Some(finally) = &stmt.finalizer {
+            let finally_label = Label::FinallyBody(id);
+            ctx.label_map.insert(finally_label, ctx.projected_pc);
+            for fs in &finally.body {
+                self.count_statement(fs, ctx);
+            }
+            ctx.projected_pc += 1; // LOAD_VAR result_reg (if finally has result)
+            ctx.projected_pc += 1; // TRY_FINALLY_END
+        }
+
+        ctx.label_map.insert(try_end_label, ctx.projected_pc);
+    }
+}