[flang-commits] [flang] 61d361d - [flang] Extension: accept NULL([MOLD=]) for ALLOCATABLE INTENT(IN) du… (#66256)
via flang-commits
flang-commits at lists.llvm.org
Mon Sep 18 12:37:49 PDT 2023
Author: Peter Klausler
Date: 2023-09-18T12:37:46-07:00
New Revision: 61d361d69bb3af183b63be3e8a7056030e92de8a
URL: https://github.com/llvm/llvm-project/commit/61d361d69bb3af183b63be3e8a7056030e92de8a
DIFF: https://github.com/llvm/llvm-project/commit/61d361d69bb3af183b63be3e8a7056030e92de8a.diff
LOG: [flang] Extension: accept NULL([MOLD=]) for ALLOCATABLE INTENT(IN) du… (#66256)
…mmy argument
Several compilers accept a null pointer (with or without a MOLD=) as an
actual argument for association with an INTENT(IN) allocatable dummy
argument. At runtime, the allocatable dummy argument appears to be in
the unallocated state. This seems useful, unambiguous, unlikely to
invalidate conforming code, and works with Intel, NAG, & XLF, so it
should be supported with an optional portability warning in this
compiler as well.
Added:
Modified:
flang/docs/Extensions.md
flang/include/flang/Common/Fortran-features.h
flang/lib/Semantics/check-call.cpp
flang/test/Semantics/call27.f90
Removed:
################################################################################
diff --git a/flang/docs/Extensions.md b/flang/docs/Extensions.md
index 4d0b2c7319818a7..68726cbd2ed932e 100644
--- a/flang/docs/Extensions.md
+++ b/flang/docs/Extensions.md
@@ -298,6 +298,8 @@ end
* Unrestricted `INTRINSIC` functions are accepted for use in
`PROCEDURE` statements in generic interfaces, as in some other
compilers.
+* A `NULL()` pointer is treated as an unallocated allocatable
+ when associated with an `INTENT(IN)` allocatable dummy argument.
### Extensions supported when enabled by options
diff --git a/flang/include/flang/Common/Fortran-features.h b/flang/include/flang/Common/Fortran-features.h
index 5cbe1d6e157f2f9..94a39c50e049b11 100644
--- a/flang/include/flang/Common/Fortran-features.h
+++ b/flang/include/flang/Common/Fortran-features.h
@@ -37,7 +37,7 @@ ENUM_CLASS(LanguageFeature, BackslashEscapes, OldDebugLines,
DistinguishableSpecifics, DefaultSave, PointerInSeqType, NonCharacterFormat,
SaveMainProgram, SaveBigMainProgramVariables,
DistinctArrayConstructorLengths, PPCVector, RelaxedIntentInChecking,
- ForwardRefImplicitNoneData)
+ ForwardRefImplicitNoneData, NullActualForAllocatable)
// Portability and suspicious usage warnings for conforming code
ENUM_CLASS(UsageWarning, Portability, PointerToUndefinable,
diff --git a/flang/lib/Semantics/check-call.cpp b/flang/lib/Semantics/check-call.cpp
index 428c29b9a6bced7..bf80dbecab009d9 100644
--- a/flang/lib/Semantics/check-call.cpp
+++ b/flang/lib/Semantics/check-call.cpp
@@ -661,17 +661,34 @@ static void CheckExplicitDataArg(const characteristics::DummyDataObject &dummy,
dummy.attrs.test(characteristics::DummyDataObject::Attr::Optional)};
bool actualIsNull{evaluate::IsNullPointer(actual)};
if (dummyIsAllocatable) {
- if (!actualIsAllocatable && !(actualIsNull && dummyIsOptional)) {
+ if (actualIsAllocatable) {
+ if (actualIsCoindexed && dummy.intent != common::Intent::In) {
+ messages.Say(
+ "ALLOCATABLE %s must have INTENT(IN) to be associated with a coindexed actual argument"_err_en_US,
+ dummyName);
+ }
+ } 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.languageFeatures().ShouldWarn(
+ common::LanguageFeature::NullActualForAllocatable)) {
+ messages.Say(
+ "Allocatable %s is associated with a null pointer"_port_en_US,
+ dummyName);
+ }
+ } else {
+ messages.Say(
+ "A null pointer may not be associated with allocatable %s without INTENT(IN)"_err_en_US,
+ dummyName);
+ }
+ } else {
messages.Say(
"ALLOCATABLE %s must be associated with an ALLOCATABLE actual argument"_err_en_US,
dummyName);
}
- if (actualIsAllocatable && actualIsCoindexed &&
- dummy.intent != common::Intent::In) {
- messages.Say(
- "ALLOCATABLE %s must have INTENT(IN) to be associated with a coindexed actual argument"_err_en_US,
- dummyName);
- }
if (!actualIsCoindexed && actualLastSymbol &&
actualLastSymbol->Corank() != dummy.type.corank()) {
messages.Say(
@@ -791,7 +808,8 @@ static void CheckExplicitDataArg(const characteristics::DummyDataObject &dummy,
}
// NULL(MOLD=) checking for non-intrinsic procedures
- if (!intrinsic && !dummyIsPointer && !dummyIsOptional && actualIsNull) {
+ if (!intrinsic && !dummyIsAllocatableOrPointer && !dummyIsOptional &&
+ actualIsNull) {
messages.Say(
"Actual argument associated with %s may not be null pointer %s"_err_en_US,
dummyName, actual.AsFortran());
@@ -1083,12 +1101,19 @@ static void CheckExplicitInterfaceArg(evaluate::ActualArgument &arg,
} else if (object.attrs.test(characteristics::DummyDataObject::
Attr::Allocatable) &&
evaluate::IsNullPointer(*expr)) {
- // Unsupported extension that more or less naturally falls
- // out of other Fortran implementations that pass separate
- // base address and descriptor address physical arguments
- messages.Say(
- "Null actual argument '%s' may not be associated with allocatable %s"_err_en_US,
- expr->AsFortran(), dummyName);
+ if (object.intent == common::Intent::In) {
+ // Extension (Intel, NAG, XLF); see CheckExplicitDataArg.
+ if (context.languageFeatures().ShouldWarn(common::
+ LanguageFeature::NullActualForAllocatable)) {
+ messages.Say(
+ "Allocatable %s is associated with NULL()"_port_en_US,
+ dummyName);
+ }
+ } else {
+ messages.Say(
+ "NULL() actual argument '%s' may not be associated with allocatable %s without INTENT(IN)"_err_en_US,
+ expr->AsFortran(), dummyName);
+ }
} else {
messages.Say(
"Actual argument '%s' associated with %s is not a variable or typed expression"_err_en_US,
diff --git a/flang/test/Semantics/call27.f90 b/flang/test/Semantics/call27.f90
index 965ec401953f430..062df6e45da8908 100644
--- a/flang/test/Semantics/call27.f90
+++ b/flang/test/Semantics/call27.f90
@@ -1,10 +1,10 @@
-! RUN: %python %S/test_errors.py %s %flang_fc1
+! 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='
+ !ERROR: NULL() actual argument 'NULL()' may not be associated with allocatable dummy argument 'a=' without INTENT(IN)
call foo1(null())
- !ERROR: Null actual argument 'NULL()' may not be associated with allocatable dummy argument 'a='
- call foo2(null()) ! perhaps permissible later on user request
+ !PORTABILITY: Allocatable dummy argument 'a=' is associated with NULL()
+ call foo2(null())
call foo3(null()) ! ok
contains
subroutine foo1(a)
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