When testing on gcc, both exitstat and cmdstat must be a kind=4 integer,
e.g. DefaultInt. This patch changes the input arg requirement from
`AnyInt` to `TypePattern{IntType, KindCode::greaterOrEqualToKind, n}`.
The standard stated in 16.9.73
- EXITSTAT (optional) shall be a scalar of type integer with a decimal
exponent range of at least nine.
- CMDSTAT (optional) shall be a scalar of type integer with a decimal
exponent range of at least four.
```fortran
program bug
implicit none
integer(kind = 2) :: exitstatvar
integer(kind = 4) :: cmdstatvar
character(len=256) :: msg
character(len=:), allocatable :: command
command='echo hello'
call execute_command_line(command, exitstat=exitstatvar, cmdstat=cmdstatvar)
end program
```
When testing the above program with exitstatvar kind<4, an error would
occur:
```
$ ../build-release/bin/flang-new test.f90
error: Semantic errors in test.f90
./test.f90:8:47: error: Actual argument for 'exitstat=' has bad type or kind 'INTEGER(2)'
call execute_command_line(command, exitstat=exitstatvar)
```
When testing the above program with exitstatvar kind<2, an error would
occur:
```
$ ../build-release/bin/flang-new test.f90
error: Semantic errors in test.f90
./test.f90:8:47: error: Actual argument for 'cmdstat=' has bad type or kind 'INTEGER(1)'
call execute_command_line(command, cmdstat=cmdstatvar)
```
Test file for this semantics has been added to `flang/test/Semantic`
Fixes: https://github.com/llvm/llvm-project/issues/77990
(cherry picked from commit 14a15103cc9dbdb3e95c04627e0b96b5e3aa4944)
Using the VALUE attribute for assumed-length CHARACTER dummy arguments
became standard in F'2008 but still lacks widespread implementation;
emit a portability warning when they are enabled.
Resolves llvm-test-suite/Fortran/gfortran/regression/value_5.f90.
The Fortran standard defines real MOD and MODULO with expressions like
MOD(a,p) = a - AINT(a/p)*p. Unfortunately, these definitions have poor
accuracy when a is much larger in magnitude than p, and every Fortran
compiler uses better algorithms instead.
Fixes llvm-test-suite/Fortran/gfortran/regression/mod_large_1.f90.
There are some very odd (even for Fortran) rules in F'2023 subclause
19.4 (paras 6 & 8) pertaining to the index variables of FORALL and DO
CONCURRENT constructs/statements, and they are not currently implemented
correctly.
Although these index variables are construct entities, they have
restrictions in the standard that would essentially allow them to also
be variables in their enclosing scopes. If their names are present in
the enclosing scope, and the construct does not have an explicit type
specification for its indices, then the names in the enclosing scope
must either be scalar variables or COMMON blocks, and their type must be
integer.
Reimplement these restrictions largely with portability warnings rather
than hard errors. Retain the semantic interpretation that the type of an
untyped index variable be taken from the type of a variable of the same
name in the enclosing scope, if it exists, although that bit of the
standard could be interpreted otherwise.
Fixes https://github.com/llvm/llvm-project/issues/76978.
This reverts commit cab156c4129e5948a6322054480e66d3ca17b919, and adds
language to Extensions.md documenting the discrepancy with the letter of
the language standard.
Detect NaN elements in data and handle them like gfortran does (at
runtime); namely, NaN can be returned if all the data are NaNs, but any
non-NaN value is preferable. Ensure that folding returns the same
results as runtime computation.
Fixes llvm-test-suite/Fortran/gfortran/regression/maxloc_2.f90 (and
probably others).
…field
When a comma appears in a fixed-width input field for integer editing,
many compilers accept it without error and interpret the comma as
terminating the field early.
Support \uNNNN and \uNNNNNNNN escape sequences for CHARACTER(KIND=2) and
CHARACTER(KIND=4) literal constants for better GNU Fortran
compatibility.
Fixes llvm-test-suite/Fortran/gfortran/regression/achar_6.F90 and
.../widechar_1.f90.
The FreeMemory function only accepts a void pointer, but it was being
called with a const char pointer, resulting in a type-casting issue.
To address this, the const was removed, use char * instead.
If DEFAULT_SYSROOT is not specfied when building flang, then the
-isysroot flag is needed to link binaries against system libraries
on Darwin. It's also needed when linking against a non-default
sysroot.
reference to gfortran fdate
https://gcc.gnu.org/onlinedocs/gfortran/FDATE.html
usage:
```fortran
CHARACTER(32) :: time
CALL fdate(time)
WRITE(*,*) time
```
fdate is used in the ECP proxy application
https://proxyapps.exascaleproject.org/app/minismac2d/f904467142/ref/smac2d.f (L1570)
`fdate` now produce the same result on flang, compare to gfortran, where
If the length is too short to fit completely, blank return.
```fortran
character(20) :: string
call fdate(string)
write(*, *) string, "X"
```
```bash
$ ../build-release/bin/flang-new test.f90
$ ./a.out
X
```
If length if larger than it requires(24), fill the rest of buffer space.
```fortran
character(30) :: string
call fdate(string)
write(*, *) string, "X"
```
```bash
$ ../build-release/bin/flang-new test.f90
$ ./a.out
Wed Nov 15 16:59:13 2023 X
```
The length value is hardcoded, because:
```c++
// Day Mon dd hh:mm:ss yyyy\n\0 is 26 characters, e.g.
// Tue May 26 21:51:03 2015\n\0
```
---------
Co-authored-by: Yi Wu <yiwu02@wdev-yiwu02.arm.com>
This patch add support of intrinsics Fortran 2008 EXECUTE_COMMAND_LINE.
The patch contains both the lowering and the runtime code and works on
both Windows and Linux. The patch contains a list of commits, to convey
the authorship and the history of changes. Some implementation specifics
or status has been added to `flang/docs/Intrinsics.md`.
I have provided a summary of the usage and the options required for the
`EXECUTE_COMMAND_LINE intrinsic`. The intrinsic supports both a
synchronous
(by default) and an asynchronous option.
| System | Mode | Implemention |
|---------|-------|---------------------------|
| Linux | Sync | std::system() |
| Windows | Sync | std::system() |
| Linux | Async | fork() |
| Windows | Async | CreateProcess |
Support for the SYSTEM GNU extension will be added in a separate PR.
Co-authored with @jeffhammond
---------
Signed-off-by: Jeff Hammond <jeff.science@gmail.com>
Co-authored-by: Jeff Hammond <jeff.science@gmail.com>
Co-authored-by: Yi Wu <yiwu02@wdev-yiwu02.arm.com>
Fortran 2023 subclause 13.7.2.3.8 discusses input rounding only in the
context of decimal-to-binary conversion. There is no mention of rounding
for hexadecimal floating-point input conversion. At least one Fortran
compiler seems to have interpreted this silence as implying no rounding.
(Note that this is not the same thing as rounding to zero (RZ), which
would return +/-HUGE() for overflow.)
Nearly every Fortran compiler supports the extension of NAMELIST input
into a storage sequence identified by its initial scalar array element.
For example,
&GROUP A(1) = 1. 2. 3. /
should be processed as if the input had been
&GROUP A(1:) = 1. 2. 3. /
Fixes llvm-test-suite/Fortran/gfortran/regression/namelist_24.f90.
The compiler doesn't USE-associate names of intrinsic procedures from
modules (in the absence of ONLY:), so that the associating scope doesn't
get populated with names of intrinsics that were used only in
declarations (e.g., SELECTED_REAL_KIND). A recent bug report (below)
shows that we should modify that policy in the case of names that appear
in explicit INTRINSIC attribute statements. The behaviors of other
Fortran compilers are not consistent and the requirements of the
standard are not clear; this fix follows the precedent set by gfortran
and nvfortran.
Fixes https://github.com/llvm/llvm-project/issues/72084.
At present, when building static or shared libraries, Flang adds
`-lFortran_main.a` (or `/WHOLEARCHIVE:Fortran.*.lib` pon Windows) to the
link line. This leads to the problem that `_QQmain` and
`_QQEnvironmentDefaults` (as of the time of this PR) are symbols marked
as used, while `main` is being defined. This should not happen and this
PR fixes this by detecting if `-shared` or `-static` is used on the
Flang command line and removing the static `Fortran_main` library.
---------
Co-authored-by: kkwli <kkwli@users.noreply.github.com>
This document describes the aspects of Fortran descriptor management
in the offload data environment and how this semantics can be
represented using MLIR OpenACC dialect.
In the document I tried to clarify some parts of the OpenACC
specification that seemed unclear to me, e.g. where the spec allowed different
interpretations (in my opinion) or did not specify the actual runtime
behavior. I tried to demonstrate how this ambiguity can affect user
programs with examples.
The document proposes using `attachRecipe` on the data operations
to represent the non-trivial pointer attachment semantics for variables
represented by descriptors. The recipe provides the actual
implementation of the pointer attachment, e.g. we can call an F18 offload runtime
function that will perform all necessary checks and actions.
It is unclear at this point if we want to expose the implementation
details in FIR, otherwise, the recipe could have contained more low
level acc operations such as is_present lookups, host to device
memory copies, etc.
Adjust the depth (number of #) for some sections.
Move an underscore prefix to a suffix in an example to let the Fortran
parser in the documentation generator pass.
Fixes section depth and removes annotation of source as HLFIR since this
is not currently understood by the lexer. Fixing these issues help
reduce warnings in the documentation CI for LLVM.
Adding this section ensures that the documentation generated by
mlir-tblgen for all the FIR operations are at the correct depth.
FIROperations are at depth 3, the new section is at depth 2. This fixes
the "Non-consecutive header level increase; H1 to H3" warning in
FIRLangRef.md.
Fortran free form line continuation with '&' works with this compiler
even across the end of an included source file, as it does with most
other Fortran compilers. This extension should be documented.
A NULL() pointer without MOLD= cannot be allowed to be associated with
an assumed-rank dummy argument, as its rank is not well-defined and
neither the RANK() intrinsic function or the SELECT RANK construct will
work in the callee.
Change the separator in the `uniqueCGIdent` method to `X`. This change
is required to enable OpenMP offloading for the NVPTX target, as dots
are not valid identifiers in PTX and `uniqueCGIdent` is used to mangle
some literals. Follow up patches will change the remainder of `.`
appearances in names to `X` and add support for the NVPTX target.
As an extension, accept the redundant use of the CONTIGUOUS attribute
when applied to scalars and to simply contiguous objects, with a
portability warning.
…fter macro expansion
When compiler directives (!$omp) and/or their continuations (!$omp &)
are produced by macro expansion, handle those continuations. Also allow
a continuation marker (&) to appear in a macro actual argument.
As is already supported as a common extension for intrinsic functions
like DIM, allow distinct kinds of integer actual arguments to the
MIL-STD bit intrinsic functions IAND, IEOR, and IOR, with the kind of
the result being the largest of the kinds of the operands. (Though one
could make a case that IAND should return the smallest kind of its
operands, that's not what other compilers do.)
Some compilers allow the `$acc routine(<name>)` to be placed at the
program unit level. To be compatible, this patch enables the use of acc
routine at this level. These acc routine directives must have a name.
I would like to start a discussion about the ways for modifying
the current trampolines approach for Fortran internal procedures
used as actual arguments or pointer targets.
As Peter Klausler noted before the current approach implies security
risks due to writeable and executable stack requirement. We may need
to agree on a new scheme that does not have this issue.
Relax the parser to accept scalar integer expression in addition to
scalar logical expression. The parser now accepts scalar expression and
the semantic checks its type.
Fortran allows forward references to type names, which can lead to
ambiguity when coupled with host association, as in:
module m
type ambiguous; integer n; end type
contains
subroutine s
type(ambiguous), pointer :: variable
type t
type(ambiguous), pointer :: component
end type
type ambiguous; real x; end type
end
end
Some other compilers resolve to a host association, some resolve to a
forward reference. This compiler will now emit an error.
