+++ /dev/null
-This is g77.info, produced by makeinfo version 4.5 from g77.texi.
-
-INFO-DIR-SECTION Programming
-START-INFO-DIR-ENTRY
-* g77: (g77). The GNU Fortran compiler.
-END-INFO-DIR-ENTRY
- This file documents the use and the internals of the GNU Fortran
-(`g77') compiler. It corresponds to the GCC-3.2.3 version of `g77'.
-
- Published by the Free Software Foundation 59 Temple Place - Suite 330
-Boston, MA 02111-1307 USA
-
- Copyright (C) 1995,1996,1997,1998,1999,2000,2001,2002 Free Software
-Foundation, Inc.
-
- Permission is granted to copy, distribute and/or modify this document
-under the terms of the GNU Free Documentation License, Version 1.1 or
-any later version published by the Free Software Foundation; with the
-Invariant Sections being "GNU General Public License" and "Funding Free
-Software", the Front-Cover texts being (a) (see below), and with the
-Back-Cover Texts being (b) (see below). A copy of the license is
-included in the section entitled "GNU Free Documentation License".
-
- (a) The FSF's Front-Cover Text is:
-
- A GNU Manual
-
- (b) The FSF's Back-Cover Text is:
-
- You have freedom to copy and modify this GNU Manual, like GNU
-software. Copies published by the Free Software Foundation raise
-funds for GNU development.
-
- Contributed by James Craig Burley (<craig@jcb-sc.com>). Inspired by
-a first pass at translating `g77-0.5.16/f/DOC' that was contributed to
-Craig by David Ronis (<ronis@onsager.chem.mcgill.ca>).
-
-\1f
-File: g77.info, Node: Real Intrinsic, Next: RealPart Intrinsic, Prev: Range Intrinsic, Up: Table of Intrinsic Functions
-
-Real Intrinsic
-..............
-
- Real(A)
-
-Real: `REAL' function. The exact type is `REAL(KIND=1)' when argument
-A is any type other than `COMPLEX', or when it is `COMPLEX(KIND=1)'.
-When A is any `COMPLEX' type other than `COMPLEX(KIND=1)', this
-intrinsic is valid only when used as the argument to `REAL()', as
-explained below.
-
-A: `INTEGER', `REAL', or `COMPLEX'; scalar; INTENT(IN).
-
-Intrinsic groups: (standard FORTRAN 77).
-
-Description:
-
- Converts A to `REAL(KIND=1)'.
-
- Use of `REAL()' with a `COMPLEX' argument (other than
-`COMPLEX(KIND=1)') is restricted to the following case:
-
- REAL(REAL(A))
-
-This expression converts the real part of A to `REAL(KIND=1)'.
-
- *Note RealPart Intrinsic::, for information on a GNU Fortran
-intrinsic that extracts the real part of an arbitrary `COMPLEX' value.
-
- *Note REAL() and AIMAG() of Complex::, for more information.
-
-\1f
-File: g77.info, Node: RealPart Intrinsic, Next: Rename Intrinsic (subroutine), Prev: Real Intrinsic, Up: Table of Intrinsic Functions
-
-RealPart Intrinsic
-..................
-
- RealPart(Z)
-
-RealPart: `REAL' function, the `KIND=' value of the type being that of
-argument Z.
-
-Z: `COMPLEX'; scalar; INTENT(IN).
-
-Intrinsic groups: `gnu'.
-
-Description:
-
- The real part of Z is returned, without conversion.
-
- _Note:_ The way to do this in standard Fortran 90 is `REAL(Z)'.
-However, when, for example, Z is `COMPLEX(KIND=2)', `REAL(Z)' means
-something different for some compilers that are not true Fortran 90
-compilers but offer some extensions standardized by Fortran 90 (such as
-the `DOUBLE COMPLEX' type, also known as `COMPLEX(KIND=2)').
-
- The advantage of `REALPART()' is that, while not necessarily more or
-less portable than `REAL()', it is more likely to cause a compiler that
-doesn't support it to produce a diagnostic than generate incorrect code.
-
- *Note REAL() and AIMAG() of Complex::, for more information.
-
-\1f
-File: g77.info, Node: Rename Intrinsic (subroutine), Next: Repeat Intrinsic, Prev: RealPart Intrinsic, Up: Table of Intrinsic Functions
-
-Rename Intrinsic (subroutine)
-.............................
-
- CALL Rename(PATH1, PATH2, STATUS)
-
-PATH1: `CHARACTER'; scalar; INTENT(IN).
-
-PATH2: `CHARACTER'; scalar; INTENT(IN).
-
-STATUS: `INTEGER(KIND=1)'; OPTIONAL; scalar; INTENT(OUT).
-
-Intrinsic groups: `unix'.
-
-Description:
-
- Renames the file PATH1 to PATH2. A null character (`CHAR(0)') marks
-the end of the names in PATH1 and PATH2--otherwise, trailing blanks in
-PATH1 and PATH2 are ignored. See `rename(2)'. If the STATUS argument
-is supplied, it contains 0 on success or a non-zero error code upon
-return.
-
- Some non-GNU implementations of Fortran provide this intrinsic as
-only a function, not as a subroutine, or do not support the (optional)
-STATUS argument.
-
- For information on other intrinsics with the same name: *Note Rename
-Intrinsic (function)::.
-
-\1f
-File: g77.info, Node: Repeat Intrinsic, Next: Reshape Intrinsic, Prev: Rename Intrinsic (subroutine), Up: Table of Intrinsic Functions
-
-Repeat Intrinsic
-................
-
- This intrinsic is not yet implemented. The name is, however,
-reserved as an intrinsic. Use `EXTERNAL Repeat' to use this name for an
-external procedure.
-
-\1f
-File: g77.info, Node: Reshape Intrinsic, Next: RRSpacing Intrinsic, Prev: Repeat Intrinsic, Up: Table of Intrinsic Functions
-
-Reshape Intrinsic
-.................
-
- This intrinsic is not yet implemented. The name is, however,
-reserved as an intrinsic. Use `EXTERNAL Reshape' to use this name for
-an external procedure.
-
-\1f
-File: g77.info, Node: RRSpacing Intrinsic, Next: RShift Intrinsic, Prev: Reshape Intrinsic, Up: Table of Intrinsic Functions
-
-RRSpacing Intrinsic
-...................
-
- This intrinsic is not yet implemented. The name is, however,
-reserved as an intrinsic. Use `EXTERNAL RRSpacing' to use this name
-for an external procedure.
-
-\1f
-File: g77.info, Node: RShift Intrinsic, Next: Scale Intrinsic, Prev: RRSpacing Intrinsic, Up: Table of Intrinsic Functions
-
-RShift Intrinsic
-................
-
- RShift(I, SHIFT)
-
-RShift: `INTEGER' function, the `KIND=' value of the type being that of
-argument I.
-
-I: `INTEGER'; scalar; INTENT(IN).
-
-SHIFT: `INTEGER'; scalar; INTENT(IN).
-
-Intrinsic groups: `f2c'.
-
-Description:
-
- Returns I shifted to the right SHIFT bits.
-
- Although similar to the expression `I/(2**SHIFT)', there are
-important differences. For example, the sign of the result is
-undefined.
-
- Currently this intrinsic is defined assuming the underlying
-representation of I is as a two's-complement integer. It is unclear at
-this point whether that definition will apply when a different
-representation is involved.
-
- *Note RShift Intrinsic::, for the inverse of this function.
-
- *Note IShft Intrinsic::, for information on a more widely available
-right-shifting intrinsic that is also more precisely defined.
-
-\1f
-File: g77.info, Node: Scale Intrinsic, Next: Scan Intrinsic, Prev: RShift Intrinsic, Up: Table of Intrinsic Functions
-
-Scale Intrinsic
-...............
-
- This intrinsic is not yet implemented. The name is, however,
-reserved as an intrinsic. Use `EXTERNAL Scale' to use this name for an
-external procedure.
-
-\1f
-File: g77.info, Node: Scan Intrinsic, Next: Second Intrinsic (function), Prev: Scale Intrinsic, Up: Table of Intrinsic Functions
-
-Scan Intrinsic
-..............
-
- This intrinsic is not yet implemented. The name is, however,
-reserved as an intrinsic. Use `EXTERNAL Scan' to use this name for an
-external procedure.
-
-\1f
-File: g77.info, Node: Second Intrinsic (function), Next: Second Intrinsic (subroutine), Prev: Scan Intrinsic, Up: Table of Intrinsic Functions
-
-Second Intrinsic (function)
-...........................
-
- Second()
-
-Second: `REAL(KIND=1)' function.
-
-Intrinsic groups: `unix'.
-
-Description:
-
- Returns the process's runtime in seconds--the same value as the UNIX
-function `etime' returns.
-
- On some systems, the underlying timings are represented using types
-with sufficiently small limits that overflows (wraparounds) are
-possible, such as 32-bit types. Therefore, the values returned by this
-intrinsic might be, or become, negative, or numerically less than
-previous values, during a single run of the compiled program.
-
- For information on other intrinsics with the same name: *Note Second
-Intrinsic (subroutine)::.
-
-\1f
-File: g77.info, Node: Second Intrinsic (subroutine), Next: Selected_Int_Kind Intrinsic, Prev: Second Intrinsic (function), Up: Table of Intrinsic Functions
-
-Second Intrinsic (subroutine)
-.............................
-
- CALL Second(SECONDS)
-
-SECONDS: `REAL'; scalar; INTENT(OUT).
-
-Intrinsic groups: `unix'.
-
-Description:
-
- Returns the process's runtime in seconds in SECONDS--the same value
-as the UNIX function `etime' returns.
-
- On some systems, the underlying timings are represented using types
-with sufficiently small limits that overflows (wraparounds) are
-possible, such as 32-bit types. Therefore, the values returned by this
-intrinsic might be, or become, negative, or numerically less than
-previous values, during a single run of the compiled program.
-
- This routine is known from Cray Fortran. *Note CPU_Time Intrinsic::,
-for a standard equivalent.
-
- For information on other intrinsics with the same name: *Note Second
-Intrinsic (function)::.
-
-\1f
-File: g77.info, Node: Selected_Int_Kind Intrinsic, Next: Selected_Real_Kind Intrinsic, Prev: Second Intrinsic (subroutine), Up: Table of Intrinsic Functions
-
-Selected_Int_Kind Intrinsic
-...........................
-
- This intrinsic is not yet implemented. The name is, however,
-reserved as an intrinsic. Use `EXTERNAL Selected_Int_Kind' to use this
-name for an external procedure.
-
-\1f
-File: g77.info, Node: Selected_Real_Kind Intrinsic, Next: Set_Exponent Intrinsic, Prev: Selected_Int_Kind Intrinsic, Up: Table of Intrinsic Functions
-
-Selected_Real_Kind Intrinsic
-............................
-
- This intrinsic is not yet implemented. The name is, however,
-reserved as an intrinsic. Use `EXTERNAL Selected_Real_Kind' to use
-this name for an external procedure.
-
-\1f
-File: g77.info, Node: Set_Exponent Intrinsic, Next: Shape Intrinsic, Prev: Selected_Real_Kind Intrinsic, Up: Table of Intrinsic Functions
-
-Set_Exponent Intrinsic
-......................
-
- This intrinsic is not yet implemented. The name is, however,
-reserved as an intrinsic. Use `EXTERNAL Set_Exponent' to use this name
-for an external procedure.
-
-\1f
-File: g77.info, Node: Shape Intrinsic, Next: Short Intrinsic, Prev: Set_Exponent Intrinsic, Up: Table of Intrinsic Functions
-
-Shape Intrinsic
-...............
-
- This intrinsic is not yet implemented. The name is, however,
-reserved as an intrinsic. Use `EXTERNAL Shape' to use this name for an
-external procedure.
-
-\1f
-File: g77.info, Node: Short Intrinsic, Next: Sign Intrinsic, Prev: Shape Intrinsic, Up: Table of Intrinsic Functions
-
-Short Intrinsic
-...............
-
- Short(A)
-
-Short: `INTEGER(KIND=6)' function.
-
-A: `INTEGER'; scalar; INTENT(IN).
-
-Intrinsic groups: `unix'.
-
-Description:
-
- Returns A with the fractional portion of its magnitude truncated and
-its sign preserved, converted to type `INTEGER(KIND=6)'.
-
- If A is type `COMPLEX', its real part is truncated and converted,
-and its imaginary part is disgregarded.
-
- *Note Int Intrinsic::.
-
- The precise meaning of this intrinsic might change in a future
-version of the GNU Fortran language, as more is learned about how it is
-used.
-
-\1f
-File: g77.info, Node: Sign Intrinsic, Next: Signal Intrinsic (subroutine), Prev: Short Intrinsic, Up: Table of Intrinsic Functions
-
-Sign Intrinsic
-..............
-
- Sign(A, B)
-
-Sign: `INTEGER' or `REAL' function, the exact type being the result of
-cross-promoting the types of all the arguments.
-
-A: `INTEGER' or `REAL'; scalar; INTENT(IN).
-
-B: `INTEGER' or `REAL'; scalar; INTENT(IN).
-
-Intrinsic groups: (standard FORTRAN 77).
-
-Description:
-
- Returns `ABS(A)*S', where S is +1 if `B.GE.0', -1 otherwise.
-
- *Note Abs Intrinsic::, for the function that returns the magnitude
-of a value.
-
-\1f
-File: g77.info, Node: Signal Intrinsic (subroutine), Next: Sin Intrinsic, Prev: Sign Intrinsic, Up: Table of Intrinsic Functions
-
-Signal Intrinsic (subroutine)
-.............................
-
- CALL Signal(NUMBER, HANDLER, STATUS)
-
-NUMBER: `INTEGER'; scalar; INTENT(IN).
-
-HANDLER: Signal handler (`INTEGER FUNCTION' or `SUBROUTINE') or
-dummy/global `INTEGER(KIND=1)' scalar.
-
-STATUS: `INTEGER(KIND=7)'; OPTIONAL; scalar; INTENT(OUT).
-
-Intrinsic groups: `unix'.
-
-Description:
-
- If HANDLER is a an `EXTERNAL' routine, arranges for it to be invoked
-with a single integer argument (of system-dependent length) when signal
-NUMBER occurs. If HANDLER is an integer, it can be used to turn off
-handling of signal NUMBER or revert to its default action. See
-`signal(2)'.
-
- Note that HANDLER will be called using C conventions, so the value
-of its argument in Fortran terms Fortran terms is obtained by applying
-`%LOC()' (or LOC()) to it.
-
- The value returned by `signal(2)' is written to STATUS, if that
-argument is supplied. Otherwise the return value is ignored.
-
- Some non-GNU implementations of Fortran provide this intrinsic as
-only a function, not as a subroutine, or do not support the (optional)
-STATUS argument.
-
- _Warning:_ Use of the `libf2c' run-time library function `signal_'
-directly (such as via `EXTERNAL SIGNAL') requires use of the `%VAL()'
-construct to pass an `INTEGER' value (such as `SIG_IGN' or `SIG_DFL')
-for the HANDLER argument.
-
- However, while `CALL SIGNAL(SIGNUM, %VAL(SIG_IGN))' works when
-`SIGNAL' is treated as an external procedure (and resolves, at link
-time, to `libf2c''s `signal_' routine), this construct is not valid
-when `SIGNAL' is recognized as the intrinsic of that name.
-
- Therefore, for maximum portability and reliability, code such
-references to the `SIGNAL' facility as follows:
-
- INTRINSIC SIGNAL
- ...
- CALL SIGNAL(SIGNUM, SIG_IGN)
-
- `g77' will compile such a call correctly, while other compilers will
-generally either do so as well or reject the `INTRINSIC SIGNAL'
-statement via a diagnostic, allowing you to take appropriate action.
-
- For information on other intrinsics with the same name: *Note Signal
-Intrinsic (function)::.
-
-\1f
-File: g77.info, Node: Sin Intrinsic, Next: SinH Intrinsic, Prev: Signal Intrinsic (subroutine), Up: Table of Intrinsic Functions
-
-Sin Intrinsic
-.............
-
- Sin(X)
-
-Sin: `REAL' or `COMPLEX' function, the exact type being that of
-argument X.
-
-X: `REAL' or `COMPLEX'; scalar; INTENT(IN).
-
-Intrinsic groups: (standard FORTRAN 77).
-
-Description:
-
- Returns the sine of X, an angle measured in radians.
-
- *Note ASin Intrinsic::, for the inverse of this function.
-
-\1f
-File: g77.info, Node: SinH Intrinsic, Next: Sleep Intrinsic, Prev: Sin Intrinsic, Up: Table of Intrinsic Functions
-
-SinH Intrinsic
-..............
-
- SinH(X)
-
-SinH: `REAL' function, the `KIND=' value of the type being that of
-argument X.
-
-X: `REAL'; scalar; INTENT(IN).
-
-Intrinsic groups: (standard FORTRAN 77).
-
-Description:
-
- Returns the hyperbolic sine of X.
-
-\1f
-File: g77.info, Node: Sleep Intrinsic, Next: Sngl Intrinsic, Prev: SinH Intrinsic, Up: Table of Intrinsic Functions
-
-Sleep Intrinsic
-...............
-
- CALL Sleep(SECONDS)
-
-SECONDS: `INTEGER(KIND=1)'; scalar; INTENT(IN).
-
-Intrinsic groups: `unix'.
-
-Description:
-
- Causes the process to pause for SECONDS seconds. See `sleep(2)'.
-
-\1f
-File: g77.info, Node: Sngl Intrinsic, Next: Spacing Intrinsic, Prev: Sleep Intrinsic, Up: Table of Intrinsic Functions
-
-Sngl Intrinsic
-..............
-
- Sngl(A)
-
-Sngl: `REAL(KIND=1)' function.
-
-A: `REAL(KIND=2)'; scalar; INTENT(IN).
-
-Intrinsic groups: (standard FORTRAN 77).
-
-Description:
-
- Archaic form of `REAL()' that is specific to one type for A. *Note
-Real Intrinsic::.
-
-\1f
-File: g77.info, Node: Spacing Intrinsic, Next: Spread Intrinsic, Prev: Sngl Intrinsic, Up: Table of Intrinsic Functions
-
-Spacing Intrinsic
-.................
-
- This intrinsic is not yet implemented. The name is, however,
-reserved as an intrinsic. Use `EXTERNAL Spacing' to use this name for
-an external procedure.
-
-\1f
-File: g77.info, Node: Spread Intrinsic, Next: SqRt Intrinsic, Prev: Spacing Intrinsic, Up: Table of Intrinsic Functions
-
-Spread Intrinsic
-................
-
- This intrinsic is not yet implemented. The name is, however,
-reserved as an intrinsic. Use `EXTERNAL Spread' to use this name for an
-external procedure.
-
-\1f
-File: g77.info, Node: SqRt Intrinsic, Next: SRand Intrinsic, Prev: Spread Intrinsic, Up: Table of Intrinsic Functions
-
-SqRt Intrinsic
-..............
-
- SqRt(X)
-
-SqRt: `REAL' or `COMPLEX' function, the exact type being that of
-argument X.
-
-X: `REAL' or `COMPLEX'; scalar; INTENT(IN).
-
-Intrinsic groups: (standard FORTRAN 77).
-
-Description:
-
- Returns the square root of X, which must not be negative.
-
- To calculate and represent the square root of a negative number,
-complex arithmetic must be used. For example, `SQRT(COMPLEX(X))'.
-
- The inverse of this function is `SQRT(X) * SQRT(X)'.
-
-\1f
-File: g77.info, Node: SRand Intrinsic, Next: Stat Intrinsic (subroutine), Prev: SqRt Intrinsic, Up: Table of Intrinsic Functions
-
-SRand Intrinsic
-...............
-
- CALL SRand(SEED)
-
-SEED: `INTEGER'; scalar; INTENT(IN).
-
-Intrinsic groups: `unix'.
-
-Description:
-
- Reinitialises the generator with the seed in SEED. *Note IRand
-Intrinsic::. *Note Rand Intrinsic::.
-
-\1f
-File: g77.info, Node: Stat Intrinsic (subroutine), Next: Stat Intrinsic (function), Prev: SRand Intrinsic, Up: Table of Intrinsic Functions
-
-Stat Intrinsic (subroutine)
-...........................
-
- CALL Stat(FILE, SARRAY, STATUS)
-
-FILE: `CHARACTER'; scalar; INTENT(IN).
-
-SARRAY: `INTEGER(KIND=1)'; DIMENSION(13); INTENT(OUT).
-
-STATUS: `INTEGER(KIND=1)'; OPTIONAL; scalar; INTENT(OUT).
-
-Intrinsic groups: `unix'.
-
-Description:
-
- Obtains data about the given file FILE and places them in the array
-SARRAY. A null character (`CHAR(0)') marks the end of the name in
-FILE--otherwise, trailing blanks in FILE are ignored. The values in
-this array are extracted from the `stat' structure as returned by
-`fstat(2)' q.v., as follows:
-
- 1. Device ID
-
- 2. Inode number
-
- 3. File mode
-
- 4. Number of links
-
- 5. Owner's uid
-
- 6. Owner's gid
-
- 7. ID of device containing directory entry for file (0 if not
- available)
-
- 8. File size (bytes)
-
- 9. Last access time
-
- 10. Last modification time
-
- 11. Last file status change time
-
- 12. Preferred I/O block size (-1 if not available)
-
- 13. Number of blocks allocated (-1 if not available)
-
- Not all these elements are relevant on all systems. If an element
-is not relevant, it is returned as 0.
-
- If the STATUS argument is supplied, it contains 0 on success or a
-non-zero error code upon return.
-
- Some non-GNU implementations of Fortran provide this intrinsic as
-only a function, not as a subroutine, or do not support the (optional)
-STATUS argument.
-
- For information on other intrinsics with the same name: *Note Stat
-Intrinsic (function)::.
-
-\1f
-File: g77.info, Node: Stat Intrinsic (function), Next: Sum Intrinsic, Prev: Stat Intrinsic (subroutine), Up: Table of Intrinsic Functions
-
-Stat Intrinsic (function)
-.........................
-
- Stat(FILE, SARRAY)
-
-Stat: `INTEGER(KIND=1)' function.
-
-FILE: `CHARACTER'; scalar; INTENT(IN).
-
-SARRAY: `INTEGER(KIND=1)'; DIMENSION(13); INTENT(OUT).
-
-Intrinsic groups: `unix'.
-
-Description:
-
- Obtains data about the given file FILE and places them in the array
-SARRAY. A null character (`CHAR(0)') marks the end of the name in
-FILE--otherwise, trailing blanks in FILE are ignored. The values in
-this array are extracted from the `stat' structure as returned by
-`fstat(2)' q.v., as follows:
-
- 1. Device ID
-
- 2. Inode number
-
- 3. File mode
-
- 4. Number of links
-
- 5. Owner's uid
-
- 6. Owner's gid
-
- 7. ID of device containing directory entry for file (0 if not
- available)
-
- 8. File size (bytes)
-
- 9. Last access time
-
- 10. Last modification time
-
- 11. Last file status change time
-
- 12. Preferred I/O block size (-1 if not available)
-
- 13. Number of blocks allocated (-1 if not available)
-
- Not all these elements are relevant on all systems. If an element
-is not relevant, it is returned as 0.
-
- Returns 0 on success or a non-zero error code.
-
- For information on other intrinsics with the same name: *Note Stat
-Intrinsic (subroutine)::.
-
-\1f
-File: g77.info, Node: Sum Intrinsic, Next: SymLnk Intrinsic (subroutine), Prev: Stat Intrinsic (function), Up: Table of Intrinsic Functions
-
-Sum Intrinsic
-.............
-
- This intrinsic is not yet implemented. The name is, however,
-reserved as an intrinsic. Use `EXTERNAL Sum' to use this name for an
-external procedure.
-
-\1f
-File: g77.info, Node: SymLnk Intrinsic (subroutine), Next: System Intrinsic (subroutine), Prev: Sum Intrinsic, Up: Table of Intrinsic Functions
-
-SymLnk Intrinsic (subroutine)
-.............................
-
- CALL SymLnk(PATH1, PATH2, STATUS)
-
-PATH1: `CHARACTER'; scalar; INTENT(IN).
-
-PATH2: `CHARACTER'; scalar; INTENT(IN).
-
-STATUS: `INTEGER(KIND=1)'; OPTIONAL; scalar; INTENT(OUT).
-
-Intrinsic groups: `unix'.
-
-Description:
-
- Makes a symbolic link from file PATH1 to PATH2. A null character
-(`CHAR(0)') marks the end of the names in PATH1 and PATH2--otherwise,
-trailing blanks in PATH1 and PATH2 are ignored. If the STATUS argument
-is supplied, it contains 0 on success or a non-zero error code upon
-return (`ENOSYS' if the system does not provide `symlink(2)').
-
- Some non-GNU implementations of Fortran provide this intrinsic as
-only a function, not as a subroutine, or do not support the (optional)
-STATUS argument.
-
- For information on other intrinsics with the same name: *Note SymLnk
-Intrinsic (function)::.
-
-\1f
-File: g77.info, Node: System Intrinsic (subroutine), Next: System_Clock Intrinsic, Prev: SymLnk Intrinsic (subroutine), Up: Table of Intrinsic Functions
-
-System Intrinsic (subroutine)
-.............................
-
- CALL System(COMMAND, STATUS)
-
-COMMAND: `CHARACTER'; scalar; INTENT(IN).
-
-STATUS: `INTEGER(KIND=1)'; OPTIONAL; scalar; INTENT(OUT).
-
-Intrinsic groups: `unix'.
-
-Description:
-
- Passes the command COMMAND to a shell (see `system(3)'). If
-argument STATUS is present, it contains the value returned by
-`system(3)', presumably 0 if the shell command succeeded. Note that
-which shell is used to invoke the command is system-dependent and
-environment-dependent.
-
- Some non-GNU implementations of Fortran provide this intrinsic as
-only a function, not as a subroutine, or do not support the (optional)
-STATUS argument.
-
- For information on other intrinsics with the same name: *Note System
-Intrinsic (function)::.
-
-\1f
-File: g77.info, Node: System_Clock Intrinsic, Next: Tan Intrinsic, Prev: System Intrinsic (subroutine), Up: Table of Intrinsic Functions
-
-System_Clock Intrinsic
-......................
-
- CALL System_Clock(COUNT, RATE, MAX)
-
-COUNT: `INTEGER(KIND=1)'; scalar; INTENT(OUT).
-
-RATE: `INTEGER(KIND=1)'; OPTIONAL; scalar; INTENT(OUT).
-
-MAX: `INTEGER(KIND=1)'; OPTIONAL; scalar; INTENT(OUT).
-
-Intrinsic groups: `f90'.
-
-Description:
-
- Returns in COUNT the current value of the system clock; this is the
-value returned by the UNIX function `times(2)' in this implementation,
-but isn't in general. RATE is the number of clock ticks per second and
-MAX is the maximum value this can take, which isn't very useful in this
-implementation since it's just the maximum C `unsigned int' value.
-
- On some systems, the underlying timings are represented using types
-with sufficiently small limits that overflows (wraparounds) are
-possible, such as 32-bit types. Therefore, the values returned by this
-intrinsic might be, or become, negative, or numerically less than
-previous values, during a single run of the compiled program.
-
-\1f
-File: g77.info, Node: Tan Intrinsic, Next: TanH Intrinsic, Prev: System_Clock Intrinsic, Up: Table of Intrinsic Functions
-
-Tan Intrinsic
-.............
-
- Tan(X)
-
-Tan: `REAL' function, the `KIND=' value of the type being that of
-argument X.
-
-X: `REAL'; scalar; INTENT(IN).
-
-Intrinsic groups: (standard FORTRAN 77).
-
-Description:
-
- Returns the tangent of X, an angle measured in radians.
-
- *Note ATan Intrinsic::, for the inverse of this function.
-
-\1f
-File: g77.info, Node: TanH Intrinsic, Next: Time Intrinsic (UNIX), Prev: Tan Intrinsic, Up: Table of Intrinsic Functions
-
-TanH Intrinsic
-..............
-
- TanH(X)
-
-TanH: `REAL' function, the `KIND=' value of the type being that of
-argument X.
-
-X: `REAL'; scalar; INTENT(IN).
-
-Intrinsic groups: (standard FORTRAN 77).
-
-Description:
-
- Returns the hyperbolic tangent of X.
-
-\1f
-File: g77.info, Node: Time Intrinsic (UNIX), Next: Time8 Intrinsic, Prev: TanH Intrinsic, Up: Table of Intrinsic Functions
-
-Time Intrinsic (UNIX)
-.....................
-
- Time()
-
-Time: `INTEGER(KIND=1)' function.
-
-Intrinsic groups: `unix'.
-
-Description:
-
- Returns the current time encoded as an integer (in the manner of the
-UNIX function `time(3)'). This value is suitable for passing to
-`CTIME', `GMTIME', and `LTIME'.
-
- This intrinsic is not fully portable, such as to systems with 32-bit
-`INTEGER' types but supporting times wider than 32 bits. Therefore,
-the values returned by this intrinsic might be, or become, negative, or
-numerically less than previous values, during a single run of the
-compiled program.
-
- *Note Time8 Intrinsic::, for information on a similar intrinsic that
-might be portable to more GNU Fortran implementations, though to fewer
-Fortran compilers.
-
- For information on other intrinsics with the same name: *Note Time
-Intrinsic (VXT)::.
-
-\1f
-File: g77.info, Node: Time8 Intrinsic, Next: Tiny Intrinsic, Prev: Time Intrinsic (UNIX), Up: Table of Intrinsic Functions
-
-Time8 Intrinsic
-...............
-
- Time8()
-
-Time8: `INTEGER(KIND=2)' function.
-
-Intrinsic groups: `unix'.
-
-Description:
-
- Returns the current time encoded as a long integer (in the manner of
-the UNIX function `time(3)'). This value is suitable for passing to
-`CTIME', `GMTIME', and `LTIME'.
-
- _Warning:_ this intrinsic does not increase the range of the timing
-values over that returned by `time(3)'. On a system with a 32-bit
-`time(3)', `TIME8' will return a 32-bit value, even though converted to
-an `INTEGER(KIND=2)' value. That means overflows of the 32-bit value
-can still occur. Therefore, the values returned by this intrinsic
-might be, or become, negative, or numerically less than previous values,
-during a single run of the compiled program.
-
- No Fortran implementations other than GNU Fortran are known to
-support this intrinsic at the time of this writing. *Note Time
-Intrinsic (UNIX)::, for information on a similar intrinsic that might
-be portable to more Fortran compilers, though to fewer GNU Fortran
-implementations.
-
-\1f
-File: g77.info, Node: Tiny Intrinsic, Next: Transfer Intrinsic, Prev: Time8 Intrinsic, Up: Table of Intrinsic Functions
-
-Tiny Intrinsic
-..............
-
- This intrinsic is not yet implemented. The name is, however,
-reserved as an intrinsic. Use `EXTERNAL Tiny' to use this name for an
-external procedure.
-
-\1f
-File: g77.info, Node: Transfer Intrinsic, Next: Transpose Intrinsic, Prev: Tiny Intrinsic, Up: Table of Intrinsic Functions
-
-Transfer Intrinsic
-..................
-
- This intrinsic is not yet implemented. The name is, however,
-reserved as an intrinsic. Use `EXTERNAL Transfer' to use this name for
-an external procedure.
-
-\1f
-File: g77.info, Node: Transpose Intrinsic, Next: Trim Intrinsic, Prev: Transfer Intrinsic, Up: Table of Intrinsic Functions
-
-Transpose Intrinsic
-...................
-
- This intrinsic is not yet implemented. The name is, however,
-reserved as an intrinsic. Use `EXTERNAL Transpose' to use this name
-for an external procedure.
-
-\1f
-File: g77.info, Node: Trim Intrinsic, Next: TtyNam Intrinsic (subroutine), Prev: Transpose Intrinsic, Up: Table of Intrinsic Functions
-
-Trim Intrinsic
-..............
-
- This intrinsic is not yet implemented. The name is, however,
-reserved as an intrinsic. Use `EXTERNAL Trim' to use this name for an
-external procedure.
-
-\1f
-File: g77.info, Node: TtyNam Intrinsic (subroutine), Next: TtyNam Intrinsic (function), Prev: Trim Intrinsic, Up: Table of Intrinsic Functions
-
-TtyNam Intrinsic (subroutine)
-.............................
-
- CALL TtyNam(UNIT, NAME)
-
-UNIT: `INTEGER'; scalar; INTENT(IN).
-
-NAME: `CHARACTER'; scalar; INTENT(OUT).
-
-Intrinsic groups: `unix'.
-
-Description:
-
- Sets NAME to the name of the terminal device open on logical unit
-UNIT or to a blank string if UNIT is not connected to a terminal.
-
- Some non-GNU implementations of Fortran provide this intrinsic as
-only a function, not as a subroutine.
-
- For information on other intrinsics with the same name: *Note TtyNam
-Intrinsic (function)::.
-
-\1f
-File: g77.info, Node: TtyNam Intrinsic (function), Next: UBound Intrinsic, Prev: TtyNam Intrinsic (subroutine), Up: Table of Intrinsic Functions
-
-TtyNam Intrinsic (function)
-...........................
-
- TtyNam(UNIT)
-
-TtyNam: `CHARACTER*(*)' function.
-
-UNIT: `INTEGER'; scalar; INTENT(IN).
-
-Intrinsic groups: `unix'.
-
-Description:
-
- Returns the name of the terminal device open on logical unit UNIT or
-a blank string if UNIT is not connected to a terminal.
-
- For information on other intrinsics with the same name: *Note TtyNam
-Intrinsic (subroutine)::.
-
-\1f
-File: g77.info, Node: UBound Intrinsic, Next: UMask Intrinsic (subroutine), Prev: TtyNam Intrinsic (function), Up: Table of Intrinsic Functions
-
-UBound Intrinsic
-................
-
- This intrinsic is not yet implemented. The name is, however,
-reserved as an intrinsic. Use `EXTERNAL UBound' to use this name for an
-external procedure.
-
-\1f
-File: g77.info, Node: UMask Intrinsic (subroutine), Next: Unlink Intrinsic (subroutine), Prev: UBound Intrinsic, Up: Table of Intrinsic Functions
-
-UMask Intrinsic (subroutine)
-............................
-
- CALL UMask(MASK, OLD)
-
-MASK: `INTEGER'; scalar; INTENT(IN).
-
-OLD: `INTEGER(KIND=1)'; OPTIONAL; scalar; INTENT(OUT).
-
-Intrinsic groups: `unix'.
-
-Description:
-
- Sets the file creation mask to MASK and returns the old value in
-argument OLD if it is supplied. See `umask(2)'.
-
- Some non-GNU implementations of Fortran provide this intrinsic as
-only a function, not as a subroutine.
-
- For information on other intrinsics with the same name: *Note UMask
-Intrinsic (function)::.
-
-\1f
-File: g77.info, Node: Unlink Intrinsic (subroutine), Next: Unpack Intrinsic, Prev: UMask Intrinsic (subroutine), Up: Table of Intrinsic Functions
-
-Unlink Intrinsic (subroutine)
-.............................
-
- CALL Unlink(FILE, STATUS)
-
-FILE: `CHARACTER'; scalar; INTENT(IN).
-
-STATUS: `INTEGER(KIND=1)'; OPTIONAL; scalar; INTENT(OUT).
-
-Intrinsic groups: `unix'.
-
-Description:
-
- Unlink the file FILE. A null character (`CHAR(0)') marks the end of
-the name in FILE--otherwise, trailing blanks in FILE are ignored. If
-the STATUS argument is supplied, it contains 0 on success or a non-zero
-error code upon return. See `unlink(2)'.
-
- Some non-GNU implementations of Fortran provide this intrinsic as
-only a function, not as a subroutine, or do not support the (optional)
-STATUS argument.
-
- For information on other intrinsics with the same name: *Note Unlink
-Intrinsic (function)::.
-
-\1f
-File: g77.info, Node: Unpack Intrinsic, Next: Verify Intrinsic, Prev: Unlink Intrinsic (subroutine), Up: Table of Intrinsic Functions
-
-Unpack Intrinsic
-................
-
- This intrinsic is not yet implemented. The name is, however,
-reserved as an intrinsic. Use `EXTERNAL Unpack' to use this name for an
-external procedure.
-
-\1f
-File: g77.info, Node: Verify Intrinsic, Next: XOr Intrinsic, Prev: Unpack Intrinsic, Up: Table of Intrinsic Functions
-
-Verify Intrinsic
-................
-
- This intrinsic is not yet implemented. The name is, however,
-reserved as an intrinsic. Use `EXTERNAL Verify' to use this name for an
-external procedure.
-
-\1f
-File: g77.info, Node: XOr Intrinsic, Next: ZAbs Intrinsic, Prev: Verify Intrinsic, Up: Table of Intrinsic Functions
-
-XOr Intrinsic
-.............
-
- XOr(I, J)
-
-XOr: `INTEGER' or `LOGICAL' function, the exact type being the result
-of cross-promoting the types of all the arguments.
-
-I: `INTEGER' or `LOGICAL'; scalar; INTENT(IN).
-
-J: `INTEGER' or `LOGICAL'; scalar; INTENT(IN).
-
-Intrinsic groups: `f2c'.
-
-Description:
-
- Returns value resulting from boolean exclusive-OR of pair of bits in
-each of I and J.
-
-\1f
-File: g77.info, Node: ZAbs Intrinsic, Next: ZCos Intrinsic, Prev: XOr Intrinsic, Up: Table of Intrinsic Functions
-
-ZAbs Intrinsic
-..............
-
- ZAbs(A)
-
-ZAbs: `REAL(KIND=2)' function.
-
-A: `COMPLEX(KIND=2)'; scalar; INTENT(IN).
-
-Intrinsic groups: `f2c'.
-
-Description:
-
- Archaic form of `ABS()' that is specific to one type for A. *Note
-Abs Intrinsic::.
-
-\1f
-File: g77.info, Node: ZCos Intrinsic, Next: ZExp Intrinsic, Prev: ZAbs Intrinsic, Up: Table of Intrinsic Functions
-
-ZCos Intrinsic
-..............
-
- ZCos(X)
-
-ZCos: `COMPLEX(KIND=2)' function.
-
-X: `COMPLEX(KIND=2)'; scalar; INTENT(IN).
-
-Intrinsic groups: `f2c'.
-
-Description:
-
- Archaic form of `COS()' that is specific to one type for X. *Note
-Cos Intrinsic::.
-
-\1f
-File: g77.info, Node: ZExp Intrinsic, Next: ZLog Intrinsic, Prev: ZCos Intrinsic, Up: Table of Intrinsic Functions
-
-ZExp Intrinsic
-..............
-
- ZExp(X)
-
-ZExp: `COMPLEX(KIND=2)' function.
-
-X: `COMPLEX(KIND=2)'; scalar; INTENT(IN).
-
-Intrinsic groups: `f2c'.
-
-Description:
-
- Archaic form of `EXP()' that is specific to one type for X. *Note
-Exp Intrinsic::.
-
-\1f
-File: g77.info, Node: ZLog Intrinsic, Next: ZSin Intrinsic, Prev: ZExp Intrinsic, Up: Table of Intrinsic Functions
-
-ZLog Intrinsic
-..............
-
- ZLog(X)
-
-ZLog: `COMPLEX(KIND=2)' function.
-
-X: `COMPLEX(KIND=2)'; scalar; INTENT(IN).
-
-Intrinsic groups: `f2c'.
-
-Description:
-
- Archaic form of `LOG()' that is specific to one type for X. *Note
-Log Intrinsic::.
-
-\1f
-File: g77.info, Node: ZSin Intrinsic, Next: ZSqRt Intrinsic, Prev: ZLog Intrinsic, Up: Table of Intrinsic Functions
-
-ZSin Intrinsic
-..............
-
- ZSin(X)
-
-ZSin: `COMPLEX(KIND=2)' function.
-
-X: `COMPLEX(KIND=2)'; scalar; INTENT(IN).
-
-Intrinsic groups: `f2c'.
-
-Description:
-
- Archaic form of `SIN()' that is specific to one type for X. *Note
-Sin Intrinsic::.
-
-\1f
-File: g77.info, Node: ZSqRt Intrinsic, Prev: ZSin Intrinsic, Up: Table of Intrinsic Functions
-
-ZSqRt Intrinsic
-...............
-
- ZSqRt(X)
-
-ZSqRt: `COMPLEX(KIND=2)' function.
-
-X: `COMPLEX(KIND=2)'; scalar; INTENT(IN).
-
-Intrinsic groups: `f2c'.
-
-Description:
-
- Archaic form of `SQRT()' that is specific to one type for X. *Note
-SqRt Intrinsic::.
-
-\1f
-File: g77.info, Node: Scope and Classes of Names, Next: I/O, Prev: Functions and Subroutines, Up: Language
-
-Scope and Classes of Symbolic Names
-===================================
-
- (The following information augments or overrides the information in
-Chapter 18 of ANSI X3.9-1978 FORTRAN 77 in specifying the GNU Fortran
-language. Chapter 18 of that document otherwise serves as the basis
-for the relevant aspects of GNU Fortran.)
-
-* Menu:
-
-* Underscores in Symbol Names::
-
-\1f
-File: g77.info, Node: Underscores in Symbol Names, Up: Scope and Classes of Names
-
-Underscores in Symbol Names
----------------------------
-
- Underscores (`_') are accepted in symbol names after the first
-character (which must be a letter).
-
-\1f
-File: g77.info, Node: I/O, Next: Fortran 90 Features, Prev: Scope and Classes of Names, Up: Language
-
-I/O
-===
-
- A dollar sign at the end of an output format specification suppresses
-the newline at the end of the output.
-
- Edit descriptors in `FORMAT' statements may contain compile-time
-`INTEGER' constant expressions in angle brackets, such as
- 10 FORMAT (I<WIDTH>)
-
- The `OPEN' specifier `NAME=' is equivalent to `FILE='.
-
- These Fortran 90 features are supported:
- * The `O' and `Z' edit descriptors are supported for I/O of integers
- in octal and hexadecimal formats, respectively.
-
- * The `FILE=' specifier may be omitted in an `OPEN' statement if
- `STATUS='SCRATCH'' is supplied. The `STATUS='REPLACE'' specifier
- is supported.
-
-\1f
-File: g77.info, Node: Fortran 90 Features, Prev: I/O, Up: Language
-
-Fortran 90 Features
-===================
-
- For convenience this section collects a list (probably incomplete) of
-the Fortran 90 features supported by the GNU Fortran language, even if
-they are documented elsewhere. *Note Characters, Lines, and Execution
-Sequence: Characters Lines Sequence, for information on additional
-fixed source form lexical issues. Further, the free source form is
-supported through the `-ffree-form' option. Other Fortran 90 features
-can be turned on by the `-ff90' option; see *Note Fortran 90::. For
-information on the Fortran 90 intrinsics available, see *Note Table of
-Intrinsic Functions::.
-
-Automatic arrays in procedures
-
-Character assignments
- In character assignments, the variable being assigned may occur on
- the right hand side of the assignment.
-
-Character strings
- Strings may have zero length and substrings of character constants
- are permitted. Character constants may be enclosed in double
- quotes (`"') as well as single quotes. *Note Character Type::.
-
-Construct names
- (Symbolic tags on blocks.) *Note Construct Names::.
-
-`CYCLE' and `EXIT'
- *Note The `CYCLE' and `EXIT' Statements: CYCLE and EXIT.
-
-`DOUBLE COMPLEX'
- *Note `DOUBLE COMPLEX' Statement: DOUBLE COMPLEX.
-
-`DO WHILE'
- *Note DO WHILE::.
-
-`END' decoration
- *Note Statements::.
-
-`END DO'
- *Note END DO::.
-
-`KIND'
-
-`IMPLICIT NONE'
-
-`INCLUDE' statements
- *Note INCLUDE::.
-
-List-directed and namelist I/O on internal files
-
-Binary, octal and hexadecimal constants
- These are supported more generally than required by Fortran 90.
- *Note Integer Type::.
-
-`O' and `Z' edit descriptors
-
-`NAMELIST'
- *Note NAMELIST::.
-
-`OPEN' specifiers
- `STATUS='REPLACE'' is supported. The `FILE=' specifier may be
- omitted in an `OPEN' statement if `STATUS='SCRATCH'' is supplied.
-
-`FORMAT' edit descriptors
- The `Z' edit descriptor is supported.
-
-Relational operators
- The operators `<', `<=', `==', `/=', `>' and `>=' may be used
- instead of `.LT.', `.LE.', `.EQ.', `.NE.', `.GT.' and `.GE.'
- respectively.
-
-`SELECT CASE'
- Not fully implemented. *Note `SELECT CASE' on `CHARACTER' Type:
- SELECT CASE on CHARACTER Type.
-
-Specification statements
- A limited subset of the Fortran 90 syntax and semantics for
- variable declarations is supported, including `KIND'. *Note Kind
- Notation::. (`KIND' is of limited usefulness in the absence of the
- `KIND'-related intrinsics, since these intrinsics permit writing
- more widely portable code.) An example of supported `KIND' usage
- is:
- INTEGER (KIND=1) :: FOO=1, BAR=2
- CHARACTER (LEN=3) FOO
- `PARAMETER' and `DIMENSION' attributes aren't supported.
-
-\1f
-File: g77.info, Node: Other Dialects, Next: Other Compilers, Prev: Compiler, Up: Top
-
-Other Dialects
-**************
-
- GNU Fortran supports a variety of features that are not considered
-part of the GNU Fortran language itself, but are representative of
-various dialects of Fortran that `g77' supports in whole or in part.
-
- Any of the features listed below might be disallowed by `g77' unless
-some command-line option is specified. Currently, some of the features
-are accepted using the default invocation of `g77', but that might
-change in the future.
-
- _Note: This portion of the documentation definitely needs a lot of
-work!_
-
-* Menu:
-
-* Source Form:: Details of fixed-form and free-form source.
-* Trailing Comment:: Use of `/*' to start a comment.
-* Debug Line:: Use of `D' in column 1.
-* Dollar Signs:: Use of `$' in symbolic names.
-* Case Sensitivity:: Uppercase and lowercase in source files.
-* VXT Fortran:: ...versus the GNU Fortran language.
-* Fortran 90:: ...versus the GNU Fortran language.
-* Pedantic Compilation:: Enforcing the standard.
-* Distensions:: Misfeatures supported by GNU Fortran.
-
-\1f
-File: g77.info, Node: Source Form, Next: Trailing Comment, Up: Other Dialects
-
-Source Form
-===========
-
- GNU Fortran accepts programs written in either fixed form or free
-form.
-
- Fixed form corresponds to ANSI FORTRAN 77 (plus popular extensions,
-such as allowing tabs) and Fortran 90's fixed form.
-
- Free form corresponds to Fortran 90's free form (though possibly not
-entirely up-to-date, and without complaining about some things that for
-which Fortran 90 requires diagnostics, such as the spaces in the
-constant in `R = 3 . 1').
-
- The way a Fortran compiler views source files depends entirely on the
-implementation choices made for the compiler, since those choices are
-explicitly left to the implementation by the published Fortran
-standards. GNU Fortran currently tries to be somewhat like a few
-popular compilers (`f2c', Digital ("DEC") Fortran, and so on).
-
- This section describes how `g77' interprets source lines.
-
-* Menu:
-
-* Carriage Returns:: Carriage returns ignored.
-* Tabs:: Tabs converted to spaces.
-* Short Lines:: Short lines padded with spaces (fixed-form only).
-* Long Lines:: Long lines truncated.
-* Ampersands:: Special Continuation Lines.
-
-\1f
-File: g77.info, Node: Carriage Returns, Next: Tabs, Up: Source Form
-
-Carriage Returns
-----------------
-
- Carriage returns (`\r') in source lines are ignored. This is
-somewhat different from `f2c', which seems to treat them as spaces
-outside character/Hollerith constants, and encodes them as `\r' inside
-such constants.
-
-\1f
-File: g77.info, Node: Tabs, Next: Short Lines, Prev: Carriage Returns, Up: Source Form
-
-Tabs
-----
-
- A source line with a <TAB> character anywhere in it is treated as
-entirely significant--however long it is--instead of ending in column
-72 (for fixed-form source) or 132 (for free-form source). This also is
-different from `f2c', which encodes tabs as `\t' (the ASCII <TAB>
-character) inside character and Hollerith constants, but nevertheless
-seems to treat the column position as if it had been affected by the
-canonical tab positioning.
-
- `g77' effectively translates tabs to the appropriate number of
-spaces (a la the default for the UNIX `expand' command) before doing
-any other processing, other than (currently) noting whether a tab was
-found on a line and using this information to decide how to interpret
-the length of the line and continued constants.
-
-\1f
-File: g77.info, Node: Short Lines, Next: Long Lines, Prev: Tabs, Up: Source Form
-
-Short Lines
------------
-
- Source lines shorter than the applicable fixed-form length are
-treated as if they were padded with spaces to that length. (None of
-this is relevant to source files written in free form.)
-
- This affects only continued character and Hollerith constants, and
-is a different interpretation than provided by some other popular
-compilers (although a bit more consistent with the traditional
-punched-card basis of Fortran and the way the Fortran standard
-expressed fixed source form).
-
- `g77' might someday offer an option to warn about cases where
-differences might be seen as a result of this treatment, and perhaps an
-option to specify the alternate behavior as well.
-
- Note that this padding cannot apply to lines that are effectively of
-infinite length--such lines are specified using command-line options
-like `-ffixed-line-length-none', for example.
-
-\1f
-File: g77.info, Node: Long Lines, Next: Ampersands, Prev: Short Lines, Up: Source Form
-
-Long Lines
-----------
-
- Source lines longer than the applicable length are truncated to that
-length. Currently, `g77' does not warn if the truncated characters are
-not spaces, to accommodate existing code written for systems that
-treated truncated text as commentary (especially in columns 73 through
-80).
-
- *Note Options Controlling Fortran Dialect: Fortran Dialect Options,
-for information on the `-ffixed-line-length-N' option, which can be
-used to set the line length applicable to fixed-form source files.
-
-\1f
-File: g77.info, Node: Ampersands, Prev: Long Lines, Up: Source Form
-
-Ampersand Continuation Line
----------------------------
-
- A `&' in column 1 of fixed-form source denotes an arbitrary-length
-continuation line, imitating the behavior of `f2c'.
-
-\1f
-File: g77.info, Node: Trailing Comment, Next: Debug Line, Prev: Source Form, Up: Other Dialects
-
-Trailing Comment
-================
-
- `g77' supports use of `/*' to start a trailing comment. In the GNU
-Fortran language, `!' is used for this purpose.
-
- `/*' is not in the GNU Fortran language because the use of `/*' in a
-program might suggest to some readers that a block, not trailing,
-comment is started (and thus ended by `*/', not end of line), since
-that is the meaning of `/*' in C.
-
- Also, such readers might think they can use `//' to start a trailing
-comment as an alternative to `/*', but `//' already denotes
-concatenation, and such a "comment" might actually result in a program
-that compiles without error (though it would likely behave incorrectly).
-
-\1f
-File: g77.info, Node: Debug Line, Next: Dollar Signs, Prev: Trailing Comment, Up: Other Dialects
-
-Debug Line
-==========
-
- Use of `D' or `d' as the first character (column 1) of a source line
-denotes a debug line.
-
- In turn, a debug line is treated as either a comment line or a
-normal line, depending on whether debug lines are enabled.
-
- When treated as a comment line, a line beginning with `D' or `d' is
-treated as if it the first character was `C' or `c', respectively.
-When treated as a normal line, such a line is treated as if the first
-character was <SPC> (space).
-
- (Currently, `g77' provides no means for treating debug lines as
-normal lines.)
-
-\1f
-File: g77.info, Node: Dollar Signs, Next: Case Sensitivity, Prev: Debug Line, Up: Other Dialects
-
-Dollar Signs in Symbol Names
-============================
-
- Dollar signs (`$') are allowed in symbol names (after the first
-character) when the `-fdollar-ok' option is specified.
-
projects / msp430-gcc.git / blobdiff