git-compat-util.h: implement checked size_t to uint32_t conversion

In a similar fashion as other checked cast functions in this header
(such as `cast_size_t_to_ulong()` and `cast_size_t_to_int()`), implement
a checked cast function for going from a size_t to a uint32_t value.

This function will be utilized in a future commit which needs to make
such a conversion.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/git-compat-util.h b/git-compat-util.h
index 3e7a59b5ff108dddce111cb372b6c846c093b4be..c3b6c2c226e912f3198e956a2d871e664524c17f 100644 (file)
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -1013,6 +1013,15 @@ static inline unsigned long cast_size_t_to_ulong(size_t a)
        return (unsigned long)a;
 }
 
+static inline uint32_t cast_size_t_to_uint32_t(size_t a)
+{
+       if (a != (uint32_t)a)
+               die("object too large to read on this platform: %"
+                   PRIuMAX" is cut off to %u",
+                   (uintmax_t)a, (uint32_t)a);
+       return (uint32_t)a;
+}
+
 static inline int cast_size_t_to_int(size_t a)
 {
        if (a > INT_MAX)