1# Copyright 2013 The Chromium Authors. All rights reserved. 2# Use of this source code is governed by a BSD-style license that can be 3# found in the LICENSE file. 4 5"""Top-level presubmit script for Chromium media component. 6 7See http://dev.chromium.org/developers/how-tos/depottools/presubmit-scripts 8for more details about the presubmit API built into gcl. 9""" 10 11def _FilterFile(affected_file): 12 """Return true if the file could contain code requiring a presubmit check.""" 13 return affected_file.LocalPath().endswith( 14 ('.h', '.cc', '.cpp', '.cxx', '.mm')) 15 16 17def _CheckForUseOfWrongClock(input_api, output_api): 18 """Make sure new lines of media code don't use a clock susceptible to skew.""" 19 20 # Regular expression that should detect any explicit references to the 21 # base::Time type (or base::Clock/DefaultClock), whether in using decls, 22 # typedefs, or to call static methods. 23 base_time_type_pattern = r'(^|\W)base::(Time|Clock|DefaultClock)(\W|$)' 24 25 # Regular expression that should detect references to the base::Time class 26 # members, such as a call to base::Time::Now. 27 base_time_member_pattern = r'(^|\W)(Time|Clock|DefaultClock)::' 28 29 # Regular expression to detect "using base::Time" declarations. We want to 30 # prevent these from triggerring a warning. For example, it's perfectly 31 # reasonable for code to be written like this: 32 # 33 # using base::Time; 34 # ... 35 # int64 foo_us = foo_s * Time::kMicrosecondsPerSecond; 36 using_base_time_decl_pattern = r'^\s*using\s+(::)?base::Time\s*;' 37 38 # Regular expression to detect references to the kXXX constants in the 39 # base::Time class. We want to prevent these from triggerring a warning. 40 base_time_konstant_pattern = r'(^|\W)Time::k\w+' 41 42 problem_re = input_api.re.compile( 43 r'(' + base_time_type_pattern + r')|(' + base_time_member_pattern + r')') 44 exception_re = input_api.re.compile( 45 r'(' + using_base_time_decl_pattern + r')|(' + 46 base_time_konstant_pattern + r')') 47 problems = [] 48 for f in input_api.AffectedSourceFiles(_FilterFile): 49 for line_number, line in f.ChangedContents(): 50 if problem_re.search(line): 51 if not exception_re.search(line): 52 problems.append( 53 ' %s:%d\n %s' % (f.LocalPath(), line_number, line.strip())) 54 55 if problems: 56 return [output_api.PresubmitPromptOrNotify( 57 'You added one or more references to the base::Time class and/or one\n' 58 'of its member functions (or base::Clock/DefaultClock). In media\n' 59 'code, it is rarely correct to use a clock susceptible to time skew!\n' 60 'Instead, could you use base::TimeTicks to track the passage of\n' 61 'real-world time?\n\n' + 62 '\n'.join(problems))] 63 else: 64 return [] 65 66 67def _CheckForMessageLoopProxy(input_api, output_api): 68 """Make sure media code only uses MessageLoopProxy for accessing the current 69 loop.""" 70 71 message_loop_proxy_re = input_api.re.compile( 72 r'\bMessageLoopProxy(?!::current\(\))') 73 74 problems = [] 75 for f in input_api.AffectedSourceFiles(_FilterFile): 76 for line_number, line in f.ChangedContents(): 77 if message_loop_proxy_re.search(line): 78 problems.append('%s:%d' % (f.LocalPath(), line_number)) 79 80 if problems: 81 return [output_api.PresubmitError( 82 'MessageLoopProxy should only be used for accessing the current loop.\n' 83 'Use the TaskRunner interfaces instead as they are more explicit about\n' 84 'the run-time characteristics. In most cases, SingleThreadTaskRunner\n' 85 'is a drop-in replacement for MessageLoopProxy.', problems)] 86 87 return [] 88 89 90def _CheckForHistogramOffByOne(input_api, output_api): 91 """Make sure histogram enum maxes are used properly""" 92 93 # A general-purpose chunk of regex to match whitespace and/or comments 94 # that may be interspersed with the code we're interested in: 95 comment = r'/\*.*?\*/|//[^\n]*' 96 whitespace = r'(?:[\n\t ]|(?:' + comment + r'))*' 97 98 # The name is assumed to be a literal string. 99 histogram_name = r'"[^"]*"' 100 101 # This can be an arbitrary expression, so just ensure it isn't a ; to prevent 102 # matching past the end of this statement. 103 histogram_value = r'[^;]*' 104 105 # In parens so we can retrieve it for further checks. 106 histogram_max = r'([^;,]*)' 107 108 # This should match a uma histogram enumeration macro expression. 109 uma_macro_re = input_api.re.compile( 110 r'\bUMA_HISTOGRAM_ENUMERATION\(' + whitespace + histogram_name + r',' + 111 whitespace + histogram_value + r',' + whitespace + histogram_max + 112 whitespace + r'\)' + whitespace + r';(?:' + whitespace + 113 r'\/\/ (PRESUBMIT_IGNORE_UMA_MAX))?') 114 115 uma_max_re = input_api.re.compile(r'.*(?:Max|MAX).* \+ 1') 116 117 problems = [] 118 119 for f in input_api.AffectedSourceFiles(_FilterFile): 120 contents = input_api.ReadFile(f) 121 122 # We want to match across lines, but still report a line number, so we keep 123 # track of the line we're on as we search through the file. 124 line_number = 1 125 126 # We search the entire file, then check if any violations are in the changed 127 # areas, this is inefficient, but simple. A UMA_HISTOGRAM_ENUMERATION call 128 # will often span multiple lines, so finding a match looking just at the 129 # deltas line-by-line won't catch problems. 130 match = uma_macro_re.search(contents) 131 while match: 132 line_number += contents.count('\n', 0, match.start()) 133 max_arg = match.group(1) # The third argument. 134 135 if (not uma_max_re.match(max_arg) and match.group(2) != 136 'PRESUBMIT_IGNORE_UMA_MAX'): 137 uma_range = range(match.start(), match.end() + 1) 138 # Check if any part of the match is in the changed lines: 139 for num, line in f.ChangedContents(): 140 if line_number <= num <= line_number + match.group().count('\n'): 141 problems.append('%s:%d' % (f, line_number)) 142 break 143 144 # Strip off the file contents up to the end of the match and update the 145 # line number. 146 contents = contents[match.end():] 147 line_number += match.group().count('\n') 148 match = uma_macro_re.search(contents) 149 150 if problems: 151 return [output_api.PresubmitError( 152 'UMA_HISTOGRAM_ENUMERATION reports in src/media/ are expected to adhere\n' 153 'to the following guidelines:\n' 154 ' - The max value (3rd argument) should be an enum value equal to the\n' 155 ' last valid value, e.g. FOO_MAX = LAST_VALID_FOO.\n' 156 ' - 1 must be added to that max value.\n' 157 'Contact rileya@chromium.org if you have questions.' , problems)] 158 159 return [] 160 161 162def _CheckChange(input_api, output_api): 163 results = [] 164 results.extend(_CheckForUseOfWrongClock(input_api, output_api)) 165 results.extend(_CheckForMessageLoopProxy(input_api, output_api)) 166 results.extend(_CheckForHistogramOffByOne(input_api, output_api)) 167 return results 168 169 170def CheckChangeOnUpload(input_api, output_api): 171 return _CheckChange(input_api, output_api) 172 173 174def CheckChangeOnCommit(input_api, output_api): 175 return _CheckChange(input_api, output_api) 176