configure_file: Add a new action 'copy'

This will copy the file to the build directory without trying to read
it or substitute values into it.

Also do this optimization if the configuration_data() object passed to
the `configuration:` kwarg is empty, and print a warning about it.

See also: https://github.com/mesonbuild/meson/issues/1542

mesonbuild/interpreter.py

@@ -1665,7 +1665,7 @@ permitted_kwargs = {'add_global_arguments': {'language'},
                     'add_test_setup': {'exe_wrapper', 'gdb', 'timeout_multiplier', 'env'},
                     'benchmark': {'args', 'env', 'should_fail', 'timeout', 'workdir', 'suite'},
                     'build_target': known_build_target_kwargs,
-                    'configure_file': {'input', 'output', 'configuration', 'command', 'install_dir', 'capture', 'install', 'format'},
+                    'configure_file': {'input', 'output', 'configuration', 'command', 'copy', 'install_dir', 'capture', 'install', 'format'},
                     'custom_target': {'input', 'output', 'command', 'install', 'install_dir', 'build_always', 'capture', 'depends', 'depend_files', 'depfile', 'build_by_default'},
                     'dependency': {'default_options', 'fallback', 'language', 'main', 'method', 'modules', 'optional_modules', 'native', 'required', 'static', 'version'},
                     'declare_dependency': {'include_directories', 'link_with', 'sources', 'dependencies', 'compile_args', 'link_args', 'link_whole', 'version'},
@@ -3126,10 +3126,19 @@ root and issuing %s.
             raise InterpreterException("configure_file takes only keyword arguments.")
         if 'output' not in kwargs:
             raise InterpreterException('Required keyword argument "output" not defined.')
-        if 'configuration' in kwargs and 'command' in kwargs:
-            raise InterpreterException('Must not specify both "configuration" '
-                                       'and "command" keyword arguments since '
-                                       'they are mutually exclusive.')
+        actions = set(['configuration', 'command', 'copy']).intersection(kwargs.keys())
+        if len(actions) == 0:
+            raise InterpreterException('Must specify an action with one of these '
+                                       'keyword arguments: \'configuration\', '
+                                       '\'command\', or \'copy\'.')
+        elif len(actions) == 2:
+            raise InterpreterException('Must not specify both {!r} and {!r} '
+                                       'keyword arguments since they are '
+                                       'mutually exclusive.'.format(*actions))
+        elif len(actions) == 3:
+            raise InterpreterException('Must specify one of {!r}, {!r}, and '
+                                       '{!r} keyword arguments since they are '
+                                       'mutually exclusive.'.format(*actions))
         if 'capture' in kwargs:
             if not isinstance(kwargs['capture'], bool):
                 raise InterpreterException('"capture" keyword must be a boolean.')
@@ -3177,6 +3186,20 @@ root and issuing %s.
             raise InterpreterException('Output file name must not contain a subdirectory.')
         (ofile_path, ofile_fname) = os.path.split(os.path.join(self.subdir, output))
         ofile_abs = os.path.join(self.environment.build_dir, ofile_path, ofile_fname)
+        # Optimize copies by not doing substitution if there's nothing to
+        # substitute, and warn about this legacy hack
+        if 'configuration' in kwargs:
+            conf = kwargs['configuration']
+            if not isinstance(conf, ConfigurationDataHolder):
+                raise InterpreterException('Argument "configuration" must be of type configuration_data')
+            if ifile_abs and not conf.keys():
+                del kwargs['configuration']
+                kwargs['copy'] = True
+                mlog.warning('Got an empty configuration_data() object: '
+                             'optimizing copy automatically; if you want to '
+                             'copy a file to the build dir, use the \'copy:\' '
+                             'keyword argument added in 0.46.0', location=node)
+        # Perform the appropriate action
         if 'configuration' in kwargs:
             conf = kwargs['configuration']
             if not isinstance(conf, ConfigurationDataHolder):
@@ -3217,8 +3240,13 @@ root and issuing %s.
                 if ifile_abs:
                     shutil.copymode(ifile_abs, dst_tmp)
                 mesonlib.replace_if_different(ofile_abs, dst_tmp)
+        elif 'copy' in kwargs:
+            os.makedirs(os.path.join(self.environment.build_dir, self.subdir), exist_ok=True)
+            shutil.copyfile(ifile_abs, ofile_abs)
+            shutil.copymode(ifile_abs, ofile_abs)
         else:
-            raise InterpreterException('Configure_file must have either "configuration" or "command".')
+            # Not reachable
+            raise AssertionError
         # If the input is a source file, add it to the list of files that we
         # need to reconfigure on when they change. FIXME: Do the same for
         # files() objects in the command: kwarg.

run_unittests.py

@@ -1827,7 +1827,7 @@ int main(int argc, char **argv) {
             r'meson.build:6: WARNING: a warning of some sort',
             r'sub' + os.path.sep + r'meson.build:4: WARNING: subdir warning',
             r'meson.build:7: WARNING: Module unstable-simd has no backwards or forwards compatibility and might not exist in future releases.',
-            r"meson.build:10: WARNING: The variable(s) 'MISSING' in the input file conf.in are not present in the given configuration data.",
+            r"meson.build:11: WARNING: The variable(s) 'MISSING' in the input file conf.in are not present in the given configuration data.",
             r'meson.build:1: WARNING: Passed invalid keyword argument "invalid".',
         ]:
             self.assertRegex(out, re.escape(expected))

test cases/common/114 multiple dir configure file/meson.build

@@ -4,8 +4,8 @@ subdir('subdir')
 
 configure_file(input : 'subdir/someinput.in',
   output : 'outputhere',
-  configuration : configuration_data())
+  copy: true)
 
 configure_file(input : cfile1,
                output : '@BASENAME@',
-               configuration : configuration_data())
+               copy: true)

test cases/common/114 multiple dir configure file/subdir/meson.build

@@ -1,7 +1,7 @@
 configure_file(input : 'someinput.in',
   output : 'outputsubdir',
   install : false,
-  configuration : configuration_data())
+  copy: true)
 
 py3 = import('python3').find_python()
 

test cases/common/16 configure file/check_file.py

@@ -3,4 +3,12 @@
 import os
 import sys
 
+if len(sys.argv) == 2:
     assert(os.path.exists(sys.argv[1]))
+elif len(sys.argv) == 3:
+    f1 = open(sys.argv[1], 'rb').read()
+    f2 = open(sys.argv[2], 'rb').read()
+    if f1 != f2:
+        raise RuntimeError('{!r} != {!r}'.format(f1, f2))
+else:
+    raise AssertionError

test cases/common/16 configure file/meson.build

@@ -35,21 +35,27 @@ ofile = '@0@/config2.h'.format(meson.current_build_dir())
 
 check_file = find_program('check_file.py')
 # Configure in source root with command and absolute paths
-configure_file(input : 'dummy.dat',
+outf = configure_file(input : 'dummy.dat',
   output : 'config2.h',
   command : [genprog, scriptfile,  ifile, ofile],
   install_dir : 'share/appdir')
-run_command(check_file, join_paths(meson.current_build_dir(), 'config2.h'))
+ret = run_command(check_file, outf)
+if ret.returncode() != 0
+  error('Error running command: @0@\n@1@'.format(ret.stdout(), ret.stderr()))
+endif
 
 # Same again as before, but an input file should not be required in
 # this case where we use a command/script to generate the output file.
 genscript2b = '@0@/generator-without-input-file.py'.format(meson.current_source_dir())
 ofile2b = '@0@/config2b.h'.format(meson.current_build_dir())
-configure_file(
+outf = configure_file(
   output : 'config2b.h',
   command : [genprog, genscript2b, ofile2b],
   install_dir : 'share/appdir')
-run_command(check_file, join_paths(meson.current_build_dir(), 'config2b.h'))
+ret = run_command(check_file, outf)
+if ret.returncode() != 0
+  error('Error running command: @0@\n@1@'.format(ret.stdout(), ret.stderr()))
+endif
 
 found_script = find_program('generator.py')
 # More configure_file tests in here
@@ -149,3 +155,22 @@ configure_file(
   configuration : conf7
 )
 test('test7', executable('prog7', 'prog7.c'))
+
+# Test empty configuration data object on invalid utf8 file
+inf = 'invalid-utf8.bin.in'
+outf = configure_file(input : inf,
+  output : 'invalid-utf8.bin',
+  configuration : configuration_data())
+ret = run_command(check_file, inf, outf)
+if ret.returncode() != 0
+  error('Error running command: @0@\n@1@'.format(ret.stdout(), ret.stderr()))
+endif
+
+# Test copy of a binary file
+outf = configure_file(input : inf,
+  output : 'somebinary.bin',
+  copy : true)
+ret = run_command(check_file, inf, outf)
+if ret.returncode() != 0
+  error('Error running command: @0@\n@1@'.format(ret.stdout(), ret.stderr()))
+endif

test cases/common/27 library versions/subdir/meson.build

@@ -3,6 +3,6 @@
 # because there is no structure in the build dir.
 genlib = configure_file(input : '../lib.c',
   output : 'genlib.c',
-  configuration : configuration_data())
+  copy: true)
 shared_library('genlib', genlib,
   install : false)

test cases/common/76 configure file in custom target/src/meson.build

@@ -12,7 +12,7 @@ endif
 
 compiler = configure_file(input : 'mycompiler.py',
   output : 'mycompiler2.py',
-  configuration : configuration_data())
+  copy: true)
 
 custom_target('thing2',
 output : 'final2.dat',

test cases/failing/27 output subdir/meson.build

@@ -2,4 +2,4 @@ project('outdir path', 'c')
 
 configure_file(input : 'foo.in',
   output : 'subdir/foo',
-  configuration : configuration_data())
+  copy: true)

test cases/unit/21 warning location/meson.build

@@ -7,4 +7,5 @@ warning('a warning of some sort')
 import('unstable-simd')
 
 conf_data = configuration_data()
+conf_data.set('NOTMISSING', 1)
 configure_file(input: 'conf.in' , output: 'conf', configuration: conf_data)