Description

There are several instances of non-portable non-conformant Fortran in the current FPM sources that are flagged as errors by some Fortran compilers.

1. At line 27433, type(toml_error), allocatable :: toml_error brings a derived type into scope via host association and then declares a symbol of the same name. This is non-conformant due to F'2023 19.3.1 p3, and diagnosed as an error by NAG and flang-new. UPDATE: this has been repaired by a recent commit.
2. At line 27225, procedure(is_equal), deferred, private :: serializable_is_same declares a procedure binding that is both DEFERRED and PRIVATE. A deferred binding must be overridden by non-abstract derived types that extend serializable_t, but due to the private accessibility, those overrides cannot be declared in other modules, as is attempted at 19 later codes sites, e.g. line 28256 procedure :: serializable_is_same => git_is_same.
3. The interface operator(==) at line 28263 declares an explicit generic interface that is ambiguous with the type-bound generic in the derived type serializable_t.
4. The generic interface set_string (line 27248) doesn't contain a matching specific procedure for references at lines 31807, 33247, 37336, & 38096. This is due to the function s (line 10833) returning an ALLOCATABLE character result. Function results may be declared allocatable, but are not allocatable objects after being returned from a reference (see 8.5.3), and thus do not associate with ALLOCATABLE dummy arguments.

Expected Behaviour

Compilation without error by most Fortran compilers.

Version of fpm

0.10.1

Platform and Architecture

x86-64 Linux

Additional Information

No response