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diff --git a/gnu/usr.bin/gcc/f/NEWS b/gnu/usr.bin/gcc/f/NEWS new file mode 100644 index 00000000000..4ecf6d3a862 --- /dev/null +++ b/gnu/usr.bin/gcc/f/NEWS @@ -0,0 +1,575 @@ +This file lists recent changes to the GNU Fortran compiler. Copyright +(C) 1995, 1996 Free Software Foundation, Inc. You may copy, +distribute, and modify it freely as long as you preserve this copyright +notice and permission notice. + +News About GNU Fortran +********************** + +In 0.5.18: +========== + + * Add some rudimentary support for `INTEGER*1', `INTEGER*2', + `INTEGER*8', and their `LOGICAL' equivalents. (This support works + on most, maybe all, `gcc' targets.) + + Thanks to Scott Snyder (`snyder@d0sgif.fnal.gov') for providing + the patch for this! + + Among the missing elements from the support for these features are + full intrinsic support and constants. + + * Add some rudimentary support for the `BYTE' and `WORD' + type-declaration statements. `BYTE' corresponds to `INTEGER*1', + while `WORD' corresponds to `INTEGER*2'. + + Thanks to Scott Snyder (`snyder@d0sgif.fnal.gov') for providing + the patch for this! + + * The compiler code handling intrinsics has been largely rewritten + to accommodate the new types. No new intrinsics or arguments for + existing intrinsics have been added, so there is, at this point, + no intrinsic to convert to `INTEGER*8', for example. + + * Support automatic arrays in procedures. + + * Reduce space/time requirements for handling large *sparsely* + initialized aggregate arrays. This improvement applies to only a + subset of the general problem to be addressed in 0.6. + + * Treat initial values of zero as if they weren't specified (in DATA + and type-declaration statements). The initial values will be set + to zero anyway, but the amount of compile time processing them + will be reduced, in some cases significantly (though, again, this + is only a subset of the general problem to be addressed in 0.6). + + A new option, `-fzeros', is introduced to enable the traditional + treatment of zeros as any other value. + + * With `-ff90' in force, `g77' incorrectly interpreted `REAL(Z)' as + returning a `REAL' result, instead of as a `DOUBLE PRECISION' + result. (Here, `Z' is `DOUBLE COMPLEX'.) + + With `-fno-f90' in force, the interpretation remains unchanged, + since this appears to be how at least some F77 code using the + `DOUBLE COMPLEX' extension expected it to work. + + Essentially, `REAL(Z)' in F90 is the same as `DBLE(Z)', while in + extended F77, it appears to be the same as `REAL(REAL(Z))'. + + * An expression involving exponentiation, where both operands were + type `INTEGER' and the right-hand operand was negative, was + erroneously evaluated. + + * Fix bugs involving `DATA' implied-`DO' constructs (these involved + an errant diagnostic and a crash, both on good code, one involving + subsequent statement-function definition). + + * Close `INCLUDE' files after processing them, so compiling source + files with lots of `INCLUDE' statements does not result in being + unable to open `INCLUDE' files after all the available file + descriptors are used up. + + * Speed up compiling, especially of larger programs, and perhaps + slightly reduce memory utilization while compiling (this is *not* + the improvement planned for 0.6 involving large aggregate + areas)--these improvements result from simply turning off some + low-level code to do self-checking that hasn't been triggered in a + long time. + + * Introduce three new options that implement optimizations in the + `gcc' back end (GBE). These options are `-fmove-all-movables', + `-freduce-all-givs', and `-frerun-loop-opt', which are enabled, by + default, for Fortran compilations. These optimizations are + intended to help toon Fortran programs. + + * Patch the GBE to do a better job optimizing certain kinds of + references to array elements. + + * Due to patches to the GBE, the version number of `gcc' also is + patched to make it easier to manage installations, especially + useful if it turns out a `g77' change to the GBE has a bug. + + The `g77'-modified version number is the `gcc' version number with + the string `.f.N' appended, where `f' identifies the version as + enhanced for Fortran, and N is `1' for the first Fortran patch for + that version of `gcc', `2' for the second, and so on. + + So, this introduces version `2.7.2.f.1' of `gcc'. + + * Make several improvements and fixes to diagnostics, including the + removal of two that were inappropriate or inadequate. + + * Warning about two successive arithmetic operators, produced by + `-Wsurprising', now produced *only* when both operators are, + indeed, arithmetic (not relational/boolean). + + * `-Wsurprising' now warns about the remaining cases of using + non-integral variables for implied-`DO' loops, instead of these + being rejected unless `-fpedantic' or `-fugly' specified. + + * Allow `SAVE' of a local variable or array, even after it has been + given an initial value via `DATA', for example. + + * Introduce an Info version of `g77' documentation, which supercedes + `gcc/f/CREDITS', `gcc/f/DOC', and `gcc/f/PROJECTS'. These files + will be removed in a future release. The files `gcc/f/BUGS', + `gcc/f/INSTALL', and `gcc/f/NEWS' now are automatically built from + the texinfo source when distributions are made. + + This effort was 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'). + + * New `-fno-second-underscore' option to specify that, when + `-funderscoring' is in effect, a second underscore is not to be + appended to Fortran names already containing an underscore. + + * Change the way iterative `DO' loops work to follow the F90 + standard. In particular, calculation of the iteration count is + still done by converting the start, end, and increment parameters + to the type of the `DO' variable, but the result of the + calculation is always converted to the default `INTEGER' type. + + (This should have no effect on existing code compiled by `g77', + but code written to assume that use of a *wider* type for the `DO' + variable will result in an iteration count being fully calculated + using that wider type (wider than default `INTEGER') must be + rewritten.) + + * Upgrade to `libf2c' as of 1996-03-23, and fix up some of the build + procedures. + + Note that the email addresses related to `f2c' have changed--the + distribution site now is named `netlib.bell-labs.com', and the + maintainer's new address is `dmg@bell-labs.com'. + +In 0.5.17: +========== + + * *Fix serious bug* in `g77 -v' command that can cause removal of a + system's `/dev/null' special file if run by user `root'. + + *All users* of version 0.5.16 should ensure that they have not + removed `/dev/null' or replaced it with an ordinary file (e.g. by + comparing the output of `ls -l /dev/null' with `ls -l /dev/zero'. + If the output isn't basically the same, contact your system + administrator about restoring `/dev/null' to its proper status). + + This bug is particularly insidious because removing `/dev/null' as + a special file can go undetected for quite a while, aside from + various applications and programs exhibiting sudden, strange + behaviors. + + I sincerely apologize for not realizing the implications of the + fact that when `g77 -v' runs the `ld' command with `-o /dev/null' + that `ld' tries to *remove* the executable it is supposed to build + (especially if it reports unresolved references, which it should + in this case)! + + * Fix crash on `CHARACTER*(*) FOO' in a main or block data program + unit. + + * Fix crash that can occur when diagnostics given outside of any + program unit (such as when input file contains `@foo'). + + * Fix crashes, infinite loops (hangs), and such involving diagnosed + code. + + * Fix `ASSIGN''ed variables so they can be `SAVE''d or dummy + arguments, and issue clearer error message in cases where target + of `ASSIGN' or `ASSIGN'ed `GOTO'/`FORMAT' is too small (which + should never happen). + + * Make `libf2c' build procedures work on more systems again by + eliminating unnecessary invocations of `ld -r -x' and `mv'. + + * Fix omission of `-funix-intrinsics-...' options in list of + permitted options to compiler. + + * Fix failure to always diagnose missing type declaration for + `IMPLICIT NONE'. + + * Fix compile-time performance problem (which could sometimes crash + the compiler, cause a hang, or whatever, due to a bug in the back + end) involving exponentiation with a large `INTEGER' constant for + the right-hand operator (e.g. `I**32767'). + + * Fix build procedures so cross-compiling `g77' (the `fini' utility + in particular) is properly built using the host compiler. + + * Add new `-Wsurprising' option to warn about constructs that are + interpreted by the Fortran standard (and `g77') in ways that are + surprising to many programmers. + + * Add `ERF()' and `ERFC()' as generic intrinsics mapping to existing + `ERF'/`DERF' and `ERFC'/`DERFC' specific intrinsics. + + *Note:* You should specify `INTRINSIC ERF,ERFC' in any code where + you might use these as generic intrinsics, to improve likelihood + of diagnostics (instead of subtle run-time bugs) when using a + compiler that doesn't support these as intrinsics (e.g. `f2c'). + + * Remove from `-fno-pedantic' the diagnostic about `DO' with + non-`INTEGER' index variable; issue that under `-Wsurprising' + instead. + + * Clarify some diagnostics that say things like "ignored" when that's + misleading. + + * Clarify diagnostic on use of `.EQ.'/`.NE.' on `LOGICAL' operands. + + * Minor improvements to code generation for various operations on + `LOGICAL' operands. + + * Minor improvement to code generation for some `DO' loops on some + machines. + + * Support `gcc' version 2.7.1. + + * Upgrade to `libf2c' as of 1995-11-15. + +In 0.5.16: +========== + + * Fix a code-generation bug involving complicated `EQUIVALENCE' + statements not involving `COMMON' + + * Fix code-generation bugs involving invoking "gratis" library + procedures in `libf2c' from code compiled with `-fno-f2c' by + making these procedures known to `g77' as intrinsics (not affected + by -fno-f2c). This is known to fix code invoking `ERF()', + `ERFC()', `DERF()', and `DERFC()'. + + * Update `libf2c' to include netlib patches through 1995-08-16, and + `#define' `WANT_LEAD_0' to 1 to make `g77'-compiled code more + consistent with other Fortran implementations by outputting + leading zeros in formatted and list-directed output. + + * Fix a code-generation bug involving adjustable dummy arrays with + high bounds whose primaries are changed during procedure + execution, and which might well improve code-generation + performance for such arrays compared to `f2c' plus `gcc' (but + apparently only when using `gcc-2.7.0' or later). + + * Fix a code-generation bug involving invocation of `COMPLEX' and + `DOUBLE COMPLEX' `FUNCTION's and doing `COMPLEX' and `DOUBLE + COMPLEX' divides, when the result of the invocation or divide is + assigned directly to a variable that overlaps one or more of the + arguments to the invocation or divide. + + * Fix crash by not generating new optimal code for `X**I' if `I' is + nonconstant and the expression is used to dimension a dummy array, + since the `gcc' back end does not support the necessary mechanics + (and the `gcc' front end rejects the equivalent construct, as it + turns out). + + * Fix crash on expressions like `COMPLEX**INTEGER'. + + * Fix crash on expressions like `(1D0,2D0)**2', i.e. raising a + `DOUBLE COMPLEX' constant to an `INTEGER' constant power. + + * Fix crashes and such involving diagnosed code. + + * Diagnose, instead of crashing on, statement function definitions + having duplicate dummy argument names. + + * Fix bug causing rejection of good code involving statement function + definitions. + + * Fix bug resulting in debugger not knowing size of local equivalence + area when any member of area has initial value (via `DATA', for + example). + + * Fix installation bug that prevented installation of `g77' driver. + Provide for easy selection of whether to install copy of `g77' as + `f77' to replace the broken code. + + * Fix `gcc' driver (affects `g77' thereby) to not gratuitously + invoke the `f771' program (e.g. when `-E' is specified). + + * Fix diagnostic to point to correct source line when it immediately + follows an `INCLUDE' statement. + + * Support more compiler options in `gcc'/`g77' when compiling + Fortran files. These options include `-p', `-pg', `-aux-info', + `-P', correct setting of version-number macros for preprocessing, + full recognition of `-O0', and automatic insertion of + configuration-specific linker specs. + + * Add new intrinsics that interface to existing routines in `libf2c': + `ABORT', `DERF', `DERFC', `ERF', `ERFC', `EXIT', `FLUSH', + `GETARG', `GETENV', `IARGC', `SIGNAL', and `SYSTEM'. Note that + `ABORT', `EXIT', `FLUSH', `SIGNAL', and `SYSTEM' are intrinsic + subroutines, not functions (since they have side effects), so to + get the return values from `SIGNAL' and `SYSTEM', append a final + argument specifying an `INTEGER' variable or array element (e.g. + `CALL SYSTEM('rm foo',ISTAT)'). + + * Add new intrinsic group named `unix' to contain the new intrinsics, + and by default enable this new group. + + * Move `LOC()' intrinsic out of the `vxt' group to the new `unix' + group. + + * Improve `g77' so that `g77 -v' by itself (or with certain other + options, including `-B', `-b', `-i', `-nostdlib', and `-V') + reports lots more useful version info, and so that long-form + options `gcc' accepts are understood by `g77' as well (even in + truncated, unambiguous forms). + + * Add new `g77' option `--driver=name' to specify driver when + default, `gcc', isn't appropriate. + + * Add support for `#' directives (as output by the preprocessor) in + the compiler, and enable generation of those directives by the + preprocessor (when compiling `.F' files) so diagnostics and + debugging info are more useful to users of the preprocessor. + + * Produce better diagnostics, more like `gcc', with info such as `In + function `foo':' and `In file included from...:'. + + * Support `gcc''s `-fident' and `-fno-ident' options. + + * When `-Wunused' in effect, don't warn about local variables used as + statement-function dummy arguments or `DATA' implied-`DO' iteration + variables, even though, strictly speaking, these are not uses of + the variables themselves. + + * When `-W -Wunused' in effect, don't warn about unused dummy + arguments at all, since there's no way to turn this off for + individual cases (`g77' might someday start warning about + these)--applies to `gcc' versions 2.7.0 and later, since earlier + versions didn't warn about unused dummy arguments. + + * New option `-fno-underscoring' that inhibits transformation of + names (by appending one or two underscores) so users may experiment + with implications of such an environment. + + * Minor improvement to `gcc/f/info' module to make it easier to build + `g77' using the native (non-`gcc') compiler on certain machines + (but definitely not all machines nor all non-`gcc' compilers). + Please do not report bugs showing problems compilers have with + macros defined in `gcc/f/target.h' and used in places like + `gcc/f/expr.c'. + + * Add warning to be printed for each invocation of the compiler if + the target machine `INTEGER', REAL, or `LOGICAL' size is not 32 + bits, since `g77' is known to not work well for such cases (to be + fixed in Version 0.6--*note Actual Bugs We Haven't Fixed Yet: + Actual Bugs.). + + * Lots of new documentation (though work is still needed to put it + into canonical GNU format). + + * Build `libf2c' with `-g0', not `-g2', in effect (by default), to + produce smaller library without lots of debugging clutter. + +In 0.5.15: +========== + + * Fix bad code generation involving `X**I' and temporary, internal + variables generated by `g77' and the back end (such as for `DO' + loops). + + * Fix crash given `CHARACTER A;DATA A/.TRUE./'. + + * Replace crash with diagnostic given `CHARACTER A;DATA A/1.0/'. + + * Fix crash or other erratic behavior when null character constant + (`''') is encountered. + + * Fix crash or other erratic behavior involving diagnosed code. + + * Fix code generation for external functions returning type `REAL' + when the `-ff2c' option is in force (which it is by default) so + that `f2c' compatibility is indeed provided. + + * Disallow `COMMON I(10)' if `I' has previously been specified with + an array declarator. + + * New `-ffixed-line-length-N' option, where N is the maximum length + of a typical fixed-form line, defaulting to 72 columns, such that + characters beyond column N are ignored, or N is `none', meaning no + characters are ignored. does not affect lines with `&' in column + 1, which are always processed as if `-ffixed-line-length-none' was + in effect. + + * No longer generate better code for some kinds of array references, + as `gcc' back end is to be fixed to do this even better, and it + turned out to slow down some code in some cases after all. + + * In `COMMON' and `EQUIVALENCE' areas with any members given initial + values (e.g. via `DATA'), uninitialized members now always + initialized to binary zeros (though this is not required by the + standard, and might not be done in future versions of `g77'). + Previously, in some `COMMON'/`EQUIVALENCE' areas (essentially + those with members of more than one type), the uninitialized + members were initialized to spaces, to cater to `CHARACTER' types, + but it seems no existing code expects that, while much existing + code expects binary zeros. + +In 0.5.14: +========== + + * Don't emit bad code when low bound of adjustable array is + nonconstant and thus might vary as an expression at run time. + + * Emit correct code for calculation of number of trips in `DO' loops + for cases where the loop should not execute at all. (This bug + affected cases where the difference between the begin and end + values was less than the step count, though probably not for + floating-point cases.) + + * Fix crash when extra parentheses surround item in `DATA' + implied-`DO' list. + + * Fix crash over minor internal inconsistencies in handling + diagnostics, just substitute dummy strings where necessary. + + * Fix crash on some systems when compiling call to `MVBITS()' + intrinsic. + + * Fix crash on array assignment `TYPEDDD(...)=...', where DDD is a + string of one or more digits. + + * Fix crash on `DCMPLX()' with a single `INTEGER' argument. + + * Fix various crashes involving code with diagnosed errors. + + * Support `-I' option for `INCLUDE' statement, plus `gcc''s + `header.gcc' facility for handling systems like MS-DOS. + + * Allow `INCLUDE' statement to be continued across multiple lines, + even allow it to coexist with other statements on the same line. + + * Incorporate Bellcore fixes to `libf2c' through 1995-03-15--this + fixes a bug involving infinite loops reading EOF with empty + list-directed I/O list. + + * Remove all the `g77'-specific auto-configuration scripts, code, + and so on, except for temporary substitutes for bsearch() and + strtoul(), as too many configure/build problems were reported in + these areas. People will have to fix their systems' problems + themselves, or at least somewhere other than `g77', which expects + a working ANSI C environment (and, for now, a GNU C compiler to + compile `g77' itself). + + * Complain if initialized common redeclared as larger in subsequent + program unit. + + * Warn if blank common initialized, since its size can vary and hence + related warnings that might be helpful won't be seen. + + * New `-fbackslash' option, on by default, that causes `\' within + `CHARACTER' and Hollerith constants to be interpreted a la GNU C. + Note that this behavior is somewhat different from `f2c''s, which + supports only a limited subset of backslash (escape) sequences. + + * Make `-fugly-args' the default. + + * New `-fugly-init' option, on by default, that allows + typeless/Hollerith to be specified as initial values for variables + or named constants (`PARAMETER'), and also allows + character<->numeric conversion in those contexts--turn off via + `-fno-ugly-init'. + + * New `-finit-local-zero' option to initialize local variables to + binary zeros. This does not affect whether they are `SAVE'd, i.e. + made automatic or static. + + * New `-Wimplicit' option to warn about implicitly typed variables, + arrays, and functions. (Basically causes all program units to + default to `IMPLICIT NONE'.) + + * `-Wall' now implies `-Wuninitialized' as with `gcc' (i.e. unless + `-O' not specified, since `-Wuninitialized' requires `-O'), and + implies `-Wunused' as well. + + * `-Wunused' no longer gives spurious messages for unused `EXTERNAL' + names (since they are assumed to refer to block data program + units, to make use of libraries more reliable). + + * Support `%LOC()' and `LOC()' of character arguments. + + * Support null (zero-length) character constants and expressions. + + * Support `f2c''s `IMAG()' generic intrinsic. + + * Support `ICHAR()', `IACHAR()', and `LEN()' of character + expressions that are valid in assignments but not normally as + actual arguments. + + * Support `f2c'-style `&' in column 1 to mean continuation line. + + * Allow `NAMELIST', `EXTERNAL', `INTRINSIC', and `VOLATILE' in + `BLOCK DATA', even though these are not allowed by the standard. + + * Allow `RETURN' in main program unit. + + * Changes to Hollerith-constant support to obey Appendix C of the + standard: + + - Now padded on the right with zeros, not spaces. + + - Hollerith "format specifications" in the form of arrays of + non-character allowed. + + - Warnings issued when non-blank truncation occurs when + converting to another type. + + - When specified as actual argument, now passed by reference to + `INTEGER' (padded on right with spaces if constant too small, + otherwise fully intact if constant wider the `INTEGER' type) + instead of by value. + + *Warning:* `f2c' differs on the interpretation of `CALL FOO(1HX)', + which it treats exactly the same as `CALL FOO('X')', but which the + standard and `g77' treat as `CALL FOO(%REF('X '))' (padded with + as many blanks as necessary to widen to `INTEGER'), essentially. + + * Changes and fixes to typeless-constant support: + + - Now treated as a typeless double-length `INTEGER' value. + + - Warnings issued when overflow occurs. + + - Padded on the left with zeros when converting to a larger + type. + + - Should be properly aligned and ordered on the target machine + for whatever type it is turned into. + + - When specified as actual argument, now passed as reference to + a default `INTEGER' constant. + + * `%DESCR()' of a non-`CHARACTER' expression now passes a pointer to + the expression plus a length for the expression just as if it were + a `CHARACTER' expression. For example, `CALL FOO(%DESCR(D))', + where `D' is `REAL*8', is the same as `CALL FOO(D,%VAL(8)))'. + + * Name of multi-entrypoint master function changed to incorporate + the name of the primary entry point instead of a decimal value, so + the name of the master function for `SUBROUTINE X' with alternate + entry points is now `__g77_masterfun_x'. + + * Remove redundant message about zero-step-count `DO' loops. + + * Clean up diagnostic messages, shortening many of them. + + * Fix typo in `g77' man page. + + * Clarify implications of constant-handling bugs in `f/BUGS'. + + * Generate better code for `**' operator with a right-hand operand of + type `INTEGER'. + + * Generate better code for `SQRT()' and `DSQRT()', also when + `-ffast-math' specified, enable better code generation for `SIN()' + and `COS()'. + + * Generate better code for some kinds of array references. + + * Speed up lexing somewhat (this makes the compilation phase + noticably faster). + |