[flang-commits] [flang] [flang] Refine handling of NULL() actual to non-optional allocatable … (PR #116126)
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flang-commits at lists.llvm.org
Wed Nov 13 16:19:19 PST 2024
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-flang-semantics
Author: Peter Klausler (klausler)
<details>
<summary>Changes</summary>
…dummy
We presently allow a NULL() actual argument to associate with a non-optional dummy allocatable argument only under INTENT(IN). This is too strict, as it precludes the case of a dummy argument with default intent. Continue to require that the actual argument be definable under INTENT(OUT) and INTENT(IN OUT), and (contra XLF) interpret NULL() as being an expression, not a definable variable, even when it is given an allocatable MOLD.
Fixes https://github.com/llvm/llvm-project/issues/115984.
---
Full diff: https://github.com/llvm/llvm-project/pull/116126.diff
4 Files Affected:
- (modified) flang/include/flang/Common/Fortran-features.h (+2-2)
- (modified) flang/lib/Common/Fortran-features.cpp (+2)
- (modified) flang/lib/Semantics/check-call.cpp (+28-23)
- (modified) flang/test/Semantics/call27.f90 (+15-1)
``````````diff
diff --git a/flang/include/flang/Common/Fortran-features.h b/flang/include/flang/Common/Fortran-features.h
index 74edbe44fdbb1c..78ba3f0d330292 100644
--- a/flang/include/flang/Common/Fortran-features.h
+++ b/flang/include/flang/Common/Fortran-features.h
@@ -38,7 +38,7 @@ ENUM_CLASS(LanguageFeature, BackslashEscapes, OldDebugLines,
DistinguishableSpecifics, DefaultSave, PointerInSeqType, NonCharacterFormat,
SaveMainProgram, SaveBigMainProgramVariables,
DistinctArrayConstructorLengths, PPCVector, RelaxedIntentInChecking,
- ForwardRefImplicitNoneData, NullActualForAllocatable,
+ NullActualForAllocatable, ForwardRefImplicitNoneData,
ActualIntegerConvertedToSmallerKind, HollerithOrCharacterAsBOZ,
BindingAsProcedure, StatementFunctionExtensions,
UseGenericIntrinsicWhenSpecificDoesntMatch, DataStmtExtensions,
@@ -72,7 +72,7 @@ ENUM_CLASS(UsageWarning, Portability, PointerToUndefinable,
PreviousScalarUse, RedeclaredInaccessibleComponent, ImplicitShared,
IndexVarRedefinition, IncompatibleImplicitInterfaces, BadTypeForTarget,
VectorSubscriptFinalization, UndefinedFunctionResult, UselessIomsg,
- MismatchingDummyProcedure)
+ MismatchingDummyProcedure, NullActualForDefaultIntentAllocatable)
using LanguageFeatures = EnumSet<LanguageFeature, LanguageFeature_enumSize>;
using UsageWarnings = EnumSet<UsageWarning, UsageWarning_enumSize>;
diff --git a/flang/lib/Common/Fortran-features.cpp b/flang/lib/Common/Fortran-features.cpp
index fff796e42552a5..719ef2b0291ff8 100644
--- a/flang/lib/Common/Fortran-features.cpp
+++ b/flang/lib/Common/Fortran-features.cpp
@@ -80,8 +80,10 @@ LanguageFeatureControl::LanguageFeatureControl() {
warnUsage_.set(UsageWarning::VectorSubscriptFinalization);
warnUsage_.set(UsageWarning::UndefinedFunctionResult);
warnUsage_.set(UsageWarning::UselessIomsg);
+ warnUsage_.set(UsageWarning::NullActualForDefaultIntentAllocatable);
// New warnings, on by default
warnLanguage_.set(LanguageFeature::SavedLocalInSpecExpr);
+ warnLanguage_.set(LanguageFeature::NullActualForAllocatable);
}
// Ignore case and any inserted punctuation (like '-'/'_')
diff --git a/flang/lib/Semantics/check-call.cpp b/flang/lib/Semantics/check-call.cpp
index a161d2bdf9dbb8..59bbd8b7da56a7 100644
--- a/flang/lib/Semantics/check-call.cpp
+++ b/flang/lib/Semantics/check-call.cpp
@@ -766,21 +766,21 @@ static void CheckExplicitDataArg(const characteristics::DummyDataObject &dummy,
}
} else if (actualIsNull) {
if (dummyIsOptional) {
- } else if (dummy.intent == common::Intent::In) {
- // Extension (Intel, NAG, XLF): a NULL() pointer is an acceptable
- // actual argument for an INTENT(IN) allocatable dummy, and it
- // is treated as an unassociated allocatable.
- if (context.ShouldWarn(
- common::LanguageFeature::NullActualForAllocatable)) {
- messages.Say(common::LanguageFeature::NullActualForAllocatable,
- "Allocatable %s is associated with a null pointer"_port_en_US,
- dummyName);
- }
- } else {
+ } else if (dummy.intent == common::Intent::Default &&
+ context.ShouldWarn(
+ common::UsageWarning::NullActualForDefaultIntentAllocatable)) {
messages.Say(
- "A null pointer may not be associated with allocatable %s without INTENT(IN)"_err_en_US,
+ "A null pointer should not be associated with allocatable %s without INTENT(IN)"_warn_en_US,
+ dummyName);
+ } else if (dummy.intent == common::Intent::In &&
+ context.ShouldWarn(
+ common::LanguageFeature::NullActualForAllocatable)) {
+ messages.Say(common::LanguageFeature::NullActualForAllocatable,
+ "Allocatable %s is associated with a null pointer"_port_en_US,
dummyName);
}
+ // INTENT(OUT) and INTENT(IN OUT) cases are caught elsewhere as being
+ // undefinable actual arguments.
} else {
messages.Say(
"ALLOCATABLE %s must be associated with an ALLOCATABLE actual argument"_err_en_US,
@@ -1265,19 +1265,24 @@ static void CheckExplicitInterfaceArg(evaluate::ActualArgument &arg,
} else if (object.attrs.test(characteristics::DummyDataObject::
Attr::Allocatable) &&
evaluate::IsNullPointer(*expr)) {
- if (object.intent == common::Intent::In) {
- // Extension (Intel, NAG, XLF); see CheckExplicitDataArg.
- if (context.ShouldWarn(common::LanguageFeature::
- NullActualForAllocatable)) {
- messages.Say(
- common::LanguageFeature::NullActualForAllocatable,
- "Allocatable %s is associated with NULL()"_port_en_US,
- dummyName);
- }
- } else {
+ if (object.intent == common::Intent::Out ||
+ object.intent == common::Intent::InOut) {
messages.Say(
- "NULL() actual argument '%s' may not be associated with allocatable %s without INTENT(IN)"_err_en_US,
+ "NULL() actual argument '%s' may not be associated with allocatable dummy argument %s that is INTENT(OUT) or INTENT(IN OUT)"_err_en_US,
expr->AsFortran(), dummyName);
+ } else if (object.intent == common::Intent::Default &&
+ context.ShouldWarn(common::UsageWarning::
+ NullActualForDefaultIntentAllocatable)) {
+ messages.Say(common::UsageWarning::
+ NullActualForDefaultIntentAllocatable,
+ "NULL() actual argument '%s' should not be associated with allocatable dummy argument %s without INTENT(IN)"_warn_en_US,
+ expr->AsFortran(), dummyName);
+ } else if (context.ShouldWarn(common::LanguageFeature::
+ NullActualForAllocatable)) {
+ messages.Say(
+ common::LanguageFeature::NullActualForAllocatable,
+ "Allocatable %s is associated with %s"_port_en_US,
+ dummyName, expr->AsFortran());
}
} else {
messages.Say(
diff --git a/flang/test/Semantics/call27.f90 b/flang/test/Semantics/call27.f90
index 062df6e45da890..135d6c06dcb4ac 100644
--- a/flang/test/Semantics/call27.f90
+++ b/flang/test/Semantics/call27.f90
@@ -1,12 +1,26 @@
! RUN: %python %S/test_errors.py %s %flang_fc1 -pedantic
! Catch NULL() actual argument association with allocatable dummy argument
program test
- !ERROR: NULL() actual argument 'NULL()' may not be associated with allocatable dummy argument 'a=' without INTENT(IN)
+ real, allocatable :: a
+ !ERROR: NULL() actual argument 'NULL()' may not be associated with allocatable dummy argument dummy argument 'a=' that is INTENT(OUT) or INTENT(IN OUT)
+ call foo0(null())
+ !WARNING: NULL() actual argument 'NULL()' should not be associated with allocatable dummy argument dummy argument 'a=' without INTENT(IN)
call foo1(null())
!PORTABILITY: Allocatable dummy argument 'a=' is associated with NULL()
call foo2(null())
call foo3(null()) ! ok
+ !ERROR: Actual argument associated with INTENT(IN OUT) dummy argument 'a=' is not definable
+ !BECAUSE: 'null(mold=a)' is a null pointer
+ call foo0(null(mold=a))
+ !WARNING: A null pointer should not be associated with allocatable dummy argument 'a=' without INTENT(IN)
+ call foo1(null(mold=a))
+ !PORTABILITY: Allocatable dummy argument 'a=' is associated with a null pointer
+ call foo2(null(mold=a))
+ call foo3(null(mold=a)) ! ok
contains
+ subroutine foo0(a)
+ real, allocatable, intent(in out) :: a
+ end subroutine
subroutine foo1(a)
real, allocatable :: a
end subroutine
``````````
</details>
https://github.com/llvm/llvm-project/pull/116126
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