Re: [PATCH for-8.2] target/riscv/kvm: fix shadowing in kvm_riscv_(get|put)_regs_csr

[Alistair Francis <alistair23@gmail.com>]

On Mon, Dec 4, 2023 at 3:00 AM Philippe Mathieu-Daudé <philmd@linaro.org> wrote:
>
> On 23/11/23 11:23, Philippe Mathieu-Daudé wrote:
> > On 23/11/23 11:13, Daniel Henrique Barboza wrote:
> >> KVM_RISCV_GET_CSR() and KVM_RISCV_SET_CSR() use an 'int ret' variable
> >> that is used to do an early 'return' if ret > 0. Both are being called
> >> in functions that are also declaring a 'ret' integer, initialized with
> >> '0', and this integer is used as return of the function.
> >>
> >> The result is that the compiler is less than pleased and is pointing
> >> shadowing errors:
> >>
> >> ../target/riscv/kvm/kvm-cpu.c: In function 'kvm_riscv_get_regs_csr':
> >> ../target/riscv/kvm/kvm-cpu.c:90:13: error: declaration of 'ret'
> >> shadows a previous local [-Werror=shadow=compatible-local]
> >>     90 |         int ret = kvm_get_one_reg(cs, RISCV_CSR_REG(env,
> >> csr), &reg); \
> >>        |             ^~~
> >> ../target/riscv/kvm/kvm-cpu.c:539:5: note: in expansion of macro
> >> 'KVM_RISCV_GET_CSR'
> >>    539 |     KVM_RISCV_GET_CSR(cs, env, sstatus, env->mstatus);
> >>        |     ^~~~~~~~~~~~~~~~~
> >> ../target/riscv/kvm/kvm-cpu.c:536:9: note: shadowed declaration is here
> >>    536 |     int ret = 0;
> >
> >
> >> The macros are doing early returns for non-zero returns and the local
> >> 'ret' variable for both functions is used just to do 'return 0', so
> >> remove them from kvm_riscv_get_regs_csr() and kvm_riscv_put_regs_csr()
> >> and do a straight 'return 0' in the end.
> >>
> >> For good measure let's also rename the 'ret' variables in
> >> KVM_RISCV_GET_CSR() and KVM_RISCV_SET_CSR() to '_ret' to make them more
> >> resilient to these kind of errors.
> >>
> >> Fixes: 937f0b4512 ("target/riscv: Implement kvm_arch_get_registers")
> >> Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
> >> ---
> >>   target/riscv/kvm/kvm-cpu.c | 19 +++++++++----------
> >>   1 file changed, 9 insertions(+), 10 deletions(-)
> >
> > Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

Alistair

>
> Also:
>
> Tested-by: Philippe Mathieu-Daudé <philmd@linaro.org>
>
> Alistair, if you don't have any pending riscv pull request
> I can take this patch with the one I plan to post tomorrow
> (this is the last fix missing to get our CI green again).

Go for it! That would be really helpful

Alistair

>