Re: [Qemu-devel] [PATCH v2 02/20] hw/i386/pc: Use size_t type to hold/return a size of array

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

On 6/20/19 5:28 PM, Michael S. Tsirkin wrote:
> On Thu, Jun 13, 2019 at 04:34:28PM +0200, Philippe Mathieu-Daudé wrote:
>> Reviewed-by: Li Qiang <liq3ea@gmail.com>
>> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> 
> Motivation? do you expect more than 2^31 entries?

Building with -Wsign-compare:

hw/i386/pc.c:973:36: warning: comparison of integers of different signs:
'unsigned int' and 'int' [-Wsign-compare]
    for (i = 0, array_count = 0; i < e820_get_num_entries(); i++) {
                                 ~ ^ ~~~~~~~~~~~~~~~~~~~~~~

>> ---
>>  hw/i386/pc.c         | 4 ++--
>>  include/hw/i386/pc.h | 2 +-
>>  2 files changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
>> index bb3c74f4ca..ff0f6bbbb3 100644
>> --- a/hw/i386/pc.c
>> +++ b/hw/i386/pc.c
>> @@ -105,7 +105,7 @@ struct e820_table {
>>  
>>  static struct e820_table e820_reserve;
>>  static struct e820_entry *e820_table;
>> -static unsigned e820_entries;
>> +static size_t e820_entries;
>>  struct hpet_fw_config hpet_cfg = {.count = UINT8_MAX};
>>  
>>  /* Physical Address of PVH entry point read from kernel ELF NOTE */
>> @@ -901,7 +901,7 @@ int e820_add_entry(uint64_t address, uint64_t length, uint32_t type)
>>      return e820_entries;
>>  }
>>  
>> -int e820_get_num_entries(void)
>> +size_t e820_get_num_entries(void)
>>  {
>>      return e820_entries;
>>  }
>> diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
>> index 3b3a0d6e59..fc29893624 100644
>> --- a/include/hw/i386/pc.h
>> +++ b/include/hw/i386/pc.h
>> @@ -290,7 +290,7 @@ void pc_madt_cpu_entry(AcpiDeviceIf *adev, int uid,
>>  #define E820_UNUSABLE   5
>>  
>>  int e820_add_entry(uint64_t, uint64_t, uint32_t);
>> -int e820_get_num_entries(void);
>> +size_t e820_get_num_entries(void);
>>  bool e820_get_entry(unsigned int, uint32_t, uint64_t *, uint64_t *);
>>  
>>  extern GlobalProperty pc_compat_4_0_1[];
>> -- 
>> 2.20.1