Re: [PATCH] xen/arm: silence ambiguous integer casting warning error

[Paran Lee <p4ranlee@gmail.com>]

Debugging with GDB from head.S with QEMU runtime was very convenient for
analysis(linux). so I have trying it in Xen. As I built it.

Wouldn't it be helpful if I fixed the code little by little?

2022-04-20 오전 1:31에 Paran Lee 이(가) 쓴 글:
> Hi, Julien Grall.
> 
> Thank you for checking it out. I'm sorry I forgot to attach the make log
> as well.
> 
> My build configuration (include CFLGAS)
> 
> export ARCH=arm64
> export XEN_TARGET_ARCH=arm64
> export $(dpkg-architecture -aarm64);
> export CROSS_COMPILE=aarch64-linux-gnu-
> export CFLAGS="-g -Wall -Wextra -Wno-unused-parameter"
> 
> And i did     make dist-xen
> 
> my arm64 compiler information are here.
> gcc version 9.4.0 (Ubuntu 9.4.0-1ubuntu1~20.04.1)
> 
> ~/xen$ aarch64-linux-gnu-gcc -v
> Using built-in specs.
> COLLECT_GCC=aarch64-linux-gnu-gcc
> COLLECT_LTO_WRAPPER=/usr/lib/gcc-cross/aarch64-linux-gnu/9/lto-wrapper
> Target: aarch64-linux-gnu
> Configured with: ../src/configure -v --with-pkgversion='Ubuntu
> 9.4.0-1ubuntu1~20.04.1'
> --with-bugurl=file:///usr/share/doc/gcc-9/README.Bugs
> --enable-languages=c,ada,c++,go,d,fortran,objc,obj-c++,gm2 --prefix=/usr
> --with-gcc-major-version-only --program-suffix=-9 --enable-shared
> --enable-linker-build-id --libexecdir=/usr/lib
> --without-included-gettext --enable-threads=posix --libdir=/usr/lib
> --enable-nls --with-sysroot=/ --enable-clocale=gnu
> --enable-libstdcxx-debug --enable-libstdcxx-time=yes
> --with-default-libstdcxx-abi=new --enable-gnu-unique-object
> --disable-libquadmath --disable-libquadmath-support --enable-plugin
> --enable-default-pie --with-system-zlib --without-target-system-zlib
> --enable-libpth-m2 --enable-multiarch --enable-fix-cortex-a53-843419
> --disable-werror --enable-checking=release --build=x86_64-linux-gnu
> --host=x86_64-linux-gnu --target=aarch64-linux-gnu
> --program-prefix=aarch64-linux-gnu-
> --includedir=/usr/aarch64-linux-gnu/include
> Thread model: posix
> gcc version 9.4.0 (Ubuntu 9.4.0-1ubuntu1~20.04.1)
> 
> In arch/arm/gic-v3.c files.
> 
> arch/arm/gic-v3.c: In function ‘gicv3_compute_target_list’:
> arch/arm/gic-v3.c:926:17: error: comparison of integer expressions of
> different signedness: ‘int’ and ‘unsigned int’ [-Werror=sign-compare]
>   926 |     while ( cpu < nr_cpu_ids )
>       |                 ^
> arch/arm/gic-v3.c:936:18: error: comparison of integer expressions of
> different signedness: ‘int’ and ‘unsigned int’ [-Werror=sign-compare]
>   936 |         if ( cpu == nr_cpu_ids )
>       |                  ^~                           ^
> 
> In arch/arm/setup.c files.
> 
> arch/arm/setup.c: In function ‘start_xen’:
> ./include/xen/cpumask.h:374:13: error: comparison of integer expressions
> of different signedness: ‘int’ and ‘unsigned int’ [-Werror=sign-compare]
>   374 |       (cpu) < nr_cpu_ids;  \
>       |             ^
> ./include/xen/cpumask.h:459:36: note: in expansion of macro ‘for_each_cpu’
>   459 | #define for_each_present_cpu(cpu)  for_each_cpu(cpu,
> &cpu_present_map)
>       |                                    ^~~~~~~~~~~~
> arch/arm/setup.c:989:5: note: in expansion of macro ‘for_each_present_cpu’
>   989 |     for_each_present_cpu ( i )
>       |     ^~~~~~~~~~~~~~~~~~~~             ^
> 
> Thank you!
> 
> 2022-04-20 오전 12:50에 Julien Grall 이(가) 쓴 글:
>> Hi,
>>
>> On Tue, 19 Apr 2022, 15:41 Paran Lee, <p4ranlee@gmail.com> wrote:
>>
>>> GCC with "-g -Wall -Wextra" option throws warning message as below:
>>
>>
>> Which version of the compiler? Also you specify the exact cflags, did you
>> tweak Xen?
>>
>>
>>> error: comparison of integer expressions of different signedness:
>>>  ‘int’ and ‘unsigned int’ [-Werror=sign-compare]
>>>
>>
>> GCC should give you a line/file. Can you provide it?
>>
>> Cheers,
>>
>>
>>> Silence the warning by correcting the integer type.
>>>
>>> Signed-off-by: Paran Lee <p4ranlee@gmail.com>
>>> ---
>>>  xen/arch/arm/gic-v3.c | 5 +++--
>>>  xen/arch/arm/setup.c  | 2 +-
>>>  2 files changed, 4 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/xen/arch/arm/gic-v3.c b/xen/arch/arm/gic-v3.c
>>> index 3c472ed768..81ac25f528 100644
>>> --- a/xen/arch/arm/gic-v3.c
>>> +++ b/xen/arch/arm/gic-v3.c
>>> @@ -916,7 +916,8 @@ static void gicv3_hyp_disable(void)
>>>      isb();
>>>  }
>>>
>>> -static u16 gicv3_compute_target_list(int *base_cpu, const struct cpumask
>>> *mask,
>>> +static u16 gicv3_compute_target_list(unsigned int *base_cpu,
>>> +                                     const struct cpumask *mask,
>>>                                       uint64_t cluster_id)
>>>  {
>>>      int cpu = *base_cpu;
>>> @@ -953,7 +954,7 @@ out:
>>>
>>>  static void gicv3_send_sgi_list(enum gic_sgi sgi, const cpumask_t
>>> *cpumask)
>>>  {
>>> -    int cpu = 0;
>>> +    unsigned int cpu = 0;
>>>      uint64_t val;
>>>
>>>      for_each_cpu(cpu, cpumask)
>>> diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c
>>> index d5d0792ed4..5ab2aaecaf 100644
>>> --- a/xen/arch/arm/setup.c
>>> +++ b/xen/arch/arm/setup.c
>>> @@ -862,7 +862,7 @@ void __init start_xen(unsigned long boot_phys_offset,
>>>                        unsigned long fdt_paddr)
>>>  {
>>>      size_t fdt_size;
>>> -    int cpus, i;
>>> +    unsigned int cpus, i;
>>>      const char *cmdline;
>>>      struct bootmodule *xen_bootmodule;
>>>      struct domain *d;
>>> --
>>> 2.25.1
>>>
>>>
>>