When a procedure pointer or procedure dummy argument has a
defined interface, the rank of the pointer (or dummy) is the
rank of the interface.
Also tweak code discovered in shape analysis when investigating
this problam so that it returns a vector of emptied extents rather
than std::nullopt when the extents are not scope-invariant, so that
the rank can at least be known.
Differential Revision: https://reviews.llvm.org/D123727
Shape analysis of RESHAPE(..., SHAPE=s) should of course return
the SHAPE= actual argument when it is constant; but when it is
not, its length is still known, and thus so is the rank of the
result of RESHAPE(), and shape analysis should at least return
a shape vector of the right length rather than a result that
makes the result appear to be a scalar, which can lead to some
bogus error messages.
Also, while here: rename a private GetShapeHelper::AsShape()
routine so that it can't be confused with the ones in the API
of shape.h.
Differential Revision: https://reviews.llvm.org/D123712
The intrinsics DREAL, DIMAG, and DCONJG are from Fortran 77 extensions.
For DREAL, the type of argument is extended to any complex. For DIMAG
and DCONJG, the type of argument for them should be complex(8). For DIMAG,
the result type should be real(8). For DCONJG, the result type should be
complex(8). Fix the intrinsic interface for them and add test cases for
the semantic checks and the lowering.
Reviewed By: Jean Perier
Differential Revision: https://reviews.llvm.org/D123459
The float number is represented as (-1)^s * 1.f * 2^(-127) for 32-bit,
where s is the signed flag, f is the mantissa. When the exponent bits
are all zeros, the float number is represented as (-1)^s * 0.f *2^(-126)
for 32-bit, in which case, the intPart is '0'.
Reviewed By: Jean Perier
https://reviews.llvm.org/D123673
During real range reduction to [0.5, 4) with
SQRT(2**(2a) * x) = SQRT(2**(2a)) * SQRT(x) = 2**a * SQRT(x)
we fall into inf. recursion if IsZero() == true.
Explicitly handle SQRT(0.0) instead of additional checks during folding. Also
add helpers for +0.0/-0.0 generation to clean up a bit.
Reviewed By: klausler
Differential Revision: https://reviews.llvm.org/D123131
In case a character component PDT length only depends on kind parameters,
fold it while instantiating the PDT. This is especially important if the
component has an initializer because later semantic phases (offset
computation or runtime type info generation) might get confused and
generate offset/type info that will lead to crashes in lowering.
Differential Revision: https://reviews.llvm.org/D122938
Previously, some semantic checks that are checking if an entity is an
allocatable were relying on the expression being a designator whose
last symbol has the allocatable attribute.
This is wrong since this was considering substrings and array sections of
allocatables as being allocatable. This is wrong (see NOTE 2 in
Fortran 2018 section 9.5.3.1).
Add evaluate::IsAllocatableDesignator to correctly test this.
Also add some semantic tests for ALLOCATED to test the newly added helper.
Note that ifort and nag are rejecting coindexed-named-object in
ALLOCATED (`allocated(coarray_scalar_alloc[2])`).
I think it is wrong given allocated argument is intent(in) as per
16.2.1 point 3.
So 15.5.2.6 point 4 regarding allocatable dummy is not violated (If the actual
argument is a coindexed object, the dummy argument shall have the INTENT (IN)
attribute.) and I think this is valid. gfortran accepts it.
The need for this helper was exposed in https://reviews.llvm.org/D122779.
Differential Revision: https://reviews.llvm.org/D122899
Co-authored-by: Peixin-Qiao <qiaopeixin@huawei.com>
When folding MAXLOC/MINLOC, the current element being compared was moved twice
in row in case it became the new extremum. With numeric and logical types, it
made no difference (std::move is a no-op for them), but for characters
where the string storage is actually moved, it caused the new extremum to
be set to the empty string, leading to wrong results.
Note: I could have left the first std::move relating to logical Findloc, but it
brings nothing and makes the code less auditable, so I also removed it.
Differential Revision: https://reviews.llvm.org/D122590
Implement constant folding for the intrinsic function NEAREST()
and the related functions IEEE_NEXT_AFTER(), IEEE_NEXT_UP(), and
IEEE_NEXT_DOWN().
Differential Revision: https://reviews.llvm.org/D122510
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
The "seenProcs" sets passed as arguments to the procedure and dummy
procedure characterization routines need to be passed by value so that
local updates to those sets do not become permanent. They are
presently passed by reference and that has led to bogus errors about
recursively defined procedures in testing.
(It might be faster to pass the sets by reference and undo those local
updates in these functions, but that's error-prone, and the performance
difference is not expected to be detectable in practice.)
Differential Revision: https://reviews.llvm.org/D122439
GetLowerBoundHelper rewrite in https://reviews.llvm.org/D121488 was
incorrect with POINTER/ALLOCATABLE components. The rewrite created a
descriptor inquiry to the component symbol only instead of the whole
named entity. The base information was lost, and not retrievable.
LBOUND(a(10)%p) became LBOUND(p).
Fix this regression, and also update DescriptorInquiry unparsing to
carry the kind information. DescriptorInquiries are KIND 8 expressions,
while LBOUND/SIZE/RANK, %LEN are default kind expressions.
This caused `print *,lbound(x,kind=8)` to unparse as `print*,lbound(x)` which is not
semantically the same (this unparsing issue was not an issue for
lowering, but I noticed it while writing my regression test).
Differential Revision: https://reviews.llvm.org/D122406
Similarly to LBOUND in https://reviews.llvm.org/D121488, UBOUND must
return zero for an empty dimension, no matter the specification
expression.
Add a GetUBOUND method to be used in expression rewrite that prevents
folding UBOUND to a bound specification expression if the extent is
not a compile time constant.
Fold the case where the extents is known to be zero (and also deal with
this case in LBOUND since we can and should to comply with constant
expression requirements).
Differential Revision: https://reviews.llvm.org/D122242
Support the names AND, OR, and XOR for the generic intrinsic
functions IAND, IOR, and IEOR respectively.
Differential Revision: https://reviews.llvm.org/D122034
`semantics::IsSaved()` was not applying -Msave/-fno-automatic for main programs.
This caused issues since lowering relies on it to allocate static
variables. This did not match nvfortran/gfortran behaviors where
-fno-automatic/-Msave control the static allocation of scalars in
main programs.
Some program may rely on main program scalars to be statically allocated in
bss (and therefore initialized to zero) with -Msave/-fno-automatic
flags.
Differential Revision: https://reviews.llvm.org/D121603
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
evaluate::IsPointerObject used to return true for pointer suboject like
`pointer(10)` while these object are not pointers. This prevented some
checks like 15.5.2.7 to be correctly enforced (e.g., it was possible to
pass `pointer(10)` to a non intent(in) dummy pointer).
After updating IsPointerObject behavior and adding a test for 15.5.2.7 in
call07.f90, a test in call03.f90 for 15.5.2.4(14) was failing.
It appeared the related semantics check was relying on IsPointerObject
to return true for `pointer(10)`. Adapt the code to detect pointer element
in another way.
While looking at the code, I also noticed that semantics was
rejecting `character(1)` pointer/assumed shape suboject when these are
allowed (the standard has a special case for character(1) in
15.5.2.4(14), and I verified that other compilers that enforce 15.5.2.4(14)
do accept this).
Differential Revision: https://reviews.llvm.org/D121377
Using recently established message severity codes, upgrade
non-fatal messages to usage and portability warnings as
appropriate.
Differential Revision: https://reviews.llvm.org/D121246
When a structure constructor does not initialize an allocatable component,
ensure that the typed expression representation contains an explicit
NULL() for the component. Expression semantics already copies default
initialized expressions for nonallocatable components into structure
constructors. This change is expected to simplify lowering.
Differential Revision: https://reviews.llvm.org/D121162
A recent patch made it possible to emit more localized error messages
pertaining to actual arguments in non-intrinsic procedure references.
Use these new powers for good and make intrinsic error messages more
precise, too.
Differential Revision: https://reviews.llvm.org/D121126
The index incrementation code used for FINDLOC, MAXLOC, and MINLOC folding
would crash if the array had a zero extent on the dimension selected with
a DIM= argument since the subscript passed to IncrementSubscripts would
have a value less than the lower bound. Fix, and add tests.
Differential Revision: https://reviews.llvm.org/D121125
Add new IsCompatibleWith() member functions to many classes in evaluate::characteristics
that apply more nuanced compatibility checking for function results, dummy
arguments, and procedure interfaces than the previous tests for complete
equivalence. Use IsCompatibleWith() in semantics for call checking.
Differential Revision: https://reviews.llvm.org/D120844
An assumed-type actual argument that corresponds to an assumed-rank dummy
argument shall be assumed-shape or assumed-rank.
Differential Revision: https://reviews.llvm.org/D120750
Calls to C_F_POINTER() without the optional SHAPE= third argument
were failing to be recognized as proper calls to the intrinsic,
but the failure was not generating any error message. This led to
a crash in lowering, which rightfully expects a typed expression
to be associated with the call.
So (1) catch silent failures to convert CALL statements as internal
errors, as is done for expressions and assignment statements; and
(2) clean up C_F_POINTER intrinsic handling to cope with only two
arguments and to emit an error for a FPTR= argument with no type.
Differential Revision: https://reviews.llvm.org/D119847
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
When a pointer assignment with bounds remapping has a function
reference as its right-hand side, don't check for array conformance.
Differential Revision: https://reviews.llvm.org/D119845
Semantic analysis was emitting a bogus error message when a structure
constructor contains a monomorphic value for a (limited) polymorphic
component of a derived type. The type compatibility test was too
strict; this patch relaxes it a little to allow values that could
be assigned or passed to a variable or dummy argument with that type.
Also add some quotes to an error message that was sometimes confusing
without them, and remove a repeated space character from another.
Differential Revision: https://reviews.llvm.org/D119744
ENTRY point symbols aren't marked PURE in the symbol table, but must
instead inherit the attribute from their containing subprograms.
There's a predicate in semantics that does this, but it wasn't being
used in the context of actual procedure argument characterization.
Differential Revision: https://reviews.llvm.org/D119564
The predicate IsInitialDataTarget() was failing to return a correct true
result in the case of a reference to the intrinsic function NULL() with a
MOLD= argument. Fix, and improve tests for "NULL()" elsewhere in semantics,
checking for an attribute set by intrinsics.cpp rather than the actual name.
Differential Revision: https://reviews.llvm.org/D119452
While one cannot of course statically initialize an allocatable component
of an instance of a derived type, its mere presence should not prevent
DATA initialization of the other nonallocatable components. Semantics
was treating the existence of an allocatable component as a case of
"default initialization", which it is, but not one that should run
afoul of C877. Add another Boolean argument to IsInitialized() to allow
for a more nuanced test.
Differential Revision: https://reviews.llvm.org/D119449
When a scope's symbol has characteriztics whose specification
expressions depend on other non-constant symbols in the same scope,
f18 rightfully emits an error. However, in the case of usage in
specification expressions involving host association, the program is not
invalid. This can arise, for example, in the case of an internal
function whose result's attributes use host-associated variables.
Differential Revision: https://reviews.llvm.org/D119565
Section 10.2.2.4, paragraph 3 states that a procedure pointer with an explicit
interface must have the same characteristics as its target. Previously, we
interpreted this as disallowing such pointers to point to procedures with
implicit interfaces. But several other compilers allow this.
We make an exception for the case where the explicit interface cannot be
called via an implicit interface.
This change makes us allow this, also
Differential Revision: https://reviews.llvm.org/D119404
The second argument to the ASSOCIATED intrinsic must be a valid pointer
or target. The test for this property only checked the last symbol
in a data-reference, but any symbol in the reference with the
POINTER or TARGET attribute will do.
Differential Revision: https://reviews.llvm.org/D119450
Fortran allows forward references to derived types, including
function results that are typed in a prefix of a FUNCTION statement.
If a type is defined in the body of the function, a reference to
that type from a prefix on the FUNCTION statement must resolve to
the local symbol, even and especially when that type shadows one
from the host scope.
The solution is to defer the processing of that type until the
end of the function's specification part. But the language doesn't
allow for forward references to other names in the prefix, so defer
the processing of the type only when it is not an intrinsic type.
The data structures in name resolution that track this information
for functions needed to become a stack in order to make this work,
since functions can contain interfaces that are functions.
Differential Revision: https://reviews.llvm.org/D119448
arguments even in situations where the arguments are required to compute
the LEN value at runtime.
Add tests.
Differential Revision: https://reviews.llvm.org/D119373
CMPLX was always rewritten as a complex constructor, but the second operand
of a complex constructor cannot be dynamically absent (i.e., a
disassociated pointer, an unallocated allocatable or an absent OPTIONAL
dummy argument), while the second argument of CMPLX can be dynamically
absent.
To avoid having to generate branches in complex constructor lowering
when Y is a pointer, keep the distinction between CMPLX and a complex
constructor when Y is a pointer, an allocatable, or an OPTIONAL entity.
Differential Revision: https://reviews.llvm.org/D118784
Some entries in the specific intrinsic function table have the
wrong argument keyword names -- they should agree with the names
of the arguments on their corresponding generic intrinsic function.
Clean them up.
Differential Revision: https://reviews.llvm.org/D118721
Apply part of a pending patch for GCC 11 warnings, and
rework a piece of code, to dodge warnings on flag from
GCC 11 build bots exposed by a recent patch.
Applying without review to get bots working again; changes
also tested against GCC 9.3.0.
The intrinsic table entry for INDEX mistakenly required
the optional BACK= argument to be scalar, but it's an
elemental intrinsic that can accept a conforming array.
Differential Revision: https://reviews.llvm.org/D117700
Accept any keyword argument names of the form "An" for
values of n >= 3 in calls to the intrinsic functions MAX, MIN,
and their variants, so long as "n" has no leading zero and
all the keywords are distinct. Previously, f18 was needlessly
requiring the names to be contiguous. When synthesizing keywords
to characterize the procedure's interface, don't conflict with
the program's keywords.
Differential Revision: https://reviews.llvm.org/D117701
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
UBOUND, SIZE, and SHAPE folding was still creating expressions that are
invalid on the caller side without the call expression context.
A previous patch intended to deal with this situation (https://reviews.llvm.org/D116933)
but it assumed the return expression would be a descriptor inquiry to
the result symbol, which is not the case if the extent expression is
"scope invariant" inside the called subroutine (e.g., referring to
intent(in) dummy arguments). Simply prevent folding from inlining non
constant extent expression on the caller side.
Folding could be later improved by having ad-hoc folding for UBOUND, SIZE, and
SHAPE on function references where it could try replacing the dummy symbols
by the actual expression, but this is left as a possible later improvement.
Differential Revision: https://reviews.llvm.org/D117686
Fold references to the intrinsic function SCALE().
(Also work around some MSVC headaches somehow exposed by
this patch: disable a bogus MSVC warning that began to appear
in unrelated source files, and avoid the otherwise-necessary
use of the "template" keyword in a call to a template member
function of a class template.)
Differential Revision: https://reviews.llvm.org/D117150
Character substrings weren't being folded correctly;
add tests and rework the implementation so that substrings
of literals and named constant character scalars & arrays
are properly folded for use in constant expressions.
Differential Revision: https://reviews.llvm.org/D117343
Peter Klausler