fpt Reference:Coercion of INTEGER to LOGICAL

fpt and WinFPT Reference Manual - Command-line Commands

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ACCEPT COERCION OF INTEGER TO LOGICAL

Syntax:

[DO NOT] ACCEPT INTEGER COERCION TO LOGICAL [DO NOT] ACCEPT COERCION [OF] INTEGER TO LOGICAL [DO NOT] ACCEPT USE OF INTEGER FOR LOGICAL

Function:

Many compilers allow integer variables to be used in a logical context. This is particularly true of the DEC heritage compilers, VMS, CVF, HP-UX, ifort and ifx. This command specifies whether fpt will allow the usage without flagging an error.

Coercion of integers to logicals is non-standard and different systems use different conventions. The DEC heritage systems all use the least significant bit of the integer to indicate .TRUE. or .FALSE. Other systems use non-zero or zero, or positive or negative. When fpt evaluates a logical expression which contains an integer coerced to a logical the convention is controlled by the command REPRESENT .TRUE. BY. fpt can also correct the use of integers in logical contexts by inserting code to generate the logical value. The command is CORRECT USE OF INTEGER FOR LOGICAL.

In some legacy codes it was common practice to use logical variables, in particular LOGICAL*1 variables, to hold integer values. fpt may systematically change all LOGICAL*1 declarations to INTEGER*1. The command is CHANGE LOGICAL*1 TO INTEGER*1. When this command is made fpt also accepts coercion of integer to logical.

Where to Use this Command

Operating system command line	Yes
Configuration file, config.fsp	Yes
Specification (fsp) files, *.fsp	Yes
Interactively, to FPT> prompt	No
Interactive command files	No
Embedded in the Fortran code	Yes

Default

By default fpt does not accept the coercion and flags a diagnostic.

(Note that defaults may be changed in the configuration file)