ceph/src/rocksdb/coverage/parse_gcov_output.py

   1 import optparse
   2 import re
   3 import sys
   4
   5 from optparse import OptionParser
   6
   7 # the gcov report follows certain pattern. Each file will have two lines
   8 # of report, from which we can extract the file name, total lines and coverage
   9 # percentage.
  10 def parse_gcov_report(gcov_input):
  11     per_file_coverage = {}
  12     total_coverage = None
  13
  14     for line in sys.stdin:
  15         line = line.strip()
  16
  17         # --First line of the coverage report (with file name in it)?
  18         match_obj = re.match("^File '(.*)'$", line)
  19         if match_obj:
  20             # fetch the file name from the first line of the report.
  21             current_file = match_obj.group(1)
  22             continue
  23
  24         # -- Second line of the file report (with coverage percentage)
  25         match_obj = re.match("^Lines executed:(.*)% of (.*)", line)
  26
  27         if match_obj:
  28             coverage = float(match_obj.group(1))
  29             lines = int(match_obj.group(2))
  30
  31             if current_file is not None:
  32                 per_file_coverage[current_file] = (coverage, lines)
  33                 current_file = None
  34             else:
  35                 # If current_file is not set, we reach the last line of report,
  36                 # which contains the summarized coverage percentage.
  37                 total_coverage = (coverage, lines)
  38             continue
  39
  40         # If the line's pattern doesn't fall into the above categories. We
  41         # can simply ignore them since they're either empty line or doesn't
  42         # find executable lines of the given file.
  43         current_file = None
  44
  45     return per_file_coverage, total_coverage
  46
  47 def get_option_parser():
  48     usage = "Parse the gcov output and generate more human-readable code " +\
  49             "coverage report."
  50     parser = OptionParser(usage)
  51
  52     parser.add_option(
  53         "--interested-files", "-i",
  54         dest="filenames",
  55         help="Comma separated files names. if specified, we will display " +
  56              "the coverage report only for interested source files. " +
  57              "Otherwise we will display the coverage report for all " +
  58              "source files."
  59     )
  60     return parser
  61
  62 def display_file_coverage(per_file_coverage, total_coverage):
  63     # To print out auto-adjustable column, we need to know the longest
  64     # length of file names.
  65     max_file_name_length = max(
  66         len(fname) for fname in per_file_coverage.keys()
  67     )
  68
  69     # -- Print header
  70     # size of separator is determined by 3 column sizes:
  71     # file name, coverage percentage and lines.
  72     header_template = \
  73         "%" + str(max_file_name_length) + "s\t%s\t%s"
  74     separator = "-" * (max_file_name_length + 10 + 20)
  75     print header_template % ("Filename", "Coverage", "Lines")
  76     print separator
  77
  78     # -- Print body
  79     # template for printing coverage report for each file.
  80     record_template = "%" + str(max_file_name_length) + "s\t%5.2f%%\t%10d"
  81
  82     for fname, coverage_info in per_file_coverage.items():
  83         coverage, lines = coverage_info
  84         print record_template % (fname, coverage, lines)
  85
  86     # -- Print footer
  87     if total_coverage:
  88         print separator
  89         print record_template % ("Total", total_coverage[0], total_coverage[1])
  90
  91 def report_coverage():
  92     parser = get_option_parser()
  93     (options, args) = parser.parse_args()
  94
  95     interested_files = set()
  96     if options.filenames is not None:
  97         interested_files = set(f.strip() for f in options.filenames.split(','))
  98
  99     # To make things simple, right now we only read gcov report from the input
 100     per_file_coverage, total_coverage = parse_gcov_report(sys.stdin)
 101
 102     # Check if we need to display coverage info for interested files.
 103     if len(interested_files):
 104         per_file_coverage = dict(
 105             (fname, per_file_coverage[fname]) for fname in interested_files
 106             if fname in per_file_coverage
 107         )
 108         # If we only interested in several files, it makes no sense to report
 109         # the total_coverage
 110         total_coverage = None
 111
 112     if not len(per_file_coverage):
 113         print >> sys.stderr, "Cannot find coverage info for the given files."
 114         return
 115     display_file_coverage(per_file_coverage, total_coverage)
 116
 117 if __name__ == "__main__":
 118     report_coverage()