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author | obrien <obrien@FreeBSD.org> | 1999-09-18 10:51:31 +0000 |
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committer | obrien <obrien@FreeBSD.org> | 1999-09-18 10:51:31 +0000 |
commit | 98e51635e2084da6cfe0d3b1782cb95b80fd2caa (patch) | |
tree | 0938eb35cebcf917f447463078144fc4832576c6 /contrib/libf2c/README | |
parent | 0bedf4fb30066e5e1d4342a1d3914dae7d37cba7 (diff) | |
download | FreeBSD-src-98e51635e2084da6cfe0d3b1782cb95b80fd2caa.zip FreeBSD-src-98e51635e2084da6cfe0d3b1782cb95b80fd2caa.tar.gz |
Virgin import of EGCS 1.1.2's libf2c
Diffstat (limited to 'contrib/libf2c/README')
-rw-r--r-- | contrib/libf2c/README | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/contrib/libf2c/README b/contrib/libf2c/README new file mode 100644 index 0000000..008654b --- /dev/null +++ b/contrib/libf2c/README @@ -0,0 +1,109 @@ +1998-08-11 + +This directory contains the libf2c library packaged for use with g77 +to configure and build automatically (in principle!) as part of the +top-level configure and make steps. g77 names this library `libg2c' +to avoid conflicts with existing copies of `libf2c' on a system. + +Some small changes have been made vis-a-vis the netlib distribution of +libf2c, which comes from <ftp:bell-labs.com/netlib/f2c/> and is maintained +(excellently) by David M. Gay <dmg@bell-labs.com>. See the Notice files +for copyright information. We usually try to get g77-specific changes +rolled back into the libf2c distribution. + +Files that come directly from netlib are either maintained in the +libf2c directory under their original names or, if they are not pertinent +for g77's version of libf2c, under their original names with `.netlib' +appended. For example, permissions.netlib is a copy of f2c's top-level +`permissions' file in the netlib distribution. In this case, it applies +only to the relevant portions of the libF77/ and libI77/ directories; it +does not apply to the libU77/ directory, which is distributed under +different licensing arrangements. Similarly, the `makefile.netlib' files +in the libF77/ and libI77/ subdirectories are copies of the respective +`makefile' files in the netlib distribution, but are not used when +building g77's version of libf2c. + +The README.netlib files in libF77/ and libI77/ thus might be +interesting, but should not be taken as guidelines for how to +configure and build libf2c in g77's distribution. + +* Read permissions.netlib for licensing conditions that apply to + distributing programs containing portions of code in the libF77/ and + libI77/ subdirectories. Also read disclaimer.netlib. + +* Read libU77/COPYING.LIB for licensing conditions that apply to + distributing programs containing portions of code in the libU77/ + subdirectory. + +Among the user-visible changes (choices) g77 makes in its version of libf2c: + +- f2c.h configured to default to padding unformatted direct reads + (#define Pad_UDread), because that's the behavior most users + expect. + +- f2c.h configured to default to outputting leading zeros before + decimal points in formatted and list-directed output, to be compatible + with many other compilers (#define WANT_LEAD_0). Either way is + standard-conforming, however, and you should try to avoid writing + code that assumes one format or another. + +- dtime_() and etime_() are from Dave Love's libU77, not from + netlib's libF77. + +- Routines that are intended to be called directly via user code + (as in `CALL EXIT', but not the support routines for `OPEN') + have been renamed from `<name>' to `G77_<name>_0'. This, in + combination with g77 recognizing these names as intrinsics and + calling them directly by those names, reduces the likelihood of + interface mismatches occurring due to use of compiler options + that change code generation, and permits use of these names as + both intrinsics and user-supplied routines in applications (as + required by the Fortran standards). f2cext.c contains "jacket" + routines named `<name>' that call `G77_<name>_0', to support + code that relies on calling the relevant routines as `EXTERNAL' + routines. + + Note that the `_0' in the name denotes version 0 of the *interface*, + not the *implementation*, of a routine. The interface of a + given routine *must not change* -- instead, introduce a new copy + of the code, with an increment (e.g. `_1') suffix, having the + new interface. Whether the previous interface is maintained is + not as important as ensuring the routine implementing the new + interface is never successfully linked to a call in existing, + e.g. previously compiled, code that expects the old interface. + +- Version.c in the subdirectories contains g77-specific version + information and a routine (per subdirectory) to print both the + netlib and g77 version information when called. The `g77 -v' + command is designed to trigger this, by compiling, linking, and + running a small program that calls the routines in sequence. + +- libF77/main.c no longer contains the actual code to copy the + argc and argv values into globals or to set up the signal-handling + environment. These have been removed to libF77/setarg.c and + libF77/setsig.c, respectively. libF77/main.c contains procedure + calls to the new code in place of the code itself. This should + simplify linking executables with a main() function other than + that in libF77/main.c (such as one written by the user in C or + C++). See the g77 documentation for more information. + +- Complex-arithmetic support routines in libF77/ take a different approach + to avoiding problems resulting from aliased input and output arguments, + which should avoid particularly unusual alias problems that netlib + libf2c might suffer from. + +- libF77/signal_.c supports systems with 64-bit pointers and 32-bit + integers. + +- I/O routines in libI77/ have code to detect attempts to do recursive + I/O more "directly", mainly to lead to a clearer diagnostic than + typically occurs under such conditions. + +- Formatted-I/O routines in libI77/ have code to pretty-print a FORMAT + string when printing a fatal diagnostic involving formatted I/O. + +- libI77/open.c supports a more robust, perhaps more secure, method + of naming temporary files on some systems. + +- Some g77-specific handling of building under Microsoft operating + systems exists, mainly in libI77/. |