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etiennebarriebyroot
etiennebarrie
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byroot
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Implement chilled strings
[Feature #20205] As a path toward enabling frozen string literals by default in the future, this commit introduce "chilled strings". From a user perspective chilled strings pretend to be frozen, but on the first attempt to mutate them, they lose their frozen status and emit a warning rather than to raise a `FrozenError`. Implementation wise, `rb_compile_option_struct.frozen_string_literal` is no longer a boolean but a tri-state of `enabled/disabled/unset`. When code is compiled with frozen string literals neither explictly enabled or disabled, string literals are compiled with a new `putchilledstring` instruction. This instruction is identical to `putstring` except it marks the String with the `STR_CHILLED (FL_USER3)` and `FL_FREEZE` flags. Chilled strings have the `FL_FREEZE` flag as to minimize the need to check for chilled strings across the codebase, and to improve compatibility with C extensions. Notes: - `String#freeze`: clears the chilled flag. - `String#-@`: acts as if the string was mutable. - `String#+@`: acts as if the string was mutable. - `String#clone`: copies the chilled flag. Co-authored-by: Jean Boussier <byroot@ruby-lang.org>
1 parent 86b1531 commit 12be40a

36 files changed

+714
-282
lines changed

‎NEWS.md

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@@ -7,6 +7,12 @@ Note that each entry is kept to a minimum, see links for details.
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## Language changes
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* String literals in files without a `frozen_string_literal` comment now behave
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as if they were frozen. If they are mutated a deprecation warning is emited.
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These warnings can be enabled with `-W:deprecated` or by setting `Warning[:deprecated] = true`.
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To disable this change you can run Ruby with the `--disable-frozen-string-literal` command line
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argument. [Feature #20205]
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* `it` is added to reference a block parameter. [[Feature #18980]]
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* Keyword splatting `nil` when calling methods is now supported.

‎bootstraptest/test_ractor.rb

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@@ -1792,3 +1792,14 @@ class C8; def self.foo = 17; end
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}
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end # if !ENV['GITHUB_WORKFLOW']
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# Chilled strings are not shareable
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assert_equal 'false', %q{
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Ractor.shareable?("chilled")
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}
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# Chilled strings can be made shareable
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assert_equal 'true', %q{
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shareable = Ractor.make_shareable("chilled")
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shareable == "chilled" && Ractor.shareable?(shareable)
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}

‎bootstraptest/test_yjit.rb

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@@ -4679,6 +4679,37 @@ def test(klass, args)
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test(KwInit, [Hash.ruby2_keywords_hash({1 => 1})])
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}
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# Chilled string setivar trigger warning
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assert_equal 'literal string will be frozen in the future', %q{
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Warning[:deprecated] = true
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$VERBOSE = true
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$warning = "no-warning"
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module ::Warning
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def self.warn(message)
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$warning = message.split("warning: ").last.strip
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end
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end
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class String
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def setivar!
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@ivar = 42
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end
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end
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def setivar!(str)
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str.setivar!
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end
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10.times { setivar!("mutable".dup) }
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10.times do
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setivar!("frozen".freeze)
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rescue FrozenError
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end
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setivar!("chilled") # Emit warning
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$warning
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}
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# arity=-2 cfuncs
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assert_equal '["", "1/2", [0, [:ok, 1]]]', %q{
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def test_cases(file, chain)

‎class.c

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@@ -2244,7 +2244,10 @@ singleton_class_of(VALUE obj)
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return klass;
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case T_STRING:
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if (FL_TEST_RAW(obj, RSTRING_FSTR)) {
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if (CHILLED_STRING_P(obj)) {
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CHILLED_STRING_MUTATED(obj);
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}
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else if (FL_TEST_RAW(obj, RSTRING_FSTR)) {
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rb_raise(rb_eTypeError, "can't define singleton");
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}
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}

‎compile.c

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@@ -4723,7 +4723,7 @@ frozen_string_literal_p(const rb_iseq_t *iseq)
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return ISEQ_COMPILE_DATA(iseq)->option->frozen_string_literal > 0;
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}
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static inline int
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static inline bool
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static_literal_node_p(const NODE *node, const rb_iseq_t *iseq, bool hash_key)
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{
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switch (nd_type(node)) {
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debugp_param("nd_lit", get_string_value(node));
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if (!popped) {
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VALUE lit = get_string_value(node);
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if (!frozen_string_literal_p(iseq)) {
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switch (ISEQ_COMPILE_DATA(iseq)->option->frozen_string_literal) {
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case ISEQ_FROZEN_STRING_LITERAL_UNSET:
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lit = rb_fstring(lit);
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ADD_INSN1(ret, node, putchilledstring, lit);
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RB_OBJ_WRITTEN(iseq, Qundef, lit);
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break;
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case ISEQ_FROZEN_STRING_LITERAL_DISABLED:
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lit = rb_fstring(lit);
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ADD_INSN1(ret, node, putstring, lit);
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RB_OBJ_WRITTEN(iseq, Qundef, lit);
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}
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else {
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break;
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case ISEQ_FROZEN_STRING_LITERAL_ENABLED:
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if (ISEQ_COMPILE_DATA(iseq)->option->debug_frozen_string_literal || RTEST(ruby_debug)) {
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VALUE debug_info = rb_ary_new_from_args(2, rb_iseq_path(iseq), INT2FIX(line));
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lit = rb_str_dup(lit);
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}
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ADD_INSN1(ret, node, putobject, lit);
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RB_OBJ_WRITTEN(iseq, Qundef, lit);
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break;
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default:
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rb_bug("invalid frozen_string_literal");
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}
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}
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break;

‎error.c

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rb_error_frozen_object(VALUE frozen_obj)
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{
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rb_yjit_lazy_push_frame(GET_EC()->cfp->pc);
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if (CHILLED_STRING_P(frozen_obj)) {
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CHILLED_STRING_MUTATED(frozen_obj);
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return;
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}
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VALUE debug_info;
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const ID created_info = id_debug_created_info;
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VALUE mesg = rb_sprintf("can't modify frozen %"PRIsVALUE": ",

‎ext/objspace/objspace_dump.c

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@@ -476,6 +476,8 @@ dump_object(VALUE obj, struct dump_config *dc)
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dump_append(dc, ", \"embedded\":true");
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if (FL_TEST(obj, RSTRING_FSTR))
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dump_append(dc, ", \"fstring\":true");
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if (CHILLED_STRING_P(obj))
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dump_append(dc, ", \"chilled\":true");
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if (STR_SHARED_P(obj))
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dump_append(dc, ", \"shared\":true");
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else

‎gems/bundled_gems

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# - repository-url: URL from where clone for test
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# - revision: revision in repository-url to test
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# if `revision` is not given, "v"+`version` or `version` will be used.
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minitest 5.22.3 https://github.com/minitest/minitest
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power_assert 2.0.3 https://github.com/ruby/power_assert
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# Waiting for https://github.com/minitest/minitest/pull/991
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minitest 5.22.3 https://github.com/Shopify/minitest b5f5202575894796e00109a8f8a5041b778991ee
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# Waiting for https://github.com/ruby/power_assert/pull/48
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power_assert 2.0.3 https://github.com/ruby/power_assert 78dd2ab3ccd93796d83c0b35b978c39bfabb938c
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rake 13.1.0 https://github.com/ruby/rake
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test-unit 3.6.2 https://github.com/test-unit/test-unit
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rexml 3.2.6 https://github.com/ruby/rexml
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net-smtp 0.4.0.1 https://github.com/ruby/net-smtp
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matrix 0.4.2 https://github.com/ruby/matrix
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prime 0.1.2 https://github.com/ruby/prime
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rbs 3.4.4 https://github.com/ruby/rbs 61b412bc7ba00519e7d6d08450bd384990d94ea2
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typeprof 0.21.11 https://github.com/ruby/typeprof
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rbs 3.4.4 https://github.com/ruby/rbs ba7872795d5de04adb8ff500c0e6afdc81a041dd
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typeprof 0.21.11 https://github.com/ruby/typeprof b19a6416da3a05d57fadd6ffdadb382b6d236ca5
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debug 1.9.1 https://github.com/ruby/debug 2d602636d99114d55a32fedd652c9c704446a749
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racc 1.7.3 https://github.com/ruby/racc
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mutex_m 0.2.0 https://github.com/ruby/mutex_m

‎include/ruby/internal/fl_type.h

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@@ -916,6 +916,9 @@ static inline void
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RB_OBJ_FREEZE_RAW(VALUE obj)
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{
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RB_FL_SET_RAW(obj, RUBY_FL_FREEZE);
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if (TYPE(obj) == T_STRING) {
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RB_FL_UNSET_RAW(obj, FL_USER3); // STR_CHILLED
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}
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}
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RUBY_SYMBOL_EXPORT_BEGIN

‎include/ruby/internal/intern/error.h

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*/
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void rb_error_frozen(const char *what);
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RBIMPL_ATTR_NORETURN()
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/**
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* Identical to rb_error_frozen(), except it takes arbitrary Ruby object
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* instead of C's string.

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