On Mon, Sep 21, 2020 at 04:29:10PM -0500, Eric Blake wrote:
> On 9/21/20 11:23 AM, Stefan Hajnoczi wrote:
Thanks for the review! Your feedback prompted me to do this more
systematically. I fixed the command-lines and published a diff of just
the manual changes I made on top of the mechanical changes (see v2).
> > clang's C11 atomic_fetch_*() functions only take a C11 atomic type
> > pointer argument. QEMU uses direct types (int, etc) and this causes a
> > compiler error when a QEMU code calls these functions in a source file
> > that also included <stdatomic.h> via a system header file:
> >
> > $ CC=clang CXX=clang++ ./configure ... && make
> > ../util/async.c:79:17: error: address argument to atomic operation must be a pointer to _Atomic type ('unsigned int *' invalid)
> >
> > Avoid using atomic_*() names in QEMU's atomic.h since that namespace is
> > used by <stdatomic.h>. Prefix QEMU's APIs with qemu_ so that atomic.h
> > and <stdatomic.h> can co-exist.
> >
> > This patch was generated using:
> >
> > $ git diff | grep -o '\<atomic_[a-z0-9_]\+' | sort -u >/tmp/changed_identifiers
>
> Missing a step in the recipe: namely, you probably modified
> include/qemu/atomic*.h prior to running 'git diff' (so that you actually had
> input to feed to grep -o). But spelling it 'git diff HEAD^
> include/qemu/atomic*.h | ...' does indeed give me a sane list of identifiers
> that looks like what you touched in the rest of the patch.
Yes, I edited the file first and then used this command-line. The one
you posted it better :).
>
> > $ for identifier in $(</tmp/changed_identifiers64); do \
>
> Also not quite the right recipe, based on the file name used in the line
> above.
Yes, "64" is when I realized the original grep expression hadn't matched
the atomic64 APIs.
These commands only show the gist of it. It involved a few manual steps.
>
> > sed -i "s%\<$identifier\>%qemu_$identifier%" $(git grep -l "\<$identifier\>") \
> > done
> >
>
> Fortunately, running "git grep -c '\<atomic_[a-z0-9_]\+'" on the pre-patch
> state of the tree gives me a list that is somewhat close to yours, where the
> obvious difference in line counts is explained by:
>
> > I manually fixed line-wrap issues and misaligned rST tables.
> >
> > Signed-off-by: Stefan Hajnoczi <stefanha@xxxxxxxxxx>
> > ---
>
> First, focusing on the change summary:
>
> > docs/devel/lockcnt.txt | 14 +-
> > docs/devel/rcu.txt | 40 +--
> > accel/tcg/atomic_template.h | 20 +-
> > include/block/aio-wait.h | 4 +-
> > include/block/aio.h | 8 +-
> > include/exec/cpu_ldst.h | 2 +-
> > include/exec/exec-all.h | 6 +-
> > include/exec/log.h | 6 +-
> > include/exec/memory.h | 2 +-
> > include/exec/ram_addr.h | 27 +-
> > include/exec/ramlist.h | 2 +-
> > include/exec/tb-lookup.h | 4 +-
> > include/hw/core/cpu.h | 2 +-
> > include/qemu/atomic.h | 258 +++++++-------
> > include/qemu/atomic128.h | 6 +-
>
> These two are the most important for the sake of this patch; perhaps it's
> worth a temporary override of your git orderfile if you have to respin, to
> list them first?
Will do in v2.
>
> > include/qemu/bitops.h | 2 +-
> > include/qemu/coroutine.h | 2 +-
> > include/qemu/log.h | 6 +-
> > include/qemu/queue.h | 8 +-
> > include/qemu/rcu.h | 10 +-
> > include/qemu/rcu_queue.h | 103 +++---
>
> Presumably, this and any other file with an odd number of changes was due to
> a difference in lines after reformatting long lines.
Yes, line-wrapping required many changes in this file.
>
> > include/qemu/seqlock.h | 8 +-
> ...
>
> > util/stats64.c | 34 +-
> > docs/devel/atomics.rst | 326 +++++++++---------
> > .../opensbi-riscv32-generic-fw_dynamic.elf | Bin 558668 -> 558698 bytes
> > .../opensbi-riscv64-generic-fw_dynamic.elf | Bin 620424 -> 620454 bytes
>
> Why are we regenerating .elf files in this patch? Is your change even
> correct for those two files?
Thanks for noticing this! The git-grep(1) man page documents the -I
option for skipping binary files. I thought this was the default.
Will fix in v2.
>
> > scripts/kernel-doc | 2 +-
> > tcg/aarch64/tcg-target.c.inc | 2 +-
> > tcg/mips/tcg-target.c.inc | 2 +-
> > tcg/ppc/tcg-target.c.inc | 6 +-
> > tcg/sparc/tcg-target.c.inc | 5 +-
> > 135 files changed, 1195 insertions(+), 1130 deletions(-)
>
> I don't spot accel/tcg/atomic_common.c.inc in the list (which declares
> functions such as atomic_trace_rmw_pre) - I guess that's intentional based
> on how you tried to edit only the identifiers you touched in
> include/qemu/atomic*.h.
Yes. The namespace cleaning only applies to atomic.h. Any other part of
QEMU uses atomic_ is unaffected.
> > diff --git a/scripts/kernel-doc b/scripts/kernel-doc
> > index 030b5c8691..9ec38a1bf1 100755
> > --- a/scripts/kernel-doc
> > +++ b/scripts/kernel-doc
> > @@ -1625,7 +1625,7 @@ sub dump_function($$) {
> > # If you mess with these regexps, it's a good idea to check that
> > # the following functions' documentation still comes out right:
> > # - parport_register_device (function pointer parameters)
> > - # - atomic_set (macro)
> > + # - qemu_atomic_set (macro)
> > # - pci_match_device, __copy_to_user (long return type)
>
> Does the result of sphinx still look good, as mentioned in this comment?
Yes.
Stefan
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