David Brazdil | 2c27f2c | 2015-05-12 18:06:38 +0100 | [diff] [blame] | 1 | # Copyright (C) 2014 The Android Open Source Project |
| 2 | # |
| 3 | # Licensed under the Apache License, Version 2.0 (the "License"); |
| 4 | # you may not use this file except in compliance with the License. |
| 5 | # You may obtain a copy of the License at |
| 6 | # |
| 7 | # http://www.apache.org/licenses/LICENSE-2.0 |
| 8 | # |
| 9 | # Unless required by applicable law or agreed to in writing, software |
| 10 | # distributed under the License is distributed on an "AS IS" BASIS, |
| 11 | # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 12 | # See the License for the specific language governing permissions and |
| 13 | # limitations under the License. |
| 14 | |
| 15 | from common.logger import Logger |
| 16 | from file_format.checker.struct import TestAssertion, RegexExpression |
| 17 | |
| 18 | import re |
| 19 | |
| 20 | def __isMatchAtStart(match): |
| 21 | """ Tests if the given Match occurred at the beginning of the line. """ |
| 22 | return (match is not None) and (match.start() == 0) |
| 23 | |
| 24 | def __generatePattern(checkLine, linePart, varState): |
| 25 | """ Returns the regex pattern to be matched in the output line. Variable |
| 26 | references are substituted with their current values provided in the |
| 27 | 'varState' argument. |
| 28 | |
| 29 | An exception is raised if a referenced variable is undefined. |
| 30 | """ |
| 31 | if linePart.variant == RegexExpression.Variant.VarRef: |
| 32 | try: |
| 33 | return re.escape(varState[linePart.name]) |
| 34 | except KeyError: |
| 35 | Logger.testFailed("Use of undefined variable \"" + linePart.name + "\"", |
| 36 | checkLine.fileName, checkLine.lineNo) |
| 37 | else: |
| 38 | return linePart.pattern |
| 39 | |
| 40 | def __isSeparated(outputLine, matchStart): |
| 41 | return (matchStart == 0) or (outputLine[matchStart - 1:matchStart].isspace()) |
| 42 | |
| 43 | def MatchLines(checkLine, outputLine, initialVarState): |
| 44 | """ Attempts to match the check line against a line from the output file with |
| 45 | the given initial variable values. It returns the new variable state if |
| 46 | successful and None otherwise. |
| 47 | """ |
| 48 | # Do the full matching on a shadow copy of the variable state. If the |
| 49 | # matching fails half-way, we will not need to revert the state. |
| 50 | varState = dict(initialVarState) |
| 51 | |
| 52 | matchStart = 0 |
| 53 | isAfterSeparator = True |
| 54 | |
| 55 | # Now try to parse all of the parts of the check line in the right order. |
| 56 | # Variable values are updated on-the-fly, meaning that a variable can |
| 57 | # be referenced immediately after its definition. |
| 58 | for part in checkLine.expressions: |
| 59 | if part.variant == RegexExpression.Variant.Separator: |
| 60 | isAfterSeparator = True |
| 61 | continue |
| 62 | |
| 63 | # Find the earliest match for this line part. |
| 64 | pattern = __generatePattern(checkLine, part, varState) |
| 65 | while True: |
| 66 | match = re.search(pattern, outputLine[matchStart:]) |
| 67 | if (match is None) or (not isAfterSeparator and not __isMatchAtStart(match)): |
| 68 | return None |
| 69 | matchEnd = matchStart + match.end() |
| 70 | matchStart += match.start() |
| 71 | |
| 72 | # Check if this is a valid match if we expect a whitespace separator |
| 73 | # before the matched text. Otherwise loop and look for another match. |
| 74 | if not isAfterSeparator or __isSeparated(outputLine, matchStart): |
| 75 | break |
| 76 | else: |
| 77 | matchStart += 1 |
| 78 | |
| 79 | if part.variant == RegexExpression.Variant.VarDef: |
| 80 | if part.name in varState: |
| 81 | Logger.testFailed("Multiple definitions of variable \"" + part.name + "\"", |
| 82 | checkLine.fileName, checkLine.lineNo) |
| 83 | varState[part.name] = outputLine[matchStart:matchEnd] |
| 84 | |
| 85 | matchStart = matchEnd |
| 86 | isAfterSeparator = False |
| 87 | |
| 88 | # All parts were successfully matched. Return the new variable state. |
| 89 | return varState |