TypeDefinition-class: Classes representing C/C++ types in a translation unit...

In omegahat/RGCCTranslationUnit: R interface to GCC source code information

Description

This is a collection of related classes that are used to describe the basic and derived types in C/C++ code.

Structures and unions in C/C++ are different types of aggregators that contain one or more fields. In this framework, we use a common base class ContainerDefinition to represent the information so that we can define methods for that virtual class to be inherited by both actual types of data structures.

The PendingType class is a little different than the others. It is used when processing a type which may have references to itself or some other types that are also being processed recursively. The simplest example is a structure which has a field that is a pointer to an instance of the same class. This occurs in a linked list, for example. Then when resolving the definitin of this structure, we would end up resolving the type of this field and so would end up in an infinite loop. The call to resolveType arranges to check the collection of already resolved classes, and if it finds a definition for the target node, it uses that. When it starts actually resolving a previously unprocessed type, it puts a PendingType definition in the catalog of definitions to avoid the potential recursive loop.

C++ReferenceType is used for typedefs and aliases where we have a type definition that refers to another type definition. In this sense, the object is a type definition but the type it represents is another type definition. This is not to be confused with the RC++Reference class which is used at run-time as the base class for a reference/pointer to a C++ instance.

Objects from the Class

Instances of these classes are typically created via resolveType. Mostly, these are constructed directly using new(class-name, ...).

Slots

name:

Object of class "character" giving the "human" readable name for the type that is used when generating code.

typeName:

Object of class "character", identifying the base type of the pointer

depth

an integer indicating the level of indirection of this pointer type, i.e. that this is a pointer to a pointer to a pointer ... A simple pointer to an actual type has a depth value of 1.

qualifiers

a character vector returned from a call to node$quals() on the underlying Perl GCC::Node object. This gives the qualifiers for the node including things such as const, C, volatile, etc. that give us more information about the definition of the type.

scope

currently, a character vector with zero or a single named entry. If this is the empty vector, then the scope is the top-level. If this contains an element, that value is the index of the node in the TU array/parser that defines the scope. The name of the element gives the human readable name. This field is used to determine whether the type is visible at the top-level, i.e. C/C++ code that interfaces to the code.

It is not clear that all TypeDefinition objects need this field, but it seems reasonable at the moment.

Methods

No methods defined with class "TypeDefinition" in the signature.

Author(s)

Duncan Temple Lang <[e-mail]>

References

http://www.omegahat.org/RGCCTranslationUnit

See Also

resolveType The built-in primitive types i.e. boolType-class, etc.

omegahat/RGCCTranslationUnit documentation built on May 24, 2019, 1:53 p.m.