Before emitting a warning message, code should check that the usage in
question should be diagnosed by calling ShouldWarn(). A fair number of
sites in the code do not, and can emit portability warnings
unconditionally, which can confuse a user that hasn't asked for them
(-pedantic) and isn't terribly concerned about portability *to* other
compilers.
Add calls to ShouldWarn() or IsEnabled() around messages that need them,
and add -pedantic to tests that now require it to test their portability
messages, and add more expected message lines to those tests when
-pedantic causes other diagnostics to fire.
TotalElementCount() was modified to return std::optional<uint64_t>,
where std::nullopt means overflow occurred. Besides the additional
check in RESHAPE folding, all callers of TotalElementCount() were
changed, to also check for overflows.
https://reviews.llvm.org/D143819 turned mismatched DATA substring from a
crash into a warning. However, the resulting DATA was incorrect when
there were subsequent DATA values after the mismatch because the DATA to
init conversion stopped. This change let the DATA to init continue.
I added a LengthMismatch tag instead of using SizeMismatch because the
other situation where SizeMismatch is returned seem like bug situations
to me (the DATA value is dropped and the offset is not advanced), so I
did not want to continue DATA processing in these cases.
To ensure that the map from symbols to their initial images has an entry
for a particular symbol, use std::map<>::find() before
std::map<>::emplace() to avoid needless memory allocation and
deallocation. Also, combine adjacent intervals in the lists of
initialized ranges so that contiguous initializations don't require long
lists.
Fixes https://github.com/llvm/llvm-project/issues/66452.
Implements compatibility checking for initializers in procedure pointer
declarations. This work exposed some inconsistency in how ELEMENTAL
interfaces were handled and checked, from both unrestricted intrinsic
functions and others, and some refinements needed for function result
compatbility checking; these have also been ironed out. Some new
warnings are now emitted, and this affected a dozen or so tests.
Differential Revision: https://reviews.llvm.org/D159026
Establish a set of optional usage warnings, and enable some
only in "-pedantic" mode that, in our subjective experience
with application codes, seem to issue frequently without
indicating usage that really needs to be corrected. By default,
with this patch the compiler should appear to be somewhat less
persnickety but not less informative.
Differential Revision: https://reviews.llvm.org/D150710
When a substring appears as the MOLD= argument to TRANSFER(),
it's possible for the compiler to assert if it can't figure
out a constant length for the substring. Fix.
Differential Revision: https://reviews.llvm.org/D145740
Some compiler (not specified) reported to issue an error on a
"default:" clause in a switch statement whose cases cover all of
the values of an "enum class". Since other compilers/versions
are known to complain in the other direction, change the switch
statement to a cascade of ifs.
When a DATA statement initializes a substring with a character constant
of the wrong length, do the right thing with blank padding or truncation,
and emit a warning. Current code is crashing due to an unhandled error
reported from the low-level data image initialization framework.
Differential Revision: https://reviews.llvm.org/D143819
Semantics can catch out-of-range subscript values already when they
appear in DATA statement objects and constant folding of name constant
array indexing; this patch fills the gap by checking known constant
subscript values in other contexts.
Differential Revision: https://reviews.llvm.org/D142764
Impose a large but finite limit on the size of a variable being
initialized in a DATA statement to provide a readable error message
for artificial test cases that's better than a memory allocation
failure crash.
Differential Revision: https://reviews.llvm.org/D140146
The infrastructure in semantics that is used to check that the
left-hand sides of normal assignment statements are really definable
variables was not being used to check whether the LHSs of pointer assignments
are modifiable, and so most cases of unmodifiable pointers are left
undiagnosed. Rework the semantics checking for pointer assignments,
NULLIFY statements, pointer dummy arguments, &c. so that cases of
unmodifiable pointers are properly caught. This has been done
by extracting all the various definability checking code that has
been implemented for different contexts in Fortran into one new
facility.
The new consolidated definability checking code returns messages
meant to be attached as "because: " explanations to context-dependent
errors like "left-hand side of assignment is not definable".
These new error message texts and their attached explanations
affect many existing tests, which have been updated. The testing
infrastructure was extended by another patch to properly compare
warnings and explanatory messages, which had been ignored until
recently.
Differential Revision: https://reviews.llvm.org/D136979
A NULL() pointer is a valid actual argument for a procedure pointer dummy
argument whose intent is INTENT(IN); it should also be acceptable for a
procedure pointer dummy argument with unspecified intent.
Also make it possible to discern null object pointers from null procedure
pointers, so that an attempt to use one in place of the other in a context
where the distinction matters will still elicit an error.
Differential Revision: https://reviews.llvm.org/D132687
The predicate IsHostAssocited() was implemented in a way that would
return true only for cases of host association into a module or inner
subprogram. Technically, the use of a name in a BLOCK construct
that is not declared therein is considered in the Fortran standard
to also be a form of host association, and this matters when doing
error checking on DATA statements.
Differential Revision: https://reviews.llvm.org/D130388
Create a TargetCharacteristics class to centralize the few items of
target specific information that are relevant to semantics. Use the
new class for all target queries, including derived type component layout
modeling.
Future work will initialize this class with target information
provided or forwarded by the drivers, and use it to fold layout-dependent
intrinsic functions like TRANSFER().
Differential Revision: https://reviews.llvm.org/D129018
Updates: Attempts to work around build issues on Windows.
When a Hollerith (or short character) literal is presented as an actual
argument that corresponds to a dummy argument for which a BOZ literal
would be acceptable, treat the Hollerith as if it had been a BOZ
literal in the same way -- and with the same code -- as f18 already
does for the similar extension in DATA statements.
Differential Revision: https://reviews.llvm.org/D126144
As is already supported for dummy procedures, we need to also accept
declarations of procedure pointers that consist of a POINTER attribute
statement followed by an INTERFACE block. (The case of an INTERFACE
block followed by a POINTER statement already works.)
While cleaning this case up, adjust the utility predicate IsProcedurePointer()
to recognize it (namely a SubprogramDetails symbol with Attr::POINTER)
and delete IsProcName(). Extend tests, and add better comments to
symbol.h to document the two ways in which procedure pointers are
represented.
Differential Revision: https://reviews.llvm.org/D125139
The code below causes flang to crash with an exception.
After fixing the crash flang with an internal error "no symbol found for 'bar'"
This change fixes all the issues.
program name
implicit none
integer, parameter :: bar = 1
integer foo(bar) /bar*2/
end program name
Reviewed By: kiranchandramohan, klausler
Differential Revision: https://reviews.llvm.org/D124914
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().
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
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
Using recently established message severity codes, upgrade
non-fatal messages to usage and portability warnings as
appropriate.
Differential Revision: https://reviews.llvm.org/D121246
We already accept assignments of INTEGER to LOGICAL (& vice versa)
as an extension, but not initialization. Extend initialization
to cover those cases.
(Also fix misspelling in nearby comment as suggested by code reviewer.)
Decouple an inadvertent dependence cycle by moving two
one-line function definitions into a header file.
Differential Revision: https://reviews.llvm.org/D117159
Implements part of the legacy "DEC structures" feature from
VMS Fortran. STRUCTUREs are processed as if they were derived
types with SEQUENCE. DATA-like object entity initialization
is supported as well (e.g., INTEGER FOO/666/) since it was used
for default component initialization in structures. Anonymous
components (named %FILL) are also supported.
These features, and UNION/MAP, were already being parsed.
An omission in the collection of structure field names in the
case of nested structures with entity declarations was fixed
in the parser.
Structures are supported in modules, but this is mostly for
testing purposes. The names of fields in structures accessed
via USE association cannot appear with dot notation in client
code (at least not yet). DEC structures antedate Fortran 90,
so their actual use in applications should not involve modules.
This patch does not implement UNION/MAP, since that feature
would impose difficulties later in lowering them to MLIR types.
In the meantime, if they appear, semantics will issue a
"not yet implemented" error message.
Differential Revision: https://reviews.llvm.org/D117151
To accommodate triangular implied DO loops in DATA statements, in which
the bounds of nested implied DO loops might depend on the values of the
indices of outer implied DO loops in the same DATA statement set, it
is necessary to run them through constant folding each time they are
encountered.
Differential Revision: https://reviews.llvm.org/D114754
Fold the legacy intrinsic functions LGE, LGT, LLE, & LLT
by rewriting them into character relational expressions and
then folding those. Also fix folding of comparisons of
character values of distinct lengths: the shorter value must
be padded with blanks. (This fix exposed some bad test cases,
which are also fixed.)
Differential Revision: https://reviews.llvm.org/D111843
The combined initializers constructed from DATA statements and explicit
static initialization in declarations needs to include derived type
component default initializations, overriding those default values
without complaint with values from explicit DATA statement or declaration
initializations when they overlap. This also has to work for objects
with storage association due to EQUIVALENCE. When storage association causes
default component initializations to overlap, emit errors if and only
if the values differ (See Fortran 2018 subclause 19.5.3, esp. paragraph
10).
The f18 front-end has a module that analyzes and converts DATA statements
into equivalent static initializers for objects. For storage-associated
objects, compiler-generated objects are created that overlay the entire
association and fill it with a combined initializer. This "data-to-inits"
module already exists, and this patch is essentially extension and
clean-up of its machinery to complete the job.
Also: emit EQUIVALENCE to module files; mark compiler-created symbols
and *don't* emit those to module files; check non-static EQUIVALENCE
sets for conflicting default component initializations, so lowering
doesn't have to check them or emit diagnostics.
Differential Revision: https://reviews.llvm.org/D109022
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
STORAGE_SIZE() is a standard inquiry intrinsic (size in bits
of an array element of the same type as the argument); SIZEOF()
is a common extension that returns the size in bytes of its
argument; C_SIZEOF() is a renaming of SIZEOF() in module ISO_C_BINDING.
STORAGE_SIZE() and SIZEOF() are implemented via rewrites to
expressions; these expressions will be constant when the necessary
type parameters and bounds are also constant.
Code to calculate the sizes of types (with and without alignment)
was isolated into Evaluate/type.* and /characteristics.*.
Code in Semantics/compute-offsets.* to calculate sizes and alignments
of derived types' scopes was exposed so that it can be called at type
instantiation time (earlier than before) so that these inquiry intrinsics
could be called from specification expressions.
Differential Revision: https://reviews.llvm.org/D93322
Remove resolved & moot TODO comments in Common/, Parser/,
and Evaluate/. Address a pending one relating to parsing
ambiguity in DATA statement constants, handling it with
symbol table information in Semantics and adding a test.
Differential Revision: https://reviews.llvm.org/D93323
This patch plugs many holes in static initializer semantics, improves error
messages for default initial values and other component properties in
parameterized derived type instantiations, and cleans up several small
issues noticed during development. We now do proper scalar expansion,
folding, and type, rank, and shape conformance checking for component
default initializers in derived types and PDT instantiations.
The initial values of named constants are now guaranteed to have been folded
when installed in the symbol table, and are no longer folded or
scalar-expanded at each use in expression folding. Semantics documentation
was extended with information about the various kinds of initializations
in Fortran and when each of them are processed in the compiler.
Some necessary concomitant changes have bulked this patch out a bit:
* contextual messages attachments, which are now produced for parameterized
derived type instantiations so that the user can figure out which
instance caused a problem with a component, have been added as part
of ContextualMessages, and their implementation was debugged
* several APIs in evaluate::characteristics was changed so that a FoldingContext
is passed as an argument rather than just its intrinsic procedure table;
this affected client call sites in many files
* new tools in Evaluate/check-expression.cpp to determine when an Expr
actually is a single constant value and to validate a non-pointer
variable initializer or object component default value
* shape conformance checking has additional arguments that control
whether scalar expansion is allowed
* several now-unused functions and data members noticed and removed
* several crashes and bogus errors exposed by testing this new code
were fixed
* a -fdebug-stack-trace option to enable LLVM's stack tracing on
a crash, which might be useful in the future
TL;DR: Initialization processing does more and takes place at the right
times for all of the various kinds of things that can be initialized.
Differential Review: https://reviews.llvm.org/D92783
Fortran defines "null-init" null pointer initializers as
being function references, syntactically, that have to resolve
to calls to the intrinsic function NULL() with no actual
arguments.
Differential revision: https://reviews.llvm.org/D91657
The shape (esp. the size) of the result of a call to TRANSFER
is implemented according to the definition in the standard.
Differential Revision: https://reviews.llvm.org/D85866
Objects that are storage associated by EQUIVALENCE and
initialized with DATA are initialized by creating a
compiler temporary data object in the same scope,
assigning it an offset, type, and size that covers the
transitive closure of the associated initialized original
symbols, and combining their initializers into one common
initializer for the temporary.
Some problems with offset assignment of EQUIVALENCE'd objects
in COMMON were exposed and corrected, and some more error
cases are checked.
Remove obsolete function.
Small bugfix (nested implied dos).
Add a test.
Fix struct/class warning.
Differential Revision: https://reviews.llvm.org/D85560
