Am Donnerstag, dem 16.01.2025 um 21:18 +0000 schrieb Qing Zhao: > .. > > Although in the previous discussion, I agreed with Martin that we should use > the > designator syntax (i.e, counted_by (.n) instead of counted_by (n)) for the > counted_by attribute for pointer fields, after more consideration and > discussion > with Bill Wendling (who is working on the same work for CLANG), we decided to > keep the current syntax of FAM for pointer fields. And leave the new syntax > (.n) > and more complicate expressions to a later work. > I think this would be a mistake. Once you have established the confusing syntax, it will not easily go away anymore. So I think you should use the unambiguous and future-prove syntax right away. Support for more complicated expressions could be left for later, of course.
Martin > This patch set includes 3 parts: > > 1.Extend "counted_by" attribute to pointer fields of structures. > 2.Convert a pointer reference with counted_by attribute to .ACCESS_WITH_SIZE > and use it in builtinin-object-size. > 3.Use the counted_by attribute of pointers in array bound checker. > > In which, the patch 1 and 2 are simple and straightforward, however, the > patch 3 > is a little complicate due to the following reason: > > Current array bound checker only instruments ARRAY_REF, and the INDEX > information is the 2nd operand of the ARRAY_REF. > > When extending the array bound checker to pointer references with > counted_by attributes, the hardest part is to get the INDEX of the > corresponding array ref from the offset computation expression of > the pointer ref. > > The whole patch set has been bootstrapped and regression tested on both > aarch64 > and x86. > > Let me know any comments and suggestions. > > Thanks. > > Qing > > Qing Zhao (3): > Extend "counted_by" attribute to pointer fields of structures. > Convert a pointer reference with counted_by attribute to > .ACCESS_WITH_SIZE and use it in builtinin-object-size. > Use the counted_by attribute of pointers in array bound checker. > > gcc/c-family/c-attribs.cc | 15 +- > gcc/c-family/c-gimplify.cc | 7 + > gcc/c-family/c-ubsan.cc | 264 ++++++++++++++++-- > gcc/c/c-decl.cc | 91 +++--- > gcc/c/c-typeck.cc | 41 +-- > gcc/doc/extend.texi | 37 ++- > gcc/testsuite/gcc.dg/flex-array-counted-by.c | 2 +- > gcc/testsuite/gcc.dg/pointer-counted-by-2.c | 8 + > gcc/testsuite/gcc.dg/pointer-counted-by-3.c | 127 +++++++++ > gcc/testsuite/gcc.dg/pointer-counted-by-4.c | 63 +++++ > gcc/testsuite/gcc.dg/pointer-counted-by-5.c | 48 ++++ > gcc/testsuite/gcc.dg/pointer-counted-by-6.c | 47 ++++ > gcc/testsuite/gcc.dg/pointer-counted-by-7.c | 30 ++ > gcc/testsuite/gcc.dg/pointer-counted-by-8.c | 30 ++ > gcc/testsuite/gcc.dg/pointer-counted-by.c | 70 +++++ > .../ubsan/pointer-counted-by-bounds-2.c | 47 ++++ > .../ubsan/pointer-counted-by-bounds-3.c | 35 +++ > .../ubsan/pointer-counted-by-bounds-4.c | 35 +++ > .../ubsan/pointer-counted-by-bounds-5.c | 46 +++ > .../ubsan/pointer-counted-by-bounds-6.c | 33 +++ > .../gcc.dg/ubsan/pointer-counted-by-bounds.c | 46 +++ > gcc/tree-object-size.cc | 11 +- > 22 files changed, 1045 insertions(+), 88 deletions(-) > create mode 100644 gcc/testsuite/gcc.dg/pointer-counted-by-2.c > create mode 100644 gcc/testsuite/gcc.dg/pointer-counted-by-3.c > create mode 100644 gcc/testsuite/gcc.dg/pointer-counted-by-4.c > create mode 100644 gcc/testsuite/gcc.dg/pointer-counted-by-5.c > create mode 100644 gcc/testsuite/gcc.dg/pointer-counted-by-6.c > create mode 100644 gcc/testsuite/gcc.dg/pointer-counted-by-7.c > create mode 100644 gcc/testsuite/gcc.dg/pointer-counted-by-8.c > create mode 100644 gcc/testsuite/gcc.dg/pointer-counted-by.c > create mode 100644 gcc/testsuite/gcc.dg/ubsan/pointer-counted-by-bounds-2.c > create mode 100644 gcc/testsuite/gcc.dg/ubsan/pointer-counted-by-bounds-3.c > create mode 100644 gcc/testsuite/gcc.dg/ubsan/pointer-counted-by-bounds-4.c > create mode 100644 gcc/testsuite/gcc.dg/ubsan/pointer-counted-by-bounds-5.c > create mode 100644 gcc/testsuite/gcc.dg/ubsan/pointer-counted-by-bounds-6.c > create mode 100644 gcc/testsuite/gcc.dg/ubsan/pointer-counted-by-bounds.c >
