[utils] Delete the 'check-coverage-regressions' script

In practice, it's way too noisy.

It's also a maintenance burden, since we apparently can't add tests for
it without breaking some Windows setups (see: D22692).

llvm-svn: 281871

utils/check-coverage-regressions.py

@@ -1,139 +0,0 @@
-#!/usr/bin/env python
-
-'''Compare two coverage summaries for regressions.
-
-You can create a coverage summary by using the `llvm-cov report` command.
-Alternatively, you can use `utils/prepare-code-coverage-artifact.py` which
-creates summaries as well as file-based html reports.
-'''
-
-from __future__ import print_function
-
-import argparse
-import collections
-import re
-import sys
-
-# This threshold must be in [0, 1]. The lower the threshold, the less likely
-# it is that a regression will be flagged and vice versa.
-kThresh = 1.0
-
-FileCoverage = collections.namedtuple('FileCoverage',
-        ['Regions', 'MissedRegions', 'RegionCoverage',
-         'Functions', 'MissedFunctions', 'Executed',
-         'Lines', 'MissedLines', 'LineCoverage'])
-
-CoverageEntry = re.compile(r'^(.*)'
-                           r' +(\d+) +(\d+) +([\d.]+)%'
-                           r' +(\d+) +(\d+) +([\d.]+)%'
-                           r' +(\d+) +(\d+) +([\d.]+)%$')
-
-def parse_file_coverage_line(line):
-    '''Parse @line as a summary of a file's coverage information.
-
-    >>> parse_file_coverage_line('report.cpp 5 2 60.00% 4 1 75.00% 13 4 69.23%')
-    ('report.cpp', FileCoverage(\
-Regions=5, MissedRegions=2, RegionCoverage=60.0, \
-Functions=4, MissedFunctions=1, Executed=75.0, \
-Lines=13, MissedLines=4, LineCoverage=69.23))
-    '''
-
-    m = re.match(CoverageEntry, line)
-    if not m:
-        print("Could not read coverage summary:", line)
-        exit(1)
-
-    groups = m.groups()
-    filename = groups[0].strip()
-    regions = int(groups[1])
-    missed_regions = int(groups[2])
-    region_coverage = float(groups[3])
-    functions = int(groups[4])
-    missed_functions = int(groups[5])
-    executed = float(groups[6])
-    lines = int(groups[7])
-    missed_lines = int(groups[8])
-    line_coverage = float(groups[9])
-    return (filename,
-            FileCoverage(regions, missed_regions, region_coverage,
-                         functions, missed_functions, executed,
-                         lines, missed_lines, line_coverage))
-
-def parse_summary(path):
-    '''Parse the summary at @path. Return a dictionary mapping filenames to
-       FileCoverage instances.'''
-
-    with open(path, 'r') as f:
-        lines = f.readlines()
-
-    # Drop the header and the cell dividers. Include "TOTAL" in this list.
-    file_coverages = lines[2:-2] + [lines[-1]]
-
-    summary = {}
-    for line in file_coverages:
-        filename, fc = parse_file_coverage_line(line)
-        summary[filename] = fc
-    return summary
-
-def find_coverage_regressions(old_coverage, new_coverage):
-    '''Given two coverage summaries, generate coverage regressions of the form:
-       (filename, old FileCoverage, new FileCoverage).'''
-
-    for filename in old_coverage.keys():
-        if filename not in new_coverage:
-            continue
-
-        old_fc = old_coverage[filename]
-        new_fc = new_coverage[filename]
-        if new_fc.RegionCoverage < kThresh * old_fc.RegionCoverage or \
-                new_fc.Executed < kThresh * old_fc.Executed:
-            yield (filename, old_fc, new_fc)
-
-def print_regression(filename, old_fc, new_fc):
-    '''Pretty-print a coverage regression in @filename. @old_fc is the old
-       FileCoverage and @new_fc is the new one.
-
-    >>> print_regression('foo.cpp', \
-                         FileCoverage(10, 5, 50.0, 10, 10, 0, 20, 10, 50.0), \
-                         FileCoverage(10, 7, 30.0, 10, 10, 0, 20, 14, 30.0))
-    Code coverage regression:
-      File: foo.cpp
-      Change in function coverage: 0.00% (0/10 -> 0/10)
-      Change in line coverage    : -20.00% (10/20 -> 6/20)
-      Change in region coverage  : -20.00% (5/10 -> 3/10)
-    '''
-
-    func_coverage_delta = new_fc.Executed - old_fc.Executed
-    line_coverage_delta = new_fc.LineCoverage - old_fc.LineCoverage
-    region_coverage_delta = new_fc.RegionCoverage - old_fc.RegionCoverage
-    print("Code coverage regression:")
-    print("  File:", filename)
-    print("  Change in function coverage: {0:.2f}% ({1}/{2} -> {3}/{4})".format(
-        func_coverage_delta, old_fc.Functions - old_fc.MissedFunctions,
-        old_fc.Functions, new_fc.Functions - new_fc.MissedFunctions,
-        new_fc.Functions))
-    print("  Change in line coverage    : {0:.2f}% ({1}/{2} -> {3}/{4})".format(
-        line_coverage_delta, old_fc.Lines - old_fc.MissedLines, old_fc.Lines,
-        new_fc.Lines - new_fc.MissedLines, new_fc.Lines))
-    print("  Change in region coverage  : {0:.2f}% ({1}/{2} -> {3}/{4})".format(
-        region_coverage_delta, old_fc.Regions - old_fc.MissedRegions,
-        old_fc.Regions, new_fc.Regions - new_fc.MissedRegions, new_fc.Regions))
-
-if __name__ == '__main__':
-    parser = argparse.ArgumentParser(description=__doc__)
-    parser.add_argument('old_summary', help='Path to the old coverage summary')
-    parser.add_argument('new_summary', help='Path to the new coverage summary')
-    args = parser.parse_args()
-
-    old_coverage = parse_summary(args.old_summary)
-    new_coverage = parse_summary(args.new_summary)
-
-    num_regressions = 0
-    for filename, old_fc, new_fc in \
-            find_coverage_regressions(old_coverage, new_coverage):
-        print_regression(filename, old_fc, new_fc)
-        num_regressions += 1
-
-    if num_regressions > 0:
-        exit(1)
-    exit(0)