R: Reflectance Information for C/Fortran routines in a DLL

getDLLRegisteredRoutines {base} | R Documentation

## Reflectance Information for C/Fortran routines in a DLL

### Description

This function allows us to query the set of routines in a DLL that are registered with R to enhance dynamic lookup, error handling when calling native routines, and potentially security in the future. This function provides a description of each of the registered routines in the DLL for the different interfaces, i.e. `.C`, `.Call`, `.Fortran` and `.External`.

### Usage

    getDLLRegisteredRoutines(dll, addNames = TRUE)

### Arguments

`dll` | a character string or `DLLInfo` object. The character string specifies the file name of the DLL of interest, and is given without the file name extension (e.g., the ‘.dll’ or ‘.so’) and with no directory/path information. So a file ‘MyPackage/libs/MyPackage.so’ would be specified as MyPackage. The `DLLInfo` objects can be obtained directly in calls to `dyn.load` and `library.dynam`, or can be found after the DLL has been loaded using `getLoadedDLLs`, which returns a list of `DLLInfo` objects (index-able by DLL file name). The `DLLInfo` approach avoids any ambiguities related to two DLLs having the same name but corresponding to files in different directories.
`addNames` | a logical value. If this is `TRUE`, the elements of the returned lists are named using the names of the routines (as seen by R via registration or raw name). If `FALSE`, these names are not computed and assigned to the lists. As a result, the call should be quicker. The name information is also available in the `NativeSymbolInfo` objects in the lists.

### Details

This takes the registration information after it has been registered and processed by the R internals. In other words, it uses the extended information.

There is `print` methods for the class, which prints only the types which have registered routines.

### Value

A list of class `"DLLRegisteredRoutines"` with four elements corresponding to the routines registered for the `.C`, `.Call`, `.Fortran` and `.External` interfaces. Each is a list (of class `"NativeRoutineList"`) with as many elements as there were routines registered for that interface.

Each element identifies a routine and is an object of class `"NativeSymbolInfo"`. An object of this class has the following fields:

`name` | the registered name of the routine (not necessarily the name in the C code).
`address` | the memory address of the routine as resolved in the loaded DLL. This may be `NULL` if the symbol has not yet been resolved.
`dll` | an object of class `DLLInfo` describing the DLL. This is same for all elements returned.
`numParameters` | the number of arguments the native routine is to be called with.

### Author(s)

Duncan Temple Lang duncan@wald.ucdavis.edu

### References

‘Writing R Extensions’ manual for symbol registration.

Duncan Temple Lang (2001). “In Search of C/C++ & FORTRAN Routines”. R News, 1(3), 20–23. https://www.r-project.org/doc/Rnews/Rnews_2001-3.pdf.

### See Also

`getLoadedDLLs`, `getNativeSymbolInfo` for information on the entry points listed.

### Examples

    dlls <- getLoadedDLLs()
    getDLLRegisteredRoutines(dlls[["base"]])

    getDLLRegisteredRoutines("stats")

[Package base version 4.0.5 Index]