The GC will not disassemble incomplete instruction sequences. So it is
important that when instructions are being assembled, any objects the
instructions point at should not be moved.
This patch implements a fixed width array that pins its references.
When the instructions are done being assembled, the pinning array goes
away and the objects inside the iseqs are allowed to move.
With compiling `CPDEBUG >= 2`, `rb_iseq_disasm` segfaults if this
table has not been created. Also `ibf_load_iseq_each` calls
`rb_iseq_insns_info_encode_positions`.
Accessing past the end of an array is technically UB. Use C99 flexible
array member instead to avoid the UB and simplify allocation size
calculation.
See also: DCL38-C in the SEI CERT C Coding Standard
Previously, passing a keyword splat to a method always allocated
a hash on the caller side, and accepting arbitrary keywords in
a method allocated a separate hash on the callee side. Passing
explicit keywords to a method that accepted a keyword splat
did not allocate a hash on the caller side, but resulted in two
hashes allocated on the callee side.
This commit makes passing a single keyword splat to a method not
allocate a hash on the caller side. Passing multiple keyword
splats or a mix of explicit keywords and a keyword splat still
generates a hash on the caller side. On the callee side,
if arbitrary keywords are not accepted, it does not allocate a
hash. If arbitrary keywords are accepted, it will allocate a
hash, but this commit uses a callinfo flag to indicate whether
the caller already allocated a hash, and if so, the callee can
use the passed hash without duplicating it. So this commit
should make it so that a maximum of a single hash is allocated
during method calls.
To set the callinfo flag appropriately, method call argument
compilation checks if only a single keyword splat is given.
If only one keyword splat is given, the VM_CALL_KW_SPLAT_MUT
callinfo flag is not set, since in that case the keyword
splat is passed directly and not mutable. If more than one
splat is used, a new hash needs to be generated on the caller
side, and in that case the callinfo flag is set, indicating
the keyword splat is mutable by the callee.
In compile_hash, used for both hash and keyword argument
compilation, if compiling keyword arguments and only a
single keyword splat is used, pass the argument directly.
On the caller side, in vm_args.c, the callinfo flag needs to
be recognized and handled. Because the keyword splat
argument may not be a hash, it needs to be converted to a
hash first if not. Then, unless the callinfo flag is set,
the hash needs to be duplicated. The temporary copy of the
callinfo flag, kw_flag, is updated if a hash was duplicated,
to prevent the need to duplicate it again. If we are
converting to a hash or duplicating a hash, we need to update
the argument array, which can including duplicating the
positional splat array if one was passed. CALLER_SETUP_ARG
and a couple other places needs to be modified to handle
similar issues for other types of calls.
This includes fairly comprehensive tests for different ways
keywords are handled internally, checking that you get equal
results but that keyword splats on the caller side result in
distinct objects for keyword rest parameters.
Included are benchmarks for keyword argument calls.
Brief results when compiled without optimization:
def kw(a: 1) a end
def kws(**kw) kw end
h = {a: 1}
kw(a: 1) # about same
kw(**h) # 2.37x faster
kws(a: 1) # 1.30x faster
kws(**h) # 2.19x faster
kw(a: 1, **h) # 1.03x slower
kw(**h, **h) # about same
kws(a: 1, **h) # 1.16x faster
kws(**h, **h) # 1.14x faster
Previously, method call keyword splats and hash keyword splats
were compiled exactly the same. This is because parse-wise, they
operate on indentical nodes when it comes to compiling the **{}.
Fix this by using an ugly hack of temporarily modifying the
nd_brace flag in the method call keyword splat case. Inside
compile_hash, only optimize the **{} case for hashes where the
nd_brace flag has been modified to reflect we are in the method
call keyword splat case and it is safe to do so.
Since compile_keyword_args is only called in one place, move the
keyword_node_p call out of that method to the single caller to
avoid duplicating the code.
This patch contains several ideas:
(1) Disposable inline method cache (IMC) for race-free inline method cache
* Making call-cache (CC) as a RVALUE (GC target object) and allocate new
CC on cache miss.
* This technique allows race-free access from parallel processing
elements like RCU.
(2) Introduce per-Class method cache (pCMC)
* Instead of fixed-size global method cache (GMC), pCMC allows flexible
cache size.
* Caching CCs reduces CC allocation and allow sharing CC's fast-path
between same call-info (CI) call-sites.
(3) Invalidate an inline method cache by invalidating corresponding method
entries (MEs)
* Instead of using class serials, we set "invalidated" flag for method
entry itself to represent cache invalidation.
* Compare with using class serials, the impact of method modification
(add/overwrite/delete) is small.
* Updating class serials invalidate all method caches of the class and
sub-classes.
* Proposed approach only invalidate the method cache of only one ME.
See [Feature #16614] for more details.
Now, rb_call_info contains how to call the method with tuple of
(mid, orig_argc, flags, kwarg). Most of cases, kwarg == NULL and
mid+argc+flags only requires 64bits. So this patch packed
rb_call_info to VALUE (1 word) on such cases. If we can not
represent it in VALUE, then use imemo_callinfo which contains
conventional callinfo (rb_callinfo, renamed from rb_call_info).
iseq->body->ci_kw_size is removed because all of callinfo is VALUE
size (packed ci or a pointer to imemo_callinfo).
To access ci information, we need to use these functions:
vm_ci_mid(ci), _flag(ci), _argc(ci), _kwarg(ci).
struct rb_call_info_kw_arg is renamed to rb_callinfo_kwarg.
rb_funcallv_with_cc() and rb_method_basic_definition_p_with_cc()
is temporary removed because cd->ci should be marked.
This behavior was deprecated in 2.7 and scheduled to be removed
in 3.0.
Calling yield in a class definition outside a method is now a
SyntaxError instead of a LocalJumpError, as well.
We were inefficient in cases where there are a lot of duplicates due to
the use of linear search. Use a hash table instead.
These cases are not that rare in the wild.
[Feature #16505]
Saves comitters' daily life by avoid #include-ing everything from
internal.h to make each file do so instead. This would significantly
speed up incremental builds.
We take the following inclusion order in this changeset:
1. "ruby/config.h", where _GNU_SOURCE is defined (must be the very
first thing among everything).
2. RUBY_EXTCONF_H if any.
3. Standard C headers, sorted alphabetically.
4. Other system headers, maybe guarded by #ifdef
5. Everything else, sorted alphabetically.
Exceptions are those win32-related headers, which tend not be self-
containing (headers have inclusion order dependencies).
On USE_LAZY_LOAD=1, the iseq should be loaded. So rb_iseq_check()
is needed. Furthermore, now lazy loading with builtin_function_table
is not supported, so it should cancel lazy loading.
`foo(*rest, post, **empty_kw)` is compiled like
`foo(*rest + [post, **empty_kw])`, and `**empty_kw` is removed by
"newarraykwsplat" instruction.
However, the method call still has a flag of KW_SPLAT, so "post" is
considered as a keyword hash, which caused a segfault.
Note that the flag cannot be removed if "empty_kw" is not always empty.
This change fixes the issue by compiling arguments with "newarray"
instead of "newarraykwsplat".
[Bug #16442]
Now, C functions written by __builtin_cexpr!(code) and others are
named as "__builtin_inline#{n}". However, it is difficult to know
what the function is. This patch rename them into
"__builtin_foo_#{lineno}" when cexpr! is in 'foo' method.
%p is for void *. Becuase fprintf is a function with variadic arguments
automatic cast from any pointer to void * does not work. We have to be
explicit.
(This is the second try of 036bc1da6c6c9b0fa9b7f5968d897a9554dd770e.)
If iseq is GC'ed, the pointer of iseq may be reused, which may hide a
deprecation warning of keyword argument change.
http://ci.rvm.jp/results/trunk-test1@phosphorus-docker/2474221
```
1) Failure:
TestKeywordArguments#test_explicit_super_kwsplat [/tmp/ruby/v2/src/trunk-test1/test/ruby/test_keyword.rb:549]:
--- expected
+++ actual
@@ -1 +1 @@
-/The keyword argument is passed as the last hash parameter.* for `m'/m
+""
```
This change ad-hocly adds iseq_unique_id for each iseq, and use it
instead of iseq pointer. This covers the case where caller is GC'ed.
Still, the case where callee is GC'ed, is not covered.
But anyway, it is very rare that iseq is GC'ed. Even when it occurs, it
just hides some warnings. It's no big deal.
This commit introduces an "inline ivar cache" struct. The reason we
need this is so compaction can differentiate from an ivar cache and a
regular inline cache. Regular inline caches contain references to
`VALUE` and ivar caches just contain references to the ivar index. With
this new struct we can easily update references for inline caches (but
not inline var caches as they just contain an int)
jump-jump optimization ignores the event flags of the jump instruction
being skipped, which leads to overlook of line events.
This changeset stops the wrong optimization when coverage measurement is
neabled and when the jump instruction has any event flag.
Note that this issue is not only for coverage but also for TracePoint,
and this change does not fix TracePoint.
However, fixing it fundamentally is tough (which requires revamp of
the compiler). This issue is critical in terms of coverage measurement,
but minor for TracePoint (ko1 said), so we here choose a stopgap
measurement.
[Bug #15980] [Bug #16397]
Note for backporters: this changeset can be viewed by `git diff -w`.
rename __builtin_inline!(code) to __builtin_cstmt(code).
Also this commit introduce the following inlining C code features.
* __builtin_cstmt!(STMT)
(renamed from __builtin_inline!)
Define a function which run STMT implicitly and call this function at
evatuation time. Note that you need to return some value in STMT.
If there is a local variables (includes method parameters), you can
read these values.
static VALUE func(ec, self) {
VALUE x = ...;
STMT
}
Usage:
def double a
# a is readable from C code.
__builtin_cstmt! 'return INT2FIX(FIX2INT(a) * 2);'
end
* __builtin_cexpr!(EXPR)
Define a function which invoke EXPR implicitly like `__builtin_cstmt!`.
Different from cstmt!, which compiled with `return EXPR;`.
(`return` and `;` are added implicitly)
static VALUE func(ec, self) {
VALUE x = ...;
return EXPPR;
}
Usage:
def double a
__builtin_cexpr! 'INT2FIX(FIX2INT(a) * 2)'
end
* __builtin_cconst!(EXPR)
Define a function which invoke EXPR implicitly like cexpr!.
However, the function is called once at compile time, not evaluated time.
Any local variables are not accessible (because there is no local variable
at compile time).
Usage:
GCC = __builtin_cconst! '__GNUC__'
* __builtin_cinit!(STMT)
STMT are writtein in auto-generated code.
This code does not return any value.
Usage:
__builtin_cinit! '#include <zlib.h>'
def no_compression?
__builtin_cconst! 'Z_NO_COMPRESSION ? Qtrue : Qfalse'
end
Nobuyoshi Nakada
Koichi Sasada
Aaron Patterson
卜部昌平
Kazuki Tsujimoto
Alan Wu
Jeremy Evans
Masataka Pocke Kuwabara
NagayamaRyoga
Seiei Miyagi
Yusuke Endoh