Revert "mesonlib: handle meson exe wrappers"

This reverts commit 0627e9d.

Breaks installation: mesonbuild#3647

Will be restored once that can be fixed.

meson.py

@@ -15,7 +15,12 @@
 # limitations under the License.
 
 from mesonbuild import mesonmain
-import sys
+import sys, os
+
+def main():
+    # Always resolve the command path so Ninja can find it for regen, tests, etc.
+    launcher = os.path.realpath(sys.argv[0])
+    return mesonmain.run(sys.argv[1:], launcher)
 
 if __name__ == '__main__':
-    sys.exit(mesonmain.main())
+    sys.exit(main())

mesonbuild/mesonlib.py

@@ -38,12 +38,58 @@
 
 from glob import glob
 
+def detect_meson_py_location():
+    c = sys.argv[0]
+    c_dir, c_fname = os.path.split(c)
+
+    # get the absolute path to the <mesontool> folder
+    m_dir = None
+    if os.path.isabs(c):
+        # $ /foo/<mesontool>.py <args>
+        m_dir = c_dir
+    elif c_dir == '':
+        # $ <mesontool> <args> (gets run from /usr/bin/<mesontool>)
+        in_path_exe = shutil.which(c_fname)
+        if in_path_exe:
+            if not os.path.isabs(in_path_exe):
+                m_dir = os.getcwd()
+                c_fname = in_path_exe
+            else:
+                m_dir, c_fname = os.path.split(in_path_exe)
+    else:
+        m_dir = os.path.abspath(c_dir)
+
+    # find meson in m_dir
+    if m_dir is not None:
+        for fname in ['meson', 'meson.py']:
+            m_path = os.path.join(m_dir, fname)
+            if os.path.exists(m_path):
+                return m_path
+
+    # No meson found, which means that either:
+    # a) meson is not installed
+    # b) meson is installed to a non-standard location
+    # c) the script that invoked mesonlib is not the one of meson tools (e.g. run_unittests.py)
+    fname = os.path.normpath(os.path.join(os.path.dirname(__file__), '..', 'meson.py'))
+    if os.path.exists(fname):
+        return fname
+    # If meson is still not found, we might be imported by out-of-source tests
+    # https://github.com/mesonbuild/meson/issues/3015
+    exe = shutil.which('meson')
+    if exe is None:
+        exe = shutil.which('meson.py')
+    if exe is not None:
+        return exe
+    # Give up.
+    raise RuntimeError('Could not determine how to run Meson. Please file a bug with details.')
+
 if os.path.basename(sys.executable) == 'meson.exe':
     # In Windows and using the MSI installed executable.
+    meson_command = [sys.executable]
     python_command = [sys.executable, 'runpython']
 else:
     python_command = [sys.executable]
-meson_command = python_command + ['-m', 'mesonbuild.mesonmain']
+    meson_command = python_command + [detect_meson_py_location()]
 
 def is_ascii_string(astring):
     try:

mesonbuild/mesonmain.py

@@ -382,11 +382,3 @@ def run(original_args, mainfile=None):
         mlog.shutdown()
 
     return 0
-
-def main():
-    # Always resolve the command path so Ninja can find it for regen, tests, etc.
-    launcher = os.path.realpath(sys.argv[0])
-    return run(sys.argv[1:], launcher)
-
-if __name__ == '__main__':
-    sys.exit(main())

run_cross_test.py

@@ -28,7 +28,6 @@
 
 from run_project_tests import gather_tests, run_tests, StopException, setup_commands
 from run_project_tests import failing_logs
-from run_tests import setup_pythonpath
 
 def runtests(cross_file):
     commontests = [('common', gather_tests(Path('test cases', 'common')), False)]
@@ -47,6 +46,5 @@ def runtests(cross_file):
 
 if __name__ == '__main__':
     setup_commands('ninja')
-    setup_pythonpath()
     cross_file = sys.argv[1]
     runtests(cross_file)

run_project_tests.py

@@ -41,7 +41,7 @@
 from run_unittests import get_fake_options, run_configure
 
 from run_tests import get_backend_commands, get_backend_args_for_dir, Backend
-from run_tests import ensure_backend_detects_changes, setup_pythonpath
+from run_tests import ensure_backend_detects_changes
 
 
 class BuildStep(Enum):
@@ -88,6 +88,12 @@ def __exit__(self, _type, value, traceback):
 
 system_compiler = None
 
+meson_command = os.path.join(os.getcwd(), 'meson')
+if not os.path.exists(meson_command):
+    meson_command += '.py'
+    if not os.path.exists(meson_command):
+        raise RuntimeError('Could not find main Meson script to run.')
+
 class StopException(Exception):
     def __init__(self):
         super().__init__('Stopped by user')
@@ -318,7 +324,7 @@ def _run_test(testdir, test_build_dir, install_dir, extra_args, compiler, backen
     if pass_libdir_to_test(testdir):
         gen_args += ['--libdir', 'lib']
     gen_args += [testdir, test_build_dir] + flags + test_args + extra_args
-    (returncode, stdo, stde) = run_configure(mesonlib.meson_command, gen_args)
+    (returncode, stdo, stde) = run_configure(meson_command, gen_args)
     try:
         logfile = Path(test_build_dir, 'meson-logs', 'meson-log.txt')
         mesonlog = logfile.open(errors='ignore', encoding='utf-8').read()
@@ -641,7 +647,7 @@ def check_format():
                 check_file(fullname)
 
 def check_meson_commands_work():
-    global backend, compile_commands, test_commands, install_commands
+    global backend, meson_command, compile_commands, test_commands, install_commands
     testdir = PurePath('test cases', 'common', '1 trivial').as_posix()
     with AutoDeletedDir(tempfile.mkdtemp(prefix='b ', dir='.')) as build_dir:
         print('Checking that configuring works...')
@@ -686,7 +692,6 @@ def detect_system_compiler():
     setup_commands(options.backend)
 
     detect_system_compiler()
-    setup_pythonpath()
     script_dir = os.path.split(__file__)[0]
     if script_dir != '':
         os.chdir(script_dir)

run_tests.py

@@ -42,28 +42,6 @@
 else:
     exe_suffix = ''
 
-def setup_pythonpath():
-    # Make sure python can import mesonbuild, even if we change directories as
-    # some tests do. Since sys.path is the final product of fairly complex code
-    # in site.py, it's hard to tell where each entry came from just by looking
-    # at sys.path, so we don't know if a given entry was set from a relative or
-    # absolute path. If an entry was set from a relative path, it won't
-    # continue to work if we change directories.  Instead of trying to guess
-    # where a given entry came from, just add the known-good mesonbuild to
-    # PYTHONPATH so that it will continue to be importable from other
-    # directories.
-    import mesonbuild
-    meson_dir = os.path.dirname(os.path.abspath(mesonbuild.__file__))
-    meson_root = os.path.realpath(os.path.join(meson_dir, os.pardir))
-    try:
-        python_path = os.environ['PYTHONPATH']
-    except KeyError:
-        python_path = meson_root
-    else:
-        paths = python_path.split(os.pathsep) + [meson_root]
-        python_path = os.pathsep.join(paths)
-    os.environ['PYTHONPATH'] = python_path
-
 def get_backend_args_for_dir(backend, builddir):
     '''
     Visual Studio backend needs to be given the solution to build

run_unittests.py

@@ -47,7 +47,7 @@
 from run_tests import exe_suffix, get_fake_options
 from run_tests import get_builddir_target_args, get_backend_commands, Backend
 from run_tests import ensure_backend_detects_changes, run_configure, meson_exe
-from run_tests import should_run_linux_cross_tests, setup_pythonpath
+from run_tests import should_run_linux_cross_tests
 
 
 def get_dynamic_section_entry(fname, entry):
@@ -3313,7 +3313,6 @@ def unset_envs():
 
 if __name__ == '__main__':
     unset_envs()
-    setup_pythonpath()
     cases = ['InternalTests', 'AllPlatformTests', 'FailureTests', 'PythonTests']
     if not is_windows():
         cases += ['LinuxlikeTests']