[WIP] Meson build system

Makefile.am

@@ -42,8 +42,7 @@ endif
 SUBDIRS=support $(GENFFT) kernel simd-support dft rdft reodft api	\
 libbench2 $(CHICKEN_EGG) tests mpi $(DOCDIR) tools m4
 EXTRA_DIST=COPYRIGHT bootstrap.sh CONVENTIONS fftw.pc.in	\
-CMakeLists.txt cmake.config.h.in FFTW3Config.cmake.in		\
-FFTW3ConfigVersion.cmake.in README-perfcnt.md
+README-perfcnt.md
 
 SIMD_LIBS = simd-support/libsimd_support.la
 
@@ -168,19 +167,6 @@ fftw3@PREC_SUFFIX@.pc: fftw.pc
 pkgconfigdir = $(libdir)/pkgconfig
 pkgconfig_DATA = fftw3@PREC_SUFFIX@.pc
 
-FFTW3@PREC_SUFFIX@Config.cmake: $(top_srcdir)/FFTW3Config.cmake.in
-	$(SED) \
-		-e 's|[@]PREC_SUFFIX@|@PREC_SUFFIX@|g' \
-		-e 's|[@]CMAKE_INSTALL_FULL_LIBDIR@|$(libdir)|g' \
-		-e 's|[@]CMAKE_INSTALL_FULL_INCLUDEDIR@|$(includedir)|g' \
-		$(top_srcdir)/FFTW3Config.cmake.in > $@
-FFTW3@PREC_SUFFIX@ConfigVersion.cmake: $(top_srcdir)/FFTW3ConfigVersion.cmake.in
-	$(SED) \
-		-e 's|[@]FFTW_VERSION@|@PACKAGE_VERSION@|g' \
-		$(top_srcdir)/FFTW3ConfigVersion.cmake.in > $@
-cmakedir = $(libdir)/cmake/fftw3
-cmake_DATA = FFTW3@PREC_SUFFIX@Config.cmake FFTW3@PREC_SUFFIX@ConfigVersion.cmake
-
 WISDOM_DIR = /etc/fftw
 WISDOM = wisdom@PREC_SUFFIX@
 

README-meson.md

@@ -0,0 +1,108 @@
+# Meson Build System
+
+A Meson-based build system is included in order to provide a modern alternative
+to Autotools for those who need it (such as for better integration with IDEs
+and easier inclusion as subproject/dependency of other software).
+
+Note that it is **EXPERIMENTAL**. It should mostly just work, but if you run
+into any problems, please report them on our issue tracker and consider using
+the Autotools system in the meantime.
+
+It might one day replace Autotools for maintainer tasks, but for the sake of
+compatibility, there are currently no plans to remove Autotools: FFTW’s build
+tasks are relatively complex, it runs on a wide variety of platforms, and some
+(paying) users are not at liberty to drastically alter their build environment.
+
+For that reason, changes to the Meson system should only touch files directly
+belonging to it until a decision has been made to promote it to the primary
+build system. This means some parts of it will not be as clean and efficient
+as they could be.
+
+## Completeness
+
+The Meson build system should have feature parity with Autotools, except for
+the following:
+
+* Fortran wrappers (needs replacements for Autoconf-provided macros)
+* ARM v7a/v8 performance counters
+* Commercialized tarballs
+
+## Requirements
+
+### General
+
+A recent enough version of [Meson](https://mesonbuild.com/) or a compatible
+implementation of it (such as [muon](https://sr.ht/~lattis/muon/)) is required.
+The exact minimum version is specified at the start of the `meson.build` file.
+
+FFTW itself needs a C compiler. GCC and Clang are well-tested.
+
+ICL and MSVC should also work, but currently only static libraries can be built
+successfully with Microsoft’s toolchains. For now, we strongly recommend using
+a MinGW-w64-based toolchain to build FFTW for Windows. [MXE](https://mxe.cc/)
+can be used to build one if necessary.
+
+Running the test suite currently requires Perl.
+
+### Git only
+
+Additionally, if you have obtained this copy of FFTW from the Git repository,
+you will need the [Dune](https://dune.build/) build system for OCaml. Much of
+FFTW’s source code is *generated*, and this is required in order to build the
+generators. This has only been tested on x86 Linux with glibc.
+GNU indent is required as well, since the generated sources in FFTW releases
+should be formatted.
+Release tarballs already contain the generated sources.
+
+To build the full documentation (already included in release tarballs),
+you need:
+
+* Perl
+* `makeinfo`
+* `fig2dev` (part of transfig)
+* `texi2pdf` (part of texinfo).
+
+To generate the Fortran wrappers (included in release tarballs), you need Perl.
+
+## Usage
+
+See the [Meson documentation](https://mesonbuild.com/Manual.html) for
+instructions, including usage with IDEs and
+[cross compilers](https://mesonbuild.com/Cross-compilation.html).
+
+The short version:
+
+```sh
+meson setup builddir
+cd builddir
+meson compile
+meson test --suite small
+meson install
+```
+
+Some IDEs, like KDevelop, already support Meson. VSCode has an extension
+you can install from the marketplace. Once that is set up, you can simply
+open the FFTW source directory and everything will be configured automatically.
+
+### Generating Release Tarballs
+
+Assuming you have all of the above and the current Git commit is tagged, you
+can simply run `meson dist` in a configured build directory. This will do the
+following by default:
+
+* Collect the sources in the current Git `HEAD` commit
+  NOTE: NOT whatever is currently checked out, and thus NOT including untracked
+  or modified files! Meson will warn about this and require a command line flag
+  to proceed if it detects uncommitted changes.
+* Cement the tarball’s version (so it won’t depend on Git)
+* Generate `ChangeLog` from Git
+* Generate all codelets and copy them to the tarball tree
+* Patch `configure.ac` to match Meson’s version info
+* Configure the resulting sources and run the full test suite
+* Upon success, generate a compressed tarball and accompanying checksum file
+
+If the commit is not tagged, the build system still packages a tarball, but it
+will print a warning and refuse to include the Autotools build system.
+
+Most of the above happens in a shell script generated from
+`support/meson_dist.sh.in`.

README.md

@@ -9,7 +9,7 @@ generated automatically.  This repository contains the *generator* and
 it does not contain the *generated code*.  *YOU WILL BE UNABLE TO
 COMPILE CODE FROM THIS REPOSITORY* unless you have special tools and
 know what you are doing.   In particular, do not expect things to
-work by simply executing `configure; make` or `cmake`.
+work by simply executing `configure; make` or `meson setup <dir>`.
 
 Most users should ignore this repository, and should instead download
 official tarballs from http://fftw.org/, which contain the generated

api/meson.build

@@ -0,0 +1,76 @@
+# TODO: Generate Fortran wrappers
+summary('Fortran wrappers', '(not supported with Meson yet)', section: 'Build')
+
+fftw_api_inc = include_directories('.')
+fftw_srcset.add(
+    files(
+        'apiplan.c',
+        'configure.c',
+        'execute-dft-c2r.c',
+        'execute-dft-r2c.c',
+        'execute-dft.c',
+        'execute-r2r.c',
+        'execute-split-dft-c2r.c',
+        'execute-split-dft-r2c.c',
+        'execute-split-dft.c',
+        'execute.c',
+        'export-wisdom-to-file.c',
+        'export-wisdom-to-string.c',
+        'export-wisdom.c',
+        'f77api.c',
+        'flops.c',
+        'forget-wisdom.c',
+        'import-system-wisdom.c',
+        'import-wisdom-from-file.c',
+        'import-wisdom-from-string.c',
+        'import-wisdom.c',
+        'malloc.c',
+        'map-r2r-kind.c',
+        'mapflags.c',
+        'mkprinter-file.c',
+        'mkprinter-str.c',
+        'mktensor-iodims.c',
+        'mktensor-iodims64.c',
+        'mktensor-rowmajor.c',
+        'plan-dft-1d.c',
+        'plan-dft-2d.c',
+        'plan-dft-3d.c',
+        'plan-dft-c2r-1d.c',
+        'plan-dft-c2r-2d.c',
+        'plan-dft-c2r-3d.c',
+        'plan-dft-c2r.c',
+        'plan-dft-r2c-1d.c',
+        'plan-dft-r2c-2d.c',
+        'plan-dft-r2c-3d.c',
+        'plan-dft-r2c.c',
+        'plan-dft.c',
+        'plan-guru-dft-c2r.c',
+        'plan-guru-dft-r2c.c',
+        'plan-guru-dft.c',
+        'plan-guru-r2r.c',
+        'plan-guru-split-dft-c2r.c',
+        'plan-guru-split-dft-r2c.c',
+        'plan-guru-split-dft.c',
+        'plan-guru64-dft-c2r.c',
+        'plan-guru64-dft-r2c.c',
+        'plan-guru64-dft.c',
+        'plan-guru64-r2r.c',
+        'plan-guru64-split-dft-c2r.c',
+        'plan-guru64-split-dft-r2c.c',
+        'plan-guru64-split-dft.c',
+        'plan-many-dft-c2r.c',
+        'plan-many-dft-r2c.c',
+        'plan-many-dft.c',
+        'plan-many-r2r.c',
+        'plan-r2r-1d.c',
+        'plan-r2r-2d.c',
+        'plan-r2r-3d.c',
+        'plan-r2r.c',
+        'print-plan.c',
+        'rdft2-pad.c',
+        'the-planner.c',
+        'version.c',
+    ),
+)
+
+install_headers(files('fftw3.h'))