Re: [PATCH v2 0/4] add variadic format checking

On 22/12/2025 16:00, Ben Dooks wrote:
> Second version of this, I think mostly sorting the issues
> identified in review.
> 
> This series (which was initially sent back in 2020) adds the
> ability to deal with __attribute__((format) and checking the
> arguments to formatted variadic functions.
> 
> I have been considering adding a -Wformat-linux to this as
> the kernel now has a number of extra formatting options and
> checking the type of these would be useful. An even nicer
> extension would be some way of informing the compiler/sparse
> of these at compile time (but would need to get agreement on
> how to do this with the compilers too)

Having tested on the kernel, there's a couple of issues with
this code, that i've mostly fixed.

Adding kernel type checking didn't come up with anything on
my riscv build other than a few signed v unsigned.

> Ben Dooks (4):
>    parse: initial parsing of __attribute__((format))
>    add -Wformat
>    evaluate: check variadic argument types against formatting info
>    tests: add varargs printf format tests
> 
>   Makefile                               |   1 +
>   builtin.c                              |   4 +-
>   evaluate.c                             |  14 +-
>   evaluate.h                             |  10 +-
>   options.c                              |   2 +
>   options.h                              |   1 +
>   parse.c                                |  83 ++++-
>   sparse.1                               |   8 +
>   symbol.h                               |  10 +-
>   validation/varargs-format-addrspace1.c |  36 ++
>   validation/varargs-format-bad.c        |  18 +
>   validation/varargs-format-checking.c   |  21 ++
>   validation/varargs-format-position.c   |  32 ++
>   validation/varargs-format-prefix.c     |  19 +
>   validation/varargs-format-tests.c      |  55 +++
>   validation/varargs-type-formattest.c   | 117 +++++++
>   verify-format.c                        | 460 +++++++++++++++++++++++++
>   verify-format.h                        |   6 +
>   18 files changed, 887 insertions(+), 10 deletions(-)
>   create mode 100644 validation/varargs-format-addrspace1.c
>   create mode 100644 validation/varargs-format-bad.c
>   create mode 100644 validation/varargs-format-checking.c
>   create mode 100644 validation/varargs-format-position.c
>   create mode 100644 validation/varargs-format-prefix.c
>   create mode 100644 validation/varargs-format-tests.c
>   create mode 100644 validation/varargs-type-formattest.c
>   create mode 100644 verify-format.c
>   create mode 100644 verify-format.h
> 


-- 
Ben Dooks				http://www.codethink.co.uk/
Senior Engineer				Codethink - Providing Genius

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