MISC.NOEFFECT : Function Call Has No Effect

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CodeSonar^® 9.2p0

CONFIDENTIAL

CodeSecure Inc

C and C++

MISC.NOEFFECT : Function Call Has No Effect

Summary

A function call has no effect.

At present, all warnings of this class refer to memory-copying function calls whose length argument is a constant-valued expression that evaluates to zero.

Properties

Class Name

Function Call Has No Effect

Significance

security

Mnemonic

MISC.NOEFFECT

Categories

MisraC2025	MisraC2025:2.2	A project shall not contain dead code
MisraC2023	MisraC2023:2.2	A project shall not contain dead code
Misra2012	Misra2012:2.2	A project shall not contain dead code
Misra2004	Misra2004:14.2	All non-null statements shall either (a) have at least one side-effect however executed, or (b) cause control flow to change
AUTOSARC++14	AUTOSARC++14:M0-1-8	All functions with void return type shall have external side effect(s).
	AUTOSARC++14:M0-1-9	There shall be no dead code.
MisraC++2008	MisraC++2008:0-1-8	All functions with void return type shall have external side effect(s).
	MisraC++2008:0-1-9	There shall be no dead code.
CWE	CWE:687	Function Call With Incorrectly Specified Argument Value
	CWE:688	Function Call With Incorrect Variable or Reference as Argument
	CWE:1164	Irrelevant Code
CERT-C	CERT-C:MSC12-C	Detect and remove code that has no effect or is never executed
JSF++	JSF++:187	All non-null statements shall potentially have a side-effect.
OWASP-2021	OWASP-2021:A4	Insecure design
OWASP-2025	OWASP-2025:A06	Insecure Design

Availability

Available for C and C++.

Enabling

Checks for this warning class are enabled by default. To disable them, add the following WARNING_FILTER rule to the project configuration file.

WARNING_FILTER += discard class="Function Call Has No Effect"

Could Indicate

CWE:683	Function Call With Incorrect Order of Arguments

Example

#include <string.h>

void f(void)
{
    char buf[10];
    memset(buf, 10, '\0'); /* Function Call Has No Effect
                            * warning issued here */
}

Triggering Functions

CodeSonar checks the following functions for this warning class. A warning is triggered if a function in the table is called with a constant-valued expression that evaluates to zero in the length parameter position, which is marked like this.

CodeSonar ships with library models that allow it to recognize functions such as libc memcpy() and Win32 StrCatBuffA()/StrCatBuffW() that copy a specified amount of memory. If one of these functions is called with a constant-valued expression that evaluates to zero in the length parameter position, a warning will be issued.

If you have created a custom library model for some function f() in terms of one of these existing models, calls to f() will also be capable of triggering Function Call Has No Effect warnings.

Relevant Configuration File Parameters

The following configuration file parameters affect checks for this warning class.

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