1011 Commits

Author SHA1 Message Date
peter klausler
b82a8c3f23 [flang] Warn about useless explicit typing of intrinsics
Fortran 2018 explicitly permits an ignored type declaration
for the result of a generic intrinsic function.  See the comment
added to Semantics/expression.cpp for an explanation of why this
is somewhat dangerous and worthy of a warning.

Differential Revision: https://reviews.llvm.org/D96879
2021-02-17 13:13:59 -08:00
peter klausler
452d7ebc09 [flang] Ensure that intrinsic procedures are PURE &/or ELEMENTAL
The intrinsic procedure table properly classify the various
intrinsics, but the PURE and ELEMENTAL attributes that these
classifications imply don't always make it to the utility
predicates that test symbols for them, leading to spurious
error messages in some contexts.  So set those attribute flags
as appropriate in name resolution, using a new function to
isolate the tests.

An alternate solution, in which the predicates would query
the intrinsic procedure table for these attributes on demand,
was something I also tried, so that this information could
come directly from an authoritative source; but it would have
required references to the intrinsic table to be passed along
on too many seemingly unrelated APIs and ended up looking messy.

Several symbol table tests needed to have their expected outputs
augmented with the PURE and ELEMENTAL flags.  Some bogus messages
that were flagged as such in test/Semantics/doconcurrent01.f90 were
removed, since they are now correctly not emitted.

Differential Revision: https://reviews.llvm.org/D96878
2021-02-17 11:31:33 -08:00
Peter Steinfeld
77dc203cd0 [flang] Detect circularly defined procedures
It's possible to define a procedure that has a procedure dummy argument which
names the procedure that contains it.  This was causing the compiler to fall
into an infinite loop when characterizing a call to the procedure.

Following a suggestion from Peter, I fixed this be maintaining a set of
procedure symbols that had already been seen while characterizing a procedure.
This required passing a new parameter to the functions that characterized a
Procedure, a DummyArgument, and a DummyProcedure.

I also added several tests that will crash the compiler without this change.

Differential Revision: https://reviews.llvm.org/D96631
2021-02-16 14:40:35 -08:00
clementval
8260232cdd [flang][fir] Add fir-opt tool
This patch introduce the fir-opt tool. Similar to mlir-opt for FIR.
It will be used in following patches to test fir opt and round-trip.

Reviewed By: schweitz, mehdi_amini

Differential Revision: https://reviews.llvm.org/D96535
2021-02-16 11:48:40 -05:00
Faris Rehman
10826ea7b1 [flang][driver] Add extension options and -finput-charset
Add the following options:
* -fimplicit-none and -fno-implicit-none
* -fbackslash and -fno-backslash
* -flogical-abbreviations and -fno-logical-abbreviations
* -fxor-operator and -fno-xor-operator
* -falternative-parameter-statement
* -finput-charset=<value>

Summary of changes:
- Enable extensions in CompilerInvocation#ParseFrontendArgs
- Add encoding_ to Fortran::frontend::FrontendOptions
- Add encoding to Fortran::parser::Options

Differential Revision: https://reviews.llvm.org/D96407
2021-02-16 11:27:06 +00:00
Andrzej Warzynski
96d229c9ab [flang][driver] Add options for unparsing
This patch adds the following compiler frontend driver options:
  * -fdebug-unparse (f18 spelling: -funparse)
  * -fdebug-unparse-with-symbols (f18 spelling: -funparse-with-symbols)
The new driver will only accept the new spelling. `f18` will accept both
the original and the new spelling.

A new base class for frontend actions is added: `PrescanAndSemaAction`.
This is added to reduce code duplication that otherwise these new
options would lead to. Implementation from
  * `ParseSyntaxOnlyAction::ExecutionAction`
is moved to:
  * `PrescanAndSemaAction::BeginSourceFileAction`
This implementation is now shared between:
  * PrescanAndSemaAction
  * ParseSyntaxOnlyAction
  * DebugUnparseAction
  * DebugUnparseWithSymbolsAction

All tests that don't require other yet unimplemented options are
updated. This way `flang-new -fc1` is used instead of `f18` when
`FLANG_BUILD_NEW_DRIVER` is set to `On`. In order to facilitate this,
`%flang_fc1` is added in the LIT configuration (lit.cfg.py).

`asFortran` from f18.cpp is duplicated as `getBasicAsFortran` in
FrontendOptions.cpp. At this stage it's hard to find a good place to
share this method. I suggest that we revisit this once a switch from
`f18` to `flang-new` is complete.

Differential Revision: https://reviews.llvm.org/D96483
2021-02-16 09:32:51 +00:00
Andrzej Warzynski
548549e88a [flang][f18] Make -fdebug-dump-{symbols|parse-tree} imply -fsyntax-only
The following _action_ options are always used with `-fsyntax-only`
(also an _action_ option):
  * -fdebug-dump-symbols
  * -fdebug-dump-parse-tree
This patch makes the above options imply `-fsyntax-only`.

From the perspective of `f18` this change saves typing and is otherwise
a non-functional change. But it will simplify things in the new driver,
`flang-new`, in which only the last action option is taken into account
and executed. In other words, the following would only run
`-fsyntax-only`:
```
flang-new -fdebug-dump-symbols -fsyntax-only <input>
```
whereas this would only run `-fdebug-dump-symbols`:
```
flang-new -fsyntax-only -fdebug-dump-symbols <input>
```

Differential Revision: https://reviews.llvm.org/D96528
2021-02-16 09:22:32 +00:00
Yashaswini
20e3a6cb62 Add Semantic check for Flang OpenMP 4.5 - 2.7.1 Do Loop restrictions.
Implementation of Do loop iteration variable check, Do while loop check, Do loop cycle restrictions.
Also to check whether the ordered clause is present on the loop construct if any ordered region ever
 binds to a loop region arising from the loop construct.

Files:

check-omp-structure.h
check-omp-structure.cpp
resolve-directives.cpp

Testcases:

omp-do06-positivecases.f90
omp-do06.f90
omp-do08.f90
omp-do09.f90
omp-do10.f90
omp-do11.f90
omp-do12.f90
omp-do13.f90
omp-do14.f90
omp-do15.f90
omp-do16.f90
omp-do17.f90

Reviewed by: Kiran Chandramohan @kiranchandramohan , Valentin Clement @clementval

Differential Revision: https://reviews.llvm.org/D92732
2021-02-15 18:39:14 +05:30
clementval
af186e9372 Revert "[flang][fir] Add fir-opt tool"
This reverts commit df1eeaa7b404f7c5a96a812479f0ee2ce8354f6a.

Buildbot failure.
2021-02-12 22:27:48 -05:00
Valentin Clement
df1eeaa7b4 [flang][fir] Add fir-opt tool
This patch introduce the fir-opt tool. Similar to mlir-opt for FIR.
It will be used in following patches to test fir opt and round-trip.

Reviewed By: schweitz, mehdi_amini

Differential Revision: https://reviews.llvm.org/D96535
2021-02-12 22:20:38 -05:00
peter klausler
0bfa4ac6c6 [flang] Improve "Error reading module file" error message
Instead of using a message attachment with further details,
emit the details as part of a single message.

Differential Revision: https://reviews.llvm.org/D96465
2021-02-11 11:08:12 -08:00
Sourabh Singh Tomar
6a7deff58e [flang] Remove LINK_WITH_FIR cmake switch
Most components required for this are already there.

Build and Testing clean.
ninja check-flang

Reviewed By: clementval, tskeith

Differential Revision: https://reviews.llvm.org/D96411
2021-02-11 22:52:13 +05:30
peter klausler
47b97d4bfb [flang] Manage per-specification-part state better
Some state in name resolution is stored in the DeclarationVisitor
instance and processed at the end of the specification part.
This state needs to accommodate nested specification parts, namely
the ones that can be nested in a subroutine or function interface
body.

Differential Revision: https://reviews.llvm.org/D96466
2021-02-10 17:23:53 -08:00
Faris Rehman
6d48a1a53f [flang][driver] Add support for -fopenmp and -fopenacc
Add support for the following options:
* -fopenmp
* -fopenacc

Update OpenMP and OpenACC semantics tests to use the new driver if it is built, otherwise use f18.
OpenMP tests that include `use omp_lib` or run `test_symbols.sh` have not been updated as they require options `-intrinsic-module-directory` and `-funparse-with-symbols` which are currently not implemented in the new driver.
Similarly OpenACC tests that run `test_symbols.sh` have not been updated.

This patch also moves semanticsContext to CompilerInvocation and creates it in CompilerInvocation#setSemanticsOpts so that the semantics context can use Fortran::parser::Options#features.

Summary of changes:
- Move semanticsContext to CompilerInvocation.h
- Update OpenMP and OpenACC semantics tests that do not rely on `-intrinsic-module-directory` and `-funparse-with-symbols` to use %flang

Differential Revision: https://reviews.llvm.org/D96032
2021-02-10 09:59:35 +00:00
Eric Schweitz
399c3d5b29 [flang][fir] Add shape, shape_shift, and slice types.
Adding the FIR types used to describe the Fortran semantics of indexing
FIR arrays.

https://github.com/flang-compiler/f18-llvm-project/pull/267

Differential Revision: https://reviews.llvm.org/D96172
2021-02-09 08:55:47 -08:00
Eric Schweitz
2cd0a113df [flang][fir] Add OpaqueAttr.
Add the opaque attribute class used in flang.

https://github.com/flang-compiler/f18-llvm-project/pull/402

Differential Revision: https://reviews.llvm.org/D96293
2021-02-08 16:02:22 -08:00
Eric Schweitz
7e20a41348 [flang][fir] Update FIR's character type.
Upstream the changes made to the !fir.char type.

https://github.com/flang-compiler/f18-llvm-project/pull/269
https://github.com/flang-compiler/f18-llvm-project/pull/557

Author: Eric Schweitz, Jean Perier

Differention Revision: https://reviews.llvm.org/D96183
2021-02-08 08:20:04 -08:00
Eric Schweitz
f6342806db [flang][fir] Add FIR's vector type.
This patch adds support for `!fir.vector`, a rank one, constant length
data type.

https://github.com/flang-compiler/f18-llvm-project/pull/413

Differential Revision: https://reviews.llvm.org/D96162
2021-02-05 12:44:19 -08:00
Eric Schweitz
9673a00995 [flang] Remove dims type and gendims op.
These are no longer part of FIR.
https://github.com/flang-compiler/f18-llvm-project/pull/267

Differential Revision: https://reviews.llvm.org/D96077
2021-02-04 14:37:07 -08:00
Andrzej Warzynski
ba000628bd [flang][driver] Fix reading from stdin when using -test-io
This patch adds logic in the InputOutputTestAction frontend action for
reading input from stdin. Without this patch the following fails:
```
    flang-new -fc1 -test-io -
```

The implementation of `InputOutputTestAction` is cleaned-up and a test
for reading from stdin is added.

Note that there's a difference between `-test-io` and e.g. `-E` in terms
of file I/O. The frontend action for the former handles all file I/O on
it's own. Conversely, the action corresponding to -E relies on the
prescanner API to handle this.

Currently we can't test reading from stdin for `flang-new -`. In this
case `libclangDriver` assumes `-x -c`. This in turn leads to `flang-new
-cc1`, which is not supported.
2021-02-04 16:51:59 +00:00
Arnamoy Bhattacharyya
985a42fdf8 [flang][driver] Add support for -J/-module-dir
Add support for option -J/-module-dir in the new Flang driver.  This
will allow for including module files in other directories, as the
default search path is currently the working folder. This also provides
an option of storing the output module in the specified folder.

Differential Revision: https://reviews.llvm.org/D95448
2021-02-04 16:31:40 +00:00
Faris Rehman
3a1513c142 [flang][driver] Add forced form flags and -ffixed-line-length
Add support for the following layout options:
* -ffree-form
* -ffixed-form
- -ffixed-line-length=n (alias -ffixed-line-length-n)
Additionally remove options `-fno-free-form` and `-fno-fixed-form` as they were initially added to forward to gfortran but gfortran does not support these flags.

This patch adds the flag FlangOnlyOption to the existing options `-ffixed-form`, `-ffree-form` and `-ffree-line-length-` in Options.td. As of commit 6a75496836ea14bcfd2f4b59d35a1cad4ac58cee, these flags are not currently forwarded to gfortran anyway.

The default fixed line length in FrontendOptions is 72, based off the current default in Fortran::parser::Options. The line length cannot be set to a negative integer, or a positive integer less than 7 excluding 0, consistent with the behaviour of gfortran.

This patch does not add `-ffree-line-length-n` as Fortran::parser::Options does not have a variable for free form columns.
Whilst the `fixedFormColumns` variable is used in f18 for `-ffree-line-length-n`, f18 only allows `-ffree-line-length-none`/`-ffree-line-length-0` and not a user-specified value. `fixedFormcolumns` cannot be used in the new driver as it is ignored in the frontend when dealing with free form files.

Summary of changes:
- Remove -fno-fixed-form and -fno-free-form from Options.td
- Make -ffixed-form, -ffree-form and -ffree-line-length-n FlangOnlyOption in Options.td
- Create AddFortranDialectOptions method in Flang.cpp
- Create FortranForm enum in FrontendOptions.h
- Add fortranForm_ and fixedFormColumns_ to Fortran::frontend::FrontendOptions
- Update fixed-form-test.f so that it guarantees that it fails when forced as a free form file to better facilitate testing.

Differential Revision: https://reviews.llvm.org/D95460
2021-02-04 12:24:15 +00:00
Peter Steinfeld
2018dafce5 [flang] Fix calls to LBOUND() intrinsic for arrays with lower bounds not 1
Constant folding for calls to LBOUND() was not working when the lower bound of
a constant array was not 1.

I fixed this and re-enabled the test in Evaluate/folding16.f90 that previously
was silently failing.  I slightly changed the test to parenthesize the first
argument to exercise all of the new code.

Differential Revision: https://reviews.llvm.org/D95894
2021-02-03 10:53:32 -08:00
Sourabh Singh Tomar
f2879559ac [flang] Enable FIR types and Dialect round trip tests
Reviewed By: schweitz, mehdi_amini

Differential Revision: https://reviews.llvm.org/D95958
2021-02-03 23:46:55 +05:30
peter klausler
34eb0adaa9 [flang] Add -fsyntax-only to f18; retain -fparse-only synonym
Now that semantics is working, the standard -fsyntax-only option of
GNU and Clang should be used as the name of the option that causes
f18 to just run the front-end.  Support both options in f18, silently
accepting the old option as a synonym for the new one (as
preferred by the code owner), and replace all instances of the
old -fparse-only option with -fsyntax-only throughout the source base.

Differential Revision: https://reviews.llvm.org/D95887
2021-02-03 09:01:39 -08:00
Praveen
5bc6e75386 [Flang][OpenMP] Add semantic checks for invalid branches into or out of OpenMP constructs
OpenMP 4.5 - Check invalid branches into OpenMP strucutred blocks.
             Check invalid branches leaving OpenMP structured blocks.

Test cases : omp-do-cycle.f90, omp-invalid-branch.f90

Resolve related test cases marked as XFAIL

Reviewed By: kiranchandramohan

Differential Revision: https://reviews.llvm.org/D92735
2021-02-03 16:09:34 +05:30
peter klausler
aa39ddd0a3 [flang] Implement IEEE_SUPPORT_xxx inquiry functions
Implement IEEE_SUPPORT_DATATYPE() and other inquiry intrinisic
functions from the intrinsic module IEEE_ARITHMETIC, folding all of
their results to .TRUE.

Differential Revision: https://reviews.llvm.org/D95830
2021-02-02 11:38:19 -08:00
peter klausler
dc6fadf708 [flang] Detect UBOUND() error on assumed-size array
UBOUND() is not allowed on the last dimension of an
assumed-size array dummy argument.

Differential Revision: https://reviews.llvm.org/D95831
2021-02-02 11:37:44 -08:00
Andrzej Warzynski
760e6c4ce5 [flang][driver] Disallow non-existent input files in the frontend driver
This patch adds a check that verifies that the input file used when
calling the frontend driver (i.e. `flang-new -fc1`) actually exists.
This was not required for the compiler driver, `flang-new`, as that's
already handled in libclangDriver.

Once all input/output file management is moved to the driver, we should
also check that for input from `stdin` the corresponding file descriptor
was successfully acquired.

This patch also makes sure that the default action in the frontend is
`ParseSyntaxOnly`. This is consistent with Clang. Before this change
`flang-new -fc1` would do nothing, which makes testing changes like the
one introduced here a bit tricky.

Reviewed By: SouraVX

Differential Revision: https://reviews.llvm.org/D95127
2021-02-02 10:03:45 +00:00
peter klausler
ebe74d9592 [flang] Support disabled alternative PARAMETER statement
Legacy Fortran implementations support an alternative form of the
PARAMETER statement; it differs syntactically from the standard's
PARAMETER statement by lacking parentheses, and semantically by
using the type and shape of the initialization expression to define
the attributes of the named constant.  (GNU Fortran gets that part
wrong; Intel Fortran and nvfortran have full support.)

This patch disables the old style PARAMETER statement by default, as
it is syntactically ambiguous with conforming assignment statements;
adds a new "-falternative-parameter-statement" option to enable it;
and implements it correctly when enabled.

Fixes https://bugs.llvm.org/show_bug.cgi?id=48774, in which a user
tripped over the syntactic ambiguity.

Differential Revision: https://reviews.llvm.org/D95697
2021-01-29 15:30:06 -08:00
Peter Steinfeld
543cd89d3f [flang] Fix problems with constant arrays with lower bounds that are not 1
There were two problems with constant arrays whose lower bound is not 1.
First, when folding the arrays, we were creating the folded array to have lower
bounds of 1 but, we were not re-adjusting their lower bounds to the
declared values.  Second, we were not calculating the extents correctly.
Both of these problems led to bogus error messages.

I fixed the first problem by adjusting the lower bounds in
NonPointerInitializationExpr() in Evaluate/check-expression.cpp.  I wrote the
class ArrayConstantBoundChanger, which is similar to the existing class
ScalarConstantExpander.  In the process of implementing and testing it, I found
a bug that I fixed in ScalarConstantExpander which caused it to infinitely
recurse on parenthesized expressions.  I also removed the unrelated class
ScalarExpansionVisitor, which was not used.

I fixed the second problem by changing the formula that calculates upper bounds
in in the function ComputeUpperBound() in Evaluate/shape.cpp.

I added tests that trigger the bogus error messages mentioned above along with
a constant folding tests that uses array operands with shapes that conform but
have different bounds.

In the process of adding tests, I discovered that tests in
Evaluate/folding09.f90 and folding16.f90 were written incorrectly, and I
fixed them.  This also revealed a bug in contant folding of the
intrinsic "lbounds" which I plan to fix in a later change.

Differential Revision: https://reviews.llvm.org/D95449
2021-01-29 08:05:10 -08:00
peter klausler
6110e7716c [flang] Search for #include "file" in right directory (take 2)
Make the #include "file" preprocessing directive begin its
search in the same directory as the file containing the directive,
as other preprocessors and our Fortran INCLUDE statement do.

Avoid current working directory for all source files except the original.

Resolve tests.

Differential Revision: https://reviews.llvm.org/D95481
2021-01-27 15:41:29 -08:00
Valentin Clement
f30c523660 [flang][openacc] Allow multiple wait clauses
kernels loop and enter data had a too restrictive constraint for the wait clause.
The wait clause is allowed multiple times and not only once. This patch fix this problem.

Reviewed By: SouraVX

Differential Revision: https://reviews.llvm.org/D95469
2021-01-27 13:18:46 -05:00
Valentin Clement
b65896ef8b [flang][openacc] Fix clause restriction for exit data directive
Restriction on clauses for the EXIT DATA directive were not fully correct.
This patch fixes the situation. The async, if and finalize clauses are allowed
only once.

Reviewed By: SouraVX

Differential Revision: https://reviews.llvm.org/D95470
2021-01-27 10:07:19 -05:00
Valentin Clement
5e09a02527 [flang][openacc] Fix clause restriction for host_data directive
Restriction on clauses for the HOST_DATA directive were not fully correct.
This patch fixes the situation. The if and if_present clauses are allowed
only once.

Reviewed By: SouraVX

Differential Revision: https://reviews.llvm.org/D95473
2021-01-27 10:06:33 -05:00
Faris Rehman
a8f51ea212 [flang][driver] Report prescanning diags during syntax-only parsing
Ensure diagnostics from the prescanner are reported when running `flang-new -fsyntax-only` (i.e. only syntax parsing).
This keeps the diagnostics output of flang-new consistent with `f18 -fparse-only` when running the syntax parsing action, ParseSyntaxOnlyAction.

Summary of changes:
- Modify ParseSyntaxOnlyAction::ExecuteAction to report diagnostics

Differential Revision: https://reviews.llvm.org/D95220
2021-01-27 10:27:21 +00:00
Valentin Clement
d2abd62b9d [flang][openacc][NFC] Organize clause validity tests by directive
Split the tests from acc-clause-validity.f90 in dedicated files by directives.
The file acc-clause-validity.f90 was getting too big to be correctly maintained.
Tests are identical.

Reviewed By: SouraVX

Differential Revision: https://reviews.llvm.org/D95328
2021-01-26 14:54:05 -05:00
Faris Rehman
1c8f199f44 [flang][driver] Update PP tests to use the new driver
Update the preprocessor regression tests to use the new driver if the new driver is built (FLANG_BUILD_NEW_DRIVER=On), otherwise the tests will still run using f18.

Summary of changes:
- Introduce %flang to the regression tests, which points to the new driver if it is built or otherwise points to f18
- Update all tests in flang/test/Preprocessing/ to use %flang

Differential Revision: https://reviews.llvm.org/D94805
2021-01-25 12:32:23 +00:00
peter klausler
59bf9a89d8 [flang] Remove some needless operations in expr rewriting
Expressions emitted to module files and error messages
sometimes contain conversions of integer results of inquiry
intrinsics; these are usually not needed, and can conflict
with "int" in the user's namespace.  Improve folding so that
these conversions don't appear, and do some other clean-up
in adjacent code.

Differential Revision: https://reviews.llvm.org/D95172
2021-01-22 10:08:51 -08:00
Peter Steinfeld
02e174e8f7 [flang] Fix typo in error message
The title says it all.

Differential Revision: https://reviews.llvm.org/D95233
2021-01-22 07:28:37 -08:00
peter klausler
2de5ea3b3e [flang] Fix bogus error message with binding
ProcedureDesignator::GetInterfaceSymbol() needs to return
the procedure bound to a bindings.

Differential Revision: https://reviews.llvm.org/D95178
2021-01-21 16:59:51 -08:00
Andrzej Warzynski
0eeb15741b [flang][driver] Make the driver report diagnostics from the prescanner
This patch makes sure that diagnostics from the prescanner are reported
when running `flang-new -E` (i.e. only the preprocessor phase is
requested). More specifically, the `PrintPreprocessedAction` action is
updated.

With this patch we make sure that the `f18` and `flang-new` provide
identical output when running the preprocessor and the prescanner
generates diagnostics.

Differential Revision: https://reviews.llvm.org/D94782
2021-01-21 15:06:32 +00:00
Peter Steinfeld
bebbe64075 [flang] Fix creation of deferred shape arrays by POINTER statement
It's possible to  declare deferred shape array using the POINTER
statement, for example:

  POINTER :: var(:)

When analyzing POINTER declarations, we were not capturing the array
specification information, if present.  I fixed this by changing the
"Post" function for "parser::PointerDecl" to check to see if the
declaration contained a "DeferredShapeSpecList".  In such cases, I
analyzed the shape and used to information to declare an "ObjectEntity"
that contains the shape information rather than an "UnknownEntity".

I also added a couple of small tests that fail to compile without these
changes.

Differential Revision: https://reviews.llvm.org/D95080
2021-01-20 13:08:11 -08:00
peter klausler
0996b590aa [flang] Infrastructure improvements in utility routines
* IsArrayElement() needs another option to control whether it
  should ignore trailing component references.
* Add IsObjectPointer().
* Add const Scope& variants of IsFunction() and IsProcedure().
* Make TypeAndShape::Characterize() work with procedure bindings.
* Handle CHARACTER length in MeasureSizeInBytes().
* Fine-tune FindExternallyVisibleObject()'s handling of dummy arguments
  to conform with Fortran 2018: only INTENT(IN) and dummy pointers
  in pure functions signify; update two tests accordingly.

Also: resolve some stylistic inconsistencies and add a missing
"const" in the expression traversal template framework.

Differential Revision: https://reviews.llvm.org/D95011
2021-01-20 12:40:25 -08:00
peter klausler
ff3b51b054 [flang] Fix ASSOCIATE statement name resolution
F18 Clause 19.4p9 says:

  The associate names of an ASSOCIATE construct have the scope of the
  block.

Clause 11.3.1p1 says the ASSOCIATE statement is not itself in the block:

  R1102 associate-construct is:  associate-stmt block end-associate-stmt

Associate statement associations are currently fully processed from left
to right, incorrectly interposing associating entities earlier in the
list on same-named entities in the host scope.

    1  program p
    2    logical :: a = .false.
    3    real :: b = 9.73
    4    associate (b => a, a => b)
    5      print*, a, b
    6    end associate
    7    print*, a, b
    8  end

Associating names 'a' and 'b' at line 4 in this code are now both
aliased to logical host entity 'a' at line 2.  This happens because the
reference to 'b' in the second association incorrectly resolves 'b' to
the entity in line 4 (already associated to 'a' at line 2), rather than
the 'b' at line 3.  With bridge code to process these associations,
f18 output is:

 F F
 F 9.73

It should be:

 9.73 F
 F 9.73

To fix this, names in right-hand side selector variables/expressions
must all be resolved before any left-hand side entities are resolved.
This is done by maintaining a stack of lists of associations, rather
than a stack of associations.  Each ASSOCIATE statement's list of
assocations is then visited once for right-hand side processing, and
once for left-hand side processing.

Note that other construct associations do not have this problem.
SELECT RANK and SELECT TYPE each have a single assocation, not a list.
Constraint C1113 prohibits the right-hand side of a CHANGE TEAM
association from referencing any left-hand side entity.

Differential Revision: https://reviews.llvm.org/D95010
2021-01-20 11:18:27 -08:00
peter klausler
24e8e21f19 [flang] Refine WhyNotModifiable()
The utility routine WhyNotModifiable() needed to become more
aware of the use of pointers in data-refs; the targets of
pointer components are sometimes modifiable even when the
leftmost ("base") symbol of a data-ref is not.

Added a new unit test for WhyNotModifiable() that uses internal
READ statements (mostly), since I/O semantic checking uses
WhyNotModifiable() for all its definability checking.

Differential Revision: https://reviews.llvm.org/D94849
2021-01-19 11:44:51 -08:00
Praveen
c42f5ca3d8 [Flang][OpenMP] Add semantic checks for OpenMP Workshare Construct
Add Semantic checks for OpenMP 4.5 - 2.7.4 Workshare Construct.

 - The structured block in a workshare construct may consist of only
   scalar or array assignments, forall or where statements,
   forall, where, atomic, critical or parallel constructs.

 - All array assignments, scalar assignments, and masked array
   assignments must be intrinsic assignments.

 - The construct must not contain any user defined function calls unless
   the function is ELEMENTAL.

Test cases : omp-workshare03.f90, omp-workshare04.f90, omp-workshare05.f90

Resolve test cases (omp-workshare01.f90 and omp-workshare02.f90) marked as XFAIL

Reviewed By: kiranchandramohan

Differential Revision: https://reviews.llvm.org/D93091
2021-01-19 20:00:12 +05:30
Faris Rehman
197d9a55f1 [flang][driver] Add standard macro predefinitions for compiler version
Add the following standard predefinitions that f18 supports:
  * `__flang__`,
  * `__flang_major__`,
  * `__flang_minor__`,
  * `__flang_patchlevel__`

Summary of changes:
- Populate Fortran::parser::Options#predefinitions with the default
  supported predefinitions

Differential Revision: https://reviews.llvm.org/D94516
2021-01-19 13:22:59 +00:00
Faris Rehman
443d6957ca [flang][driver] Add support for fixed form detection
Currently the new flang driver always runs in free form mode. This patch
adds support for fixed form mode detection based on the file extensions.

Like `f18`, `flang-new` will treat files ending with ".f", ".F" and
".ff" as fixed form. Additionally, ".for", ".FOR", ".fpp" and ".FPP"
file extensions are recognised as fixed form files. This is consistent
with gfortran [1]. In summary, files with the following extensions are
treated as fixed-form:
  * ".f", ".F", ".ff", ".for", ".FOR", ".fpp", ".FPP"

For consistency with flang/test/lit.cfg.py and f18, this patch also adds
support for the following file extensions:
  * ".ff", ".FOR", ".for", ".ff90", ".fpp", ".FPP"
This is added in flang/lib/Frontend/FrontendOptions.cpp. Additionally,
the following extensions are included:
  * ".f03", ".F03", ".f08", ".F08"
This is for compatibility with gfortran [1] and other popular Fortran
compilers [2].

NOTE: internally Flang will only differentiate between fixed and free
form files. Currently Flang does not support switching between language
standards, so in this regard file extensions are irrelevant. More
specifically, both `file.f03` and `file.f18` are represented with
`Language::Fortran` (as opposed to e.g. `Language::Fortran03`).

Summary of changes:
- Set Fortran::parser::Options::sFixedForm according to the file type
- Add isFixedFormSuffix and isFreeFormSuffix helper functions to
  FrontendTool/Utils.h
- Change FrontendOptions::GetInputKindForExtension to support the missing
  file extensions that f18 supports and some additional ones
- FrontendActionTest.cpp is updated to make sure that the test input is
  treated as free-form

[1] https://gcc.gnu.org/onlinedocs/gfortran/GNU-Fortran-and-GCC.html
[2] https://github.com/llvm/llvm-project/blob/master/flang/docs/OptionComparison.md#notes

Differential Revision: https://reviews.llvm.org/D94228
2021-01-19 12:58:01 +00:00
Faris Rehman
87dfd5e012 [flang][driver] Add support for -I in the new driver
Add support for option -I in the new Flang driver. This will allow for
included headers and module files in other directories, as the default
search path is currently the working folder. The behaviour of this is
consistent with the current f18 driver, where the current folder (i.e.
".") has the highest priority followed by the order of '-I's taking
priority from first to last.

Summary of changes:
- Add SearchDirectoriesFromDashI to PreprocessorOptions, to be forwarded
  into the parser's searchDirectories
- Add header files and non-functional module files to be used in
  regression tests. The module files are just text files and are used to
  demonstrated that paths specified with `-I` are taken into account when
  searching for .mod files.

Differential Revision: https://reviews.llvm.org/D93453
2021-01-19 11:20:56 +00:00