C and C++


LANG.STRUCT.DEF.NOEXT : Missing External Definition

Summary

An identifier with external linkage has no associated definition.

Properties

Class Name Missing External Definition
Significance style
Mnemonic LANG.STRUCT.DEF.NOEXT
Categories
MisraC2023 MisraC2023:8.6 An identifier with external linkage shall have exactly one external definition
Misra2012 Misra2012:8.6 An identifier with external linkage shall have exactly one external definition
Misra2004 Misra2004:8.9 An identifier with external linkage shall have exactly one external definition
AUTOSARC++14 AUTOSARC++14:M3-2-2 The One Definition Rule shall not be violated.
  AUTOSARC++14:M3-2-4 An identifier with external linkage shall have exactly one definition.
MisraC++2008 MisraC++2008:3-2-2 The One Definition Rule shall not be violated.
  MisraC++2008:3-2-4 An identifier with external linkage shall have exactly one definition.
MisraC++2023 MisraC++2023:6.2.1 The one-definition rule shall not be violated
Availability Available for C and C++.
Enabling Checks for this warning class are disabled by default, and require the unnormalized C ASTs for the project. To enable them, add the following WARNING_FILTER rule and RETAIN_UNNORMALIZED_C_AST specification to the project configuration file.
RETAIN_UNNORMALIZED_C_AST = Yes
INCREMENTAL_BUILD = No
WARNING_FILTER += allow class="Missing External Definition"
Note that retaining the unnormalized ASTs will increase the disk space used to store the project representation, and may make the analysis take longer.

Incrementality Note: This warning class is not available for incremental analyses, even if the class is explicitly enabled.

Example

Suppose the project consists of LANG.STRUCT.DEF.NOEXT.a.c and LANG.STRUCT.DEF.NOEXT.b.c.

/* LANG.STRUCT.DEF.NOEXT.a.c */

int i_def=5;

int f_def( int i){return i;}
/* LANG.STRUCT.DEF.NOEXT.b.c */

extern int i_def;                               /* defined in LANG.STRUCT.DEF.NOEXT.a.c */

extern int i_nodef;         /* 'Missing External Definition' warning issued here */

extern int f_def( int i);                       /* defined in LANG.STRUCT.DEF.NOEXT.a.c */

extern int f_nodef( int i); /* 'Missing External Definition' warning issued here */

Relevant Configuration File Parameters

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