twister: Check lcov exit codes

Don't ignore lcov exit codes, but instead log and return if one of the
lcov commands fails.

Signed-off-by: Jeremy Bettis <jbettis@google.com>

scripts/pylib/twister/twisterlib/coverage.py

@@ -301,28 +301,40 @@ def _generate(self, outdir, coveragelog, build_dirs=None):
                 invalid_chars = re.compile(r"[^A-Za-z0-9_]")
                 cmd.append("--test-name")
                 cmd.append(invalid_chars.sub("_", next(iter(self.instances))))
-        self.run_lcov(cmd, coveragelog)
+        ret = self.run_lcov(cmd, coveragelog)
+        if ret:
+            logger.error("LCOV capture report stage failed with %s", ret)
+            return ret, {}
 
         # We want to remove tests/* and tests/ztest/test/* but save tests/ztest
         cmd = ["--extract", coveragefile,
                os.path.join(self.base_dir, "tests", "ztest", "*"),
                "--output-file", ztestfile]
-        self.run_lcov(cmd, coveragelog)
+        ret = self.run_lcov(cmd, coveragelog)
+        if ret:
+            logger.error("LCOV extract report stage failed with %s", ret)
+            return ret, {}
 
         files = []
         if os.path.exists(ztestfile) and os.path.getsize(ztestfile) > 0:
             cmd = ["--remove", ztestfile,
                    os.path.join(self.base_dir, "tests/ztest/test/*"),
                    "--output-file", ztestfile]
-            self.run_lcov(cmd, coveragelog)
+            ret = self.run_lcov(cmd, coveragelog)
+            if ret:
+                logger.error("LCOV remove ztest report stage failed with %s", ret)
+                return ret, {}
 
             files = [coveragefile, ztestfile]
         else:
             files = [coveragefile]
 
         for i in self.ignores:
             cmd = ["--remove", coveragefile, i, "--output-file", coveragefile]
-            self.run_lcov(cmd, coveragelog)
+            ret = self.run_lcov(cmd, coveragelog)
+            if ret:
+                logger.error("LCOV remove ignores report stage failed with %s", ret)
+                return ret, {}
 
         if 'html' not in self.output_formats.split(','):
             return 0, {}
@@ -334,6 +346,8 @@ def _generate(self, outdir, coveragelog, build_dirs=None):
             cmd.append("--show-details")
         cmd += files
         ret = self.run_command(cmd, coveragelog)
+        if ret:
+            logger.error("LCOV genhtml report stage failed with %s", ret)
 
         # TODO: Add LCOV summary coverage report.
         return ret, { 'report': coveragefile, 'ztest': ztestfile, 'summary': None }