Add MPI dependency.

We prefer pkg-config files, though only OpenMPI supplies them.
Otherwise, check environment variables and search for wrappers and ask
them for what to do.

6 files changed, 215 insertions, 2 deletions

diff --git a/mesonbuild/dependencies/__init__.py b/mesonbuild/dependencies/__init__.py
index f153b97..fb57e3d 100644
--- a/mesonbuild/dependencies/__init__.py
+++ b/mesonbuild/dependencies/__init__.py
@@ -17,7 +17,7 @@ from .base import (  # noqa: F401
     ExternalDependency, ExternalLibrary, ExtraFrameworkDependency, InternalDependency,
     PkgConfigDependency, find_external_dependency, get_dep_identifier, packages)
 from .dev import GMockDependency, GTestDependency, LLVMDependency, ValgrindDependency
-from .misc import BoostDependency, Python3Dependency, ThreadDependency
+from .misc import (BoostDependency, MPIDependency, Python3Dependency, ThreadDependency)
 from .platform import AppleFrameworks
 from .ui import GLDependency, GnuStepDependency, Qt4Dependency, Qt5Dependency, SDL2Dependency, WxDependency, VulkanDependency
 
@@ -31,6 +31,7 @@ packages.update({
 
     # From misc:
     'boost': BoostDependency,
+    'mpi': MPIDependency,
     'python3': Python3Dependency,
     'threads': ThreadDependency,
 
diff --git a/mesonbuild/dependencies/misc.py b/mesonbuild/dependencies/misc.py
index 99df587..71f7369 100644
--- a/mesonbuild/dependencies/misc.py
+++ b/mesonbuild/dependencies/misc.py
@@ -16,6 +16,8 @@
 
 import glob
 import os
+import re
+import shlex
 import stat
 import sysconfig
 
@@ -24,7 +26,7 @@ from .. import mesonlib
 from ..environment import detect_cpu_family
 
 from .base import DependencyException, DependencyMethods
-from .base import ExternalDependency, ExtraFrameworkDependency, PkgConfigDependency
+from .base import ExternalDependency, ExternalProgram, ExtraFrameworkDependency, PkgConfigDependency
 
 
 class BoostDependency(ExternalDependency):
@@ -277,6 +279,133 @@ class BoostDependency(ExternalDependency):
         return 'thread' in self.requested_modules
 
 
+class MPIDependency(ExternalDependency):
+    def __init__(self, environment, kwargs):
+        language = kwargs.get('language', 'c')
+        super().__init__('mpi', environment, language, kwargs)
+        required = kwargs.pop('required', True)
+        kwargs['required'] = False
+        kwargs['silent'] = True
+        self.is_found = False
+
+        # NOTE: Only OpenMPI supplies a pkg-config file at the moment.
+        if language == 'c':
+            env_vars = ['MPICC']
+            pkgconfig_files = ['ompi-c']
+            default_wrappers = ['mpicc']
+        elif language == 'cpp':
+            env_vars = ['MPICXX']
+            pkgconfig_files = ['ompi-cxx']
+            default_wrappers = ['mpic++', 'mpicxx', 'mpiCC']
+        elif language == 'fortran':
+            env_vars = ['MPIFC', 'MPIF90', 'MPIF77']
+            pkgconfig_files = ['ompi-fort']
+            default_wrappers = ['mpifort', 'mpif90', 'mpif77']
+        else:
+            raise DependencyException('Language {} is not supported with MPI.'.format(language))
+
+        for pkg in pkgconfig_files:
+            try:
+                pkgdep = PkgConfigDependency(pkg, environment, kwargs)
+                if pkgdep.found():
+                    self.compile_args = pkgdep.get_compile_args()
+                    self.link_args = pkgdep.get_link_args()
+                    self.version = pkgdep.get_version()
+                    self.is_found = True
+                    break
+            except Exception:
+                pass
+
+        if not self.is_found:
+            # Prefer environment.
+            for var in env_vars:
+                if var in os.environ:
+                    wrappers = [os.environ[var]]
+                    break
+            else:
+                # Or search for default wrappers.
+                wrappers = default_wrappers
+
+            for prog in wrappers:
+                result = self._try_openmpi_wrapper(prog)
+                if result is not None:
+                    self.is_found = True
+                    self.version = result[0]
+                    self.compile_args = result[1]
+                    self.link_args = result[2]
+                    break
+                result = self._try_other_wrapper(prog)
+                if result is not None:
+                    self.is_found = True
+                    self.version = result[0]
+                    self.compile_args = result[1]
+                    self.link_args = result[2]
+                    break
+
+        if self.is_found:
+            mlog.log('Dependency', mlog.bold(self.name), 'for', self.language, 'found:', mlog.green('YES'), self.version)
+        else:
+            mlog.log('Dependency', mlog.bold(self.name), 'for', self.language, 'found:', mlog.red('NO'))
+            if required:
+                raise DependencyException('MPI dependency {!r} not found'.format(self.name))
+
+    def _try_openmpi_wrapper(self, prog):
+        prog = ExternalProgram(prog, silent=True)
+        if prog.found():
+            cmd = prog.get_command() + ['--showme:compile']
+            p, o, e = mesonlib.Popen_safe(cmd)
+            p.wait()
+            if p.returncode != 0:
+                mlog.debug('Command', mlog.bold(cmd), 'failed to run:')
+                mlog.debug(mlog.bold('Standard output\n'), o)
+                mlog.debug(mlog.bold('Standard error\n'), e)
+                return
+            cargs = shlex.split(o)
+
+            cmd = prog.get_command() + ['--showme:link']
+            p, o, e = mesonlib.Popen_safe(cmd)
+            p.wait()
+            if p.returncode != 0:
+                mlog.debug('Command', mlog.bold(cmd), 'failed to run:')
+                mlog.debug(mlog.bold('Standard output\n'), o)
+                mlog.debug(mlog.bold('Standard error\n'), e)
+                return
+            libs = shlex.split(o)
+
+            cmd = prog.get_command() + ['--showme:version']
+            p, o, e = mesonlib.Popen_safe(cmd)
+            p.wait()
+            if p.returncode != 0:
+                mlog.debug('Command', mlog.bold(cmd), 'failed to run:')
+                mlog.debug(mlog.bold('Standard output\n'), o)
+                mlog.debug(mlog.bold('Standard error\n'), e)
+                return
+            version = re.search('\d+.\d+.\d+', o)
+            if version:
+                version = version.group(0)
+            else:
+                version = 'none'
+
+            return version, cargs, libs
+
+    def _try_other_wrapper(self, prog):
+        prog = ExternalProgram(prog, silent=True)
+        if prog.found():
+            cmd = prog.get_command() + ['-show']
+            p, o, e = mesonlib.Popen_safe(cmd)
+            p.wait()
+            if p.returncode != 0:
+                mlog.debug('Command', mlog.bold(cmd), 'failed to run:')
+                mlog.debug(mlog.bold('Standard output\n'), o)
+                mlog.debug(mlog.bold('Standard error\n'), e)
+                return
+            args = shlex.split(o)
+
+            version = 'none'
+
+            return version, args, args
+
+
 class ThreadDependency(ExternalDependency):
     def __init__(self, environment, kwargs):
         super().__init__('threads', environment, None, {})
diff --git a/test cases/common/157 mpi/main.c b/test cases/common/157 mpi/main.c
new file mode 100644
index 0000000..e44357a
--- /dev/null
+++ b/test cases/common/157 mpi/main.c
@@ -0,0 +1,27 @@
+#include <stdio.h>
+#include <mpi.h>
+
+int main(int argc, char **argv)
+{
+    int ier, flag;
+    ier = MPI_Init(&argc, &argv);
+    if (ier) {
+        printf("Unable to initialize MPI: %d\n", ier);
+        return 1;
+    }
+    ier = MPI_Initialized(&flag);
+    if (ier) {
+        printf("Unable to check MPI initialization state: %d\n", ier);
+        return 1;
+    }
+    if (!flag) {
+        printf("MPI did not initialize!\n");
+        return 1;
+    }
+    ier = MPI_Finalize();
+    if (ier) {
+        printf("Unable to finalize MPI: %d\n", ier);
+        return 1;
+    }
+    return 0;
+}
diff --git a/test cases/common/157 mpi/main.cpp b/test cases/common/157 mpi/main.cpp
new file mode 100644
index 0000000..0e0b621
--- /dev/null
+++ b/test cases/common/157 mpi/main.cpp
@@ -0,0 +1,11 @@
+#include <mpi.h>
+
+int main(int argc, char **argv)
+{
+    MPI::Init(argc, argv);
+    if (!MPI::Is_initialized()) {
+        printf("MPI did not initialize!\n");
+        return 1;
+    }
+    MPI::Finalize();
+}
diff --git a/test cases/common/157 mpi/main.f90 b/test cases/common/157 mpi/main.f90
new file mode 100644
index 0000000..d379e96
--- /dev/null
+++ b/test cases/common/157 mpi/main.f90
@@ -0,0 +1,21 @@
+program mpitest
+  implicit none
+  include 'mpif.h'
+  logical :: flag
+  integer :: ier
+  call MPI_Init(ier)
+  if (ier /= 0) then
+    print *, 'Unable to initialize MPI: ', ier
+    stop 1
+  endif
+  call MPI_Initialized(flag, ier)
+  if (ier /= 0) then
+    print *, 'Unable to check MPI initialization state: ', ier
+    stop 1
+  endif
+  call MPI_Finalize(ier)
+  if (ier /= 0) then
+    print *, 'Unable to finalize MPI: ', ier
+    stop 1
+  endif
+end program mpitest
diff --git a/test cases/common/157 mpi/meson.build b/test cases/common/157 mpi/meson.build
new file mode 100644
index 0000000..f36b039
--- /dev/null
+++ b/test cases/common/157 mpi/meson.build
@@ -0,0 +1,24 @@
+project('mpi', 'c', 'cpp')
+
+mpic = dependency('mpi', language : 'c')
+exec = executable('exec',
+  'main.c',
+  dependencies : [mpic])
+
+test('MPI C', exec)
+
+mpicpp = dependency('mpi', language : 'cpp')
+execpp = executable('execpp',
+  'main.cpp',
+  dependencies : [mpicpp])
+
+test('MPI C++', execpp)
+
+if add_languages('fortran', required : false)
+  mpifort = dependency('mpi', language : 'fortran')
+  exef = executable('exef',
+    'main.f90',
+    dependencies : [mpifort])
+
+  test('MPI Fortran', exef)
+endif