Fix coverage-xml and coverage-text targets for gcovr >= 3.1

In gcovr 3.1 the -r/--rootdir argument changed meaning causing
reports generated with gcovr 3.1 to not find the source files
and look for *.gcda in the whole source tree rather than the
build dir.

So, detect gcovr version and if 3.1 give build_root to -r instead
of source_root.

1 files changed, 8 insertions, 3 deletions

diff --git a/mesonbuild/scripts/coverage.py b/mesonbuild/scripts/coverage.py
index 47f4cda..4746134 100644
--- a/mesonbuild/scripts/coverage.py
+++ b/mesonbuild/scripts/coverage.py
@@ -17,15 +17,20 @@ from mesonbuild import environment
 import sys, os, subprocess, pathlib
 
 def coverage(source_root, build_root, log_dir):
-    (gcovr_exe, lcov_exe, genhtml_exe) = environment.find_coverage_tools()
+    (gcovr_exe, gcovr_3_1, lcov_exe, genhtml_exe) = environment.find_coverage_tools()
     if gcovr_exe:
+        # gcovr >= 3.1 interprets rootdir differently
+        if gcovr_3_1:
+            rootdir = build_root
+        else:
+            rootdir = source_root
         subprocess.check_call([gcovr_exe,
                                '-x',
-                               '-r', source_root,
+                               '-r', rootdir,
                                '-o', os.path.join(log_dir, 'coverage.xml'),
                                ])
         subprocess.check_call([gcovr_exe,
-                               '-r', source_root,
+                               '-r', rootdir,
                                '-o', os.path.join(log_dir, 'coverage.txt'),
                                ])
     if lcov_exe and genhtml_exe: