+++ /dev/null
-_Note:_ This file is automatically generated from the files
-`bugs0.texi' and `bugs.texi'. `BUGS' is _not_ a source file, although
-it is normally included within source distributions.
-
- This file lists known bugs in the GCC-3.1 version of the GNU Fortran
-compiler. Copyright (C) 1995,1996,1997,1998,1999,2000 Free Software
-Foundation, Inc. You may copy, distribute, and modify it freely as
-long as you preserve this copyright notice and permission notice.
-
-Known Bugs In GNU Fortran
-*************************
-
- This section identifies bugs that `g77' _users_ might run into in
-the GCC-3.1 version of `g77'. This includes bugs that are actually in
-the `gcc' back end (GBE) or in `libf2c', because those sets of code are
-at least somewhat under the control of (and necessarily intertwined
-with) `g77', so it isn't worth separating them out.
-
- For information on bugs in _other_ versions of `g77', see
-`gcc/gcc/f/NEWS'. There, lists of bugs fixed in various versions of
-`g77' can help determine what bugs existed in prior versions.
-
- _Warning:_ The information below is still under development, and
-might not accurately reflect the `g77' code base of which it is a part.
-Efforts are made to keep it somewhat up-to-date, but they are
-particularly concentrated on any version of this information that is
-distributed as part of a _released_ `g77'.
-
- In particular, while this information is intended to apply to the
-GCC-3.1 version of `g77', only an official _release_ of that version is
-expected to contain documentation that is most consistent with the
-`g77' product in that version.
-
- An online, "live" version of this document (derived directly from
-the mainline, development version of `g77' within `gcc') is available
-via `http://www.gnu.org/software/gcc/onlinedocs/g77_bugs.html'. Follow
-the "Known Bugs" link.
-
- For information on bugs that might afflict people who configure,
-port, build, and install `g77', see "Problems Installing" in
-`gcc/gcc/f/INSTALL'.
-
- The following information was last updated on 2000-11-05:
-
- * `g77' fails to warn about use of a "live" iterative-DO variable as
- an implied-DO variable in a `WRITE' or `PRINT' statement (although
- it does warn about this in a `READ' statement).
-
- * Something about `g77''s straightforward handling of label
- references and definitions sometimes prevents the GBE from
- unrolling loops. Until this is solved, try inserting or removing
- `CONTINUE' statements as the terminal statement, using the `END DO'
- form instead, and so on.
-
- * Some confusion in diagnostics concerning failing `INCLUDE'
- statements from within `INCLUDE''d or `#include''d files.
-
- * `g77' assumes that `INTEGER(KIND=1)' constants range from `-2**31'
- to `2**31-1' (the range for two's-complement 32-bit values),
- instead of determining their range from the actual range of the
- type for the configuration (and, someday, for the constant).
-
- Further, it generally doesn't implement the handling of constants
- very well in that it makes assumptions about the configuration
- that it no longer makes regarding variables (types).
-
- Included with this item is the fact that `g77' doesn't recognize
- that, on IEEE-754/854-compliant systems, `0./0.' should produce a
- NaN and no warning instead of the value `0.' and a warning. This
- is to be fixed in version 0.6, when `g77' will use the `gcc' back
- end's constant-handling mechanisms to replace its own.
-
- * `g77' uses way too much memory and CPU time to process large
- aggregate areas having any initialized elements.
-
- For example, `REAL A(1000000)' followed by `DATA A(1)/1/' takes up
- way too much time and space, including the size of the generated
- assembler file. This is to be mitigated somewhat in version 0.6.
-
- Version 0.5.18 improves cases like this--specifically, cases of
- _sparse_ initialization that leave large, contiguous areas
- uninitialized--significantly. However, even with the
- improvements, these cases still require too much memory and CPU
- time.
-
- (Version 0.5.18 also improves cases where the initial values are
- zero to a much greater degree, so if the above example ends with
- `DATA A(1)/0/', the compile-time performance will be about as good
- as it will ever get, aside from unrelated improvements to the
- compiler.)
-
- Note that `g77' does display a warning message to notify the user
- before the compiler appears to hang.
-
- * Previous versions of `g77' didn't emit information on variable and
- array members of common blocks and equivalences for use with a
- debugger (the `-g' command-line option). As of the version of
- `g77' shipped with version 3.0 of `GCC', this is corrected.
-
- As of Version 0.5.19, a temporary kludge solution is provided
- whereby some rudimentary information on a member is written as a
- string that is the member's value as a character string.
-
- * When debugging, after starting up the debugger but before being
- able to see the source code for the main program unit, the user
- must currently set a breakpoint at `MAIN__' (or `MAIN___' or
- `MAIN_' if `MAIN__' doesn't exist) and run the program until it
- hits the breakpoint. At that point, the main program unit is
- activated and about to execute its first executable statement, but
- that's the state in which the debugger should start up, as is the
- case for languages like C.
-
- * Debugging `g77'-compiled code using debuggers other than `gdb' is
- likely not to work.
-
- Getting `g77' and `gdb' to work together is a known
- problem--getting `g77' to work properly with other debuggers, for
- which source code often is unavailable to `g77' developers, seems
- like a much larger, unknown problem, and is a lower priority than
- making `g77' and `gdb' work together properly.
-
- On the other hand, information about problems other debuggers have
- with `g77' output might make it easier to properly fix `g77', and
- perhaps even improve `gdb', so it is definitely welcome. Such
- information might even lead to all relevant products working
- together properly sooner.
-
- * `g77' doesn't work perfectly on 64-bit configurations such as the
- Digital Semiconductor ("DEC") Alpha.
-
- This problem is largely resolved as of version 0.5.23. Version
- 0.6 should solve most or all remaining problems (such as
- cross-compiling involving 64-bit machines).
-
- * `g77' currently inserts needless padding for things like `COMMON
- A,IPAD' where `A' is `CHARACTER*1' and `IPAD' is `INTEGER(KIND=1)'
- on machines like x86, because the back end insists that `IPAD' be
- aligned to a 4-byte boundary, but the processor has no such
- requirement (though it is usually good for performance).
-
- The `gcc' back end needs to provide a wider array of
- specifications of alignment requirements and preferences for
- targets, and front ends like `g77' should take advantage of this
- when it becomes available.
-
- * The `libf2c' routines that perform some run-time arithmetic on
- `COMPLEX' operands were modified circa version 0.5.20 of `g77' to
- work properly even in the presence of aliased operands.
-
- While the `g77' and `netlib' versions of `libf2c' differ on how
- this is accomplished, the main differences are that we believe the
- `g77' version works properly even in the presence of _partially_
- aliased operands.
-
- However, these modifications have reduced performance on targets
- such as x86, due to the extra copies of operands involved.
-
+++ /dev/null
-_Note:_ This file is automatically generated from the files
-`news0.texi' and `news.texi'. `NEWS' is _not_ a source file, although
-it is normally included within source distributions.
-
- This file lists news about the GCC-3.1 version (and some other
-versions) of the GNU Fortran compiler. Copyright (C)
-1995,1996,1997,1998,1999,2000 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
-**********************
-
- Changes made to recent versions of GNU Fortran are listed below,
-with the most recent version first.
-
- The changes are generally listed in order:
-
- 1. Code-generation and run-time-library bug-fixes
-
- 2. Compiler and run-time-library crashes involving valid code that
- have been fixed
-
- 3. New features
-
- 4. Fixes and enhancements to existing features
-
- 5. New diagnostics
-
- 6. Internal improvements
-
- 7. Miscellany
-
- This order is not strict--for example, some items involve a
-combination of these elements.
-
- Note that two variants of `g77' are tracked below. The `egcs'
-variant is described vis-a-vis previous versions of `egcs' and/or an
-official FSF version, as appropriate. Note that all such variants are
-now obsolete - the information is retained here only for its historical
-value.
-
- Therefore, `egcs' versions sometimes have multiple listings to help
-clarify how they differ from other versions, though this can make
-getting a complete picture of what a particular `egcs' version contains
-somewhat more difficult.
-
- _Warning:_ The information below is still under development, and
-might not accurately reflect the `g77' code base of which it is a part.
-Efforts are made to keep it somewhat up-to-date, but they are
-particularly concentrated on any version of this information that is
-distributed as part of a _released_ `g77'.
-
- In particular, while this information is intended to apply to the
-GCC-3.1 version of `g77', only an official _release_ of that version is
-expected to contain documentation that is most consistent with the
-`g77' product in that version.
-
- Nevertheless, information on _previous_ releases of `g77', below, is
-likely to be more up-to-date and accurate than the equivalent
-information that accompanied those releases, assuming the last-updated
-date of the information below is later than the dates of those releases.
-
- That's due to attempts to keep this development version of news
-about previous `g77' versions up-to-date.
-
- An online, "live" version of this document (derived directly from
-the mainline, development version of `g77' within `gcc') is available at
-`http://www.gnu.org/software/gcc/onlinedocs/g77_news.html'.
-
- The following information was last updated on 2000-11-05:
-
-In development:
-===============
-
- * Using options `-g', `-ggdb' or `-gdwarf[-2]' (where appropriate
- for your target) now also enables debugging information for COMMON
- BLOCK and EQUIVALENCE items to be emitted.
-
- * The `TtyNam' intrinsics now set NAME to all spaces (at run time)
- if the system has no `ttyname' implementation available.
-
- * Upgrade to `libf2c' as of 1999-06-28.
-
- This fixes a bug whereby input to a `NAMELIST' read involving a
- repeat count, such as `K(5)=10*3', was not properly handled by
- `libf2c'. The first item was written to `K(5)', but the remaining
- nine were written elsewhere (still within the array), not
- necessarily starting at `K(6)'.
-
-In 0.5.25, `GCC' 2.95 (`EGCS' 1.2) versus `EGCS' 1.1.2:
-=======================================================
-
- * `g77' no longer generates bad code for assignments, or other
- conversions, of `REAL' or `COMPLEX' constant expressions to type
- `INTEGER(KIND=2)' (often referred to as `INTEGER*8').
-
- For example, `INTEGER*8 J; J = 4E10' now works as documented.
-
- * `g77' no longer truncates `INTEGER(KIND=2)' (usually `INTEGER*8')
- subscript expressions when evaluating array references on systems
- with pointers widers than `INTEGER(KIND=1)' (such as Alphas).
-
- * `g77' no longer generates bad code for an assignment to a
- `COMPLEX' variable or array that partially overlaps one or more of
- the sources of the same assignment (a very rare construction). It
- now assigns through a temporary, in cases where such partial
- overlap is deemed possible.
-
- * `libg2c' (`libf2c') no longer loses track of the file being worked
- on during a `BACKSPACE' operation.
-
- * `libg2c' (`libf2c') fixes a bug whereby input to a `NAMELIST' read
- involving a repeat count, such as `K(5)=10*3', was not properly
- handled by `libf2c'. The first item was written to `K(5)', but
- the remaining nine were written elsewhere (still within the array),
- not necessarily starting at `K(6)'.
-
- * Automatic arrays now seem to be working on HP-UX systems.
-
- * The `Date' intrinsic now returns the correct result on big-endian
- systems.
-
- * Fix `g77' so it no longer crashes when compiling I/O statements
- using keywords that define `INTEGER' values, such as `IOSTAT=J',
- where J is other than default `INTEGER' (such as `INTEGER*2').
- Instead, it issues a diagnostic.
-
- * Fix `g77' so it properly handles `DATA A/RPT*VAL/', where RPT is
- not default `INTEGER', such as `INTEGER*2', instead of producing a
- spurious diagnostic. Also fix `DATA (A(I),I=1,N)', where `N' is
- not default `INTEGER' to work instead of crashing `g77'.
-
- * The `-ax' option is now obeyed when compiling Fortran programs.
- (It is passed to the `f771' driver.)
-
- * The new `-fbounds-check' option causes `g77' to compile run-time
- bounds checks of array subscripts, as well as of substring start
- and end points.
-
- * `libg2c' now supports building as multilibbed library, which
- provides better support for systems that require options such as
- `-mieee' to work properly.
-
- * Source file names with the suffixes `.FOR' and `.FPP' now are
- recognized by `g77' as if they ended in `.for' and `.fpp',
- respectively.
-
- * The order of arguments to the _subroutine_ forms of the `CTime',
- `DTime', `ETime', and `TtyNam' intrinsics has been swapped. The
- argument serving as the returned value for the corresponding
- function forms now is the _second_ argument, making these
- consistent with the other subroutine forms of `libU77' intrinsics.
-
- * `g77' now warns about a reference to an intrinsic that has an
- interface that is not Year 2000 (Y2K) compliant. Also, `libg2c'
- has been changed to increase the likelihood of catching references
- to the implementations of these intrinsics using the `EXTERNAL'
- mechanism (which would avoid the new warnings).
-
- * `g77' now warns about a reference to a function when the
- corresponding _subsequent_ function program unit disagrees with
- the reference concerning the type of the function.
-
- * `-fno-emulate-complex' is now the default option. This should
- result in improved performance of code that uses the `COMPLEX'
- data type.
-
- * The `-malign-double' option now reliably aligns _all_
- double-precision variables and arrays on Intel x86 targets.
-
- * Even without the `-malign-double' option, `g77' reliably aligns
- local double-precision variables that are not in `EQUIVALENCE'
- areas and not `SAVE''d.
-
- * `g77' now open-codes ("inlines") division of `COMPLEX' operands
- instead of generating a run-time call to the `libf2c' routines
- `c_div' or `z_div', unless the `-Os' option is specified.
-
- * `g77' no longer generates code to maintain `errno', a C-language
- concept, when performing operations such as the `SqRt' intrinsic.
-
- * `g77' developers can temporarily use the `-fflatten-arrays' option
- to compare how the compiler handles code generation using C-like
- constructs as compared to the Fortran-like method constructs
- normally used.
-
- * A substantial portion of the `g77' front end's code-generation
- component was rewritten. It now generates code using facilities
- more robustly supported by the `gcc' back end. One effect of this
- rewrite is that some codes no longer produce a spurious "label LAB
- used before containing binding contour" message.
-
- * Support for the `-fugly' option has been removed.
-
- * Improve documentation and indexing, including information on Year
- 2000 (Y2K) compliance, and providing more information on internals
- of the front end.
-
- * Upgrade to `libf2c' as of 1999-05-10.
-
-In 0.5.24 versus 0.5.23:
-========================
-
- There is no `g77' version 0.5.24 at this time, or planned. 0.5.24
-is the version number designated for bug fixes and, perhaps, some new
-features added, to 0.5.23. Version 0.5.23 requires `gcc' 2.8.1, as
-0.5.24 was planned to require.
-
- Due to `EGCS' becoming `GCC' (which is now an acronym for "GNU
-Compiler Collection"), and `EGCS' 1.2 becoming officially designated
-`GCC' 2.95, there seems to be no need for an actual 0.5.24 release.
-
- To reduce the confusion already resulting from use of 0.5.24 to
-designate `g77' versions within `EGCS' versions 1.0 and 1.1, as well as
-in versions of `g77' documentation and notices during that period,
-"mainline" `g77' version numbering resumes at 0.5.25 with `GCC' 2.95
-(`EGCS' 1.2), skipping over 0.5.24 as a placeholder version number.
-
- To repeat, there is no `g77' 0.5.24, but there is now a 0.5.25.
-Please remain calm and return to your keypunch units.
-
-In `EGCS' 1.1.2 versus `EGCS' 1.1.1:
-====================================
-
- * Fix the `IDate' intrinsic (VXT) (in `libg2c') so the returned year
- is in the documented, non-Y2K-compliant range of 0-99, instead of
- being returned as 100 in the year 2000.
-
- * Fix the `Date_and_Time' intrinsic (in `libg2c') to return the
- milliseconds value properly in VALUES(8).
-
- * Fix the `LStat' intrinsic (in `libg2c') to return device-ID
- information properly in SARRAY(7).
-
- * Improve documentation.
-
-In `EGCS' 1.1.1 versus `EGCS' 1.1:
-==================================
-
- * Fix `libg2c' so it performs an implicit `ENDFILE' operation (as
- appropriate) whenever a `REWIND' is done.
-
- (This bug was introduced in 0.5.23 and `egcs' 1.1 in `g77''s
- version of `libf2c'.)
-
- * Fix `libg2c' so it no longer crashes with a spurious diagnostic
- upon doing any I/O following a direct formatted write.
-
- (This bug was introduced in 0.5.23 and `egcs' 1.1 in `g77''s
- version of `libf2c'.)
-
- * Fix `g77' so it no longer crashes compiling references to the
- `Rand' intrinsic on some systems.
-
- * Fix `g77' portion of installation process so it works better on
- some systems (those with shells requiring `else true' clauses on
- `if' constructs for the completion code to be set properly).
-
-In `EGCS' 1.1 versus `EGCS' 1.0.3:
-==================================
-
- * Fix bugs in the `libU77' intrinsic `HostNm' that wrote one byte
- beyond the end of its `CHARACTER' argument, and in the `libU77'
- intrinsics `GMTime' and `LTime' that overwrote their arguments.
-
- * Assumed arrays with negative bounds (such as `REAL A(-1:*)') no
- longer elicit spurious diagnostics from `g77', even on systems
- with pointers having different sizes than integers.
-
- This bug is not known to have existed in any recent version of
- `gcc'. It was introduced in an early release of `egcs'.
-
- * Valid combinations of `EXTERNAL', passing that external as a dummy
- argument without explicitly giving it a type, and, in a subsequent
- program unit, referencing that external as an external function
- with a different type no longer crash `g77'.
-
- * `CASE DEFAULT' no longer crashes `g77'.
-
- * The `-Wunused' option no longer issues a spurious warning about
- the "master" procedure generated by `g77' for procedures
- containing `ENTRY' statements.
-
- * Support `FORMAT(I<EXPR>)' when EXPR is a compile-time constant
- `INTEGER' expression.
-
- * Fix `g77' `-g' option so procedures that use `ENTRY' can be
- stepped through, line by line, in `gdb'.
-
- * Allow any `REAL' argument to intrinsics `Second' and `CPU_Time'.
-
- * Use `tempnam', if available, to open scratch files (as in
- `OPEN(STATUS='SCRATCH')') so that the `TMPDIR' environment
- variable, if present, is used.
-
- * `g77''s version of `libf2c' separates out the setting of global
- state (such as command-line arguments and signal handling) from
- `main.o' into distinct, new library archive members.
-
- This should make it easier to write portable applications that
- have their own (non-Fortran) `main()' routine properly set up the
- `libf2c' environment, even when `libf2c' (now `libg2c') is a
- shared library.
-
- * `g77' no longer installs the `f77' command and `f77.1' man page in
- the `/usr' or `/usr/local' heirarchy, even if the `f77-install-ok'
- file exists in the source or build directory. See the
- installation documentation for more information.
-
- * `g77' no longer installs the `libf2c.a' library and `f2c.h'
- include file in the `/usr' or `/usr/local' heirarchy, even if the
- `f2c-install-ok' or `f2c-exists-ok' files exist in the source or
- build directory. See the installation documentation for more
- information.
-
- * The `libf2c.a' library produced by `g77' has been renamed to
- `libg2c.a'. It is installed only in the `gcc' "private" directory
- heirarchy, `gcc-lib'. This allows system administrators and users
- to choose which version of the `libf2c' library from `netlib' they
- wish to use on a case-by-case basis. See the installation
- documentation for more information.
-
- * The `f2c.h' include (header) file produced by `g77' has been
- renamed to `g2c.h'. It is installed only in the `gcc' "private"
- directory heirarchy, `gcc-lib'. This allows system administrators
- and users to choose which version of the include file from
- `netlib' they wish to use on a case-by-case basis. See the
- installation documentation for more information.
-
- * The `g77' command now expects the run-time library to be named
- `libg2c.a' instead of `libf2c.a', to ensure that a version other
- than the one built and installed as part of the same `g77' version
- is picked up.
-
- * During the configuration and build process, `g77' creates
- subdirectories it needs only as it needs them. Other cleaning up
- of the configuration and build process has been performed as well.
-
- * `install-info' now used to update the directory of Info
- documentation to contain an entry for `g77' (during installation).
-
- * Some diagnostics have been changed from warnings to errors, to
- prevent inadvertent use of the resulting, probably buggy, programs.
- These mostly include diagnostics about use of unsupported features
- in the `OPEN', `INQUIRE', `READ', and `WRITE' statements, and
- about truncations of various sorts of constants.
-
- * Improve compilation of `FORMAT' expressions so that a null byte is
- appended to the last operand if it is a constant. This provides a
- cleaner run-time diagnostic as provided by `libf2c' for statements
- like `PRINT '(I1', 42'.
-
- * Improve documentation and indexing.
-
- * The upgrade to `libf2c' as of 1998-06-18 should fix a variety of
- problems, including those involving some uses of the `T' format
- specifier, and perhaps some build (porting) problems as well.
-
-In `EGCS' 1.1 versus `g77' 0.5.23:
-==================================
-
- * Fix a code-generation bug that afflicted Intel x86 targets when
- `-O2' was specified compiling, for example, an old version of the
- `DNRM2' routine.
-
- The x87 coprocessor stack was being mismanaged in cases involving
- assigned `GOTO' and `ASSIGN'.
-
- * `g77' no longer produces incorrect code and initial values for
- `EQUIVALENCE' and `COMMON' aggregates that, due to "unnatural"
- ordering of members vis-a-vis their types, require initial padding.
-
- * Fix `g77' crash compiling code containing the construct
- `CMPLX(0.)' or similar.
-
- * `g77' no longer crashes when compiling code containing
- specification statements such as `INTEGER(KIND=7) PTR'.
-
- * `g77' no longer crashes when compiling code such as `J = SIGNAL(1,
- 2)'.
-
- * `g77' now treats `%LOC(EXPR)' and `LOC(EXPR)' as "ordinary"
- expressions when they are used as arguments in procedure calls.
- This change applies only to global (filewide) analysis, making it
- consistent with how `g77' actually generates code for these cases.
-
- Previously, `g77' treated these expressions as denoting special
- "pointer" arguments for the purposes of filewide analysis.
-
- * Fix `g77' crash (or apparently infinite run-time) when compiling
- certain complicated expressions involving `COMPLEX' arithmetic
- (especially multiplication).
-
- * Align static double-precision variables and arrays on Intel x86
- targets regardless of whether `-malign-double' is specified.
-
- Generally, this affects only local variables and arrays having the
- `SAVE' attribute or given initial values via `DATA'.
-
- * The `g77' driver now ensures that `-lg2c' is specified in the link
- phase prior to any occurrence of `-lm'. This prevents
- accidentally linking to a routine in the SunOS4 `-lm' library when
- the generated code wants to link to the one in `libf2c' (`libg2c').
-
- * `g77' emits more debugging information when `-g' is used.
-
- This new information allows, for example, `which __g77_length_a'
- to be used in `gdb' to determine the type of the phantom length
- argument supplied with `CHARACTER' variables.
-
- This information pertains to internally-generated type, variable,
- and other information, not to the longstanding deficiencies
- vis-a-vis `COMMON' and `EQUIVALENCE'.
-
- * The F90 `Date_and_Time' intrinsic now is supported.
-
- * The F90 `System_Clock' intrinsic allows the optional arguments
- (except for the `Count' argument) to be omitted.
-
- * Upgrade to `libf2c' as of 1998-06-18.
-
- * Improve documentation and indexing.
-
-In previous versions:
-=====================
-
- Information on previous versions is not provided in this
-`gcc/gcc/f/NEWS' file, to keep it short. See `gcc/gcc/f/news.texi', or
-any of its other derivations (Info, HTML, dvi forms) for such
-information.
-
projects / gcc.git / commitdiff