[Draft] Build with meson-python backend

.github/environment.yml

@@ -4,6 +4,7 @@ dependencies:
   - numpy >=2.0
   - swig
   - meson >=1.3.2
+  - meson-python
   - compilers
   - pkg-config
   - pip

meson.build

@@ -1,24 +1,33 @@
-# Much of this is from SciPy
-
 project(
   'pyoptsparse',
   'c', 'cpp',
-# unnecessary metadata commented out until Meson supports PEP517 and installation with pip
-#  version: 'x.x.x',
-#  license: 'GPL-3',
-  meson_version: '>= 0.60',
+  version: run_command(
+        'python', '-c',
+        '''
+import re
+from pathlib import Path
+init_file = Path("pyoptsparse/__init__.py")
+match = re.search(r'__version__ = ["\\\']([\d\\.]+)["\\\']', init_file.read_text())
+print(match.group(1))
+        '''
+    ).stdout().strip(),
+  meson_version: '>= 0.64',
   default_options: [
     'buildtype=debugoptimized',
-    'c_std=c99',
-    'cpp_std=c++14',
+    'b_ndebug=if-release',
+    'c_std=c17',
+    'cpp_std=c++17',
   ],
 )
 
-fortranobject_c = '../fortranobject.c'
+# <!-- from https://github.com/scipy/scipy/blob/4d9f5e65af06d4cc3f770407f1a66a185675eea9/meson.build
 
 cc = meson.get_compiler('c')
 cpp = meson.get_compiler('cpp')
 
+py3 = import('python').find_installation(pure: false)
+py3_dep = py3.dependency()
+
 # We need -lm for all C code (assuming it uses math functions, which is safe to
 # assume for SciPy). For C++ it isn't needed, because libstdc++/libc++ is
 # guaranteed to depend on it. For Fortran code, Meson already adds `-lm`.
@@ -29,17 +38,29 @@ endif
 
 # Adding at project level causes many spurious -lgfortran flags.
 add_languages('fortran', native: false)
+ff = meson.get_compiler('fortran')
+if ff.get_id() == 'gcc'
+  # -std=legacy is not supported by all Fortran compilers, but very useful with
+  # gfortran since it avoids a ton of warnings that we don't care about.
+  # Needs fixing in Meson, see https://github.com/mesonbuild/meson/issues/11633.
+  add_project_arguments('-std=legacy', language: 'fortran')
+endif
 
-# https://mesonbuild.com/Python-module.html
-# Here we differentiate from the python used by meson, py3_command, and that python target, py3_target. This is useful
-# when cross compiling like on conda-forge
-py_mod = import('python')
-py3_command = py_mod.find_installation()
-if get_option('python_target') != ''
-    py3_target = py_mod.find_installation(get_option('python_target'))
-else
-    py3_target = py3_command
+if ff.has_argument('-Wno-conversion')
+  add_project_arguments('-Wno-conversion', language: 'fortran')
 endif
-py3_dep = py3_target.dependency()
 
-subdir('pyoptsparse')
+if host_machine.system() == 'darwin'
+  if cc.has_link_argument('-Wl,-dead_strip')
+    # Allow linker to strip unused symbols
+    add_project_link_arguments('-Wl,-dead_strip', language : ['c', 'cpp', 'fortran'])
+  endif
+endif
+
+# --!>
+
+# install python sources
+install_subdir('pyoptsparse', install_dir: py3.get_install_dir())
+
+# install non-python sources
+subdir('pyoptsparse')

pyoptsparse/meson.build

@@ -1,97 +1,61 @@
-# NumPy include directory - needed in all submodules
-incdir_numpy = get_option('incdir_numpy')
-if incdir_numpy == ''
-    incdir_numpy = run_command(py3_target,
-      [
-        '-c',
-        'import os; os.chdir(".."); import numpy; print(numpy.get_include())'
-      ],
-      check: true
-    ).stdout().strip()
+# <!-- from https://github.com/scipy/scipy/blob/4d9f5e65af06d4cc3f770407f1a66a185675eea9/scipy/meson.build
+
+incdir_numpy = meson.get_external_property('numpy-include-dir', 'not-given')
+if incdir_numpy == 'not-given'
+  incdir_numpy = run_command(py3,
+    [
+      '-c',
+      '''import os
+import numpy as np
+try:
+  incdir = os.path.relpath(np.get_include())
+except Exception:
+  incdir = np.get_include()
+print(incdir)
+  '''
+    ],
+    check: true
+  ).stdout().strip()
+
+  # We do need an absolute path to feed to `cc.find_library` below
+  _incdir_numpy_abs = run_command(py3,
+    ['-c', 'import os; os.chdir(".."); import numpy; print(numpy.get_include())'],
+    check: true
+  ).stdout().strip()
+else
+  _incdir_numpy_abs = incdir_numpy
 endif
-# this creates a raw string which is useful for Windows use of '\' for paths
-incdir_numpy = '''@0@'''.format(incdir_numpy)
-
-# HACK: Meson prefixes filenames of intermediate compiled objects with their filepath. This poses a problem for conda builds
-# since conda ensures the host environment directory has 255 characters so the meson object filenames then exceed 255
-# characters. To remedy this, the fortranobject.c file from numpy is copied into pyoptsparse so that the meson build
-# uses a relative path, rather than an absolute path, thus reducing the auto generated object filename
-# see for example https://github.com/mesonbuild/meson/issues/4226
-run_command(py3_command,
-  [
-    '-c',
-    'import os; os.chdir(".."); import shutil; shutil.copy(os.path.join(r"' + incdir_numpy + '", "..", "..", "f2py", "src", "fortranobject.c"), "pyoptsparse")'
-  ],
-  check: true
-)
-
 inc_np = include_directories(incdir_numpy)
 
+# Don't use the deprecated NumPy C API. Define this to a fixed version instead of
+# NPY_API_VERSION in order not to break compilation for released SciPy versions
+# when NumPy introduces a new deprecation.
+numpy_nodepr_api = ['-DNPY_NO_DEPRECATED_API=NPY_1_9_API_VERSION']
+np_dep = declare_dependency(include_directories: inc_np, compile_args: numpy_nodepr_api)
 
-# TODO: pyoptsparse supports numpy>=1.16 but numpy.f2py.get_include() wasnt added until later, raise numpy version?
-#incdir_f2py = run_command(py3_target,
-#  [
-#    '-c',
-#    'import os; os.chdir(".."); import numpy.f2py; print(numpy.f2py.get_include())'
-#  ],
-#  check : true
-#).stdout().strip()
 incdir_f2py = incdir_numpy / '..' / '..' / 'f2py' / 'src'
 inc_f2py = include_directories(incdir_f2py)
+fortranobject_c = incdir_f2py / 'fortranobject.c'
+
+# Share this object across multiple modules.
+fortranobject_lib = static_library('_fortranobject',
+  fortranobject_c,
+  c_args: numpy_nodepr_api,
+  dependencies: py3_dep,
+  include_directories: [inc_np, inc_f2py],
+  gnu_symbol_visibility: 'hidden',
+)
+fortranobject_dep = declare_dependency(
+  link_with: fortranobject_lib,
+  include_directories: [inc_np, inc_f2py],
+)
 
-
-# TODO: this is kept in here so that when meson becomes pep517-compliant
-# we can uncomment these to have meson install the source files
-
-#python_sources = [
-#    '__init__.py',
-#    'pyOpt_MPI.py',
-#    'pyOpt_constraint.py',
-#    'pyOpt_error.py',
-#    'pyOpt_gradient.py',
-#    'pyOpt_history.py',
-#    'pyOpt_objective.py',
-#    'pyOpt_optimization.py',
-#    'pyOpt_optimizer.py',
-#    'pyOpt_solution.py',
-#    'pyOpt_utils.py',
-#    'pyOpt_variable.py',
-#    'types.py'
-#]
-
-#py3_target.install_sources(
-#  python_sources,
-#  pure: true,
-#  subdir: 'pyoptsparse'
-#)
+# --!>
 
 subdir('pySNOPT')
 subdir('pySLSQP')
 subdir('pyCONMIN')
 subdir('pyNLPQLP')
 subdir('pyNSGA2')
 subdir('pyPSQP')
-#subdir('pyALPSO')
-#subdir('pyParOpt')
-#subdir('postprocessing')
-
-# test imports
-# envdata = environment()
-# python_paths = [join_paths(meson.current_build_dir(), '..')]
-# envdata.prepend('PYTHONPATH', python_paths)
-
-# progs = [['SLSQP',  'pySLSQP',  'slsqp'],
-#          ['CONMIN', 'pyCONMIN', 'conmin'],
-#          ['PSQP',   'pyPSQP',   'psqp'],
-#          ['NSGA2',  'pyNSGA2',  'nsga2']]
-
 
-# foreach p : progs
-#   import_command = 'from pyoptsparse.' + p[1] + ' import '+p[2]+'; print('+p[2]+'.__file__)'
-#   test(
-#     'import test for '+p[0],
-#     py3_command,
-#     args: ['-c', import_command],
-#     env: envdata
-#   )
-# endforeach

pyoptsparse/pyCONMIN/meson.build

@@ -2,11 +2,11 @@ conmin_source = custom_target('conminmodule.c',
                             input : ['source/f2py/conmin.pyf',
                                     ],
                             output : ['conminmodule.c', 'conmin-f2pywrappers.f'],
-                            command: [py3_command, '-m', 'numpy.f2py', '@INPUT@',
+                            command: [py3, '-m', 'numpy.f2py', '@INPUT@',
                             '--lower', '--build-dir', 'pyoptsparse/pyCONMIN']
                             )
 
-py3_target.extension_module('conmin',
+py3.extension_module('conmin',
                     'source/openunit.f',
                     'source/cnmn00.f',
                     'source/cnmn01.f',
@@ -21,21 +21,7 @@ py3_target.extension_module('conmin',
                     'source/conmin.f',
                     'source/closeunit.f',
                 conmin_source,
-                fortranobject_c,
-                include_directories: [inc_np, inc_f2py],
-                dependencies : py3_dep,
+                dependencies: [fortranobject_dep],
                 subdir: 'pyoptsparse/pyCONMIN',
-                install : false,
+                install: true,
                 build_rpath: '')
-
-#python_sources = [
-#    '__init__.py',
-#    'pyCONMIN.py',
-#    'LICENSE'
-#]
-#
-#py3_target.install_sources(
-#  python_sources,
-#  pure: false,
-#  subdir: 'pyoptsparse/pyCONMIN'
-#)

pyoptsparse/pyNLPQLP/meson.build

@@ -11,11 +11,11 @@ if HAS_NLPQLP
   nlpqlp_source = custom_target('nlpqlpmodule.c',
     input : ['source/f2py/nlpqlp.pyf'],
     output : ['nlpqlpmodule.c'],
-    command: [py3_command, '-m', 'numpy.f2py', '@INPUT@',
+    command: [py3, '-m', 'numpy.f2py', '@INPUT@',
     '--lower', '--build-dir', 'pyoptsparse/pyNLPQLP']
   )
 
-  py3_target.extension_module('nlpqlp',
+  py3.extension_module('nlpqlp',
     'source/wrapper.F90',
     'source/NLPQLP.F',
     'source/QL.F',
@@ -24,18 +24,6 @@ if HAS_NLPQLP
     include_directories: [inc_np, inc_f2py],
     dependencies : py3_dep,
     subdir: 'pyoptsparse/pyNLPQLP',
-    install : false
+    install: true
   )
 endif
-
-#python_sources = [
-#    '__init__.py',
-#    'pyNLPQLP.py',
-#    'LICENSE'
-#]
-#
-#py3_target.install_sources(
-#  python_sources,
-#  pure: false,
-#  subdir: 'pyoptsparse/pyNLPQLP'
-#)

pyoptsparse/pyNSGA2/meson.build

@@ -7,7 +7,7 @@ if swig.found()
                                 command: ['swig', '-o', 'pyoptsparse/pyNSGA2/nsga2_wrap.c', '-python', '-interface', 'nsga2', '@INPUT@']
                                 )
 
-    py3_target.extension_module('nsga2',
+    py3.extension_module('nsga2',
                     'source/allocate.c',
                     'source/auxiliary.c',
                     'source/crossover.c',
@@ -31,19 +31,7 @@ if swig.found()
                     dependencies : py3_dep,
                     subdir: 'pyoptsparse/pyNSGA2',
                     link_language: 'c',
-                    install : false)
+                    install: true)
 else
     message('SWIG was not found, therefore NSGA2 will not be built.')
 endif
-
-#python_sources = [
-#    '__init__.py',
-#    'pyNSGA2.py',
-#    'LICENSE'
-#]
-#
-#py3_target.install_sources(
-#  python_sources,
-#  pure: false,
-#  subdir: 'pyoptsparse/pyNSGA2'
-#)