This patch removes the `VALUE flags` member from the `rb_ast_t` structure making `rb_ast_t` no longer an IMEMO object.
## Background
We are trying to make the Ruby parser generated from parse.y a universal parser that can be used by other implementations such as mruby.
To achieve this, it is necessary to exclude VALUE and IMEMO from parse.y, AST, and NODE.
## Summary (file by file)
- `rubyparser.h`
- Remove the `VALUE flags` member from `rb_ast_t`
- `ruby_parser.c` and `internal/ruby_parser.h`
- Use TypedData_Make_Struct VALUE which wraps `rb_ast_t` `in ast_alloc()` so that GC can manage it
- You can retrieve `rb_ast_t` from the VALUE by `rb_ruby_ast_data_get()`
- Change the return type of `rb_parser_compile_XXXX()` functions from `rb_ast_t *` to `VALUE`
- rb_ruby_ast_new() which internally `calls ast_alloc()` is to create VALUE vast outside ruby_parser.c
- `iseq.c` and `vm_core.h`
- Amend the first parameter of `rb_iseq_new_XXXX()` functions from `rb_ast_body_t *` to `VALUE`
- This keeps the VALUE of AST on the machine stack to prevent being removed by GC
- `ast.c`
- Almost all change is replacement `rb_ast_t *ast` with `VALUE vast` (sorry for the big diff)
- Fix `node_memsize()`
- Now it includes `rb_ast_local_table_link`, `tokens` and script_lines
- `compile.c`, `load.c`, `node.c`, `parse.y`, `proc.c`, `ruby.c`, `template/prelude.c.tmpl`, `vm.c` and `vm_eval.c`
- Follow-up due to the above changes
- `imemo.{c|h}`
- If an object with `imemo_ast` appears, considers it a bug
Co-authored-by: Nobuyoshi Nakada <nobu@ruby-lang.org>
Previously it would bypass the `FL_ABLE` check, but
since shapes introduction, it started having a different
behavior than `OBJ_FREEZE`, as it would onyl set the `FL_FREEZE`
flag, but not update the shape.
I have no indication of this causing a bug yet, but it seems
like a trap waiting to happen.
This patch is part of universal parser work.
## Summary
- Decouple VALUE from members below:
- `(struct parser_params *)->debug_lines`
- `(rb_ast_t *)->body.script_lines`
- Instead, they are now `rb_parser_ary_t *`
- They can also be a `(VALUE)FIXNUM` as before to hold line count
- `ISEQ_BODY(iseq)->variable.script_lines` remains VALUE
- In order to do this,
- Add `VALUE script_lines` param to `rb_iseq_new_with_opt()`
- Introduce `rb_parser_build_script_lines_from()` to convert `rb_parser_ary_t *` into `VALUE`
## Other details
- Extend `rb_parser_ary_t *`. It previously could only store `rb_parser_ast_token *`, now can store script_lines, too
- Change tactics of building the top-level `SCRIPT_LINES__` in `yycompile0()`
- Before: While parsing, each line of the script is added to `SCRIPT_LINES__[path]`
- After: After `yyparse(p)`, `SCRIPT_LINES__[path]` will be built from `p->debug_lines`
- Remove the second parameter of `rb_parser_set_script_lines()` to make it simple
- Introduce `script_lines_free()` to be called from `rb_ast_free()` because the GC no longer takes care of the script_lines
- Introduce `rb_parser_string_deep_copy()` in parse.y to maintain script_lines when `rb_ruby_parser_free()` called
- With regard to this, please see *Future tasks* below
## Future tasks
- Decouple IMEMO from `rb_ast_t *`
- This lifts the five-members-restriction of Ruby object,
- So we will be able to move the ownership of the `lex.string_buffer` from parser to AST
- Then we remove `rb_parser_string_deep_copy()` to make the whole thing simple
Additional flags are comma separated list preceeded by `-` or `+`.
Before:
```sh
$ ruby --dump=insns+without_opt
```
After:
```sh
$ ruby --dump=insns-opt,-optimize
```
At the same time, `parsetree_with_comment` is split to `parsetree`
option and additional `comment` flag.
Before:
```sh
$ ruby --dump=parsetree_with_comment
```
After:
```sh
$ ruby --dump=parsetree,+comment
```
Also flags can be separate `--dump`.
```sh
$ ruby --dump=parsetree --dump=+comment --dump=+error_tolerant
```
Ineffective flags are ignored silently.
```sh
$ ruby --dump=parsetree --dump=+comment --dump=+error_tolerant
```
This patch suggests relocating the code dealing with `SCRIPT_LINES__` from ast.c to ruby_parser.c.
## Background
- I guess `AbstractSyntaxTree.of` method used to use `SCRIPT_LINES__` internally for some reason before
- However, now it appears `SCRIPT_LINES__` is no longer used meaningfully by the method
- As evidence of this, (and as my patch shows,) removing the function call of `rb_script_lines_for()` from `ast_s_of()` does not affect the result of `test/ruby/test_ast.rb`
Given the above, I think two possibilities can be considered:
- (A) `AbstractSyntaxTree.of` has not needed `SCRIPT_LINES__` already (I pick this)
- (B) We lack a test case of `AbstractSyntaxTree.of` that needs to use `SCRIPT_LINES__`
## Besides,
The current implementation causes strange behavior:
```console
ruby -e"SCRIPT_LINES__ = {__FILE__ => []}; puts RubyVM::AbstractSyntaxTree.of(->{ 1 + 2 }, keep_script_lines: true).script_lines"
=> `-e:1:in '<main>': undefined method 'script_lines' for nil (NoMethodError)`
```
I think this is a bug because `AbstractSyntaxTree.of` is not supposed to return `nil` even in this case.
This happens due to the ast.c's dependence on `SCRIPT_LINES__`.
And at the end of the `ast_s_of()`, `node_find()` can not find the target child node obviously because it doesn't make sense to look for a corresponding node made from the parameter of `AbstractSyntaxTree.of` in the AST tree made from the value of `{__FILE__ => []}`
## Solution
Since I think it's good enough `SCRIPT_LINES__` to be only referred by ruby.c, I chose the possibility "(A)" and wrote this patch which moves `rb_script_lines_for()` from ast.c to ruby_parser.c.
So as the result:
- `ast_s_of()` function no longer look up `SCRIPT_LINES__`
- Even so, this patched code passes the existing tests
- The strange behavior above no longer happens (I also added a test for it)
Please correct me if I miss something🙏
[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>
In preparation for https://bugs.ruby-lang.org/issues/20205.
The `frozen_string_literal` compilation option will no longer
be a boolean but a tri-state: `on/off/default`.
The following parts will not be shown for `-h` option. And not to
reach 80 columns. Some terminal emulators (Windows command prompt at
least) wrap the cursor to the next line when reaching the rightmost
column, before exceeding.
This `st_table` is used to both mark and pin classes
defined from the C API. But `vm->mark_object_ary` already
does both much more efficiently.
Currently a Ruby process starts with 252 rooted classes,
which uses `7224B` in an `st_table` or `2016B` in an `RArray`.
So a baseline of 5kB saved, but since `mark_object_ary` is
preallocated with `1024` slots but only use `405` of them,
it's a net `7kB` save.
`vm->mark_object_ary` is also being refactored.
Prior to this changes, `mark_object_ary` was a regular `RArray`, but
since this allows for references to be moved, it was marked a second
time from `rb_vm_mark()` to pin these objects.
This has the detrimental effect of marking these references on every
minors even though it's a mostly append only list.
But using a custom TypedData we can save from having to mark
all the references on minor GC runs.
Addtionally, immediate values are now ignored and not appended
to `vm->mark_object_ary` as it's just wasted space.
Before this commit, we were mixing a lot of concerns with the prism
compile between RubyVM::InstructionSequence and the general entry
points to the prism parser/compiler.
This commit makes all of the various prism-related APIs mirror
their corresponding APIs in the existing parser/compiler. This means
we now have the correct frame naming, and it's much easier to follow
where the logic actually flows. Furthermore this consolidates a lot
of the prism initialization, making it easier to see where we could
potentially be raising errors.
[Bug #20071]
Currently Ruby crashes when the --parser=prism flag is used either with
no input, or with input that is being redirected from stdin. So all of
the following will crash
ruby --parser=prism
ruby --parser=prism < test_code.rb
cat test_code.rb | ruby --parser=prism
This commit checks whether the input is assumed to be from stdin, and
then processes that as a file.
This will fix the second and third case above, but will cause a slight
behavioural changes for the first case - Ruby will treat stdin as an
empty file in this case and exit, rather than waiting for data to be
piped into stdin.
HASUMI Hitoshi
Kevin Newton
Jean Boussier
Nobuyoshi Nakada
Étienne Barrié
Takashi Kokubun
Burdette Lamar
Yusuke Endoh
Matt Valentine-House
HParker
Aaron Patterson