[flang] Admit trailing blanks when checking I/O specifiers

Fortran specifically allows character-valued I/O specifiers
to have trailing blanks, e.g. OPEN(666,STATUS='SCRATCH ').
The runtime I/O libr

[flang] Admit trailing blanks when checking I/O specifiers

Fortran specifically allows character-valued I/O specifiers
to have trailing blanks, e.g. OPEN(666,STATUS='SCRATCH ').
The runtime I/O library already handles them, but the I/O
static checks in semantics do not.

Differential Revision: https://reviews.llvm.org/D130381

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[flang] Add & use a better visit() (take 2)

Adds flang/include/flang/Common/log2-visit.h, which defines
a Fortran::common::visit() template function that is a drop-in
replacement for std::visit().

[flang] Add & use a better visit() (take 2)

Adds flang/include/flang/Common/log2-visit.h, which defines
a Fortran::common::visit() template function that is a drop-in
replacement for std::visit(). Modifies most use sites in
the front-end and runtime to use common::visit().

The C++ standard mandates that std::visit() have O(1) execution
time, which forces implementations to build dispatch tables.
This new common::visit() is O(log2 N) in the number of alternatives
in a variant<>, but that N tends to be small and so this change
produces a fairly significant improvement in compiler build
memory requirements, a 5-10% improvement in compiler build time,
and a small improvement in compiler execution time.

Building with -DFLANG_USE_STD_VISIT causes common::visit()
to be an alias for std::visit().

Calls to common::visit() with multiple variant arguments
are referred to std::visit(), pending further work.

This change is enabled only for GCC builds with GCC >= 9;
an earlier attempt (D122441) ran into bugs in some versions of
clang and was reverted rather than simply disabled; and it is
not well tested with MSVC. In non-GCC and older GCC builds,
common::visit() is simply an alias for std::visit().

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[flang] Finer control over error recovery with GetExpr()

Prior to this patch, the semantics utility GetExpr() will crash
unconditionally if it encounters a typed expression in the parse
tree that ha

[flang] Finer control over error recovery with GetExpr()

Prior to this patch, the semantics utility GetExpr() will crash
unconditionally if it encounters a typed expression in the parse
tree that has not been set by expression semantics. This is the
right behavior when called from lowering, by which time it is known
that the program had no fatal user errors, since it signifies a
fatal internal error. However, prior to lowering, in the statement
semantics checking code, a more nuanced test should be used before
crashing -- specifically, we should not crash in the face of a
missing typed expression when in error recovery mode.

Getting this right requires GetExpr() and its helper class to have
access to the semantics context, so that it can check AnyFatalErrors()
before crashing. So this patch touches nearly all of its call sites.

Differential Revision: https://reviews.llvm.org/D123873

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Revert "[flang] Add & use a better visit()"

This reverts commit 2ab9990c9eb79682a4d4b183dfbc7612d3e55328. It has
caused multiple build failures:
* https://lab.llvm.org/buildbot/#/builders/177/build

Revert "[flang] Add & use a better visit()"

This reverts commit 2ab9990c9eb79682a4d4b183dfbc7612d3e55328. It has
caused multiple build failures:
* https://lab.llvm.org/buildbot/#/builders/177/builds/4346
* https://lab.llvm.org/buildbot/#/builders/180/builds/3803
* https://lab.llvm.org/buildbot/#/builders/175/builds/10419
* https://lab.llvm.org/buildbot/#/builders/191/builds/4318
* https://lab.llvm.org/buildbot/#/builders/173/builds/4274
* https://lab.llvm.org/buildbot/#/builders/181/builds/4297

All these bots failed with a time-out:
```
command timed out: 1200 seconds without output running [b'ninja', b'-j', b'32'], attempting to kill
```
I'm guessing that that's due to template instantiations failing at some
point (https://reviews.llvm.org/D122441 introduced a custom
implementation of std::visit). Everything seems fine when either:
* building on X86 with GCC or Clang (tested with GCC 9.3 and Clang 12)
* building on AArch64 with GCC (tested with GCC 11)

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[flang] Add & use a better visit()

Adds flang/include/flang/Common/visit.h, which defines
a Fortran::common::visit() template function that is a drop-in
replacement for std::visit(). Modifies most

[flang] Add & use a better visit()

Adds flang/include/flang/Common/visit.h, which defines
a Fortran::common::visit() template function that is a drop-in
replacement for std::visit(). Modifies most use sites in
the front-end and runtime to use common::visit().

The C++ standard mandates that std::visit() have O(1) execution
time, which forces implementations to build dispatch tables.
This new common::visit() is O(log2 N) in the number of alternatives
in a variant<>, but that N tends to be small and so this change
produces a fairly significant improvement in compiler build
memory requirements, a 5-10% improvement in compiler build time,
and a small improvement in compiler execution time.

Building with -DFLANG_USE_STD_VISIT causes common::visit()
to be an alias for std::visit().

Calls to common::visit() with multiple variant arguments
are referred to std::visit(), pending further work.

Differential Revision: https://reviews.llvm.org/D122441

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[flang] Distinguish usage and portability warning messages

Using recently established message severity codes, upgrade
non-fatal messages to usage and portability warnings as
appropriate.

Differenti

[flang] Distinguish usage and portability warning messages

Using recently established message severity codes, upgrade
non-fatal messages to usage and portability warnings as
appropriate.

Differential Revision: https://reviews.llvm.org/D121246

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[flang] Add nonfatal message classes

F18 presently has fatal and non-fatal diagnostic messages. We'd like
to make non-fatal warnings stand out better in the output of the compiler.

This will turn

[flang] Add nonfatal message classes

F18 presently has fatal and non-fatal diagnostic messages. We'd like
to make non-fatal warnings stand out better in the output of the compiler.

This will turn out to be a large change that affects many files.
This patch is just the first part. It converts a Boolean isFatal_ data
member of the message classes into a severity code, and defines four
of these codes (Error, Warning, Portability, and a catch-all Other).

Later patches will result from sweeping over the parser and semantics,
changing most non-fatal diagnostic messages into warnings and portability
notes.

Differential Revision: https://reviews.llvm.org/D121228

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[flang] Catch I/O of bad derived type at compile time

Derived types with allocatable and pointer components cannot
be used in I/O data transfer statements unless they have defined
I/O procedures ava

[flang] Catch I/O of bad derived type at compile time

Derived types with allocatable and pointer components cannot
be used in I/O data transfer statements unless they have defined
I/O procedures available (as type-bound or regular generics).
These cases are caught as errors by the I/O runtime library,
but it would be better if they were flagged during compilation.

(Address comment in review: don't use explicit name string lengths.)

Differential Revision: https://reviews.llvm.org/D120675

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[flang] Legacy extension: non-character formats

Very old (pre-'77 standard) codes would use arrays initialized
with Hollerith literals, typically in DATA, as modifiable
formats.

Differential Revisi

[flang] Legacy extension: non-character formats

Very old (pre-'77 standard) codes would use arrays initialized
with Hollerith literals, typically in DATA, as modifiable
formats.

Differential Revision: https://reviews.llvm.org/D117344

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[flang] Disallow BOZ literal constants as output list items

According to C7109, "A boz-literal-constant shall appear only as a
data-stmt-constant in a DATA statement, or where explicitly allowed in

[flang] Disallow BOZ literal constants as output list items

According to C7109, "A boz-literal-constant shall appear only as a
data-stmt-constant in a DATA statement, or where explicitly allowed in
16.9 as an actual argument of an intrinsic procedure." This change
enforces that constraint for output list items.

I also added a general interface to determine if an expression is a BOZ
literal constant and changed all of the places I could find where it
could be used.

I also added a test.

This change stemmed from the following issue --
https://gitlab-master.nvidia.com/fortran/f18-stage/issues/108

Differential Revision: https://reviews.llvm.org/D106893

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[flang] Fix crashes due to failure to find a subprogram

In error recovery situations, the mappings from source locations
to scopes were failing in a way that tripped some asserts.
Specifically, Find

[flang] Fix crashes due to failure to find a subprogram

In error recovery situations, the mappings from source locations
to scopes were failing in a way that tripped some asserts.
Specifically, FindPureProcedureContaining() wasn't coping well
when starting at the global scope. (And since the global scope
no longer has a source range, clean up the Semantics constructor
to avoid confusion.)

Differential Revision: https://reviews.llvm.org/D103567

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[flang] Accept OPEN(ACCESS='APPEND') legacy extension even without warnings enabled

My earlier patch to accept ACCESS='APPEND' only worked when warnings
were enabled; fix it.

Differential Revision:

[flang] Accept OPEN(ACCESS='APPEND') legacy extension even without warnings enabled

My earlier patch to accept ACCESS='APPEND' only worked when warnings
were enabled; fix it.

Differential Revision: https://reviews.llvm.org/D102653

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[flang] Support legacy extension OPEN(ACCESS='APPEND')

It should of course be POSITION='APPEND' but Sun Fortran
supported it on ACCESS=.

Differential Revision: https://reviews.llvm.org/D102350

[flang] Order Symbols by source provenance

In parser::AllCookedSources, implement a map from CharBlocks to
the CookedSource instances that they cover. This permits a fast
Find() operation based on

[flang] Order Symbols by source provenance

In parser::AllCookedSources, implement a map from CharBlocks to
the CookedSource instances that they cover. This permits a fast
Find() operation based on std::map::equal_range to map a CharBlock
to its enclosing CookedSource instance.

Add a creation order number to each CookedSource. This allows
AllCookedSources to provide a Precedes(x,y) predicate that is a
true source stream ordering between two CharBlocks -- x is less
than y if it is in an earlier CookedSource, or in the same
CookedSource at an earlier position.

Add a reference to the singleton SemanticsContext to each Scope.

All of this allows operator< to be implemented on Symbols by
means of a true source ordering. From a Symbol, we get to
its Scope, then to the SemanticsContext, and then use its
AllCookedSources reference to call Precedes().

Differential Revision: https://reviews.llvm.org/D98743

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[flang] Ensure pointer function results are acceptable variables

Fortran permits a reference to a function whose result is a pointer
to be used as a definable variable in any context where a
designa

[flang] Ensure pointer function results are acceptable variables

Fortran permits a reference to a function whose result is a pointer
to be used as a definable variable in any context where a
designator could appear. This patch wrings out remaining bugs
with such usage and adds more testing.

The utility predicate IsProcedurePointer(expr) had a misleading
name which has been corrected to IsProcedurePointerTarget(expr).

Differential Revision: https://reviews.llvm.org/D98555

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[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 e

[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

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[flang] Semantic checks for bad usage of whole assumed-size arrays

The semantics pass currently checks for several constraints
that apply to the use of whole assumed-size arrays in various
contexts,

[flang] Semantic checks for bad usage of whole assumed-size arrays

The semantics pass currently checks for several constraints
that apply to the use of whole assumed-size arrays in various
contexts, but C1002 wasn't really implemented. This patch
implements C1002 by disallowing the use of whole assumed-size
arrays in expressions and variables unless specifically
allowed by the context. This centralizes the error reporting,
which has been improved with a link to the array's declaration.

Differential revision: https://reviews.llvm.org/D88691

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[flang] Implement nonstandard OPEN statement CARRIAGECONTROL specifier

Differential Revision: https://reviews.llvm.org/D87052

[flang] Check that various variables referenced in I/O statements may be defined

A number of I/O syntax rules involve variables that will be written to,
and must therefore be definable. This includ

[flang] Check that various variables referenced in I/O statements may be defined

A number of I/O syntax rules involve variables that will be written to,
and must therefore be definable. This includes internal file variables,
IOSTAT= and IOMSG= specifiers, most INQUIRE statement specifiers, a few
other specifiers, and input variables. This patch checks for
these violations, and implements several additional I/O TODO constraint
checks.

Differential Revision: https://reviews.llvm.org/D86557

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[flang] Add missing check for unresolved name

Summary:
The name in an InputItem isn't necessarily resolved if an error occurred,
so it needs to be checked.

Fixes https://bugs.llvm.org/show_bug.cgi?

[flang] Add missing check for unresolved name

Summary:
The name in an InputItem isn't necessarily resolved if an error occurred,
so it needs to be checked.

Fixes https://bugs.llvm.org/show_bug.cgi?id=45477

Reviewers: klausler, PeteSteinfeld, DavidTruby, jdoerfert, sscalpone

Reviewed By: klausler, sscalpone

Subscribers: llvm-commits

Tags: #llvm, #flang

Differential Revision: https://reviews.llvm.org/D78685

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[flang] Add message formatting for std::int64_t

There is no printf formatting string for std::int64_t. Instead we have
to cast to std::intmax_t and use `%jd`. This change simplifies that by
automati

[flang] Add message formatting for std::int64_t

There is no printf formatting string for std::int64_t. Instead we have
to cast to std::intmax_t and use `%jd`. This change simplifies that by
automatically converting std::int64_t to std::intmax_t when formatting
messages.

Original-commit: flang-compiler/f18@8a2343dfffc9ccb04bdfe4c16ca47128255d47bd
Reviewed-on: https://github.com/flang-compiler/f18/pull/1101
Tree-same-pre-rewrite: false

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[flang] Process names in ASSIGN and assigned GOTO

Allow ASSIGNed integer variables as formats

Address review comment

Original-commit: flang-compiler/f18@361a151508b4a1940fc0669dead180be67964d8d
Re

[flang] Process names in ASSIGN and assigned GOTO

Allow ASSIGNed integer variables as formats

Address review comment

Original-commit: flang-compiler/f18@361a151508b4a1940fc0669dead180be67964d8d
Reviewed-on: https://github.com/flang-compiler/f18/pull/1099

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[flang] Reformat with latest clang-format and .clang-format

Original-commit: flang-compiler/f18@9fe84f45d7fd685051004678d6b5775dcc4c6f8f
Reviewed-on: https://github.com/flang-compiler/f18/pull/1094

[flang] [LLVMify F18] Compiler module folders should have capitalised names (flang-compiler/f18#980)

This patch renames the modules in f18 to use a capital letter in the
module name

Signed-off-b

[flang] [LLVMify F18] Compiler module folders should have capitalised names (flang-compiler/f18#980)

This patch renames the modules in f18 to use a capital letter in the
module name

Signed-off-by: Caroline Concatto <[email protected]>

Original-commit: flang-compiler/f18@d2eb7a1c443d1539ef12b6f027074a0eb15b1ea0
Reviewed-on: https://github.com/flang-compiler/f18/pull/980

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