6.5.2.2. Nodes (Entities)

In the following we describe the possible types of nodes contained in C RFGs. In general it holds that if node type B inherits from a node type A, nodes of type B can also have attributes that are defined for A.

A node either represents an entity in the source code (e.g., a global variable), or describes one or more units of the file system, like a file, a directory, or a module.

Common Attributes for all Node Types

Source.Name

The Source.Name (of type string) is the name the entity possesses in the source code. If an entity does not have a name, for instance anonymous structs or unions, their name will be a question mark ?.

Linkage.Name

The Linkage.Name (of type string) unambiguously identifies the entity within one RFG.

Source.File, Source.Path, Source.Line, Source.Column

These four attributes characterize the source location of the definition of the entity, or one of the declarations if no definition has been seen at all. Source.File and Source.Path are of type string, Source.Line and Source.Column are of type int.

The option -B of cafeCC influences the prefix of the path used in the source location information, see Tool Reference.

Note

If there is no definition, one of the possibly multiple declarations is arbitrarily chosen for the source location. This happens if a system is only partially analyzed. This also happens for elements that originate in a library where you do not have the source code but only the header files.

Caution

Please note that types in C/C++ generally do not have a single point of definition throughout a system unless defined in a single header file, so for them, one of the source locations of their definitions is arbitrarily chosen.

Note

As long as any entity has a unique point of declaration (only in one header or C source file), the source location information will be the same, no matter which order of translation and linking of the system is performed.

Source.Region_Start, Source.Region_Length

: These attributes denote the start line and length (in lines) of the source entity. Both attributes are of type int.

Source.Physical_File, Source.Physical_Path

: These attributes characterize the actual source location in the presence of #line directives.

Source.Physical_Region_Start, Source.Physical_Region_Length

: These attributes denote the actual start line and length (in lines) of the source entity in the presence of #line directives.

Element.Has_Ambiguous_Declaration

This attribute of type toggle indicates that there is more than one declaration for the represented entity. This is only used for typedefs and undefined entities.

Note

Nodes that have Element.Has_Ambiguous_Declaration are ignored in the architecture analysis because they will most likely lead to confusing results.

Linkage.Is_Definition

The attribute of type toggle indicates whether the node represents a definition (toggle set) or a declaration (toggle unset).

For nodes in the Code Facts view holds the following: Nodes that do not possess this attribute are from the environment (e.g., printf) or in parts of the system under analysis that are not yet analyzed. If you create partial RFG files for IR libraries or single unit files, the parts that are not inside the partial RFG are also not marked with Linkage.Is_Definition.

For nodes in the Declaration Facts view holds the following: Nodes that do possess this attribute are definitions, nodes that do not posses this attributes are declarations. There is a Declare edge from a declaration to its matching definition.

Linkage.LIR_Node, Linkage.PIR_Node

In an RFG generated by Architecture-Dependencies, the nodes in the Code Facts view have the Linkage.LIR_Node attribute. Nodes in the Declaration Facts view have the Linkage.PIR_Node attribute. These attributes create a mapping between the nodes in the RFG file and the nodes in the IR file it has been created from.

Class

Class (inherits from: Type)

Subtypes

none

Containing Views

Code Facts, Declaration Facts, File, Module

Description

A Class represents the user-defined C type constructs struct, union, and enum.

Attributes

Attribute name	Attribute type	Inherited from
Element.Is_Anonymous	Toggle	-
Element.Is_Enum	Toggle	-
Element.Is_Struct	Toggle	-
Element.Is_Typedef_To_Anonymous	Toggle	-
Element.Is_Union	Toggle	-
Linkage.Is_Definition	Toggle	-
Element.Has_Ambiguous_Declaration	Toggle	Type
Element.Is_Anonymous	Toggle	Type
Element.Is_Enum	Toggle	Type
Element.Is_Struct	Toggle	Type
Element.Is_Typedef_To_Anonymous	Toggle	Type
Element.Is_Union	Toggle	Type
Linkage.Is_Ambiguous_Name	Toggle	Source_Entity
Linkage.Is_Definition	Toggle	Source_Entity
Linkage.LIR_Node	Integer	Source_Entity
Linkage.Name	String	Source_Entity
Linkage.PIR_Node	Integer	Source_Entity
Source.Body_End_Column	Integer	Source_Entity
Source.Body_End_Line	Integer	Source_Entity
Source.Body_Start_Column	Integer	Source_Entity
Source.Body_Start_Line	Integer	Source_Entity
Source.Column	Integer	Source_Entity
Source.Declaration_Start	Integer	Source_Entity
Source.File	String	Source_Entity
Source.Line	Integer	Source_Entity
Source.Name	String	Source_Entity
Source.Path	String	Source_Entity
Source.Physical_File	String	Source_Entity
Source.Physical_Path	String	Source_Entity
Source.Physical_Region_Length	Integer	Source_Entity
Source.Physical_Region_Start	Integer	Source_Entity
Source.Region_Length	Integer	Source_Entity
Source.Region_Start	Integer	Source_Entity
Source.Signature_Start	Integer	Source_Entity

The appropriate toggle attribute Element.Is_Struct , Element.Is_Union , and Element.Is_Enum is set to indicate the exact kind of modelled type.

Note

The struct, union, and enum constructs are represented as classes to facilitate linking of parts of a system written in C and C++.

Note

Code Example

struct {
int i;
} global_variable;

Example: Unnamed struct.

Constant

Constant (inherits from: Object)

Subtypes

none

Containing Views

Code Facts, Declaration Facts, File, Module

Description

A Constant represents an enumerator constant; it is contained in the node representing its enumeration type by Enclosing edges.

Attributes

Attribute name	Attribute type	Inherited from
Element.Is_Static	Toggle	Object
Linkage.Is_Ambiguous_Name	Toggle	Source_Entity
Linkage.Is_Definition	Toggle	Source_Entity
Linkage.LIR_Node	Integer	Source_Entity
Linkage.Name	String	Source_Entity
Linkage.PIR_Node	Integer	Source_Entity
Source.Body_End_Column	Integer	Source_Entity
Source.Body_End_Line	Integer	Source_Entity
Source.Body_Start_Column	Integer	Source_Entity
Source.Body_Start_Line	Integer	Source_Entity
Source.Column	Integer	Source_Entity
Source.Declaration_Start	Integer	Source_Entity
Source.File	String	Source_Entity
Source.Line	Integer	Source_Entity
Source.Name	String	Source_Entity
Source.Path	String	Source_Entity
Source.Physical_File	String	Source_Entity
Source.Physical_Path	String	Source_Entity
Source.Physical_Region_Length	Integer	Source_Entity
Source.Physical_Region_Start	Integer	Source_Entity
Source.Region_Length	Integer	Source_Entity
Source.Region_Start	Integer	Source_Entity
Source.Signature_Start	Integer	Source_Entity

Note

Code Example

enum NameOfEnum
{
    someEnumerator,
    anotherName
    // ...
};

Example: Enum type with two enumerator values.

Directory

Directory (inherits from: File_System_Entity)

Subtypes

none

Containing Views

File, Include, Module

Description

In addition to the language representation, the Axivion Suite captures the containment of declarations/definitions in modules, files, and directories.

A Directory represents a directory in the file system. A Directory node can contain File nodes, Module nodes, and Directory nodes depending on the kind of view.

Attributes

Attribute name	Attribute type	Inherited from
Linkage.Name	String	File_System_Entity
Linkage.PIR_Node	Integer	File_System_Entity
Source.Column	Integer	File_System_Entity
Source.File	String	File_System_Entity
Source.Line	Integer	File_System_Entity
Source.Name	String	File_System_Entity
Source.Path	String	File_System_Entity
Source.Physical_File	String	File_System_Entity
Source.Physical_Path	String	File_System_Entity
Source.Physical_Region_Length	Integer	File_System_Entity
Source.Physical_Region_Start	Integer	File_System_Entity
Source.Region_Length	Integer	File_System_Entity
Source.Region_Start	Integer	File_System_Entity

File

File (inherits from: File_System_Entity)

Subtypes

none

Containing Views

File, Include

Description

A File node represents a source file. It contains all declarations and definitions by incoming Enclosing edges. A File node itself may be contained in a Directory node. The path is expressed by the hierarchy of Directory nodes.

Attributes

Attribute name	Attribute type	Inherited from
Element.Is_Preinclude_File	Toggle	-
Element.Is_System_Header	Toggle	-
Linkage.Name	String	File_System_Entity
Linkage.PIR_Node	Integer	File_System_Entity
Source.Column	Integer	File_System_Entity
Source.File	String	File_System_Entity
Source.Line	Integer	File_System_Entity
Source.Name	String	File_System_Entity
Source.Path	String	File_System_Entity
Source.Physical_File	String	File_System_Entity
Source.Physical_Path	String	File_System_Entity
Source.Physical_Region_Length	Integer	File_System_Entity
Source.Physical_Region_Start	Integer	File_System_Entity
Source.Region_Length	Integer	File_System_Entity
Source.Region_Start	Integer	File_System_Entity

The Source.Name of a File node is the name of the file in the file system (with extension).

File_System_Entity

File_System_Entity

Subtypes

Directory, File, Module

Containing Views

none (only subtypes of File_System_Entity are contained in views)

Description

The File_System_Entity node type is the base type of all nodes representing entities of the file system, like directories, files, and modules.

Attributes

Attribute name	Attribute type	Inherited from
Linkage.Name	String	-
Linkage.PIR_Node	Integer	-
Source.Column	Integer	-
Source.File	String	-
Source.Line	Integer	-
Source.Name	String	-
Source.Path	String	-
Source.Physical_File	String	-
Source.Physical_Path	String	-
Source.Physical_Region_Length	Integer	-
Source.Physical_Region_Start	Integer	-
Source.Region_Length	Integer	-
Source.Region_Start	Integer	-

Macro

Macro (inherits from: Source_Entity)

Subtypes

none

Containing Views

Call, Code Facts, Declaration Facts, File, Module

Description

A Macro node represents a macro in the C/C++ language.

Macros are often used like constants and inline functions and the Axivion Suite tries to get as close as possible to allow analyzing such code. On the other hand, heavy use of token pasting etc. leads to very detailed invocation trees.

The treatment of macros can be configured, see option macro_options.represent_macros of rule /Analysis/Architecture/Architecture-Dependencies.

Note

Because macro expansion can lead to different expansions in different contexts, you may see more macro nodes than you would expect on first sight from the source code.

Attributes

Attribute name	Attribute type	Inherited from
Linkage.Is_Ambiguous_Name	Toggle	Source_Entity
Linkage.Is_Definition	Toggle	Source_Entity
Linkage.LIR_Node	Integer	Source_Entity
Linkage.Name	String	Source_Entity
Linkage.PIR_Node	Integer	Source_Entity
Source.Body_End_Column	Integer	Source_Entity
Source.Body_End_Line	Integer	Source_Entity
Source.Body_Start_Column	Integer	Source_Entity
Source.Body_Start_Line	Integer	Source_Entity
Source.Column	Integer	Source_Entity
Source.Declaration_Start	Integer	Source_Entity
Source.File	String	Source_Entity
Source.Line	Integer	Source_Entity
Source.Name	String	Source_Entity
Source.Path	String	Source_Entity
Source.Physical_File	String	Source_Entity
Source.Physical_Path	String	Source_Entity
Source.Physical_Region_Length	Integer	Source_Entity
Source.Physical_Region_Start	Integer	Source_Entity
Source.Region_Length	Integer	Source_Entity
Source.Region_Start	Integer	Source_Entity
Source.Signature_Start	Integer	Source_Entity

Member

Member (inherits from: Source_Entity)

Subtypes

none

Containing Views

Code Facts, Declaration Facts, File, Module

Description

A Member represents components of structs and unions. Member nodes are contained in the respective type by Enclosing edges leading from the member to the type as depicted in Figure  Example: Type with enclosed member nodes shown flat and hierarchically.. In hierarchical graph windows of gravis, the containment is shown by the layout of the members inside the rectangle representing the interior of a type.

Note

A component of an enum is represented as a Constant.

Attributes

Attribute name	Attribute type	Inherited from
Element.Has_Public_Visibility	Toggle	-
Element.Is_Anonymous	Toggle	-
Element.Is_Const	Toggle	-
Linkage.Is_Ambiguous_Name	Toggle	Source_Entity
Linkage.Is_Definition	Toggle	Source_Entity
Linkage.LIR_Node	Integer	Source_Entity
Linkage.Name	String	Source_Entity
Linkage.PIR_Node	Integer	Source_Entity
Source.Body_End_Column	Integer	Source_Entity
Source.Body_End_Line	Integer	Source_Entity
Source.Body_Start_Column	Integer	Source_Entity
Source.Body_Start_Line	Integer	Source_Entity
Source.Column	Integer	Source_Entity
Source.Declaration_Start	Integer	Source_Entity
Source.File	String	Source_Entity
Source.Line	Integer	Source_Entity
Source.Name	String	Source_Entity
Source.Path	String	Source_Entity
Source.Physical_File	String	Source_Entity
Source.Physical_Path	String	Source_Entity
Source.Physical_Region_Length	Integer	Source_Entity
Source.Physical_Region_Start	Integer	Source_Entity
Source.Region_Length	Integer	Source_Entity
Source.Region_Start	Integer	Source_Entity
Source.Signature_Start	Integer	Source_Entity

A Member in a C RFG is always tagged with the attribute Element.Has_Public_Visibility ().

Note

Code Example

Example: Type with enclosed member nodes shown flat and hierarchically.

Module

Module (inherits from: File_System_Entity)

Subtypes

none

Containing Views

Module

Description

A Module M represents the combination of a C source file M.c and its corresponding header file M.h. A Module contains all definitions in the corresponding files by incoming Enclosing edges. It may be contained in a Directory node.

Attributes

Attribute name	Attribute type	Inherited from
Linkage.Name	String	File_System_Entity
Linkage.PIR_Node	Integer	File_System_Entity
Source.Column	Integer	File_System_Entity
Source.File	String	File_System_Entity
Source.Line	Integer	File_System_Entity
Source.Name	String	File_System_Entity
Source.Path	String	File_System_Entity
Source.Physical_File	String	File_System_Entity
Source.Physical_Path	String	File_System_Entity
Source.Physical_Region_Length	Integer	File_System_Entity
Source.Physical_Region_Start	Integer	File_System_Entity
Source.Region_Length	Integer	File_System_Entity
Source.Region_Start	Integer	File_System_Entity

The Source.Name of a Module is the name of the corresponding source file(s) without extension.

Object

Object (inherits from: Source_Entity)

Subtypes

Constant, Variable

Containing Views

none (only subtypes of Object are contained in views)

Description

Object specializes into Variable which represents global variables and Constant which represents global constants and enumerator constants.

Attributes

Attribute name	Attribute type	Inherited from
Element.Is_Static	Toggle	-
Linkage.Is_Ambiguous_Name	Toggle	Source_Entity
Linkage.Is_Definition	Toggle	Source_Entity
Linkage.LIR_Node	Integer	Source_Entity
Linkage.Name	String	Source_Entity
Linkage.PIR_Node	Integer	Source_Entity
Source.Body_End_Column	Integer	Source_Entity
Source.Body_End_Line	Integer	Source_Entity
Source.Body_Start_Column	Integer	Source_Entity
Source.Body_Start_Line	Integer	Source_Entity
Source.Column	Integer	Source_Entity
Source.Declaration_Start	Integer	Source_Entity
Source.File	String	Source_Entity
Source.Line	Integer	Source_Entity
Source.Name	String	Source_Entity
Source.Path	String	Source_Entity
Source.Physical_File	String	Source_Entity
Source.Physical_Path	String	Source_Entity
Source.Physical_Region_Length	Integer	Source_Entity
Source.Physical_Region_Start	Integer	Source_Entity
Source.Region_Length	Integer	Source_Entity
Source.Region_Start	Integer	Source_Entity
Source.Signature_Start	Integer	Source_Entity

The toggle attribute Element.Is_Static ( ) indicates whether the variable is declared static.

Routine

Routine (inherits from: Source_Entity)

Subtypes

none

Containing Views

Call, Code Facts, Declaration Facts, File, Module

Description

A Routine represents a C function.

Attributes

Attribute name	Attribute type	Inherited from
Analysis.Dead_Code	Toggle	-
Element.Has_Ambiguous_Declaration	Toggle	-
Element.Has_Ellipsis	Toggle	-
Element.Is_Anonymous	Toggle	-
Element.Is_Artificial	Toggle	-
Element.Is_Destructor	Toggle	-
Element.Is_Inline	Toggle	-
Element.Is_Interrupt	Toggle	-
Element.Is_Static	Toggle	-
Linkage.Is_Ambiguous_Name	Toggle	Source_Entity
Linkage.Is_Definition	Toggle	Source_Entity
Linkage.LIR_Node	Integer	Source_Entity
Linkage.Name	String	Source_Entity
Linkage.PIR_Node	Integer	Source_Entity
Source.Body_End_Column	Integer	Source_Entity
Source.Body_End_Line	Integer	Source_Entity
Source.Body_Start_Column	Integer	Source_Entity
Source.Body_Start_Line	Integer	Source_Entity
Source.Column	Integer	Source_Entity
Source.Declaration_Start	Integer	Source_Entity
Source.File	String	Source_Entity
Source.Line	Integer	Source_Entity
Source.Name	String	Source_Entity
Source.Path	String	Source_Entity
Source.Physical_File	String	Source_Entity
Source.Physical_Path	String	Source_Entity
Source.Physical_Region_Length	Integer	Source_Entity
Source.Physical_Region_Start	Integer	Source_Entity
Source.Region_Length	Integer	Source_Entity
Source.Region_Start	Integer	Source_Entity
Source.Signature_Start	Integer	Source_Entity

A Routine has the attribute Element.Number_Of_Parameters of type Integer which contains the number of parameters of the routine. The toggle attribute Element.Is_Static ( ) indicates whether the function is declared static.

Note

Code Example

void f(void)
{
}

static void g(void)
{
}

Example: Routines.

Source_Entity

Source_Entity

Subtypes

Macro, Member, Object, Routine, Type

Containing Views

none (only subtypes of Source_Entity are contained in views)

Description

The Source_Entity node type is the base type of all source-related entities like types, routines, variables, and members.

Attributes

Attribute name	Attribute type	Inherited from
Linkage.Is_Ambiguous_Name	Toggle	-
Linkage.Is_Definition	Toggle	-
Linkage.LIR_Node	Integer	-
Linkage.Name	String	-
Linkage.PIR_Node	Integer	-
Source.Body_End_Column	Integer	-
Source.Body_End_Line	Integer	-
Source.Body_Start_Column	Integer	-
Source.Body_Start_Line	Integer	-
Source.Column	Integer	-
Source.Declaration_Start	Integer	-
Source.File	String	-
Source.Line	Integer	-
Source.Name	String	-
Source.Path	String	-
Source.Physical_File	String	-
Source.Physical_Path	String	-
Source.Physical_Region_Length	Integer	-
Source.Physical_Region_Start	Integer	-
Source.Region_Length	Integer	-
Source.Region_Start	Integer	-
Source.Signature_Start	Integer	-

Type

Type (inherits from: Source_Entity)

Subtypes

Class

Containing Views

Code Facts, Declaration Facts, File, Module

Description

A Type represents a user-defined C type alias introduced by typedef, as well as enum types.

Attributes

Attribute name	Attribute type	Inherited from
Element.Has_Ambiguous_Declaration	Toggle	-
Element.Is_Anonymous	Toggle	-
Element.Is_Enum	Toggle	-
Element.Is_Struct	Toggle	-
Element.Is_Typedef_To_Anonymous	Toggle	-
Element.Is_Union	Toggle	-
Linkage.Is_Ambiguous_Name	Toggle	Source_Entity
Linkage.Is_Definition	Toggle	Source_Entity
Linkage.LIR_Node	Integer	Source_Entity
Linkage.Name	String	Source_Entity
Linkage.PIR_Node	Integer	Source_Entity
Source.Body_End_Column	Integer	Source_Entity
Source.Body_End_Line	Integer	Source_Entity
Source.Body_Start_Column	Integer	Source_Entity
Source.Body_Start_Line	Integer	Source_Entity
Source.Column	Integer	Source_Entity
Source.Declaration_Start	Integer	Source_Entity
Source.File	String	Source_Entity
Source.Line	Integer	Source_Entity
Source.Name	String	Source_Entity
Source.Path	String	Source_Entity
Source.Physical_File	String	Source_Entity
Source.Physical_Path	String	Source_Entity
Source.Physical_Region_Length	Integer	Source_Entity
Source.Physical_Region_Start	Integer	Source_Entity
Source.Region_Length	Integer	Source_Entity
Source.Region_Start	Integer	Source_Entity
Source.Signature_Start	Integer	Source_Entity

If the configuration option node_options.merge_typedef_to_anonymous of rule Architecture-Dependencies is set to True (which is the default), the node for the typedef defining a type name for an anonymous struct or union subsumes the definition of the anonymous type and gets the toggle Element.Is_Typedef_To_Anonymous attached. If the configuration key is set to False, the type node representing the typedef is not marked by the above mentioned toggle.

If toggle attribute Element.Is_Anonymous is attached, the type has been declared without a name (see the following example).

Note

The RFG does not represent primitive types such as float and int. However, typedefs to primitive types are represented.

Note

Code Example

struct Struct {
  int field;
  // ...
};

union Union {
  int field;
  // ...
};

enum Enum {
  enumerator
  // ...
};

Example: Structures, unions, and enumerations in C.

Variable

Variable (inherits from: Object)

Subtypes

none

Containing Views

Code Facts, Declaration Facts, File, Module

Description

A Variable represents global variables (also const, static and volatile ones).

Note

Bauhaus does not extract local variables at the RFG level because they are the secret of routines and therefore not relevant at the architectural level.

Attributes

Attribute name	Attribute type	Inherited from
Element.Has_Ambiguous_Declaration	Toggle	-
Element.Is_Const	Toggle	-
Element.Is_Static	Toggle	-
Element.Is_Volatile	Toggle	-
Element.Is_Static	Toggle	Object
Linkage.Is_Ambiguous_Name	Toggle	Source_Entity
Linkage.Is_Definition	Toggle	Source_Entity
Linkage.LIR_Node	Integer	Source_Entity
Linkage.Name	String	Source_Entity
Linkage.PIR_Node	Integer	Source_Entity
Source.Body_End_Column	Integer	Source_Entity
Source.Body_End_Line	Integer	Source_Entity
Source.Body_Start_Column	Integer	Source_Entity
Source.Body_Start_Line	Integer	Source_Entity
Source.Column	Integer	Source_Entity
Source.Declaration_Start	Integer	Source_Entity
Source.File	String	Source_Entity
Source.Line	Integer	Source_Entity
Source.Name	String	Source_Entity
Source.Path	String	Source_Entity
Source.Physical_File	String	Source_Entity
Source.Physical_Path	String	Source_Entity
Source.Physical_Region_Length	Integer	Source_Entity
Source.Physical_Region_Start	Integer	Source_Entity
Source.Region_Length	Integer	Source_Entity
Source.Region_Start	Integer	Source_Entity
Source.Signature_Start	Integer	Source_Entity

Note

Code Example

/* We are in the global scope */
int globalvariable;

Example: Global variable.