Re: [PATCH v5 0/5] P1689R5 support

[Harald Anlauf <anlauf@gmx.de>]

Hi Ben,

Am 25.01.23 um 22:06 schrieb Ben Boeckel via Gcc-patches:
> Hi,
>
> This patch series adds initial support for ISO C++'s [P1689R5][], a
> format for describing C++ module requirements and provisions based on
> the source code. This is required because compiling C++ with modules is
> not embarrassingly parallel and need to be ordered to ensure that
> `import some_module;` can be satisfied in time by making sure that any
> TU with `export import some_module;` is compiled first.
>
> [P1689R5]: https://isocpp.org/files/papers/P1689R5.html

while that paper mentions Fortran, the patch in its present version
does not seem to implement anything related to Fortran and does not
touch the gfortran frontend.  Or am I missing anything?  Otherwise,
could you give an example how it would be used with Fortran?

Thus I'd say that it is OK from the gfortran side.

Thanks,
Harald

> I've also added patches to include imported module CMI files and the
> module mapper file as dependencies of the compilation. I briefly looked
> into adding dependencies on response files as well, but that appeared to
> need some code contortions to have a `class mkdeps` available before
> parsing the command line or to keep the information around until one was
> made.
>
> I'd like feedback on the approach taken here with respect to the
> user-visible flags. I'll also note that header units are not supported
> at this time because the current `-E` behavior with respect to `import
> <some_header>;` is to search for an appropriate `.gcm` file which is not
> something such a "scan" can support. A new mode will likely need to be
> created (e.g., replacing `-E` with `-fc++-module-scanning` or something)
> where headers are looked up "normally" and processed only as much as
> scanning requires.
>
> FWIW, Clang as taken an alternate approach with its `clang-scan-deps`
> tool rather than using the compiler directly.
>
> Thanks,
>
> --Ben
>
> ---
> v4 -> v5:
>
> - add dependency tracking for imported modules to `-MF`
> - add dependency tracking for static module mapper files given to
>    `-fmodule-mapper=`
>
> v3 -> v4:
>
> - add missing spaces between function names and arguments
>
> v2 -> v3:
>
> - changelog entries moved to commit messages
> - documentation updated/added in the UTF-8 routine editing
>
> v1 -> v2:
>
> - removal of the `deps_write(extra)` parameter to option-checking where
>    ndeeded
> - default parameter of `cpp_finish(fdeps_stream = NULL)`
> - unification of libcpp UTF-8 validity functions from v1
> - test cases for flag parsing states (depflags-*) and p1689 output
>    (p1689-*)
>
> Ben Boeckel (5):
>    libcpp: reject codepoints above 0x10FFFF
>    libcpp: add a function to determine UTF-8 validity of a C string
>    p1689r5: initial support
>    c++modules: report imported CMI files as dependencies
>    c++modules: report module mapper files as a dependency
>
>   gcc/c-family/c-opts.cc                        |  40 +++-
>   gcc/c-family/c.opt                            |  12 +
>   gcc/cp/mapper-client.cc                       |   4 +
>   gcc/cp/mapper-client.h                        |   1 +
>   gcc/cp/module.cc                              |  23 +-
>   gcc/doc/invoke.texi                           |  15 ++
>   gcc/testsuite/g++.dg/modules/depflags-f-MD.C  |   2 +
>   gcc/testsuite/g++.dg/modules/depflags-f.C     |   1 +
>   gcc/testsuite/g++.dg/modules/depflags-fi.C    |   3 +
>   gcc/testsuite/g++.dg/modules/depflags-fj-MD.C |   3 +
>   gcc/testsuite/g++.dg/modules/depflags-fj.C    |   4 +
>   .../g++.dg/modules/depflags-fjo-MD.C          |   4 +
>   gcc/testsuite/g++.dg/modules/depflags-fjo.C   |   5 +
>   gcc/testsuite/g++.dg/modules/depflags-fo-MD.C |   3 +
>   gcc/testsuite/g++.dg/modules/depflags-fo.C    |   4 +
>   gcc/testsuite/g++.dg/modules/depflags-j-MD.C  |   2 +
>   gcc/testsuite/g++.dg/modules/depflags-j.C     |   3 +
>   gcc/testsuite/g++.dg/modules/depflags-jo-MD.C |   3 +
>   gcc/testsuite/g++.dg/modules/depflags-jo.C    |   4 +
>   gcc/testsuite/g++.dg/modules/depflags-o-MD.C  |   2 +
>   gcc/testsuite/g++.dg/modules/depflags-o.C     |   3 +
>   gcc/testsuite/g++.dg/modules/modules.exp      |   1 +
>   gcc/testsuite/g++.dg/modules/p1689-1.C        |  18 ++
>   gcc/testsuite/g++.dg/modules/p1689-1.exp.json |  27 +++
>   gcc/testsuite/g++.dg/modules/p1689-2.C        |  16 ++
>   gcc/testsuite/g++.dg/modules/p1689-2.exp.json |  16 ++
>   gcc/testsuite/g++.dg/modules/p1689-3.C        |  14 ++
>   gcc/testsuite/g++.dg/modules/p1689-3.exp.json |  16 ++
>   gcc/testsuite/g++.dg/modules/p1689-4.C        |  14 ++
>   gcc/testsuite/g++.dg/modules/p1689-4.exp.json |  14 ++
>   gcc/testsuite/g++.dg/modules/p1689-5.C        |  14 ++
>   gcc/testsuite/g++.dg/modules/p1689-5.exp.json |  14 ++
>   gcc/testsuite/g++.dg/modules/test-p1689.py    | 222 ++++++++++++++++++
>   gcc/testsuite/lib/modules.exp                 |  71 ++++++
>   libcpp/charset.cc                             |  28 ++-
>   libcpp/include/cpplib.h                       |  12 +-
>   libcpp/include/mkdeps.h                       |  17 +-
>   libcpp/init.cc                                |  13 +-
>   libcpp/internal.h                             |   2 +
>   libcpp/mkdeps.cc                              | 149 +++++++++++-
>   40 files changed, 789 insertions(+), 30 deletions(-)
>   create mode 100644 gcc/testsuite/g++.dg/modules/depflags-f-MD.C
>   create mode 100644 gcc/testsuite/g++.dg/modules/depflags-f.C
>   create mode 100644 gcc/testsuite/g++.dg/modules/depflags-fi.C
>   create mode 100644 gcc/testsuite/g++.dg/modules/depflags-fj-MD.C
>   create mode 100644 gcc/testsuite/g++.dg/modules/depflags-fj.C
>   create mode 100644 gcc/testsuite/g++.dg/modules/depflags-fjo-MD.C
>   create mode 100644 gcc/testsuite/g++.dg/modules/depflags-fjo.C
>   create mode 100644 gcc/testsuite/g++.dg/modules/depflags-fo-MD.C
>   create mode 100644 gcc/testsuite/g++.dg/modules/depflags-fo.C
>   create mode 100644 gcc/testsuite/g++.dg/modules/depflags-j-MD.C
>   create mode 100644 gcc/testsuite/g++.dg/modules/depflags-j.C
>   create mode 100644 gcc/testsuite/g++.dg/modules/depflags-jo-MD.C
>   create mode 100644 gcc/testsuite/g++.dg/modules/depflags-jo.C
>   create mode 100644 gcc/testsuite/g++.dg/modules/depflags-o-MD.C
>   create mode 100644 gcc/testsuite/g++.dg/modules/depflags-o.C
>   create mode 100644 gcc/testsuite/g++.dg/modules/p1689-1.C
>   create mode 100644 gcc/testsuite/g++.dg/modules/p1689-1.exp.json
>   create mode 100644 gcc/testsuite/g++.dg/modules/p1689-2.C
>   create mode 100644 gcc/testsuite/g++.dg/modules/p1689-2.exp.json
>   create mode 100644 gcc/testsuite/g++.dg/modules/p1689-3.C
>   create mode 100644 gcc/testsuite/g++.dg/modules/p1689-3.exp.json
>   create mode 100644 gcc/testsuite/g++.dg/modules/p1689-4.C
>   create mode 100644 gcc/testsuite/g++.dg/modules/p1689-4.exp.json
>   create mode 100644 gcc/testsuite/g++.dg/modules/p1689-5.C
>   create mode 100644 gcc/testsuite/g++.dg/modules/p1689-5.exp.json
>   create mode 100644 gcc/testsuite/g++.dg/modules/test-p1689.py
>   create mode 100644 gcc/testsuite/lib/modules.exp
>
>
> base-commit: 9d4c00cdaccc3decd07740e817387ce844ef3ac9