Bug #14425: rb_funcall too strict on extra args

• Status: Closed
• Assignee: -
• Target version: -
• Backport: 2.3: DONTNEED, 2.4: DONTNEED, 2.5: DONE

[normalperson (Eric Wong)]

Ruby 2.5 instroduces extra checking for rb_funcall checking,
but apparently it is too strict for some compilers and extra
args should not cause fatal problems (only warnings).

Jeremy first reported this to me in:
https://bogomips.org/kgio-public/[e-mail]/
but there's apparently hundreds of instances on RubyGems.org alone.

Attached are over 500 gem-codesearch results of latest gems.

/me goes to setup a sid chroot again...

[normalperson (Eric Wong)]

• Backport changed from 2.3: UNKNOWN, 2.4: UNKNOWN, 2.5: UNKNOWN to 2.3: DONTNEED, 2.4: DONTNEED, 2.5: REQUIRED

[normalperson (Eric Wong)]

• File 0001-ruby.h-relax-rb_funcall-check-on-extra-args-for-clan.patch 0001-ruby.h-relax-rb_funcall-check-on-extra-args-for-clan.patch added

• Status changed from Open to Closed

Applied in changeset trunk|r62116.

---

ruby.h: relax rb_funcall check on extra args for clang

clang 5.+ (tested clang 7.0.0) seems to be attempting division-by-zero
and giving a very large number for static args to rb_funcall.

• include/ruby/ruby.h (rb_varargs_bad_length): relax check for clang
• ext/-test-/funcall/funcall.c: renamed from passing_block.c
  define extra_args_name function
• test/-ext-/funcall/test_funcall.rb: new test
  [ruby-core:85266] [Bug #14425]

From: Eric Wong [e-mail]

[mame (Yusuke Endoh)]

normalperson (Eric Wong) wrote:

Attached are over 500 gem-codesearch results of latest gems.

nitpick: Your query includes rb_funcall2, rb_funcall3, and rb_funcallv which are safe to pass "0, 0".

[normalperson (Eric Wong)]

[e-mail] wrote:

normalperson (Eric Wong) wrote:

Attached are over 500 gem-codesearch results of latest gems.

nitpick: Your query includes rb_funcall2, rb_funcall3, and rb_funcallv which are safe to pass "0, 0".

Oops :x

Btw, I guess this is undefined behavior?
In a standalone case, gcc prints "0", clang prints a randomly high
number. I expected compilation to fail with both compilers.

/* $CC -O2 -Wextra -Wall -o divzero /path/to/this/file.c */
#include <stdio.h>
int main(void)
{
	int a = 0;
	int b = 1;
	int c = a / (a == b);

	printf("%d\n", c);
	return 0;
}

[naruse (Yui NARUSE)]

• Backport changed from 2.3: DONTNEED, 2.4: DONTNEED, 2.5: REQUIRED to 2.3: DONTNEED, 2.4: DONTNEED, 2.5: DONE

ruby_2_5 r62501 merged revision(s) 62116,62151.