# dyncom, Qdyncom

Enables dynamic allocation of common blocks at run time.

## Syntax

Linux: | -dyncom "common1,common2,..."

macOS: | -dyncom "common1,common2,..."

Windows: | /Qdyncom "common1,common2,..."

## Arguments

common1,common2,... | Are the names of the common blocks to be dynamically allocated. The list of names must be within quotes.

## Default

OFF | Common blocks are not dynamically allocated at run time.

## Description

This option enables dynamic allocation of the specified common blocks at run time. For example, to enable dynamic allocation of common blocks a, b, and c at run time, use this syntax:

Linux and macOS

    -dyncom "a,b,c"

Windows

    /Qdyncom "a,b,c"

The following are some limitations that you should be aware of when using this option:

- An entity in a dynamic common cannot be initialized in a DATA statement.

- Only named common blocks can be designated as dynamic COMMON.

- An entity in a dynamic common block must not be used in an EQUIVALENCE expression with an entity in a static common block or a DATA-initialized variable.

### Note

On macOS systems, to successfully enable dynamic allocation of common blocks, you must specify the link-time option -undefined dynamic_lookup as well as option -dyncom.

## IDE Equivalent

Visual Studio: Data > Dynamic Common Blocks

## Alternate Options

None

Parent topic: Data Options

## See Also

Allocating Common Blocks
FOR__SET_FTN_ALLOC