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| author | Harald Anlauf <anlauf@gmx.de> | 2025-03-02 22:20:28 +0100 |
|---|---|---|
| committer | Harald Anlauf <anlauf@gmx.de> | 2025-03-03 20:18:04 +0100 |
| commit | f9f16b9f74b767ca799a82f25be66a5fed25756d (patch) | |
| tree | 3d1d967666f76188417cc846a216c164f8f8fe86 | |
| parent | 71355700432b15590123dc13833304c75ad8a0b6 (diff) | |
| download | gcc-f9f16b9f74b767ca799a82f25be66a5fed25756d.zip gcc-f9f16b9f74b767ca799a82f25be66a5fed25756d.tar.gz gcc-f9f16b9f74b767ca799a82f25be66a5fed25756d.tar.bz2 | |
Fortran: reject empty derived type with bind(C) attribute [PR101577]
PR fortran/101577
gcc/fortran/ChangeLog:
* symbol.cc (verify_bind_c_derived_type): Generate error message
for derived type with no components in standard conformance mode,
indicating that this is a GNU extension.
gcc/testsuite/ChangeLog:
* gfortran.dg/empty_derived_type.f90: Adjust dg-options.
* gfortran.dg/empty_derived_type_2.f90: New test.
| -rw-r--r-- | gcc/fortran/symbol.cc | 23 | ||||
| -rw-r--r-- | gcc/testsuite/gfortran.dg/empty_derived_type.f90 | 1 | ||||
| -rw-r--r-- | gcc/testsuite/gfortran.dg/empty_derived_type_2.f90 | 11 |
3 files changed, 32 insertions, 3 deletions
diff --git a/gcc/fortran/symbol.cc b/gcc/fortran/symbol.cc index c689481..81aa81d 100644 --- a/gcc/fortran/symbol.cc +++ b/gcc/fortran/symbol.cc @@ -4624,12 +4624,29 @@ verify_bind_c_derived_type (gfc_symbol *derived_sym) entity may be defined by means of C and the Fortran entity is said to be interoperable with the C entity. There does not have to be such an interoperating C entity." + + However, later discussion on the J3 mailing list + (https://mailman.j3-fortran.org/pipermail/j3/2021-July/013190.html) + found this to be a defect, and Fortran 2018 added in section 18.3.4 + the following constraint: + "C1805: A derived type with the BIND attribute shall have at least one + component." + + We thus allow empty derived types only as GNU extension while giving a + warning by default, or reject empty types in standard conformance mode. */ if (curr_comp == NULL) { - gfc_warning (0, "Derived type %qs with BIND(C) attribute at %L is empty, " - "and may be inaccessible by the C companion processor", - derived_sym->name, &(derived_sym->declared_at)); + if (!gfc_notify_std (GFC_STD_GNU, "Derived type %qs with BIND(C) " + "attribute at %L has no components", + derived_sym->name, &(derived_sym->declared_at))) + return false; + else if (!pedantic) + /* Generally emit warning, but not twice if -pedantic is given. */ + gfc_warning (0, "Derived type %qs with BIND(C) attribute at %L " + "is empty, and may be inaccessible by the C " + "companion processor", + derived_sym->name, &(derived_sym->declared_at)); derived_sym->ts.is_c_interop = 1; derived_sym->attr.is_bind_c = 1; return true; diff --git a/gcc/testsuite/gfortran.dg/empty_derived_type.f90 b/gcc/testsuite/gfortran.dg/empty_derived_type.f90 index 6bf616c..496262d 100644 --- a/gcc/testsuite/gfortran.dg/empty_derived_type.f90 +++ b/gcc/testsuite/gfortran.dg/empty_derived_type.f90 @@ -1,4 +1,5 @@ ! { dg-do compile } +! { dg-options "" } module stuff implicit none type, bind(C) :: junk ! { dg-warning "may be inaccessible by the C companion" } diff --git a/gcc/testsuite/gfortran.dg/empty_derived_type_2.f90 b/gcc/testsuite/gfortran.dg/empty_derived_type_2.f90 new file mode 100644 index 0000000..1ef56da --- /dev/null +++ b/gcc/testsuite/gfortran.dg/empty_derived_type_2.f90 @@ -0,0 +1,11 @@ +! { dg-do compile } +! { dg-additional-options "-std=f2018" } +! +! PR fortran/101577 +! +! Contributed by Tobias Burnus + +type, bind(C) :: t ! { dg-error "has no components" } + ! Empty! +end type t +end |