On 08.06.2023 13:02, Roberto Bagnara wrote: > On 07/06/23 23:53, Stefano Stabellini wrote: >> On Wed, 7 Jun 2023, Jan Beulich wrote: >>>> + * - `Rule 5.6 >>>> <https://gitlab.com/MISRA/MISRA-C/MISRA-C-2012/Example-Suite/-/blob/master/R_05_06.c>`_ >>>> + - Required >>>> + - A typedef name shall be a unique identifier >>>> + - >>> >>> Considering that the rule requires uniqueness across the entire code >>> base (and hence precludes e.g. two functions having identically named >>> local typedefs), I'm a little puzzled this was adopted. I for one >>> question that a use like the one mentioned is really at risk of being >>> confusing. Instead I think that the need to change at least one of >>> the names is at risk of making the code less readable then, even if >>> ever so slightly. (All of this said - I don't know if we have any >>> violations of this rule.) >> >> I don't think we have many local typedefs and I think we have only few >> violations if I remember right. I'll let Roberto confirm how many. This >> rule was considered not a difficult rule (some difficult rules were >> found, namely 2.1, 5.5 and 7.4.) > > There currently are 30 violations for ARM64: > > - some involve a typedef module_name (in the call it was said this should > be renamed module_name_t, which will solve the issue); > - most concern repeated typedefs (UINT64 and similar) which are repeated > in xen/arch/arm/include/asm/arm64/efibind.h > and xen/include/acpi/actypes.h > - ret_t and phys_addr_t are also redefined in a couple of places. > > There are 90 violations for X86_64, for the same reasons, plus > > - another set of typedefs for basic types (such as u8); > - repeated typedefs for things like guest_l1e_t in the same header file: > > xen/arch/x86/include/asm/guest_pt.h:60.39-60.49: > for program `xen/.xen-syms.0', the identifier for typedef `guest_l1e_t' is > reused > xen/arch/x86/include/asm/guest_pt.h:128.22-128.32: > for program `xen/.xen-syms.0', the identifier for typedef `guest_l1e_t' is > reused > > The indicated lines read as follows: > > typedef struct { guest_intpte_t l1; } guest_l1e_t; > typedef l1_pgentry_t guest_l1e_t;
So this is an example where I don't think we can sensibly do away with the re-use of the same typedef name: We use it so we can build the same source files multiple ways, dealing with different paging modes guests may be in. Jan
