[metadata]
id = "INT00-C"
type = "recommendation"
category = "INT"
number = 0
title = "Understand the data model used by your implementation(s)"
description = """
Adata modeldefines the sizes assigned to standard data types. It is important to
understand the data models used by yourimplementation. However, if your code
depends on any assumptions not guaranteed by the standard, you should provide
static assertions to ensure that your assumptions are valid. (SeeDCL03-C. Use a
static assertion to test the value of a constant expression.) Assumptions
concerning integer sizes may become invalid, for example, when porting from a
32-bit architecture to a 64-bit architecture. Data
TypeiAPX86IA-32IA-64SPARC-64ARM-32Alpha64-bit Linux, FreeBSD,NetBSD, and
OpenBSDchar8888888short16161616161616int16323232323232long32323264326464long
longN/A646464646464Pointer16/32326464326464 Code frequently embeds assumptions
about data models. For example, some code bases require pointer andlongto have
the same size, whereas other large code bases requireintandlongto be the same
size [van de Voort 2007]. These types of assumptions, while common, make the
code difficult to port and make the ports error prone. One solution is to avoid
anyimplementation-defined behavior. However, this practice can result in
inefficient code. Another solution is to include either static or runtime
assertions near any platform-specific assumptions, so they can be easily
detected and corrected during porting.
"""
severity = "High"
likelihood = "Unlikely"
priority = "P3"
level = "L3"
cert_version = "2016 Edition (Wiki)"
last_modified = "May 20, 2025"
[rules.cert_c.INT00-C]
enabled = true
[references]
wiki = "https://wiki.sei.cmu.edu/confluence/pages/viewpage.action?pageId=87152417"