JavaScript is not currently enabled, but is required for full CodeSonar manual search and browse functionality.

If you are viewing this file in your hub's Web GUI, enable JavaScript in your browser: you will also need it for GUI functionality.

If you opened this file directly from disk, your browser may be directly suppressing JavaScript functionality: certain browsers perform this suppression on local files (but not files delivered by web servers) for security reasons.

CodeSonar® 9.2p0 CONFIDENTIAL CodeSecure Inc
C and C++

LANG.STRUCT.DECL.MULTIEXT : Multiple External Declarations

Summary

An identifier with external linkage has multiple associated non-defining extern declarations.

Properties

Class Name Multiple External Declarations
Significance style
Mnemonic LANG.STRUCT.DECL.MULTIEXT
Categories
MisraC2025 MisraC2025:8.5 An external object or function shall be declared once in one and only one file
MisraC2023 MisraC2023:8.5 An external object or function shall be declared once in one and only one file
Misra2012 Misra2012:8.5 An external object or function shall be declared once in one and only one file
Misra2004 Misra2004:8.8 An external object or function shall be declared in one and only one file
AUTOSARC++14 AUTOSARC++14:M3-2-3 A type, object or function that is used in multiple translation units shall be declared in one and only one file.
MisraC++2008 MisraC++2008:3-2-3 A type, object or function that is used in multiple translation units shall be declared in one and only one file.
JSF++ JSF++:40 Every implementation file shall include the header files that uniquely define the inline functions, types, and templates used.
  JSF++:139 External objects will not be declared in more than one file.
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="Multiple External Declarations"
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.DECL.MULTIEXT.a.c and LANG.STRUCT.DECL.MULTIEXT.b.c.

/* LANG.STRUCT.DECL.MULTIEXT.a.c */
        
int i_oneext=5;  

extern int i_twoext;

int f_oneext( int i){return i;}

extern int f_twoext( int i);

/* LANG.STRUCT.DECL.MULTIEXT.b.c */

extern int i_oneext;                           /* defined in LANG.STRUCT.DECL.MULTIEXT.a.c */

extern int i_twoext;         /* 'Multiple External Declarations' warning issued here:
                              * also declared extern in LANG.STRUCT.DECL.MULTIEXT.a.c,
                              * but not defined there.
                              */

extern int f_oneext( int i);                   /* defined in LANG.STRUCT.DECL.MULTIEXT.a.c */

extern int f_twoext( int i); /* 'Multiple External Declarations' warning issued here:
                              * also declared extern in LANG.STRUCT.DECL.MULTIEXT.a.c,
                              * but not defined there.
                              */

Relevant Configuration File Parameters

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

 

To report problems with this documentation, please visit https://support.codesecure.com/.