If __builtin_assume() is enables and RUBY_DEBUG=0, RUBY_ASSERT(expr)
will be compiled to __builtin_assume(expr) and compiler can assume
expr is true and apply aggressive optimizations. However we observed
doubtful behavior because of compiler optimizations, we introduce
new macro RUBY_ASSERT_NOASSUME to disable __builtin_assume().
With this macro, we can try without __builtin_assume().
Assertions in header files slows down an interpreter, so they should be
turned off by default (simple `make`). To enable them, define a macro
`RUBY_DEBUG=1` (e.g. `make cppflags=-DRUBY_DEBUG` or use `#define` at
the very beggining of the file. Note that even if `NDEBUG=1` is defined,
`RUBY_DEBUG=1` enables all assertions.
[Feature #16837]
related: https://github.com/ruby/ruby/pull/3120
`assert()` lines in MRI *.c is not disabled even if `RUBY_DEBUG=0` and
it can be disabled with `NDEBUG=1`. So please consider to use
`RUBY_ASSERT()` if you want to disable them when `RUBY_DEBUG=0`.
We observed combination of multiple __builtin_assume() can cause
strange compile results on clang-6 (-DNDEBUG exposed this issue).
To avoid this problem, __builtin_assume() is from clang-7.
https://github.com/ruby/ruby/pull/3120#issuecomment-630821333
https://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html says:
> GCC never returns 1 when you call the inline function with a string
> constant or ...
Because rb_str_new and familiy take string constants, it was a bad idea
for them to contain RB_CONSTANT_P. We should instead do so in
corresponding macros. [ruby-core:98212]
[Bug #16465] [Bug #16801]
[Fix GH-2795] [Fix GH-2944] [Fix GH-3045] [Fix GH-3093]
Note: Backporting shouldn't modify object.h and instead can use
struct_new_kw which is basically a duplicate implementation of
rb_class_new_instance_pass_kw
Co-authored-by: Yusuke Endoh <mame@ruby-lang.org>
Co-authored-by: John Hawthorn <john@hawthorn.email>
Co-authored-by: Adam Hess <HParker@github.com>
Co-authored-by: Jose Cortinas <jacortinas@gmail.com>
Co-authored-by: Jean Boussier <jean.boussier@gmail.com>
As zero variadic macro argument, `rb_scan_args(argc, argv, "")`
(or `"0"`), means 0-arity method and should be defined so, that
case doesn't need to consider.
It seems gcc prior to 5 suffered from preprocessor bug. We have to
provide workarounds.
See https://github.com/ruby/ruby/runs/591138012
----
Here is something interesting. According to C99, strictly speaking,
the gcc behaviour was in fact legal(!) and everything else were
wrong. This was not a bug of gcc, rather a bug of the ISO C Standard.
This defect was reported to the committee as DR#412, and fixed
accordingly. All tested compilers now conform C17's updated
preprocessor description.
See http://www.open-std.org/JTC1/SC22/WG14/www/docs/dr_412.htm
This reverts commit 443389effc.
This reverts commit d94960f22e.
Inclusion of header files must be explicit. Every file shall directly
include what is necessary.
https://github.com/include-what-you-use/include-what-you-use says:
> When every file includes what it uses, then it is possible to edit any
> file and remove unused headers, without fear of accidentally breaking
> the upwards dependencies of that file. It also becomes easy to
> automatically track and update dependencies in the source code.
Though we don't use iwyu itself, the principle quoted above is a good
thing that we can agree.
Now that include guards were added to every and all of the headers
inside of our project this changeset does not increase compile time, at
least on my machine.
According to MSVC manual (*1), cl.exe can skip including a header file
when that:
- contains #pragma once, or
- starts with #ifndef, or
- starts with #if ! defined.
GCC has a similar trick (*2), but it acts more stricter (e. g. there
must be _no tokens_ outside of #ifndef...#endif).
Sun C lacked #pragma once for a looong time. Oracle Developer Studio
12.5 finally implemented it, but we cannot assume such recent version.
This changeset modifies header files so that each of them include
strictly one #ifndef...#endif. I believe this is the most portable way
to trigger compiler optimizations. [Bug #16770]
*1: https://docs.microsoft.com/en-us/cpp/preprocessor/once
*2: https://gcc.gnu.org/onlinedocs/cppinternals/Guard-Macros.html
Revert "Revert "include/ruby/3/core/rtypeddata.h: Use 0 instead of NULL for C++ compiler""
Revert "include/ruby/3/core/rtypeddata.h: Use 0 instead of NULL for C++ compiler"
Revert "include/ruby/3: Skip RUBY3_UNREACHABLE_RETURN for icc"
Revert "include/ruby/3: Stop RUBY3_UNREACHABLE_RETURN to suppress a SunC warning"
This reverts commit b965e7e05e.
This reverts commit d2bb2e066b.
This reverts commit 8ab4c55e7a.
This reverts commit 78eec3cdc5.
After https://github.com/ruby/ruby/pull/3011, we no longer need these
ifdef guards.
icc warns at this line.
> include/ruby/3/core/rstring.h(126): warning #413: variable "retval" has an uninitialized const field
> struct RString retval;
> ^
This must not be a problem because uninitialized const field is not used
at all. But the warnings are annoying. Let us suppress them.
icc warns side effects for RUBY3_ASSUME like this:
> ./include/ruby/3/value_type.h(202): warning #2261: __assume expression with side effects discarded
> RUBY3_ASSUME(RB_FLONUM_P(obj));
> ^
Which is a false positive (RB_FLONUM_P has no side effect). It seems
there is no way for us to tell icc that a functin is safe inside of
__assume. Just suppress the warning instead.
Without this patch, 20k files are opened (openat syscall) because
of duplicate includes. This patch reduced it to 3k and build time
was reduced compile time of range.o from 15sec -> 3sec on my machine.
[Bug #16772]
This reverts commit d2bb2e066b.
It didn't work:
https://rubyci.org/logs/rubyci.s3.amazonaws.com/icc-x64/ruby-master/log/20200409T050004Z.log.html.gz#end
```
In file included from ../../.././include/ruby/3/core.h(32),
from ../../.././include/ruby/ruby.h(28),
from ../../.././include/ruby.h(33),
from init.c(1):
../../.././include/ruby/3/core/rtypeddata.h(164): warning #967: conversion from "int" to "const struct rb_data_type_struct *"; sizes do not match
RUBY3_UNREACHABLE_RETURN(0);
```
I'm unsure why, but it fails on icc.
https://rubyci.org/logs/rubyci.s3.amazonaws.com/icc-x64/ruby-master/log/20200408T220004Z.log.html.gz
```
In file included from ../../.././include/ruby/3/core.h(32),
from ../../.././include/ruby/ruby.h(28),
from cxxanyargs.cpp(1):
../../.././include/ruby/3/core/rtypeddata.h(163): error: return value type does not match the function type
RUBY3_UNREACHABLE_RETURN(NULL);
```
I don't find how to suppress a false positive "unreachable" warning of
the Sun compiler:
```
"./include/ruby/3/core/rtypeddata.h", line 163: warning: statement not
reached
"./include/ruby/3/memory.h", line 256: warning: statement not reached
```
This warnings make mkmf test fail:
https://rubyci.org/logs/rubyci.s3.amazonaws.com/solaris10-sunc/ruby-master/log/20200408T170004Z.fail.html.gz
```
1) Failure:
TestMkmf::TestConvertible#test_typeof_builtin
[/export/home/users/chkbuild/cb-sunc/tmp/build/20200408T170004Z/ruby/test/mkmf/test_convertible.rb:9]:
convertible_int: checking for convertible type of short...
-------------------- short
--------------------
convertible_int: checking for convertible type of int...
-------------------- int
--------------------
convertible_int: checking for convertible type of long...
-------------------- long
--------------------
convertible_int: checking for convertible type of signed short...
-------------------- failed
...
"cc -I.
-I/export/home/users/chkbuild/cb-sunc/tmp/build/20200408T170004Z/ruby/.ext/include/sparc-solaris2.10
-I/export/home/users/chkbuild/cb-sunc/tmp/build/20200408T170004Z/ruby/include
-I./test -I/opt/csw/include -D_XOPEN_SOURCE=600 -DFFI_NO_RAW_API -g
-c conftest.c"
"/export/home/users/chkbuild/cb-sunc/tmp/build/20200408T170004Z/ruby/include/ruby/3/core/rtypeddata.h",
line 163: warning: statement not reached
"/export/home/users/chkbuild/cb-sunc/tmp/build/20200408T170004Z/ruby/include/ruby/3/memory.h",
line 256: warning: statement not reached
checked program was:
/* begin */
1: #include "ruby.h"
2:
3: typedef signed short rbcv_typedef_;
4:
5: extern rbcv_typedef_ foo();
6: extern short foo();
/* end */
```
RUBY3_CAST is a macro to suppress g++/clang++ warnings about C-style
casts. Though Ruby core don't have to bother C++ situations, extension
libraries can benefit from this.
Samuel Williams
卜部昌平
Koichi Sasada
Nobuyoshi Nakada
Marc-Andre Lafortune
Jeremy Evans
Kazuhiro NISHIYAMA
Yusuke Endoh