Substitute output file then check for conflict.

Fixes Issue #4323.
The check to see if a call to configure_file() overwrites the output of
a preceding call should perform the substitution for the output file
before doing the check.

Added tests to ensure the proper behaviour.

1 files changed, 5 insertions, 5 deletions

diff --git a/mesonbuild/interpreter.py b/mesonbuild/interpreter.py
index c05b92a..cf94fe5 100644
--- a/mesonbuild/interpreter.py
+++ b/mesonbuild/interpreter.py
@@ -3540,9 +3540,13 @@ root and issuing %s.
             raise InterpreterException('@INPUT@ used as command argument, but no input file specified.')
         # Validate output
         output = kwargs['output']
-        ofile_rpath = os.path.join(self.subdir, output)
         if not isinstance(output, str):
             raise InterpreterException('Output file name must be a string')
+        if ifile_abs:
+            values = mesonlib.get_filenames_templates_dict([ifile_abs], None)
+            outputs = mesonlib.substitute_values([output], values)
+            output = outputs[0]
+        ofile_rpath = os.path.join(self.subdir, output)
         if ofile_rpath in self.configure_file_outputs:
             mesonbuildfile = os.path.join(self.subdir, 'meson.build')
             current_call = "{}:{}".format(mesonbuildfile, self.current_lineno)
@@ -3550,10 +3554,6 @@ root and issuing %s.
             mlog.warning('Output file', mlog.bold(ofile_rpath, True), 'for configure_file() at', current_call, 'overwrites configure_file() output at', first_call)
         else:
             self.configure_file_outputs[ofile_rpath] = self.current_lineno
-        if ifile_abs:
-            values = mesonlib.get_filenames_templates_dict([ifile_abs], None)
-            outputs = mesonlib.substitute_values([output], values)
-            output = outputs[0]
         if os.path.dirname(output) != '':
             raise InterpreterException('Output file name must not contain a subdirectory.')
         (ofile_path, ofile_fname) = os.path.split(os.path.join(self.subdir, output))