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lib: test_scanf: Remove pointless use of type_min() with unsigned types

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sparse was producing warnings of the form:

 sparse: cast truncates bits from constant value (ffff0001 becomes 1)

There is no actual problem here. Using type_min() on an unsigned type
results in an (expected) truncation.

However, there is no need to test an unsigned value against type_min().
The minimum value of an unsigned is obviously 0, and any value cast to
an unsigned type is >= 0, so for unsigneds only type_max() need be tested.

This patch also takes the opportunity to clean up the implementation of
simple_numbers_loop() to use a common pattern for the positive and
negative test.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20210525122012.6336-2-rf@opensource.cirrus.com
This commit is contained in:
Richard Fitzgerald 2021-05-25 13:20:11 +01:00 committed by Petr Mladek
parent ef04d4ff4b
commit 1b932689c7
1 changed files with 6 additions and 7 deletions
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13
lib/test_scanf.c
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@ -187,8 +187,8 @@ static const unsigned long long numbers[] __initconst = {
#define value_representable_in_type(T, val) \ #define value_representable_in_type(T, val) \
(is_signed_type(T) \ (is_signed_type(T) \
? ((long long)(val) >= type_min(T)) && ((long long)(val) <= type_max(T)) \ ? ((long long)(val) >= type_min(T)) && ((long long)(val) <= type_max(T)) \
: ((unsigned long long)(val) >= type_min(T)) && \ : ((unsigned long long)(val) <= type_max(T)))
((unsigned long long)(val) <= type_max(T)))
#define test_one_number(T, gen_fmt, scan_fmt, val, fn) \ #define test_one_number(T, gen_fmt, scan_fmt, val, fn) \
do { \ do { \
@ -204,12 +204,11 @@ do { \
int i; \ int i; \
\ \
for (i = 0; i < ARRAY_SIZE(numbers); i++) { \ for (i = 0; i < ARRAY_SIZE(numbers); i++) { \
if (!value_representable_in_type(T, numbers[i])) \ if (value_representable_in_type(T, numbers[i])) \
continue; \ test_one_number(T, gen_fmt, scan_fmt, \
numbers[i], fn); \
\ \
test_one_number(T, gen_fmt, scan_fmt, numbers[i], fn); \ if (value_representable_in_type(T, -numbers[i])) \
\
if (is_signed_type(T)) \
test_one_number(T, gen_fmt, scan_fmt, \ test_one_number(T, gen_fmt, scan_fmt, \
-numbers[i], fn); \ -numbers[i], fn); \
} \ } \