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.
