Re: [V4][PATCH 0/2] Handle component_ref to a structure/union field including FAM for builtin_object_size

[Qing Zhao <qing.zhao@oracle.com>]

Ping

Qing

> On Feb 24, 2023, at 1:35 PM, Qing Zhao <qing.zhao@oracle.com> wrote:
> 
> Hi, Joseph and Richard,
> 
> Could you please review this patch and let me know whether it’s ready
> for committing into GCC13?
> 
> The fix to Bug PR101832 is an important patch for kernel security
> purpose. it's better to be put into GCC13.
> 
> =============================
> 
> These are the 4th version of the patches for PR101832, to fix
> builtin_object_size to correctly handle component_ref to a
> structure/union field that includes a flexible array member.
> 
> also includes a documentation update for the GCC extension on embedding
> a structure/union with flexible array member into another structure.
> which includes a fix to PR77650.
> 
> compared to the 3rd version of the patch, the major changes are:
> 
> 1. update the documentation part per Joseph's comments.
> 
> compared to the 2nd version of the patch, the major changes are:
> 
> 1. only include C99 flexible array member to this extension, trailing [0], [1]
>  and [4] are all excluded.
> 2. for the new bit type_include_flexarray in tree_type_common, print it
>  and also stream in/out it. 
> 3. update testing cases.
> 4. more clarification on the documentation. warnings for deprecating the 
>  case when the structure with C99 FAM is embedded in the middle of
>  another structure. 
> 5. add a new warning option -Wgnu-variable-sized-type-not-at-end for
>  identifing all such cases.
> 
> bootstrapped and regression tested on aarch64 and x86.
> 
> Okay for commit?
> 
> thanks.
> 
> Qing
> 
> Qing Zhao (2):
>  Handle component_ref to a structre/union field including C99 FAM
>    [PR101832]
>  Update documentation to clarify a GCC extension
> 
> gcc/c-family/c.opt                            |   5 +
> gcc/c/c-decl.cc                               |  19 +++
> gcc/cp/module.cc                              |   2 +
> gcc/doc/extend.texi                           |  48 ++++++-
> gcc/print-tree.cc                             |   5 +
> .../gcc.dg/builtin-object-size-pr101832.c     | 134 ++++++++++++++++++
> .../gcc.dg/variable-sized-type-flex-array.c   |  31 ++++
> gcc/tree-core.h                               |   4 +-
> gcc/tree-object-size.cc                       |  79 +++++++----
> gcc/tree-streamer-in.cc                       |   1 +
> gcc/tree-streamer-out.cc                      |   1 +
> gcc/tree.h                                    |   6 +
> 12 files changed, 305 insertions(+), 30 deletions(-)
> create mode 100644 gcc/testsuite/gcc.dg/builtin-object-size-pr101832.c
> create mode 100644 gcc/testsuite/gcc.dg/variable-sized-type-flex-array.c
> 
> -- 
> 2.31.1
>