This is Info file g77.info, produced by Makeinfo version 1.68 from the input file g77.texi. This file explains how to use the GNU Fortran system. Published by the Free Software Foundation 59 Temple Place - Suite 330 Boston, MA 02111-1307 USA Copyright (C) 1995-1997 Free Software Foundation, Inc. Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided also that the sections entitled "GNU General Public License," "Funding for Free Software," and "Protect Your Freedom--Fight `Look And Feel'" are included exactly as in the original, and provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Permission is granted to copy and distribute translations of this manual into another language, under the above conditions for modified versions, except that the sections entitled "GNU General Public License," "Funding for Free Software," and "Protect Your Freedom--Fight `Look And Feel'", and this permission notice, may be included in translations approved by the Free Software Foundation instead of in the original English. Contributed by James Craig Burley (). Inspired by a first pass at translating `g77-0.5.16/f/DOC' that was contributed to Craig by David Ronis (). INFO-DIR-SECTION Fortran Programming START-INFO-DIR-ENTRY * g77: (g77). The GNU Fortran compilation system. END-INFO-DIR-ENTRY  File: g77.info, Node: JIAbs Intrinsic, Next: JIAnd Intrinsic, Prev: IZExt Intrinsic, Up: Other Intrinsics JIAbs Intrinsic ............... This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL JIAbs' to use this name for an external procedure.  File: g77.info, Node: JIAnd Intrinsic, Next: JIBClr Intrinsic, Prev: JIAbs Intrinsic, Up: Other Intrinsics JIAnd Intrinsic ............... This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL JIAnd' to use this name for an external procedure.  File: g77.info, Node: JIBClr Intrinsic, Next: JIBits Intrinsic, Prev: JIAnd Intrinsic, Up: Other Intrinsics JIBClr Intrinsic ................ This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL JIBClr' to use this name for an external procedure.  File: g77.info, Node: JIBits Intrinsic, Next: JIBSet Intrinsic, Prev: JIBClr Intrinsic, Up: Other Intrinsics JIBits Intrinsic ................ This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL JIBits' to use this name for an external procedure.  File: g77.info, Node: JIBSet Intrinsic, Next: JIDiM Intrinsic, Prev: JIBits Intrinsic, Up: Other Intrinsics JIBSet Intrinsic ................ This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL JIBSet' to use this name for an external procedure.  File: g77.info, Node: JIDiM Intrinsic, Next: JIDInt Intrinsic, Prev: JIBSet Intrinsic, Up: Other Intrinsics JIDiM Intrinsic ............... This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL JIDiM' to use this name for an external procedure.  File: g77.info, Node: JIDInt Intrinsic, Next: JIDNnt Intrinsic, Prev: JIDiM Intrinsic, Up: Other Intrinsics JIDInt Intrinsic ................ This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL JIDInt' to use this name for an external procedure.  File: g77.info, Node: JIDNnt Intrinsic, Next: JIEOr Intrinsic, Prev: JIDInt Intrinsic, Up: Other Intrinsics JIDNnt Intrinsic ................ This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL JIDNnt' to use this name for an external procedure.  File: g77.info, Node: JIEOr Intrinsic, Next: JIFix Intrinsic, Prev: JIDNnt Intrinsic, Up: Other Intrinsics JIEOr Intrinsic ............... This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL JIEOr' to use this name for an external procedure.  File: g77.info, Node: JIFix Intrinsic, Next: JInt Intrinsic, Prev: JIEOr Intrinsic, Up: Other Intrinsics JIFix Intrinsic ............... This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL JIFix' to use this name for an external procedure.  File: g77.info, Node: JInt Intrinsic, Next: JIOr Intrinsic, Prev: JIFix Intrinsic, Up: Other Intrinsics JInt Intrinsic .............. This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL JInt' to use this name for an external procedure.  File: g77.info, Node: JIOr Intrinsic, Next: JIQint Intrinsic, Prev: JInt Intrinsic, Up: Other Intrinsics JIOr Intrinsic .............. This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL JIOr' to use this name for an external procedure.  File: g77.info, Node: JIQint Intrinsic, Next: JIQNnt Intrinsic, Prev: JIOr Intrinsic, Up: Other Intrinsics JIQint Intrinsic ................ This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL JIQint' to use this name for an external procedure.  File: g77.info, Node: JIQNnt Intrinsic, Next: JIShft Intrinsic, Prev: JIQint Intrinsic, Up: Other Intrinsics JIQNnt Intrinsic ................ This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL JIQNnt' to use this name for an external procedure.  File: g77.info, Node: JIShft Intrinsic, Next: JIShftC Intrinsic, Prev: JIQNnt Intrinsic, Up: Other Intrinsics JIShft Intrinsic ................ This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL JIShft' to use this name for an external procedure.  File: g77.info, Node: JIShftC Intrinsic, Next: JISign Intrinsic, Prev: JIShft Intrinsic, Up: Other Intrinsics JIShftC Intrinsic ................. This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL JIShftC' to use this name for an external procedure.  File: g77.info, Node: JISign Intrinsic, Next: JMax0 Intrinsic, Prev: JIShftC Intrinsic, Up: Other Intrinsics JISign Intrinsic ................ This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL JISign' to use this name for an external procedure.  File: g77.info, Node: JMax0 Intrinsic, Next: JMax1 Intrinsic, Prev: JISign Intrinsic, Up: Other Intrinsics JMax0 Intrinsic ............... This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL JMax0' to use this name for an external procedure.  File: g77.info, Node: JMax1 Intrinsic, Next: JMin0 Intrinsic, Prev: JMax0 Intrinsic, Up: Other Intrinsics JMax1 Intrinsic ............... This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL JMax1' to use this name for an external procedure.  File: g77.info, Node: JMin0 Intrinsic, Next: JMin1 Intrinsic, Prev: JMax1 Intrinsic, Up: Other Intrinsics JMin0 Intrinsic ............... This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL JMin0' to use this name for an external procedure.  File: g77.info, Node: JMin1 Intrinsic, Next: JMod Intrinsic, Prev: JMin0 Intrinsic, Up: Other Intrinsics JMin1 Intrinsic ............... This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL JMin1' to use this name for an external procedure.  File: g77.info, Node: JMod Intrinsic, Next: JNInt Intrinsic, Prev: JMin1 Intrinsic, Up: Other Intrinsics JMod Intrinsic .............. This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL JMod' to use this name for an external procedure.  File: g77.info, Node: JNInt Intrinsic, Next: JNot Intrinsic, Prev: JMod Intrinsic, Up: Other Intrinsics JNInt Intrinsic ............... This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL JNInt' to use this name for an external procedure.  File: g77.info, Node: JNot Intrinsic, Next: JZExt Intrinsic, Prev: JNInt Intrinsic, Up: Other Intrinsics JNot Intrinsic .............. This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL JNot' to use this name for an external procedure.  File: g77.info, Node: JZExt Intrinsic, Next: Kill Intrinsic (function), Prev: JNot Intrinsic, Up: Other Intrinsics JZExt Intrinsic ............... This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL JZExt' to use this name for an external procedure.  File: g77.info, Node: Kill Intrinsic (function), Next: Link Intrinsic (function), Prev: JZExt Intrinsic, Up: Other Intrinsics Kill Intrinsic (function) ......................... Kill(PID, SIGNAL) Kill: `INTEGER(KIND=1)' function. PID: `INTEGER'; scalar; INTENT(IN). SIGNAL: `INTEGER'; scalar; INTENT(IN). Intrinsic groups: `badu77'. Description: Sends the signal specified by SIGNAL to the process PID. Returns 0 on success or a non-zero error code. See `kill(2)'. Due to the side effects performed by this intrinsic, the function form is not recommended. For information on other intrinsics with the same name: *Note Kill Intrinsic (subroutine)::.  File: g77.info, Node: Link Intrinsic (function), Next: QAbs Intrinsic, Prev: Kill Intrinsic (function), Up: Other Intrinsics Link Intrinsic (function) ......................... Link(PATH1, PATH2) Link: `INTEGER(KIND=1)' function. PATH1: `CHARACTER'; scalar; INTENT(IN). PATH2: `CHARACTER'; scalar; INTENT(IN). Intrinsic groups: `badu77'. Description: Makes a (hard) 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. Returns 0 on success or a non-zero error code. See `link(2)'. Due to the side effects performed by this intrinsic, the function form is not recommended. For information on other intrinsics with the same name: *Note Link Intrinsic (subroutine)::.  File: g77.info, Node: QAbs Intrinsic, Next: QACos Intrinsic, Prev: Link Intrinsic (function), Up: Other Intrinsics QAbs Intrinsic .............. This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL QAbs' to use this name for an external procedure.  File: g77.info, Node: QACos Intrinsic, Next: QACosD Intrinsic, Prev: QAbs Intrinsic, Up: Other Intrinsics QACos Intrinsic ............... This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL QACos' to use this name for an external procedure.  File: g77.info, Node: QACosD Intrinsic, Next: QASin Intrinsic, Prev: QACos Intrinsic, Up: Other Intrinsics QACosD Intrinsic ................ This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL QACosD' to use this name for an external procedure.  File: g77.info, Node: QASin Intrinsic, Next: QASinD Intrinsic, Prev: QACosD Intrinsic, Up: Other Intrinsics QASin Intrinsic ............... This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL QASin' to use this name for an external procedure.  File: g77.info, Node: QASinD Intrinsic, Next: QATan Intrinsic, Prev: QASin Intrinsic, Up: Other Intrinsics QASinD Intrinsic ................ This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL QASinD' to use this name for an external procedure.  File: g77.info, Node: QATan Intrinsic, Next: QATan2 Intrinsic, Prev: QASinD Intrinsic, Up: Other Intrinsics QATan Intrinsic ............... This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL QATan' to use this name for an external procedure.  File: g77.info, Node: QATan2 Intrinsic, Next: QATan2D Intrinsic, Prev: QATan Intrinsic, Up: Other Intrinsics QATan2 Intrinsic ................ This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL QATan2' to use this name for an external procedure.  File: g77.info, Node: QATan2D Intrinsic, Next: QATanD Intrinsic, Prev: QATan2 Intrinsic, Up: Other Intrinsics QATan2D Intrinsic ................. This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL QATan2D' to use this name for an external procedure.  File: g77.info, Node: QATanD Intrinsic, Next: QCos Intrinsic, Prev: QATan2D Intrinsic, Up: Other Intrinsics QATanD Intrinsic ................ This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL QATanD' to use this name for an external procedure.  File: g77.info, Node: QCos Intrinsic, Next: QCosD Intrinsic, Prev: QATanD Intrinsic, Up: Other Intrinsics QCos Intrinsic .............. This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL QCos' to use this name for an external procedure.  File: g77.info, Node: QCosD Intrinsic, Next: QCosH Intrinsic, Prev: QCos Intrinsic, Up: Other Intrinsics QCosD Intrinsic ............... This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL QCosD' to use this name for an external procedure.  File: g77.info, Node: QCosH Intrinsic, Next: QDiM Intrinsic, Prev: QCosD Intrinsic, Up: Other Intrinsics QCosH Intrinsic ............... This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL QCosH' to use this name for an external procedure.  File: g77.info, Node: QDiM Intrinsic, Next: QExp Intrinsic, Prev: QCosH Intrinsic, Up: Other Intrinsics QDiM Intrinsic .............. This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL QDiM' to use this name for an external procedure.  File: g77.info, Node: QExp Intrinsic, Next: QExt Intrinsic, Prev: QDiM Intrinsic, Up: Other Intrinsics QExp Intrinsic .............. This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL QExp' to use this name for an external procedure.  File: g77.info, Node: QExt Intrinsic, Next: QExtD Intrinsic, Prev: QExp Intrinsic, Up: Other Intrinsics QExt Intrinsic .............. This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL QExt' to use this name for an external procedure.  File: g77.info, Node: QExtD Intrinsic, Next: QFloat Intrinsic, Prev: QExt Intrinsic, Up: Other Intrinsics QExtD Intrinsic ............... This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL QExtD' to use this name for an external procedure.  File: g77.info, Node: QFloat Intrinsic, Next: QInt Intrinsic, Prev: QExtD Intrinsic, Up: Other Intrinsics QFloat Intrinsic ................ This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL QFloat' to use this name for an external procedure.  File: g77.info, Node: QInt Intrinsic, Next: QLog Intrinsic, Prev: QFloat Intrinsic, Up: Other Intrinsics QInt Intrinsic .............. This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL QInt' to use this name for an external procedure.  File: g77.info, Node: QLog Intrinsic, Next: QLog10 Intrinsic, Prev: QInt Intrinsic, Up: Other Intrinsics QLog Intrinsic .............. This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL QLog' to use this name for an external procedure.  File: g77.info, Node: QLog10 Intrinsic, Next: QMax1 Intrinsic, Prev: QLog Intrinsic, Up: Other Intrinsics QLog10 Intrinsic ................ This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL QLog10' to use this name for an external procedure.  File: g77.info, Node: QMax1 Intrinsic, Next: QMin1 Intrinsic, Prev: QLog10 Intrinsic, Up: Other Intrinsics QMax1 Intrinsic ............... This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL QMax1' to use this name for an external procedure.  File: g77.info, Node: QMin1 Intrinsic, Next: QMod Intrinsic, Prev: QMax1 Intrinsic, Up: Other Intrinsics QMin1 Intrinsic ............... This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL QMin1' to use this name for an external procedure.  File: g77.info, Node: QMod Intrinsic, Next: QNInt Intrinsic, Prev: QMin1 Intrinsic, Up: Other Intrinsics QMod Intrinsic .............. This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL QMod' to use this name for an external procedure.  File: g77.info, Node: QNInt Intrinsic, Next: QSin Intrinsic, Prev: QMod Intrinsic, Up: Other Intrinsics QNInt Intrinsic ............... This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL QNInt' to use this name for an external procedure.  File: g77.info, Node: QSin Intrinsic, Next: QSinD Intrinsic, Prev: QNInt Intrinsic, Up: Other Intrinsics QSin Intrinsic .............. This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL QSin' to use this name for an external procedure.  File: g77.info, Node: QSinD Intrinsic, Next: QSinH Intrinsic, Prev: QSin Intrinsic, Up: Other Intrinsics QSinD Intrinsic ............... This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL QSinD' to use this name for an external procedure.  File: g77.info, Node: QSinH Intrinsic, Next: QSqRt Intrinsic, Prev: QSinD Intrinsic, Up: Other Intrinsics QSinH Intrinsic ............... This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL QSinH' to use this name for an external procedure.  File: g77.info, Node: QSqRt Intrinsic, Next: QTan Intrinsic, Prev: QSinH Intrinsic, Up: Other Intrinsics QSqRt Intrinsic ............... This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL QSqRt' to use this name for an external procedure.  File: g77.info, Node: QTan Intrinsic, Next: QTanD Intrinsic, Prev: QSqRt Intrinsic, Up: Other Intrinsics QTan Intrinsic .............. This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL QTan' to use this name for an external procedure.  File: g77.info, Node: QTanD Intrinsic, Next: QTanH Intrinsic, Prev: QTan Intrinsic, Up: Other Intrinsics QTanD Intrinsic ............... This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL QTanD' to use this name for an external procedure.  File: g77.info, Node: QTanH Intrinsic, Next: Rename Intrinsic (function), Prev: QTanD Intrinsic, Up: Other Intrinsics QTanH Intrinsic ............... This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL QTanH' to use this name for an external procedure.  File: g77.info, Node: Rename Intrinsic (function), Next: Secnds Intrinsic, Prev: QTanH Intrinsic, Up: Other Intrinsics Rename Intrinsic (function) ........................... Rename(PATH1, PATH2) Rename: `INTEGER(KIND=1)' function. PATH1: `CHARACTER'; scalar; INTENT(IN). PATH2: `CHARACTER'; scalar; INTENT(IN). Intrinsic groups: `badu77'. 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)'. Returns 0 on success or a non-zero error code. Due to the side effects performed by this intrinsic, the function form is not recommended. For information on other intrinsics with the same name: *Note Rename Intrinsic (subroutine)::.  File: g77.info, Node: Secnds Intrinsic, Next: Signal Intrinsic (function), Prev: Rename Intrinsic (function), Up: Other Intrinsics Secnds Intrinsic ................ Secnds(T) Secnds: `REAL(KIND=1)' function. T: `REAL(KIND=1)'; scalar; INTENT(IN). Intrinsic groups: `vxt'. Description: Returns the local time in seconds since midnight minus the value T.  File: g77.info, Node: Signal Intrinsic (function), Next: SinD Intrinsic, Prev: Secnds Intrinsic, Up: Other Intrinsics Signal Intrinsic (function) ........................... Signal(NUMBER, HANDLER) Signal: `INTEGER(KIND=7)' function. NUMBER: `INTEGER'; scalar; INTENT(IN). HANDLER: Signal handler (`INTEGER FUNCTION' or `SUBROUTINE') or dummy/global `INTEGER(KIND=1)' scalar. Intrinsic groups: `badu77'. 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 is obtained by applying `%LOC()' (or LOC()) to it. The value returned by `signal(2)' is returned. Due to the side effects performed by this intrinsic, the function form is not recommended. *Warning:* If the returned value is stored in an `INTEGER(KIND=1)' (default `INTEGER') argument, truncation of the original return value occurs on some systems (such as Alphas, which have 64-bit pointers but 32-bit default integers), with no warning issued by `g77' under normal circumstances. Therefore, the following code fragment might silently fail on some systems: INTEGER RTN EXTERNAL MYHNDL RTN = SIGNAL(SIGNUM, MYHNDL) ... ! Restore original handler: RTN = SIGNAL(SIGNUM, RTN) The reason for the failure is that `RTN' might not hold all the information on the original handler for the signal, thus restoring an invalid handler. This bug could manifest itself as a spurious run-time failure at an arbitrary point later during the program's execution, for example. *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 `RTN = 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 ... RTN = 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 (subroutine)::.  File: g77.info, Node: SinD Intrinsic, Next: SnglQ Intrinsic, Prev: Signal Intrinsic (function), Up: Other Intrinsics SinD Intrinsic .............. This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL SinD' to use this name for an external procedure.  File: g77.info, Node: SnglQ Intrinsic, Next: SymLnk Intrinsic (function), Prev: SinD Intrinsic, Up: Other Intrinsics SnglQ Intrinsic ............... This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL SnglQ' to use this name for an external procedure.  File: g77.info, Node: SymLnk Intrinsic (function), Next: System Intrinsic (function), Prev: SnglQ Intrinsic, Up: Other Intrinsics SymLnk Intrinsic (function) ........................... SymLnk(PATH1, PATH2) SymLnk: `INTEGER(KIND=1)' function. PATH1: `CHARACTER'; scalar; INTENT(IN). PATH2: `CHARACTER'; scalar; INTENT(IN). Intrinsic groups: `badu77'. 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. Returns 0 on success or a non-zero error code (`ENOSYS' if the system does not provide `symlink(2)'). Due to the side effects performed by this intrinsic, the function form is not recommended. For information on other intrinsics with the same name: *Note SymLnk Intrinsic (subroutine)::.  File: g77.info, Node: System Intrinsic (function), Next: TanD Intrinsic, Prev: SymLnk Intrinsic (function), Up: Other Intrinsics System Intrinsic (function) ........................... System(COMMAND) System: `INTEGER(KIND=1)' function. COMMAND: `CHARACTER'; scalar; INTENT(IN). Intrinsic groups: `badu77'. Description: Passes the command COMMAND to a shell (see `system(3)'). Returns 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. Due to the side effects performed by this intrinsic, the function form is not recommended. However, the function form can be valid in cases where the actual side effects performed by the call are unimportant to the application. For example, on a UNIX system, `SAME = SYSTEM('cmp a b')' does not perform any side effects likely to be important to the program, so the programmer would not care if the actual system call (and invocation of `cmp') was optimized away in a situation where the return value could be determined otherwise, or was not actually needed (`SAME' not actually referenced after the sample assignment statement). For information on other intrinsics with the same name: *Note System Intrinsic (subroutine)::.  File: g77.info, Node: TanD Intrinsic, Next: Time Intrinsic (VXT), Prev: System Intrinsic (function), Up: Other Intrinsics TanD Intrinsic .............. This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL TanD' to use this name for an external procedure.  File: g77.info, Node: Time Intrinsic (VXT), Next: UMask Intrinsic (function), Prev: TanD Intrinsic, Up: Other Intrinsics Time Intrinsic (VXT) .................... CALL Time(TIME) TIME: `CHARACTER*8'; scalar; INTENT(OUT). Intrinsic groups: `vxt'. Description: Returns in TIME a character representation of the current time as obtained from `ctime(3)'. *Note Fdate Intrinsic (subroutine):: for an equivalent routine. For information on other intrinsics with the same name: *Note Time Intrinsic (UNIX)::.  File: g77.info, Node: UMask Intrinsic (function), Next: Unlink Intrinsic (function), Prev: Time Intrinsic (VXT), Up: Other Intrinsics UMask Intrinsic (function) .......................... UMask(MASK) UMask: `INTEGER(KIND=1)' function. MASK: `INTEGER'; scalar; INTENT(IN). Intrinsic groups: `badu77'. Description: Sets the file creation mask to MASK and returns the old value. See `umask(2)'. Due to the side effects performed by this intrinsic, the function form is not recommended. For information on other intrinsics with the same name: *Note UMask Intrinsic (subroutine)::.  File: g77.info, Node: Unlink Intrinsic (function), Next: ZExt Intrinsic, Prev: UMask Intrinsic (function), Up: Other Intrinsics Unlink Intrinsic (function) ........................... Unlink(FILE) Unlink: `INTEGER(KIND=1)' function. FILE: `CHARACTER'; scalar; INTENT(IN). Intrinsic groups: `badu77'. 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. Returns 0 on success or a non-zero error code. See `unlink(2)'. Due to the side effects performed by this intrinsic, the function form is not recommended. For information on other intrinsics with the same name: *Note Unlink Intrinsic (subroutine)::.  File: g77.info, Node: ZExt Intrinsic, Prev: Unlink Intrinsic (function), Up: Other Intrinsics ZExt Intrinsic .............. This intrinsic is not yet implemented. The name is, however, reserved as an intrinsic. Use `EXTERNAL ZExt' to use this name for an external procedure.  File: g77.info, Node: Other Compilers, Next: Other Languages, Prev: Other Dialects, Up: Top Other Compilers *************** An individual Fortran source file can be compiled to an object (`*.o') file instead of to the final program executable. This allows several portions of a program to be compiled at different times and linked together whenever a new version of the program is needed. However, it introduces the issue of "object compatibility" across the various object files (and libraries, or `*.a' files) that are linked together to produce any particular executable file. Object compatibility is an issue when combining, in one program, Fortran code compiled by more than one compiler (or more than one configuration of a compiler). If the compilers disagree on how to transform the names of procedures, there will normally be errors when linking such programs. Worse, if the compilers agree on naming, but disagree on issues like how to pass parameters, return arguments, and lay out `COMMON' areas, the earliest detected errors might be the incorrect results produced by the program (and that assumes these errors are detected, which is not always the case). Normally, `g77' generates code that is object-compatible with code generated by a version of `f2c' configured (with, for example, `f2c.h' definitions) to be generally compatible with `g77' as built by `gcc'. (Normally, `f2c' will, by default, conform to the appropriate configuration, but it is possible that older or perhaps even newer versions of `f2c', or versions having certain configuration changes to `f2c' internals, will produce object files that are incompatible with `g77'.) For example, a Fortran string subroutine argument will become two arguments on the C side: a `char *' and an `int' length. Much of this compatibility results from the fact that `g77' uses the same run-time library, `libf2c', used by `f2c'. Other compilers might or might not generate code that is object-compatible with `libf2c' and current `g77', and some might offer such compatibility only when explicitly selected via a command-line option to the compiler. *Note: This portion of the documentation definitely needs a lot of work!* * Menu: * Dropping f2c Compatibility:: When speed is more important. * Compilers Other Than f2c:: Interoperation with code from other compilers.  File: g77.info, Node: Dropping f2c Compatibility, Next: Compilers Other Than f2c, Up: Other Compilers Dropping `f2c' Compatibility ============================ Specifying `-fno-f2c' allows `g77' to generate, in some cases, faster code, by not needing to allow to the possibility of linking with code compiled by `f2c'. For example, this affects how `REAL(KIND=1)', `COMPLEX(KIND=1)', and `COMPLEX(KIND=2)' functions are called. With `-fno-f2c', they are compiled as returning the appropriate `gcc' type (`float', `__complex__ float', `__complex__ double', in many configurations). With `-ff2c' in force, they are compiled differently (with perhaps slower run-time performance) to accommodate the restrictions inherent in `f2c''s use of K&R C as an intermediate language--`REAL(KIND=1)' functions return C's `double' type, while `COMPLEX' functions return `void' and use an extra argument pointing to a place for the functions to return their values. It is possible that, in some cases, leaving `-ff2c' in force might produce faster code than using `-fno-f2c'. Feel free to experiment, but remember to experiment with changing the way *entire programs and their Fortran libraries are compiled* at a time, since this sort of experimentation affects the interface of code generated for a Fortran source file--that is, it affects object compatibility. Note that `f2c' compatibility is a fairly static target to achieve, though not necessarily perfectly so, since, like `g77', it is still being improved. However, specifying `-fno-f2c' causes `g77' to generate code that will probably be incompatible with code generated by future versions of `g77' when the same option is in force. You should make sure you are always able to recompile complete programs from source code when upgrading to new versions of `g77' or `f2c', especially when using options such as `-fno-f2c'. Therefore, if you are using `g77' to compile libraries and other object files for possible future use and you don't want to require recompilation for future use with subsequent versions of `g77', you might want to stick with `f2c' compatibility for now, and carefully watch for any announcements about changes to the `f2c'/`libf2c' interface that might affect existing programs (thus requiring recompilation). It is probable that a future version of `g77' will not, by default, generate object files compatible with `f2c', and that version probably would no longer use `libf2c'. If you expect to depend on this compatibility in the long term, use the options `-ff2c -ff2c-library' when compiling all of the applicable code. This should cause future versions of `g77' either to produce compatible code (at the expense of the availability of some features and performance), or at the very least, to produce diagnostics.  File: g77.info, Node: Compilers Other Than f2c, Prev: Dropping f2c Compatibility, Up: Other Compilers Compilers Other Than `f2c' ========================== On systems with Fortran compilers other than `f2c' and `g77', code compiled by `g77' is not expected to work well with code compiled by the native compiler. (This is true for `f2c'-compiled objects as well.) Libraries compiled with the native compiler probably will have to be recompiled with `g77' to be used with `g77'-compiled code. Reasons for such incompatibilities include: * There might be differences in the way names of Fortran procedures are translated for use in the system's object-file format. For example, the statement `CALL FOO' might be compiled by `g77' to call a procedure the linker `ld' sees given the name `_foo_', while the apparently corresponding statement `SUBROUTINE FOO' might be compiled by the native compiler to define the linker-visible name `_foo', or `_FOO_', and so on. * There might be subtle type mismatches which cause subroutine arguments and function return values to get corrupted. This is why simply getting `g77' to transform procedure names the same way a native compiler does is not usually a good idea--unless some effort has been made to ensure that, aside from the way the two compilers transform procedure names, everything else about the way they generate code for procedure interfaces is identical. * Native compilers use libraries of private I/O routines which will not be available at link time unless you have the native compiler--and you would have to explicitly ask for them. For example, on the Sun you would have to add `-L/usr/lang/SCx.x -lF77 -lV77' to the link command.  File: g77.info, Node: Other Languages, Next: Installation, Prev: Other Compilers, Up: Top Other Languages *************** *Note: This portion of the documentation definitely needs a lot of work!* * Menu: * Interoperating with C and C++::  File: g77.info, Node: Interoperating with C and C++, Up: Other Languages Tools and advice for interoperating with C and C++ ================================================== The following discussion assumes that you are running `g77' in `f2c' compatibility mode, i.e. not using `-fno-f2c'. It provides some advice about quick and simple techniques for linking Fortran and C (or C++), the most common requirement. For the full story consult the description of code generation. *Note Debugging and Interfacing::. When linking Fortran and C, it's usually best to use `g77' to do the linking so that the correct libraries are included (including the maths one). If you're linking with C++ you will want to add `-lstdc++', `-lg++' or whatever. If you need to use another driver program (or `ld' directly), you can find out what linkage options `g77' passes by running `g77 -v'. * Menu: * C Interfacing Tools:: * C Access to Type Information:: * f2c Skeletons and Prototypes:: * C++ Considerations:: * Startup Code::  File: g77.info, Node: C Interfacing Tools, Next: C Access to Type Information, Up: Interoperating with C and C++ C Interfacing Tools ------------------- Even if you don't actually use it as a compiler, `f2c' from `ftp://ftp.netlib.org/f2c/src', can be a useful tool when you're interfacing (linking) Fortran and C. *Note Generating Skeletons and Prototypes with `f2c': f2c Skeletons and Prototypes. To use `f2c' for this purpose you only need retrieve and build the `src' directory from the distribution, consult the `README' instructions there for machine-specifics, and install the `f2c' program on your path. Something else that might be useful is `cfortran.h' from `ftp://zebra/desy.de/cfortran'. This is a fairly general tool which can be used to generate interfaces for calling in both directions between Fortran and C. It can be used in `f2c' mode with `g77'--consult its documentation for details.  File: g77.info, Node: C Access to Type Information, Next: f2c Skeletons and Prototypes, Prev: C Interfacing Tools, Up: Interoperating with C and C++ Accessing Type Information in C ------------------------------- Generally, C code written to link with `g77' code--calling and/or being called from Fortran--should `#include ' to define the C versions of the Fortran types. Don't assume Fortran `INTEGER' types correspond to C `int's, for instance; instead, declare them as `integer', a type defined by `f2c.h'. `f2c.h' is installed where `gcc' will find it by default, assuming you use a copy of `gcc' compatible with `g77', probably built at the same time as `g77'.  File: g77.info, Node: f2c Skeletons and Prototypes, Next: C++ Considerations, Prev: C Access to Type Information, Up: Interoperating with C and C++ Generating Skeletons and Prototypes with `f2c' ---------------------------------------------- A simple and foolproof way to write `g77'-callable C routines--e.g. to interface with an existing library--is to write a file (named, for example, `fred.f') of dummy Fortran skeletons comprising just the declaration of the routine(s) and dummy arguments plus `END' statements. Then run `f2c' on file `fred.f' to produce `fred.c' into which you can edit useful code, confident the calling sequence is correct, at least. (There are some errors otherwise commonly made in generating C interfaces with f2c conventions, such as not using `doublereal' as the return type of a `REAL' `FUNCTION'.) `f2c' also can help with calling Fortran from C, using its `-P' option to generate C prototypes appropriate for calling the Fortran.(1) If the Fortran code containing any routines to be called from C is in file `joe.f', use the command `f2c -P joe.f' to generate the file `joe.P' containing prototype information. `#include' this in the C which has to call the Fortran routines to make sure you get it right. *Note Arrays (DIMENSION: Arrays, for information on the differences between the way Fortran (including compilers like `g77') and C handle arrays. ---------- Footnotes ---------- (1) The files generated like this can also be used for inter-unit consistency checking of dummy and actual arguments, although the `ftnchek' tool from `ftp://ftp.netlib.org/fortran' or `ftp://ftp.dsm.fordham.edu' is probably better for this purpose.  File: g77.info, Node: C++ Considerations, Next: Startup Code, Prev: f2c Skeletons and Prototypes, Up: Interoperating with C and C++ C++ Considerations ------------------ `f2c' can be used to generate suitable code for compilation with a C++ system using the `-C++' option. The important thing about linking `g77'-compiled code with C++ is that the prototypes for the `g77' routines must specify C linkage to avoid name mangling. So, use an `extern "C"' declaration. `f2c''s `-C++' option will take care of this when generating skeletons or prototype files as above, and also avoid clashes with C++ reserved words in addition to those in C.  File: g77.info, Node: Startup Code, Prev: C++ Considerations, Up: Interoperating with C and C++ Startup Code ------------ Unlike with some runtime systems, it shouldn't be necessary (unless there are bugs) to use a Fortran main program to ensure the runtime--specifically the i/o system--is initialized. However, to use the `g77' intrinsics `GETARG()' and `IARGC()' the `main()' routine from the `libf2c' library must be used, either explicitly or implicitly by using a Fortran main program. This `main()' program calls `MAIN__()' (where the names are C-type `extern' names, i.e. not mangled). You need to provide this nullary procedure as the entry point for your C code if using `libf2c''s `main'. In some cases it might be necessary to provide a dummy version of this to avoid linkers complaining about failure to resolve `MAIN__()' if linking against `libf2c' and not using `main()' from it.  File: g77.info, Node: Installation, Next: Debugging and Interfacing, Prev: Other Languages, Up: Top Installing GNU Fortran ********************** The following information describes how to install `g77'. The information in this file generally pertains to dealing with *source* distributions of `g77' and `gcc'. It is possible that some of this information will be applicable to some *binary* distributions of these products--however, since these distributions are not made by the maintainers of `g77', responsibility for binary distributions rests with whoever built and first distributed them. Nevertheless, efforts to make `g77' easier to both build and install from source and package up as a binary distribution are ongoing. * Menu: * Prerequisites:: Make sure your system is ready for `g77'. * Problems Installing:: Known trouble areas. * Settings:: Changing `g77' internals before building. * Quick Start:: The easier procedure for non-experts. * Complete Installation:: For experts, or those who want to be: the details. * Distributing Binaries:: If you plan on distributing your `g77'.