[flang-commits] [flang] [flang] Propogate the BIND(C) attribute into procedures from their in… (PR #93994)
Peter Klausler via flang-commits
flang-commits at lists.llvm.org
Fri May 31 10:39:59 PDT 2024
https://github.com/klausler created https://github.com/llvm/llvm-project/pull/93994
…terfaces
In "PROCEDURE(iface) :: proc", if "iface" has the BIND(C) attribute, then so should proc, as if the declaration had been "PROCEDURE(iface), BIND(C) :: proc". This had been working in name resolution only in cases where "iface" had been declared before "proc".
Note that if "iface" is declared with an empty binding name ("BIND(C,NAME='')"), "proc" does not inherit that property. Use an explicit "BIND(C,NAME='')" on the "PROCEDURE" statement for that.
This behavior is not clearly defined in the standard, but seems to match what some other Fortran compilers do.
>From 2b0d0141d896c0db650d08cbf8d43d80cff1a7a8 Mon Sep 17 00:00:00 2001
From: Peter Klausler <pklausler at nvidia.com>
Date: Fri, 31 May 2024 10:33:21 -0700
Subject: [PATCH] [flang] Propogate the BIND(C) attribute into procedures from
their interfaces
In "PROCEDURE(iface) :: proc", if "iface" has the BIND(C) attribute,
then so should proc, as if the declaration had been
"PROCEDURE(iface), BIND(C) :: proc". This had been working in name
resolution only in cases where "iface" had been declared before "proc".
Note that if "iface" is declared with an empty binding name ("BIND(C,NAME='')"),
"proc" does not inherit that property. Use an explicit "BIND(C,NAME='')"
on the "PROCEDURE" statement for that.
This behavior is not clearly defined in the standard, but seems to
match what some other Fortran compilers do.
---
flang/lib/Semantics/resolve-names.cpp | 27 ++++++---
flang/test/Semantics/bind-c02.f90 | 1 +
flang/test/Semantics/bind-c16.f90 | 86 +++++++++++++++++++++++++++
3 files changed, 107 insertions(+), 7 deletions(-)
create mode 100644 flang/test/Semantics/bind-c16.f90
diff --git a/flang/lib/Semantics/resolve-names.cpp b/flang/lib/Semantics/resolve-names.cpp
index 68cfc8641b9b2..2004363abea2e 100644
--- a/flang/lib/Semantics/resolve-names.cpp
+++ b/flang/lib/Semantics/resolve-names.cpp
@@ -5068,13 +5068,6 @@ Symbol &DeclarationVisitor::DeclareProcEntity(
} else if (interface->test(Symbol::Flag::Subroutine)) {
symbol.set(Symbol::Flag::Subroutine);
}
- if (IsBindCProcedure(*interface) && !IsPointer(symbol) &&
- !IsDummy(symbol)) {
- // Inherit BIND_C attribute from the interface, but not the NAME="..."
- // if any. This is not clearly described in the standard, but matches
- // the behavior of other compilers.
- SetImplicitAttr(symbol, Attr::BIND_C);
- }
} else if (auto *type{GetDeclTypeSpec()}) {
SetType(name, *type);
symbol.set(Symbol::Flag::Function);
@@ -8631,6 +8624,20 @@ void ResolveNamesVisitor::FinishSpecificationPart(
if (!symbol.has<HostAssocDetails>()) {
CheckPossibleBadForwardRef(symbol);
}
+ // Propagate BIND(C) attribute to procedure entities from their interfaces,
+ // but not the NAME=, even if it is empty (which would be a reasonable
+ // and useful behavior, actually). This interpretation is not at all
+ // clearly described in the standard, but matches the behavior of several
+ // other compilers.
+ if (auto *proc{symbol.detailsIf<ProcEntityDetails>()}; proc &&
+ !proc->isDummy() && !IsPointer(symbol) &&
+ !symbol.attrs().test(Attr::BIND_C)) {
+ if (const Symbol * iface{proc->procInterface()};
+ iface && IsBindCProcedure(*iface)) {
+ SetImplicitAttr(symbol, Attr::BIND_C);
+ SetBindNameOn(symbol);
+ }
+ }
}
currScope().InstantiateDerivedTypes();
for (const auto &decl : decls) {
@@ -9176,6 +9183,9 @@ void ResolveNamesVisitor::AddSubpNames(ProgramTree &node) {
if (child.HasModulePrefix()) {
SetExplicitAttr(symbol, Attr::MODULE);
}
+ if (child.bindingSpec()) {
+ SetExplicitAttr(symbol, Attr::BIND_C);
+ }
auto childKind{child.GetKind()};
if (childKind == ProgramTree::Kind::Function) {
symbol.set(Symbol::Flag::Function);
@@ -9192,6 +9202,9 @@ void ResolveNamesVisitor::AddSubpNames(ProgramTree &node) {
if (child.HasModulePrefix()) {
SetExplicitAttr(symbol, Attr::MODULE);
}
+ if (child.bindingSpec()) {
+ SetExplicitAttr(symbol, Attr::BIND_C);
+ }
}
}
for (const auto &generic : node.genericSpecs()) {
diff --git a/flang/test/Semantics/bind-c02.f90 b/flang/test/Semantics/bind-c02.f90
index d0c7940744131..416d071542fe6 100644
--- a/flang/test/Semantics/bind-c02.f90
+++ b/flang/test/Semantics/bind-c02.f90
@@ -15,6 +15,7 @@ subroutine proc()
!ERROR: Only variable and named common block can be in BIND statement
bind(c) :: pc1
+ !ERROR: BIND_C attribute was already specified on 'sub'
!ERROR: Only variable and named common block can be in BIND statement
bind(c) :: sub
diff --git a/flang/test/Semantics/bind-c16.f90 b/flang/test/Semantics/bind-c16.f90
new file mode 100644
index 0000000000000..b9dfb03e35eec
--- /dev/null
+++ b/flang/test/Semantics/bind-c16.f90
@@ -0,0 +1,86 @@
+!RUN: %flang_fc1 -fdebug-dump-symbols %s 2>&1 | FileCheck %s
+!CHECK: p1a, BIND(C), EXTERNAL, PUBLIC (Subroutine): ProcEntity s1 bindName:p1a
+!CHECK: p1b, BIND(C), EXTERNAL, PUBLIC (Subroutine): ProcEntity s1 bindName:p1b
+!CHECK: p1c, BIND(C), EXTERNAL, PUBLIC (Subroutine): ProcEntity s1 bindName:P1c
+!CHECK: p2a, BIND(C), EXTERNAL, PUBLIC (Subroutine): ProcEntity s2 bindName:p2a
+!CHECK: p2b, BIND(C), EXTERNAL, PUBLIC (Subroutine): ProcEntity s2 bindName:p2b
+!CHECK: p2c, BIND(C), EXTERNAL, PUBLIC (Subroutine): ProcEntity s2 bindName:P2c
+!CHECK: p3a, BIND(C), EXTERNAL, PUBLIC (Subroutine): ProcEntity s3 bindName:p3a
+!CHECK: p3b, BIND(C), EXTERNAL, PUBLIC (Subroutine): ProcEntity s3 bindName:p3b
+!CHECK: p3c, BIND(C), EXTERNAL, PUBLIC (Subroutine): ProcEntity s3 bindName:P3c
+module m1
+ procedure(s1) :: p1a
+ procedure(s1), bind(c) :: p1b
+ procedure(s1), bind(c,name='P1c') :: p1c
+ procedure(s2) :: p2a
+ procedure(s2), bind(c) :: p2b
+ procedure(s2), bind(c,name='P2c') :: p2c
+ procedure(s3) :: p3a
+ procedure(s3), bind(c) :: p3b
+ procedure(s3), bind(c,name='P3c') :: p3c
+ contains
+ subroutine s1() bind(c)
+ end
+ subroutine s2() bind(c,name='')
+ end
+ subroutine s3() bind(c,name='foo')
+ end
+end
+
+!CHECK: p1a, BIND(C), EXTERNAL, PUBLIC (Subroutine): ProcEntity s1 bindName:p1a
+!CHECK: p1b, BIND(C), EXTERNAL, PUBLIC (Subroutine): ProcEntity s1 bindName:p1b
+!CHECK: p1c, BIND(C), EXTERNAL, PUBLIC (Subroutine): ProcEntity s1 bindName:P1c
+!CHECK: p2a, BIND(C), EXTERNAL, PUBLIC (Subroutine): ProcEntity s2 bindName:p2a
+!CHECK: p2b, BIND(C), EXTERNAL, PUBLIC (Subroutine): ProcEntity s2 bindName:p2b
+!CHECK: p2c, BIND(C), EXTERNAL, PUBLIC (Subroutine): ProcEntity s2 bindName:P2c
+!CHECK: p3a, BIND(C), EXTERNAL, PUBLIC (Subroutine): ProcEntity s3 bindName:p3a
+!CHECK: p3b, BIND(C), EXTERNAL, PUBLIC (Subroutine): ProcEntity s3 bindName:p3b
+!CHECK: p3c, BIND(C), EXTERNAL, PUBLIC (Subroutine): ProcEntity s3 bindName:P3c
+module m2
+ interface
+ subroutine s1() bind(c)
+ end
+ subroutine s2() bind(c,name='')
+ end
+ subroutine s3() bind(c,name='foo')
+ end
+ end interface
+ procedure(s1) :: p1a
+ procedure(s1), bind(c) :: p1b
+ procedure(s1), bind(c,name='P1c') :: p1c
+ procedure(s2) :: p2a
+ procedure(s2), bind(c) :: p2b
+ procedure(s2), bind(c,name='P2c') :: p2c
+ procedure(s3) :: p3a
+ procedure(s3), bind(c) :: p3b
+ procedure(s3), bind(c,name='P3c') :: p3c
+end
+
+!CHECK: p1a, BIND(C), EXTERNAL, PUBLIC (Subroutine): ProcEntity s1 bindName:p1a
+!CHECK: p1b, BIND(C), EXTERNAL, PUBLIC (Subroutine): ProcEntity s1 bindName:p1b
+!CHECK: p1c, BIND(C), EXTERNAL, PUBLIC (Subroutine): ProcEntity s1 bindName:P1c
+!CHECK: p2a, BIND(C), EXTERNAL, PUBLIC (Subroutine): ProcEntity s2 bindName:p2a
+!CHECK: p2b, BIND(C), EXTERNAL, PUBLIC (Subroutine): ProcEntity s2 bindName:p2b
+!CHECK: p2c, BIND(C), EXTERNAL, PUBLIC (Subroutine): ProcEntity s2 bindName:P2c
+!CHECK: p3a, BIND(C), EXTERNAL, PUBLIC (Subroutine): ProcEntity s3 bindName:p3a
+!CHECK: p3b, BIND(C), EXTERNAL, PUBLIC (Subroutine): ProcEntity s3 bindName:p3b
+!CHECK: p3c, BIND(C), EXTERNAL, PUBLIC (Subroutine): ProcEntity s3 bindName:P3c
+module m3
+ procedure(s1) :: p1a
+ procedure(s1), bind(c) :: p1b
+ procedure(s1), bind(c,name='P1c') :: p1c
+ procedure(s2) :: p2a
+ procedure(s2), bind(c) :: p2b
+ procedure(s2), bind(c,name='P2c') :: p2c
+ procedure(s3) :: p3a
+ procedure(s3), bind(c) :: p3b
+ procedure(s3), bind(c,name='P3c') :: p3c
+ interface
+ subroutine s1() bind(c)
+ end
+ subroutine s2() bind(c,name='')
+ end
+ subroutine s3() bind(c,name='foo')
+ end
+ end interface
+end
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