Merge pull request #16129 from JuliaLang/jb/fix16023

fix #16023, undef var error with local in statement position

src/codegen.cpp

@@ -3052,12 +3052,17 @@ static Value *emit_condition(jl_value_t *cond, const std::string &msg, jl_codect
 
 static void emit_stmtpos(jl_value_t *expr, jl_codectx_t *ctx)
 {
- if (jl_is_symbol(expr) || jl_is_slot(expr))
- return; // value not used, no point in attempting codegen for it
  if (jl_is_gensym(expr))
  return; // value not used, no point in attempting codegen for it
  if (jl_is_linenode(expr))
  return;
+ if (jl_is_slot(expr)) {
+ size_t sl = jl_slot_number(expr) - 1;
+ jl_varinfo_t &vi = ctx->slots[sl];
+ if (vi.usedUndef)
+ (void)emit_expr(expr, ctx);
+ return;
+ }
  if (jl_is_newvarnode(expr)) {
  jl_value_t *var = jl_fieldref(expr, 0);
  assert(jl_is_slot(var));

test/core.jl

@@ -3857,3 +3857,10 @@ type Issue8712; end
 f16089(args...) = typeof(args)
 g16089() = f16089(UInt8)
 @test g16089() === Tuple{DataType}
+
+# issue #16023
+function f16023()
+ x
+ x = 1
+end
+@test_throws UndefVarError f16023()