Add tests for warnings in configure_file()

Add tests to run_unittests.py to assert warnings are printed and not
printed where appropriate.

run_unittests.py

@@ -2293,6 +2293,10 @@ recommended as it is not supported on some platforms''')
         self.assertRegex(out, "WARNING:.*'FOO_BAR'.*nosubst-nocopy2.txt.in.*not present.*")
         self.assertRegex(out, "WARNING:.*'empty'.*config.h.in.*not present.*")
         self.assertRegex(out, "WARNING:.*empty configuration_data.*test.py.in")
+        # Warnings for configuration files that are overwritten.
+        self.assertRegex(out, "WARNING:.*double_output.txt.*overwrites")
+        self.assertRegex(out, "WARNING:.*subdir/double_output2.txt.*overwrites")
+        self.assertNotRegex(out, "WARNING:.*no_write_conflict.txt.*overwrites")
         # No warnings about empty configuration data objects passed to files with substitutions
         self.assertNotRegex(out, "WARNING:.*empty configuration_data.*nosubst-nocopy1.txt.in")
         self.assertNotRegex(out, "WARNING:.*empty configuration_data.*nosubst-nocopy2.txt.in")

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

@@ -193,15 +193,15 @@ configure_file(
   configuration : configuration_data()
 )
 
-# Test that passing an empty configuration_data() object to a file with
-# @FOO@ substitutions does not print the warning.
+# test that passing an empty configuration_data() object to a file with
+# @foo@ substitutions does not print the warning.
 configure_file(
   input: 'nosubst-nocopy2.txt.in',
   output: 'nosubst-nocopy2.txt',
   configuration : configuration_data()
 )
 
-# Test that passing a configured file object to test() works, and that passing
+# test that passing a configured file object to test() works, and that passing
 # an empty configuration_data() object to a file that leads to no substitutions
 # prints a warning (see unit tests)
 test_file = configure_file(
@@ -210,6 +210,25 @@ test_file = configure_file(
   configuration: configuration_data()
 )
 
+# Test that overwriting an existing file creates a warning.
+configure_file(
+  input: 'test.py.in',
+  output: 'double_output.txt',
+  configuration: conf
+)
+configure_file(
+  input: 'test.py.in',
+  output: 'double_output.txt',
+  configuration: conf
+)
+
+# Test that the same file name in a different subdir will not create a warning
+configure_file(
+  input: 'test.py.in',
+  output: 'no_write_conflict.txt',
+  configuration: conf
+)
+
 test('configure-file', test_file)
 
 cdata = configuration_data()

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

@@ -17,3 +17,22 @@ configure_file(input : '../dummy.dat',
   output : 'config2-3.h',
   command : [found_script,  '@INPUT@', '@OUTPUT@'])
 run_command(check_file, join_paths(meson.current_build_dir(), 'config2-3.h'))
+
+# Test that overwriting an existing file creates a warning.
+configure_file(
+  input: '../test.py.in',
+  output: 'double_output2.txt',
+  configuration: conf
+)
+configure_file(
+  input: '../test.py.in',
+  output: 'double_output2.txt',
+  configuration: conf
+)
+
+# Test that the same file name in a different subdir will not create a warning
+configure_file(
+  input: '../test.py.in',
+  output: 'no_write_conflict.txt',
+  configuration: conf
+)