On 2020-11-21 07:22, Brian C. Lane wrote:
On Mon, Nov 16, 2020 at 03:39:58PM -0500, Phillip Susi wrote:
Brian C. Lane writes:
From: Shin'ichiro Kawasaki <[email protected]>
GCC 8 suggests to add 'pure' attribute to a number of functions but the
warnings might be false positive. The suggested functions have PED_ASSERT
macro which may call abort() function. One of the functions
fat_table_get() calls exit() function also. Once abort() or exit()
If that is true then we need to remove that exit() call. As a library,
libparted should not be calling exit().
I think we should wait until after this release. It's buried down in the
fat resize code and appears to be there because it doesn't have a good
way to indicate an error. It may require a change to the public API in
order to clean it up.
called, the program execution stops. It is controversial if the functions
are pure or not, and consequence of compiler optimization with the pure
attribute is not explicit.
Doesn't "pure" mean that it does not modify any variables with static
storage duration, so the caller can assume that any variables it has
already loaded into registers that are preserved across the call do not
need to be reloaded? If so, then it should be perfectly safe to assume
that abort() or exit() are pure.
I agree, the functions all only depend on what's passed to them for
their return value and the assert decision so behavior should be exactly
the same.
Okay, this discussion clarifies what is expected to the pure functions with
assertions.
I confirmed Brian already added the pure attributes to the function in the
branch. Thank you!
--
Best Regards,
Shin'ichiro Kawasaki
With this unclear situation, I suggest not to add _GL_ATTRIBUTE_PURE to
the functions. Instead, I suggest to avoid the warning message using GCC
pragma 'diagnostic ignored' pragma, which disables specific GCC warnings
only for target functions.
The pragma needs protected so that it is only used with gcc and not if
you are using a different compiler that does not understand that pragma.
I dropped that patch and added pure to those functions so that no longer
matters.
Is anyone using llvm (or something else) to build parted? And is that
something that we really want to encourage? Seems simpler if we just say
'use gcc'.
Brian
