Front-end

The front-end is responsible for parsing the source code and issuing warning and error messages when the parse fails. Command-line options enable you to control the front end’s assumptions about the source code, including whether the source is in fixed or free format, uses implicit or explicit typing, and contains extensions. Other front-end options control the level of error messages and their language (Native Language Support), default data sizes, and search rules for .mod files. For a list of the options that control the front end, see Table 3 (page 11).

Table 3 Options for controlling the front end

Option

Function

 

 

+[no]autodbl

Promote [do not promote] all integer, logical, and real

 

items to 8 bytes, and all double-precision and complex

 

items to 16 bytes. The default is +noautodbl.

 

nl

 

For information about using this option, see “Increasing

 

default data sizes” (page 70).

 

 

+[no]autodbl4

Promote [do not promote] all integer, logical, and real

 

items to 8 bytes, and complex items to 16 bytes. The

 

+autodbl4 option does not promote the size of

 

double-precision and double-complex items. The default is

 

+noautodbl4.

 

nl

 

For information about using this option, see “Increasing

 

default data sizes” (page 70).

 

 

+check={allnone}

Enable (+check=all) or disable (+check=none)

 

compile-time range checking of array subscripts and

 

uninitialized stack variables at runtime. The default is

 

+check=none.

 

nl

 

For information about using this option, see “Segmentation

 

violation exception” (page 79).

 

 

+[no]dlines

Compile debug lines as source statements [comments].

 

Source lines must be in fixed format. The default,

 

+nodlines, is to treat source lines with a D or d in column

 

1 as comments.

 

nl

 

For information on using this option, see “Using debugging

 

lines” (page 80).

 

 

+[no]escape

Treat the backslash character (\) as a C-like escape [literal]

 

character. The default is +noescape.

 

nl

 

For information on using this option when porting, see

 

“Escape sequences” (page 148).

 

 

+[no]extend_source

Allow [do not allow] up to 254 characters on a single

 

source line. The default, +noextend_source, is 72

 

characters for fixed format and 132 for free format.

 

nl

 

For information on using this option when porting, see

 

“Source formats” (page 147).

 

 

+f2003

Enable compiling of Fortran 2003 standard code.

 

 

+f2003allocassign

Enables automatic allocation or re-allocation of arrays

 

when an assignment happens to an allocatable array that

 

is part of F2003 standard.

 

 

-Idirectory

Add directory to the list of directories searched for files

 

specified inINCLUDE lines and include directives, and for

 

.mod files. The command line can have multiple instances

 

of this option, each specifying a different directory.

 

nl

 

For information about using this option, see “Managing

 

.mod files” (page 58).

 

 

Front-end 11