[PATCH iproute2] json_print: fix print_uint hidden type promotion

Kevin Darbyshire-Bryant
2018-03-29T19:22:36Z

print_int used 'int' type internally, whereas print_uint used 'uint64_t'

These helper functions eventually call vfprintf(fp, fmt, args) which is
a variable argument list function and is dependent upon 'fmt' containing
correct information about the length of the passed arguments.

Unfortunately print_int v print_uint offered no clue to the programmer
that internally passed ints to print_uint were being promoted to 64bits,
thus the format passed in 'fmt' string vs the actual passed integer
could be different lengths. This is even more interesting on big endian
architectures where 'vfprintf' would be looking in the middle of an
int64 type.

print_u/int now stick with native int size.

Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
---
include/json_print.h | 2 +-
lib/json_print.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/json_print.h b/include/json_print.h
index 2ca7830a..45bc653d 100644
--- a/include/json_print.h
+++ b/include/json_print.h
@@ -56,10 +56,10 @@ void close_json_array(enum output_type type, const char *delim);
print_color_##type_name(t, COLOR_NONE, key, fmt, value); \
}
_PRINT_FUNC(int, int);
+_PRINT_FUNC(uint, unsigned int);
_PRINT_FUNC(bool, bool);
_PRINT_FUNC(null, const char*);
_PRINT_FUNC(string, const char*);
-_PRINT_FUNC(uint, uint64_t);
_PRINT_FUNC(hu, unsigned short);
_PRINT_FUNC(hex, unsigned int);
_PRINT_FUNC(0xhex, unsigned int);
diff --git a/lib/json_print.c b/lib/json_print.c
index 6518ba98..8d54d1d4 100644
--- a/lib/json_print.c
+++ b/lib/json_print.c
@@ -117,8 +117,8 @@ void close_json_array(enum output_type type, const char *str)
} \
}
_PRINT_FUNC(int, int);
+_PRINT_FUNC(uint, unsigned int);
_PRINT_FUNC(hu, unsigned short);
-_PRINT_FUNC(uint, uint64_t);
_PRINT_FUNC(lluint, unsigned long long int);
_PRINT_FUNC(float, double);
#undef _PRINT_FUNC
--
2.14.3 (Apple Git-98)