1 *Note:* This file is automatically generated from the files
2 `news0.texi' and `news.texi'. `NEWS' is *not* a source file, although
3 it is normally included within source distributions.
5 This file lists news about the EGCS-1.2 version (and some other
6 versions) of the GNU Fortran compiler. Copyright (C) 1995-1999 Free
7 Software Foundation, Inc. You may copy, distribute, and modify it
8 freely as long as you preserve this copyright notice and permission
11 News About GNU Fortran
12 **********************
14 Changes made to recent versions of GNU Fortran are listed below,
15 with the most recent version first.
17 The changes are generally listed in order:
19 1. Code-generation and run-time-library bug-fixes
21 2. Compiler and run-time-library crashes involving valid code that
26 4. Fixes and enhancements to existing features
30 6. Internal improvements
34 This order is not strict--for example, some items involve a
35 combination of these elements.
37 Note that two variants of `g77' are tracked below. The `egcs'
38 variant is described vis-a-vis previous versions of `egcs' and/or an
39 official FSF version, as appropriate.
41 Therefore, `egcs' versions sometimes have multiple listings to help
42 clarify how they differ from other versions, though this can make
43 getting a complete picture of what a particular `egcs' version contains
44 somewhat more difficult.
46 *Warning:* The information below is still under development, and
47 might not accurately reflect the `g77' code base of which it is a part.
48 Efforts are made to keep it somewhat up-to-date, but they are
49 particularly concentrated on any version of this information that is
50 distributed as part of a *released* `g77'.
52 In particular, while this information is intended to apply to the
53 EGCS-1.2 version of `g77', only an official *release* of that version
54 is expected to contain documentation that is most consistent with the
55 `g77' product in that version.
57 Nevertheless, information on *previous* releases of `g77', below, is
58 likely to be more up-to-date and accurate than the equivalent
59 information that accompanied those releases, assuming the last-updated
60 date of the information below is later than the dates of those releases.
62 That's due to attempts to keep this development version of news
63 about previous `g77' versions up-to-date.
65 An online, "live" version of this document (derived directly from
66 the mainline, development version of `g77' within `egcs') is available
67 at `http://egcs.cygnus.com/onlinedocs/g77_news.html'.
69 The following information was last updated on 1999-03-13:
71 In `egcs' 1.2 (versus 1.1.2):
72 =============================
74 1. Fix `g77' so it no longer crashes when compiling I/O statements
75 using keywords that define `INTEGER' values, such as `IOSTAT=J',
76 where J is other than default `INTEGER' (such as `INTEGER*2').
77 Instead, it issues a diagnostic.
79 2. The `-ax' option is now obeyed when compiling Fortran programs.
80 (It is passed to the `f771' driver.)
82 * Source file names with the suffixes `.FOR' and `.FPP' now are
83 recognized by `g77' as if they ended in `.for' and `.fpp',
86 * `g77' now warns about a reference to an intrinsic that has an
87 interface that is not Year 2000 (Y2K) compliant. Also, the
88 `libg2c' has been changed to increase the likelihood of catching
89 references to the implementations of these intrinsics using the
90 `EXTERNAL' mechanism (which would avoid the new warnings).
92 3. `g77' now warns about a reference to a function when the
93 corresponding *subsequent* function program unit disagrees with
94 the reference concerning the type of the function.
96 4. Improve documentation and indexing, including information on Year
97 2000 (Y2K) compliance.
99 In 0.5.24 and `egcs' 1.1.2 (versus 0.5.23 and 1.1.1):
100 =====================================================
102 * Fix the `IDate' Intrinsic (VXT) so the returned year is in the
103 documented, non-Y2K-compliant range of 0-99, instead of being
104 returned as 100 in the year 2000.
106 * Fix the `Date_and_Time' intrinsic (in `libg2c') to return the
107 milliseconds value properly in VALUES(8).
109 * Fix the `LStat' intrinsic (in `libg2c') to return device-ID
110 information properly in SARRAY(7).
112 * Improve documentation.
114 In 0.5.24 and `egcs' 1.1.1 (versus 0.5.23 and 1.1):
115 ===================================================
117 * Fix `libg2c' so it performs an implicit `ENDFILE' operation (as
118 appropriate) whenever a `REWIND' is done.
120 (This bug was introduced in 0.5.23 and `egcs' 1.1 in `g77''s
121 version of `libf2c'.)
123 * Fix `libg2c' so it no longer crashes with a spurious diagnostic
124 upon doing any I/O following a direct formatted write.
126 (This bug was introduced in 0.5.23 and `egcs' 1.1 in `g77''s
127 version of `libf2c'.)
129 * Fix `g77' so it no longer crashes compiling references to the
130 `Rand' intrinsic on some systems.
132 * Fix `g77' portion of installation process so it works better on
133 some systems (those with shells requiring `else true' clauses on
134 `if' constructs for the completion code to be set properly).
136 In `egcs' 1.1 (versus 0.5.24):
137 ==============================
139 5. Fix `g77' crash compiling code containing the construct
140 `CMPLX(0.)' or similar.
142 6. Fix `g77' crash (or apparently infinite run-time) when compiling
143 certain complicated expressions involving `COMPLEX' arithmetic
144 (especially multiplication).
146 7. Fix a code-generation bug that afflicted Intel x86 targets when
147 `-O2' was specified compiling, for example, an old version of the
150 The x87 coprocessor stack was being mismanaged in cases involving
151 assigned `GOTO' and `ASSIGN'.
153 * Align static double-precision variables and arrays on Intel x86
154 targets regardless of whether `-malign-double' is specified.
156 Generally, this affects only local variables and arrays having the
157 `SAVE' attribute or given initial values via `DATA'.
159 In `egcs' 1.1 (versus `egcs' 1.0.3):
160 ====================================
162 8. Fix bugs in the `libU77' intrinsic `HostNm' that wrote one byte
163 beyond the end of its `CHARACTER' argument, and in the `libU77'
164 intrinsics `GMTime' and `LTime' that overwrote their arguments.
166 9. Assumed arrays with negative bounds (such as `REAL A(-1:*)') no
167 longer elicit spurious diagnostics from `g77', even on systems
168 with pointers having different sizes than integers.
170 This bug is not known to have existed in any recent version of
171 `gcc'. It was introduced in an early release of `egcs'.
173 10. Valid combinations of `EXTERNAL', passing that external as a dummy
174 argument without explicitly giving it a type, and, in a subsequent
175 program unit, referencing that external as an external function
176 with a different type no longer crash `g77'.
178 11. `CASE DEFAULT' no longer crashes `g77'.
180 12. The `-Wunused' option no longer issues a spurious warning about
181 the "master" procedure generated by `g77' for procedures
182 containing `ENTRY' statements.
184 * Support `FORMAT(I<EXPR>)' when EXPR is a compile-time constant
185 `INTEGER' expression.
187 * Fix `g77' `-g' option so procedures that use `ENTRY' can be
188 stepped through, line by line, in `gdb'.
190 * Allow any `REAL' argument to intrinsics `Second' and `CPU_Time'.
192 * Use `tempnam', if available, to open scratch files (as in
193 `OPEN(STATUS='SCRATCH')') so that the `TMPDIR' environment
194 variable, if present, is used.
196 * `g77''s version of `libf2c' separates out the setting of global
197 state (such as command-line arguments and signal handling) from
198 `main.o' into distinct, new library archive members.
200 This should make it easier to write portable applications that
201 have their own (non-Fortran) `main()' routine properly set up the
202 `libf2c' environment, even when `libf2c' (now `libg2c') is a
205 13. `g77' no longer installs the `f77' command and `f77.1' man page in
206 the `/usr' or `/usr/local' heirarchy, even if the `f77-install-ok'
207 file exists in the source or build directory. See the
208 installation documentation for more information.
210 14. `g77' no longer installs the `libf2c.a' library and `f2c.h'
211 include file in the `/usr' or `/usr/local' heirarchy, even if the
212 `f2c-install-ok' or `f2c-exists-ok' files exist in the source or
213 build directory. See the installation documentation for more
216 15. The `libf2c.a' library produced by `g77' has been renamed to
217 `libg2c.a'. It is installed only in the `gcc' "private" directory
218 heirarchy, `gcc-lib'. This allows system administrators and users
219 to choose which version of the `libf2c' library from `netlib' they
220 wish to use on a case-by-case basis. See the installation
221 documentation for more information.
223 16. The `f2c.h' include (header) file produced by `g77' has been
224 renamed to `g2c.h'. It is installed only in the `gcc' "private"
225 directory heirarchy, `gcc-lib'. This allows system administrators
226 and users to choose which version of the include file from
227 `netlib' they wish to use on a case-by-case basis. See the
228 installation documentation for more information.
230 * The `g77' command now expects the run-time library to be named
231 `libg2c.a' instead of `libf2c.a', to ensure that a version other
232 than the one built and installed as part of the same `g77' version
235 17. During the configuration and build process, `g77' creates
236 subdirectories it needs only as it needs them. Other cleaning up
237 of the configuration and build process has been performed as well.
239 18. `install-info' now used to update the directory of Info
240 documentation to contain an entry for `g77' (during installation).
242 * Some diagnostics have been changed from warnings to errors, to
243 prevent inadvertent use of the resulting, probably buggy, programs.
244 These mostly include diagnostics about use of unsupported features
245 in the `OPEN', `INQUIRE', `READ', and `WRITE' statements, and
246 about truncations of various sorts of constants.
248 19. Improve compilation of `FORMAT' expressions so that a null byte is
249 appended to the last operand if it is a constant. This provides a
250 cleaner run-time diagnostic as provided by `libf2c' for statements
251 like `PRINT '(I1', 42'.
253 20. Improve documentation and indexing.
255 21. The upgrade to `libf2c' as of 1998-06-18 should fix a variety of
256 problems, including those involving some uses of the `T' format
257 specifier, and perhaps some build (porting) problems as well.
259 In 0.5.24 and `egcs' 1.1 (versus 0.5.23):
260 =========================================
262 22. `g77' no longer produces incorrect code and initial values for
263 `EQUIVALENCE' and `COMMON' aggregates that, due to "unnatural"
264 ordering of members vis-a-vis their types, require initial padding.
266 23. `g77' no longer crashes when compiling code containing
267 specification statements such as `INTEGER(KIND=7) PTR'.
269 24. `g77' no longer crashes when compiling code such as `J = SIGNAL(1,
272 * `g77' now treats `%LOC(EXPR)' and `LOC(EXPR)' as "ordinary"
273 expressions when they are used as arguments in procedure calls.
274 This change applies only to global (filewide) analysis, making it
275 consistent with how `g77' actually generates code for these cases.
277 Previously, `g77' treated these expressions as denoting special
278 "pointer" arguments for the purposes of filewide analysis.
280 * The `g77' driver now ensures that `-lg2c' is specified in the link
281 phase prior to any occurrence of `-lm'. This prevents
282 accidentally linking to a routine in the SunOS4 `-lm' library when
283 the generated code wants to link to the one in `libf2c' (`libg2c').
285 * `g77' emits more debugging information when `-g' is used.
287 This new information allows, for example, `which __g77_length_a'
288 to be used in `gdb' to determine the type of the phantom length
289 argument supplied with `CHARACTER' variables.
291 This information pertains to internally-generated type, variable,
292 and other information, not to the longstanding deficiencies
293 vis-a-vis `COMMON' and `EQUIVALENCE'.
295 * The F90 `Date_and_Time' intrinsic now is supported.
297 * The F90 `System_Clock' intrinsic allows the optional arguments
298 (except for the `Count' argument) to be omitted.
300 25. Upgrade to `libf2c' as of 1998-06-18.
302 26. Improve documentation and indexing.
304 In previous versions:
305 =====================
307 Information on previous versions is not provided in this
308 `egcs/gcc/f/NEWS' file, to keep it short. See `egcs/gcc/f/news.texi',
309 or any of its other derivations (Info, HTML, dvi forms) for such