/[no]fpscomp

Syntax:

/fpscomp[:keyword...] or /nofpscomp

The /fpscomp option controls whether certain aspects of the run-time system and semantic language features within the compiler are compatible with Visual Fortran or Microsoft Fortran PowerStation.

If you experience problems when porting applications from Fortran PowerStation, specify /fpscomp:keyword (or /fpscomp:all). When porting applications from Compaq Fortran, use /fpscomp:none or /fpscomp:libs (the default).

In the visual development environment, specify the PowerStation 4.0 Compatibility Options in the Compatibility Compiler Option Category. The /fpscomp options and their visual development environment names are:

/fpscomp:[no]filesfromcmd

Specifying /fpscomp:filesfromcmd for a file where the OPEN statement FILE specifier is blank (FILE=' '), requests that the following actions be taken at run-time:

• The program reads a filename from the list of arguments (if any) in the command line that invoked the program. If any of the command-line arguments contain a null string (''), the program asks the user for the corresponding filename. Each additional OPEN statement with a nameless FILE specifier reads the next command-line argument.
• If there are more nameless OPEN statements than command-line arguments, the program prompts for additional file names.
• In a QuickWin application, a File Select dialog box appears to request file names.

Specifying /fpscomp:nofilesfromcmd disables the run-time system from using the filename specified on the command line when the OPEN statement FILE specifier is omitted, allowing the application of default directory, file name, and extensions like Compaq Fortran, such as the FORTn environment variable and the FORT.n file name (where n is the unit number).

Specifying /fpscomp:filesfromcmd affects the following Fortran features:

• The OPEN statement FILE specifier

  For example, assume a program OPENTEST contains the following statements:

    OPEN(UNIT = 2, FILE = ' ')
    OPEN(UNIT = 3, FILE = ' ')
    OPEN(UNIT = 4, FILE = ' ')
   

  The following command line assigns the file TEST.DAT to Unit 2, prompts the user for a filename to associate with Unit 3, then prompts again for a filename to associate with Unit 4:
  

    opentest test.dat '' ''
   

• Implicit file open statements such as the WRITE, READ, and ENDFILE statements

  Unopened files referred to in READ or WRITE statements are opened implicitly as if there had been an OPEN statement with a name specified as all blanks. The name is read from the command line.

  WRITE(UNIT = 8, FMT='(2I5)') int1, int2 ! Where "8" has not been
                                          ! explicitly associated with a file.
   

For more information about running Visual Fortran programs with the /fpscomp:filesfromcmd option or the use of alternative routines, see Running Fortran Applications.

/fpscomp:[no]general

Specifying /fpscomp:[no]general controls which run-time behavior is used when a difference exists between Visual Fortran and Microsoft Fortran PowerStation and either semantic must remain available for compatibility reasons:

• Specify /fpscomp:general to request Microsoft Fortran PowerStation semantics.
• Specify /fpscomp:nogeneral to request Visual Fortran semantics.

This affects the following Fortran features:

• The BACKSPACE statement:
  
  • Allows files opened with ACCESS='APPEND' to be used with the BACKSPACE statement.
  • Allows files opened with ACCESS='DIRECT' to be used with the BACKSPACE statement.

  Note: Allowing files that are not opened with sequential access (such as ACCESS='DIRECT') to be used with the BACKSPACE statement violates the Fortran 90 standard and may be removed in the future. Section 9.5 states the following: "A file that is not connected for sequential access must not be referred to by a BACKSPACE, an ENDFILE, or a REWIND statement..."

• The READ statement:
  
  • Formatted: READ(eunit, format [, advance][, iostat]...)
    Reading from a formatted file opened for direct access will read records that have the same record type format as Fortran PowerStation when /fpscomp:general is set. This consists of accounting for the trailing Carriage Return/Line Feed pair (<CR><LF>) that is part of the record.
    Allows sequential reads from a formatted file opened for direct access.

    Note: Allowing files that are not opened with sequential access (such as ACCESS='DIRECT') to be used with the sequential READ statement violates the Fortran 90 standard and may be removed in the future. Section 9.2.1.2.2 states the following: "Reading and writing records is accomplished only by direct access input/output statements."

  • Allows the last record in a file opened with FORM='FORMATTED' and a record type of STREAM_LF or STREAM_CR that does not end with a proper record terminator (<line feed> or <carriage return>) to be read without producing an error.
  • Unformatted: READ(eunit [, iostat]...)
    Allows sequential reads from an unformatted file opened for direct access.

    Note: Allowing files that are not opened with sequential access (such as ACCESS='DIRECT') to be read with the sequential READ statement violates the Fortran 90 standard and may be removed in the future. Section 9.2.1.2.2 states the following: "Reading and writing records is accomplished only by direct access input/output statements."

• The INQUIRE statement:
  • The CARRIAGECONTROL specifier returns the value "UNDEFINED" instead of "UNKNOWN" when the carriage control is not known and when /fpscomp:general is set.
  • The NAME specifier returns the file name "UNKNOWN" instead of space filling the file name when the file name is not known and when /fpscomp:general is set.
  • The SEQUENTIAL specifier returns the value "YES" instead of "NO" for a direct access formatted file when /fpscomp:general is set.
  • The UNFORMATTED specifier returns the value "NO" instead of "UNKNOWN" when it is not known whether unformatted I/O can be performed to the file and when /fpscomp:general is set.

    Note: Returning the value "NO" instead of "UNKNOWN" for this specifier violates the Fortran 90 standard and may be removed in the future. See Section 9.6.1.12.

• The OPEN statement:
  • If a file is opened with an unspecified STATUS keyword value, and is not named (no FILE specifier), the file is opened as a scratch file when /fpscomp:general is set. For example:

     OPEN (UNIT = 4)
    	

    
    In contrast, when /fpscomp:nogeneral is in effect with an unspecified STATUS value with no FILE specifier, the FORTn environment variable and the FORT.n file name are used (where n is the unit number).
  • If the STATUS value was not specified and if the name of the file is "USER", the file is marked for deletion when it is closed when /fpscomp:general is set.
  • Allows a file to be opened with the APPEND and READONLY characteristics when /fpscomp:general is set.
  • If the CARRIAGECONTROL specifier is defaulted, gives "LIST" carriage control to direct access formatted files instead of "NONE" when /fpscomp:general is set.
  • Gives an opened file the additional default of write sharing when /fpscomp:general is set.
  • Gives the file a default block size of 1024 when /fpscomp:general is set as compared to 8192 (see Efficient Use of Record Buffers and Disk I/O).
  • If the MODE and ACTION specifier is defaulted and there was an error opening the file, then try opening the file read only, then write only.
  • If the CARRIAGECONTROL specifier is defaulted and if the device type is a terminal file, the file is given the default carriage control value of "FORTRAN" as compared to "LIST" when /fpscomp:general is set.
  • If a file that is being re-opened has a different file type than the current existing file, an error is returned when /fpscomp:general is set.
  • Gives direct access formatted files the same record type as Fortran PowerStation when /fpscomp:general is set. This means accounting for the trailing Carriage Return/Line Feed pair (<CR><LF>) which is part of the record.
    
    
• The STOP statement:
  • Writes the Fortran PowerStation output string and/or returns the same exit condition values when /fpscomp:general is set.

• The WRITE statement:
  • Formatted: WRITE(eunit, format [, advance][, iostat]...)
    
    • Writing to formatted direct files

      When writing to a formatted file opened for direct access, records are written in the same record type format as Fortran PowerStation when /fpscomp:general is set. This consists of adding the trailing Carriage Return/Line Feed pair (<CR><LF>) that is part of the record.

      Ignores the CARRIAGECONTROL specifier setting when writing to a formatted direct access file.
      
      
    • Interpreting Fortran carriage control characters

      When interpreting Fortran carriage control characters during formatted I/O, carriage control sequences are written which are the same as Fortran PowerStation when /fpscomp:general is set. This is true for the "Space, 0, 1 and + " characters.

    • Performing non-advancing I/O to the terminal.

      When performing non-advancing I/O to the terminal, output is written in the same format as Fortran PowerStation when /fpscomp:general is set.

    • Interpreting the backslash (\) and dollar ($) edit descriptors
      When interpreting backslash and dollar edit descriptors during formatted I/O, sequences are written the same as Fortran PowerStation when /fpscomp:general is set.
      
      
  • Unformatted: WRITE(eunit [, iostat]...)

    Allows sequential writes from an unformatted file opened for direct access.

    Note: Allowing files that are not opened with sequential access (such as ACCESS='DIRECT') to be read with the sequential WRITE statement violates the Fortran 90 standard and may be removed in the future. Section 9.2.1.2.2 states the following: "Reading and writing records is accomplished only by direct access input/output statements."

• Specifying /fpscomp:general sets /fpscomp:ldio_spacing.

/fpscomp:[no]ioformat

Controls which run-time behavior is used for the semantic format for list-directed formatted I/O and unformatted I/O. Specify /fpscomp:ioformat to request Microsoft Fortran PowerStation semantic conventions and record formats (see Microsoft Fortran PowerStation Compatible Files). Specify /fpscomp:noioformat to request Compaq Fortran semantic conventions. This affects the following Fortran features:

• The WRITE statement:
  
  • Formatted List-Directed: WRITE(eunit, * [, iostat]...)
  • Formatted Internal List-Directed: WRITE(iunit, * [, iostat]...)
  • Formatted Namelist: WRITE(eunit, nml-group [, iostat]...)

    If /fpscomp:ioformat is set, the output line, field width values, and the list-directed data type semantics are dictated according to the following sample for real constants (N below):

    • For 1 <= N < 10**7, use F15.6 for single precision or F24.15 for double.
    • For N < 1 or N >= 10**7, use E15.6E2 for single precision or E24.15E3 for double.

    See the Fortran PowerStation documentation for more detailed information about the other data types affected.

  • Unformatted: WRITE(eunit [, iostat]...)

    If /fpscomp:ioformat is set, the unformatted file semantics are dictated according to the Fortran PowerStation documentation. Be aware that the file format differs from that used by Compaq Fortran. See the Fortran PowerStation documentation for more detailed information.

    The following table summarizes the default output formats for list-directed output with the intrinsic data types:

    Default Formats for List-Directed Output

    Data Type	Output Format with /fpscomp:noioformat	Output Format with /fpscomp:ioformat
    BYTE	I5	I12
    LOGICAL (all)	L2	L2
    INTEGER(1)	I5	I12
    INTEGER(2)	I7	I12
    INTEGER(4)	I12	I12
    INTEGER(8)	I22	I22
    REAL(4)	1PG15.7E2	1PG16.6E2
    REAL(8)	1PG24.15E3	1PG25.15E3
    COMPLEX(4)	'( ',1PG14.7E2, ', ',1PG14.7E2, ') '	'( ',1PG16.6E2, ', ',1PG16.6E2, ') '
    COMPLEX(8)	'( ',1PG23.15E3, ', ',1PG23.15E3, ') '	'( ',1PG25.15E3, ', ',1PG25.15E3, ') '
    CHARACTER	Aw	Aw

    
    
• The READ statement:
  
  • Formatted List-Directed: READ(eunit, * [, iostat]...)
  • Formatted Internal List-Directed: READ(iunit, * [, iostat]...)
  • Formatted Namelist: READ(eunit, nml-group [, iostat]...)

    If /fpscomp:ioformat is set, the field width values and the list-directed semantics are dictated according to the following sample for real constants (N below):

    • For 1 <= N < 10**7, use F15.6 for single precision or F24.15 for double.
    • For N < 1 or N >= 10**7, use E15.6E2 for single precision or E24.15E3 for double.

    See the Fortran PowerStation documentation for more detailed information about the other data types affected.

  • Unformatted: READ(eunit [, iostat]...)

    If /fpscomp:ioformat is set, the unformatted file semantics are dictated according to the Fortran PowerStation documentation. Be aware that the file format to read differs from that used by Compaq Fortran. See the Fortran PowerStation documentation for more detailed information.

/fpscomp:[no]ldio_spacing

For list-directed output, controls whether a blank is inserted at run-time after a numeric value before a character value (undelimited character string). The default is /fpscomp:noldio_spacing, which conforms to the Fortran 95 standard by inserting a blank after a numeric value before a character value. To request non-standard behavior for compatibility with Microsoft Fortran PowerStation and Visual Fortran releases before Version 6.6, either specify /fpscomp:ldio_spacing or specify /fpscomp:general, which sets /fpscomp:ldio_spacing.

/fpscomp:[no]libs

Controls whether the library dfport.lib (Portability library) is passed to the compiler and linker. The default is /fpscomp:libs, which passes this library. Specifying /fpscomp:nolibs does not pass this library.

/fpscomp:[no]logicals

Controls the value used for logical true. Microsoft Fortran PowerStation and Compaq Fortran with the /fpscomp:logical option set uses any non-zero value (default is 1) for true. Compaq Fortran with the /fpscomp:nological option set only looks at the low bit of the value, using a -1 for true. Differences can occur when a logical is stored into an integer. Both use 0 (zero) for false.

This affects the results of all logical expressions and affects the return value for the following Fortran features:

• The INQUIRE statement specifiers OPENED, IOFOCUS, EXISTS, and NAMED.
• The EOF intrinsic function.
• The BTEST intrinsic function.
• The lexical intrinsic functions LLT, LLE, LGT, and LGE.

/fpscomp:[no]symbols

Adds one or more symbols related to Microsoft Fortran PowerStation to preprocessor and compiler invocations. The symbol currently set by specifying /fpscomp:symbols is _MSFORTRAN_=401.

/fpscomp:all and /fpscomp

Enable full Microsoft Fortran PowerStation compatibility or /fpscomp:(filesfromcmd,general,ioformat,ldio_spacing,libs,logicals,symbols).

/nofpscomp or /fpscomp:none

Enables full Compaq Fortran compatibility or /fpscomp:(nofilesfromcmd,nogeneral,noioformat,noldio_spacing,nolibs,nologicals,nosymbols).

If you omit /fpscomp, the default is /fpscomp:libs.

The /fpscomp and /vms options are not allowed in the same command.