[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>
The documentation for `rb_enc_interned_str_cstr` notes that `enc` can be
a null pointer, but this currently causes a segmentation fault when
trying to autoload the encoding. This commit fixes the issue by checking
for NULL before calling `rb_enc_autoload`.
* YJIT: Lazily push a frame for specialized C funcs
Co-authored-by: Maxime Chevalier-Boisvert <maxime.chevalierboisvert@shopify.com>
* Fix a comment on pc_to_cfunc
* Rename rb_yjit_check_pc to rb_yjit_lazy_push_frame
* Rename it to jit_prepare_lazy_frame_call
* Fix a typo
* Optimize String#getbyte as well
* Optimize String#byteslice as well
---------
Co-authored-by: Maxime Chevalier-Boisvert <maxime.chevalierboisvert@shopify.com>
The allocation could re-embed `orig_str` and invalidate the data
pointer from RSTRING_GETMEM() if the string is embedded.
Found on CI, where the test introduced in 7002e776944 ("Fix
Symbol#inspect for GC compaction") recently failed.
See: <https://github.com/ruby/ruby/actions/runs/7880657560/job/21503019659>
* Specialize String#byteslice(a, b)
This adds a specialization for String#byteslice when there are two
parameters.
This makes our protobuf parser go from 5.84x slower to 5.33x slower
```
Comparison:
decode upstream (53738 bytes): 7228.5 i/s
decode protobuff (53738 bytes): 1236.8 i/s - 5.84x slower
Comparison:
decode upstream (53738 bytes): 7024.8 i/s
decode protobuff (53738 bytes): 1318.5 i/s - 5.33x slower
```
* Update yjit/src/codegen.rs
---------
Co-authored-by: Maxime Chevalier-Boisvert <maximechevalierb@gmail.com>
assert does not print the bug report, only the file and line number of
the assertion that failed. RUBY_ASSERT prints the full bug report, which
makes it much easier to debug.
[Bug #20169]
Embedded strings are not safe for system calls without the GVL because
compaction can cause pages to be locked causing the operation to fail
with EFAULT. This commit changes io_fwrite to use rb_str_tmp_frozen_no_embed_acquire,
which guarantees that the return string is not embedded.
Appending valid encoding character can change coderange from invalid to valid.
Example: "\x95".force_encoding('sjis')<<0x5C will be a valid string "\x{955C}"
[Bug #20150]
String#grapheme_cluters and String#each_grapheme_cluster leaks memory
because if the string is not UTF-8, then the created regex will not
be freed.
For example:
str = "hello world".encode(Encoding::UTF_32LE)
10.times do
1_000.times do
str.grapheme_clusters
end
puts `ps -o rss= -p #{$$}`
end
Before:
26000
42256
59008
75792
92528
109232
125936
142672
159392
176160
After:
9264
9504
9808
10000
10128
10224
10352
10544
10704
10896
The test fails when RGENGC_CHECK_MODE is turned on:
1) Failure:
TestSymbol#test_inspect_under_gc_compact_stress [test/ruby/test_symbol.rb:123]:
<":testing"> expected but was
<":\x00\x00\x00\x00\x00\x00\x00">.
The test fails when RGENGC_CHECK_MODE is turned on:
TestString#test_sub_gc_compact_stress = 9.42 s
1) Failure:
TestString#test_sub_gc_compact_stress [test/ruby/test_string.rb:2089]:
<"aaa [amp] yyy"> expected but was
<"aaa [] yyy">.
Embedded shared strings cannot be moved because strings point into the
slot of the shared string. There may be code using the RSTRING_PTR on
the stack, which would pin the string but not pin the shared string,
causing it to move.
`String#+@` is 2-3 times faster than `String#dup` because it can
directly go through `rb_str_dup` instead of using the generic
much slower `rb_obj_dup`.
This fact led to the existance of the ugly `Performance/UnfreezeString`
rubocop performance rule that encourage users to rewrite the much
more readable and convenient `"foo".dup` into the ugly `(+"foo")`.
Let's make that rubocop rule useless.
```
compare-ruby: ruby 3.3.0dev (2023-11-20T02:02:55Z master 701b0650de) [arm64-darwin22]
last_commit=[ruby/prism] feat: add encoding for IBM865 (https://github.com/ruby/prism/pull/1884)
built-ruby: ruby 3.3.0dev (2023-11-20T12:51:45Z faster-str-lit-dup 6b745bbc5d) [arm64-darwin22]
warming up..
| |compare-ruby|built-ruby|
|:------|-----------:|---------:|
|uplus | 16.312M| 16.332M|
| | -| 1.00x|
|dup | 5.912M| 16.329M|
| | -| 2.76x|
```
Some code out there blind calls `force_encoding` without checking
what the original encoding was, which clears the coderange uselessly.
If the String is big, it can be a rather costly mistake.
For instance the `rack-utf8_sanitizer` gem does this on request
bodies.
Previously we used the next character following the found prefix to
determine if the match ended on a broken character.
This had caused surprising behaviour when a valid character was followed
by a UTF-8 continuation byte.
This commit changes the behaviour to instead look for the end of the
last character in the prefix.
[Bug #19784]
Co-authored-by: ywenc <ywenc@github.com>
Co-authored-by: Nobuyoshi Nakada <nobu@ruby-lang.org>
Previously, the following crashed due to use-after-free
with AArch64 Alpine Linux 3.18.3 (aarch64-linux-musl):
```ruby
str = 'a' * (32*1024*1024)
p({z: str})
```
32 MiB is the default for `GC_MALLOC_LIMIT_MAX`, and the crash
could be dodged by setting `RUBY_GC_MALLOC_LIMIT_MAX` to large values.
Under a debugger, one can see the `str2` of rb_str_buf_append()
getting prematurely collected while str_buf_cat4() allocates capacity.
Add GC guards so the buffer of `str2` lives across the GC run
initiated in str_buf_cat4().
[Bug #19792]
Leave callers to convert byte index to char index, as well as
`rb_str_index`, so that `rb_str_rpartition` does not need to
re-convert char index to byte index.
