Apply the default PUBLIC/PRIVATE accessibility of a module to its symbols
a second time after it is known that all symbols, including implicitly typed
names from NAMELIST groups and specification expressions in module subprograms,
have been created in its scope.
Fixes https://github.com/llvm/llvm-project/issues/62598.
Differential Revision: https://reviews.llvm.org/D150307
Instead of filling uninitialized global variables with "undef",
initialize them with 0. Only for Integer, Float or Logical type
variables. Complex, user defined data structures, arrays, etc
are not supported at this point.
This patch fixes the main problem of
https://github.com/llvm/llvm-project/issues/62432
Reviewed By: jeanPerier
Differential Revision: https://reviews.llvm.org/D149877
The extents, if any, of the HARVEST= actual argument must be known
at execution time for the call to be implemented.
Differential Revision: https://reviews.llvm.org/D147391
When the same name is pulled into a scope more than once via
USE and IMPORT, emit an error if its resolutions are ambiguous,
or (as an extension like some other compilers) emit a portability
warning when the names all resolve to the same symbol.
Differential Revision: https://reviews.llvm.org/D147388
Add an entry to the Extensions document describing how we
don't care about conflicts between module names and non-global
items. (This is a case where it would be a nontrivial amount
of work to catch an "error" that is only a standard conformance
issue, not anything that would prevent a program from working.)
Differential Revision: https://reviews.llvm.org/D147387
Flang was missing value normalization for logical<->integer conversions
which is required by Flang specification. The shrinking logical<->logical
conversions were also incorrectly truncating the input.
This change performs value normalization for all logical<->integer
conversions and logical<->logical conversions between different kinds.
Note that value normalization is not strictly required for
logical(kind=k1)->logical(kind=k2) conversions when k1 < k2.
Differential Revision: https://reviews.llvm.org/D147019
Presently, semantics doesn't check for discrepancies between known
constant corresponding LEN type parameters between the declared type
of an allocatable/pointer and either the type-spec or the SOURCE=/MOLD=
on an ALLOCATE statement.
This allows discrepancies between character lengths to go unchecked.
Some compilers accept mismatched character lengths on SOURCE=/MOLD=
and the allocate object, and that's useful and unambiguous feature
that already works in f18 via truncation or padding. A portability
warning should issue, however.
But for mismatched character lengths between an allocate object and
an explicit type-spec, and for any mismatch between derived type
LEN type parameters, an error is appropriate.
Differential Revision: https://reviews.llvm.org/D146583
Constraint C1406 in Fortran 2018 prohibits the USE of the same module
name as both an intrinsic module and a non-intrinsic module in a scope.
The current check misinterprets the constraint as applying only to
explicitly INTRINSIC or NON_INTRINSIC module natures.
Change the check to also apply to non-explicit module natures, and
also downgrade it to a portability warning, since there is no ambiguity
and I suspect that we need to accept this usage when building f18's
own intrinsic modules.
Differential Revision: https://reviews.llvm.org/D146576
Some Fortran compilers allow kinds of LOGICAL other than C_BOOL
for the types of dummy arguments to interoperable (BIND(C))
procedures. As any kind of LOGICAL can be converted to any
other without loss of information, this seems to be a useful
unambiguous extension that is attested in real codes; accept it
for scalars with a portability warning.
Differential Revision: https://reviews.llvm.org/D145968
Declaration checking in semantics was only examining symbols with
explicit BIND(C) attributes; extend it to also check dummy arguments
to such procedures.
Differential Revision: https://reviews.llvm.org/D145746
As a near-universal extension, Fortran compilers permit forward references
to dummy arguments and variables in COMMON blocks from specification expressions
before an explicit type-declaration-stmt appears for those variables
under IMPLICIT NONE, so long as those variables are later explicitly typed
with the types that regular implicit typing rules would have given them
(usually default INTEGER).
F18 implemented this extension for dummy arguments, but not variables in
COMMON blocks. Extend the extension to also accept variables in COMMON.
Differential Revision: https://reviews.llvm.org/D145743
The Fortran 2018 standard, perhaps as an attempt to prevent ambiguity
in older compilers, requires that a statement function appear in an
explicit type declaration statement if its name is also accessible
from a host scope. F18 processes the specification parts of inner
procedures first, so we don't need this requirement to prevent
ambiguity, and can only really check it retrospectively after name
resolution. Emit a portability warning when appropriate.
Differential Revision: https://reviews.llvm.org/D145100
f18 accepts statement labels in fixed form source even if they follow
a semicolon -- i.e., they're not in the fixed form's label field.
Emit a warning for such usage.
Differential Revision: https://reviews.llvm.org/D143817
When a USE of a module precedes its definition in the same source
file, ensure that the module is processed by name resolution before
the USE statement. This prevents the risk of the USE statement using
an obsolete module file that is later overwritten during the same
compilation.
Differential Revision: https://reviews.llvm.org/D143799
f18 implements BLOCK scoping for construct names, like most but not all Fortran
compilers, but in the 2018 standard such names are defined to be local identifiers
whose scope is the inclusive scope -- i.e., the subprogram or main program.
Detect usage that depends on this extension and emit a portability warning.
Differential Revision: https://reviews.llvm.org/D143776
The standard's specification for the ASSOCIATED() intrinsic function
describes its optional second argument (TARGET=) as being required
to be a valid target for a pointer assignment statement in which the
first argument (POINTER=) was the left-hand side. Some Fortran compilers
apparently interpret this text as a requirement that the POINTER= argument
actually be a valid left-hand side to a pointer assignment statement,
and emit an error if it is not so. This particularly affects the
use of an explicit NULL pointer as the first argument.
Such usage is well-defined, benign, useful, and supported by at least
two other compilers, so we should continue to accept it. This patch
adds a portability warning and some documentation.
In order to implement the portability warning in the best way, the
special checks on calls to the ASSOCIATED() intrinsic function have
been moved from intrinsic processing to Semantics/check-calls.cpp,
whence they have access to semantics' toolchest. Special checks for
other intrinsic functions might also migrate in the future in order
to keep them all in one place.
Differential Revision: https://reviews.llvm.org/D142768
Constraint C1529 requires that the base object of a type-bound procedure
reference be a scalar if the TBP has the NOPASS attribute. Most
compilers do not enforce this constraint and it does not appear to
have any implementation justification, so emit portability warning.
On the other hand, we fail to enforce C919 for references to
procedure pointer components, whose base objects must of course
be scalars in order to avoid ambiguity and empty arrays, whether
NOPASS is present or not.
Differential Revision: https://reviews.llvm.org/D140148
Most attributes apply to only object or only procedure entities,
and attempts to apply them to other kinds of symbol table entries
are caught in name resolution when ConvertToObjectEntity() or
ConvertToProcEntity() fails. However, the POINTER attribute can
be applied to both, and name resolution can't perform that conversion
yet, and as a result we don't catch many kinds of silly errors.
Fix by ensuring that the symbol is of a type that could eventually
become an object or procedure entity if it is not one already.
Differential Revision: https://reviews.llvm.org/D140137
Modules, submodules, main programs, and BLOCK DATA subprograms have names
that cannot be used within their scope, so we allow those names to be
used for other entities in the scope. This might not be entirely
conformant with the language standard, so warn about it.
Differential Revision: https://reviews.llvm.org/D139146
Standard Fortran allows type-bound procedure bindings to only
be called, and disallows them from being used in other contexts
where a procedure name can be: as the target of a procedure pointer
assignment statement, and as an actual argument that corresponds
to a dummy procedure. So long as the interfaces match, there's
no good reason for these uses to be errors, and there some obvious
use cases in polymorphic programming. So emit portability warnings
rather than errors, and document this usage as an extension.
Differential Revision: https://reviews.llvm.org/D139127
In a derived type definition, a type bound procedure declaration
statement with neither interface nor attributes is required by constraint
C768 to have the optional "::" between the PROCEDURE keyword and the
bindings if any binding has a renaming with "=>". The colons are
not actually necessary for a correct and unambiguous parse, so
emit a warning when they are missing.
Differential Revision: https://reviews.llvm.org/D139065
When checking the specific procedures of a generic interface for a
match against a given set of actual arguments, be sure to not match
a function against a subroutine call or vice versa. (We generally
catch and warn about attempts to declare mixed interfaces, but they
are usually conforming and can be inadvertently created when generics
are merged due to USE and host association.)
Differential Revision: https://reviews.llvm.org/D139059
f18 doesn't have any limit on continuation lines in fixed or free form
source (other than available memory), but the standard does. Emit
a portability warning when it is exceeded.
Differential Revision: https://reviews.llvm.org/D139055
The standard does *not* require that a real or imaginary part of a complex
literal constant be a scalar if it is a named constant. Downgrade a
recently installed check to a portability warning, and document it.
Differential Revision: https://reviews.llvm.org/D139046
We implemented 19.3.4p1 literally in name resolution:
A component name has the scope of its derived-type definition. Outside the type definition,
it may also appear within a designator of a component of a structure of that type or as a
component keyword in a structure constructor for that type.
and within the derived-type definition would resolve the "bare"
names of components in specification inquiries and other contexts to
those components, not to any symbols in the enclosing scopes.
It turns out that most Fortran compilers resolve only "bare" names thus
when they are type parameters, and the names of data and procedure components
do not shadow exterior symbols. Adjust name resolution to follow that
precedent rather than what seems to be clear language in the standard.
Differential Revision: https://reviews.llvm.org/D136984
An ASSOCIATE or SELECT TYPE statement's selector whose "right-hand side" is the result
of a reference to a function that returns a pointer must be usable as a valid target
(but not as a pointer).
Differential Revision: https://reviews.llvm.org/D135211
f18 emits an error message when the same name is used in a scope
for both a procedure and a generic interface, and the procedure is
not a specific procedure of the generic interface. It may be
questionable usage, and not portable, but it does not appear to
be non-conforming by a strict reading of the standard, and many
popular Fortran compilers accept it.
Differential Revision: https://reviews.llvm.org/D135205
Some Fortran compilers accept user-defined ELEMENTAL procedures as actual
arguments corresponding to (necessarily) non-ELEMENTAL dummy procedures;
most do not, and f18 is one of them. Document the fact that this is not
a supported extension.
Differential Revision: https://reviews.llvm.org/D134399
Fortran is not clear about the semantics of
```
subroutine subr
integer n = 1
block
data n/2/
end block
end subroutine
```
which could be interpreted as having two variables, each
named 'n', or as having one variable 'n' with invalid double
initialization. Precedents from existing compilers are also
in disagreement.
The most common interpretation, however, agrees with a subtle
reading of the standard: BLOCK constructs scope names that have
local specifications, and a DATA statement is a declaration
construct, not a specification construct. So this example is
*not* acceptable.
Differential Revision: https://reviews.llvm.org/D134391
I went over the output of the following mess of a command:
`(ulimit -m 2000000; ulimit -v 2000000; git ls-files -z | parallel --xargs -0 cat | aspell list --mode=none --ignore-case | grep -E '^[A-Za-z][a-z]*$' | sort | uniq -c | sort -n | grep -vE '.{25}' | aspell pipe -W3 | grep : | cut -d' ' -f2 | less)`
and proceeded to spend a few days looking at it to find probable typos
and fixed a few hundred of them in all of the llvm project (note, the
ones I found are not anywhere near all of them, but it seems like a
good start).
Reviewed By: awarzynski, clementval
Differential Revision: https://reviews.llvm.org/D130844
Support these legacy extension intrinsic functions with unambiguous
semantics in those existing compilers that support them by means
of recognizing them as aliases for standard intrinsics (IMAG) or
with simple rewrites (IZEXT, JZEXT). Note that ZEXT has different
semantics in different existing compilers, so we will not support it
due to lack of a broad unambiguous precedent.
Differential Revision: https://reviews.llvm.org/D132154
f18 intentionally does not support the spottily-implemented language extension
in which one can pass NULL() for an allocatable dummy argument. This is perhaps
a sanctioned side effect in other compilers of the fact that they pass distinct
"base address" and "descriptor address" physical arguments.
Make the error message in this case more specific to the circumstances, and
add a note to Extensions.md to clarify that this behavior is intended.
(We could, with some effort in lowering, support passing NULL for an INTENT(IN)
allocatable dummy, but let's see whether such nonconforming usage appears
in a real application before spending any more time on it.)
Differential Revision: https://reviews.llvm.org/D130380
The prescanner does not support VMS Fortran listing control directives
(%LIST, %NOLIST, %EJECT) or continuation lines on INCLUDE lines.
Differential Revision: https://reviews.llvm.org/D127791
The restrictions on the relationship between a "kP" scale factor
and a Ew.d/Dw.d/Gw.d significant digit count are not enforced for
output editing when there is no nonzero scale factor in effect.
(An error message about a bad scale factor is confusing if no kP
control edit descriptor has been used.) Document this usage in
Extensions.md.
Differential Revision: https://reviews.llvm.org/D127435
F18 doesn't accept INTEGER operands to the intrinsic LOGICAL operations;
some compilers do. This usage is not portable, and not just because it's
non-conforming -- the bit representations of LOGICAL also vary between
compilers and options. The "MIL-STD" bit intrinsics IAND() & al. have been
avaiable since the late 70's and should be used instead.
Differential Revision: https://reviews.llvm.org/D126798
As an extension for REAL literals, we allow an exponent letter which
matches an explicit kind-param. The standard requires the exponent
to be 'E' if a kind-param is present. This patch
- documents this extension in Extensions.md
- enables a portability warning if it is used with -pedantic
The test case for this, kinds05.f90, needs D125804, which makes
test_errors.py test warnings as well, to actually test the warnings.
I include it already now to keep things together, it will do no harm
(I hope ...).
We also add WARNING-directives to the test kinds04.f90 in preparation
for D125804. As the exponent-letter 'Q' does not imply the same kind
on all platforms, the emitted warnings are platform-dependent.
Therefore, the test is duplicated into two variants which are run
conditionally.
Finally, we promote the portability warning for when the exponent letter
is neither 'E' nor matching the kind-param to a standard warning.
Reviewed By: klausler
Differential Revision: https://reviews.llvm.org/D126459
When processing the literal constants of the various kinds of
INTEGER that are too large by 1 (e.g., 2147483648_4) in expression
analysis, emit a portability warning rather than a fatal error if
the literal constant appears as the operand to a unary minus, since
the folded result will be in range. And don't emit any warning if
the negated literal is coming from a module file -- f18 wrote the
module file and the warning would simply be confusing, especially to
the programmer that wrote (-2147483647_4-1) in the first place.
Further, emit portability warnings for the canonical expressions for
infinities and NaN (-1./0., 0./0., & 1./0.), but not when they appear
in a module file, for the same reason. The Fortran language has no
syntax for these special values so we have to emit expressions that
fold to them.
Fixes LLVM bugs https://github.com/llvm/llvm-project/issues/55086 and
https://github.com/llvm/llvm-project/issues/55081.
Differential Revision: https://reviews.llvm.org/D126584
Semantics is not preventing a named common block to appear with
different size in a same file (named common block should always have
the same storage size (see Fortran 2018 8.10.2.5), but it is a common
extension to accept different sizes).
Lowering was not coping with this well, since it just use the first
common block appearance, starting with BLOCK DATAs to define common
blocks (this also was an issue with the blank common block, which can
legally appear with different size in different scoping units).
Semantics is also not preventing named common from being initialized
outside of a BLOCK DATA, and lowering was dealing badly with this,
since it only gave an initial value to common blocks Globals if the
first common block appearance, starting with BLOCK DATAs had an initial
value.
Semantics is also allowing blank common to be initialized, while
lowering was assuming this would never happen, and was never creating
an initial value for it.
Lastly, semantics was not complaining if a COMMON block was initialized
in several scoping unit in a same file, while lowering can only generate
one of these initial value.
To fix this, add a structure to keep track of COMMON block properties
(biggest size, and initial value if any) at the Program level. Once the
size of a common block appearance is know, the common block appearance
is checked against this information. It allows semantics to emit an error
in case of multiple initialization in different scopes of a same common
block, and to warn in case named common blocks appears with different
sizes. Lastly, this allows lowering to use the Program level info about
common blocks to emit the right GlobalOp for a Common Block, regardless
of the COMMON Block appearances order: It emits a GlobalOp with the
biggest size, whose lowest bytes are initialized with the initial value
if any is given in a scope where the common block appears.
Lowering is updated to go emit the common blocks before anything else so
that the related GlobalOps are available when lowering the scopes where
common block appear. It is also updated to not assume that blank common
are never initialized.
Differential Revision: https://reviews.llvm.org/D124622
To avoid clashing with names of user derived types, the redundant
syntax TYPE(intrinsic type spec) must be interpreted as a monomorphic
derived type when "intrinsic type spec" is a single word. This
affects TYPE(BYTE) and TYPE(DOUBLECOMPLEX), but not TYPE(DOUBLE COMPLEX)
in free form source.
Differential Revision: https://reviews.llvm.org/D123724
Support the names AND, OR, and XOR for the generic intrinsic
functions IAND, IOR, and IEOR respectively.
Differential Revision: https://reviews.llvm.org/D122034
LBOUND must return 1 for an empty dimension, no matter what
explicit expression might appear in a declaration or arrive in
a descriptor.
Differential Revision: https://reviews.llvm.org/D121488
The standard explicitly allows a comma to be omitted between a 'P'
edit descriptor and a following numeric edit descriptor (e.g., 1PE10.1),
and before and after a '/' edit descriptor, but otherwise requires them
between edit descriptors. Most implementations, however, only require
commas where they prevent ambiguity, and accept things like 1XI10.
This extension is already assumed by the static FORMAT checker in
semantics. Patch the runtime to behave accordingly.
Differential Revision: https://reviews.llvm.org/D120747
EQUIVALENCE storage association of objects whose types are not
both default-kind numeric storage sequences, or not both default-kind
character storage sequences, are not standard conformant.
However, most Fortran compilers admit such usage, with warnings
in strict conformance mode. This patch allos EQUIVALENCE of objects
that have sequence types that are either identical, both numeric
sequences (of default kind or not), or both character sequences.
Non-sequence types, and sequences types that are not homogeneously
numeric or character, remain errors.
Differential Revision: https://reviews.llvm.org/D119848
Implements a near-universal extension in which NAMELIST
input will skip over unrelated namelist groups in the
input stream until the group with the requested name appears.
Differential Revision: https://reviews.llvm.org/D117843
Consistent with previously documented policy, in which
BOZ literals are accepted in non-standard-conforming circumstances
where they can be converted to an unambiguous known numeric type,
allow BOZ literals to be passed as an actual argument in a reference
to a procedure whose explicit interface has a corresponding dummy
argument with a numeric type to which the BOZ literal may be
converted. Improve error messages associated with BOZ literal
actual arguments, too: don't emit multiple errors.
Differential Revision: https://reviews.llvm.org/D117698
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
