Alex Light | eb7c144 | 2015-08-31 13:17:42 -0700 | [diff] [blame] | 1 | #!/usr/bin/python3 |
| 2 | # |
| 3 | # Copyright (C) 2015 The Android Open Source Project |
| 4 | # |
| 5 | # Licensed under the Apache License, Version 2.0 (the "License"); |
| 6 | # you may not use this file except in compliance with the License. |
| 7 | # You may obtain a copy of the License at |
| 8 | # |
| 9 | # http://www.apache.org/licenses/LICENSE-2.0 |
| 10 | # |
| 11 | # Unless required by applicable law or agreed to in writing, software |
| 12 | # distributed under the License is distributed on an "AS IS" BASIS, |
| 13 | # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 14 | # See the License for the specific language governing permissions and |
| 15 | # limitations under the License. |
| 16 | |
| 17 | """ |
| 18 | Common functions useful for writing test generators in python |
| 19 | """ |
| 20 | |
| 21 | import itertools |
| 22 | import os |
| 23 | import string |
| 24 | from pathlib import Path |
| 25 | |
| 26 | BUILD_TOP = os.getenv("ANDROID_BUILD_TOP") |
| 27 | if BUILD_TOP is None: |
| 28 | print("ANDROID_BUILD_TOP not set. Please run build/envsetup.sh", file=sys.stderr) |
| 29 | sys.exit(1) |
| 30 | |
| 31 | # An iterator which yields strings made from lowercase letters. First yields |
| 32 | # all 1 length strings, then all 2 and so on. It does this alphabetically. |
| 33 | NAME_GEN = itertools.chain.from_iterable( |
| 34 | map(lambda n: itertools.product(string.ascii_lowercase, repeat=n), |
| 35 | itertools.count(1))) |
| 36 | |
| 37 | def gensym(): |
| 38 | """ |
| 39 | Returns a new, globally unique, identifier name that is a valid Java symbol |
| 40 | on each call. |
| 41 | """ |
| 42 | return ''.join(next(NAME_GEN)) |
| 43 | |
| 44 | def filter_blanks(s): |
| 45 | """ |
| 46 | Takes a string returns the same string sans empty lines |
| 47 | """ |
| 48 | return "\n".join(a for a in s.split("\n") if a.strip() != "") |
| 49 | |
| 50 | def get_copyright(filetype = "java"): |
| 51 | """ |
| 52 | Returns the standard copyright header for the given filetype |
| 53 | """ |
| 54 | if filetype == "smali": |
| 55 | return "\n".join(map(lambda a: "# " + a, get_copyright("java").split("\n"))) |
| 56 | else: |
| 57 | fname = filetype + ".txt" |
| 58 | with (Path(BUILD_TOP)/"development"/"docs"/"copyright-templates"/fname).open() as template: |
| 59 | return "".join(template.readlines()) |
| 60 | |
| 61 | def subtree_sizes(n): |
| 62 | """ |
| 63 | A generator that yields a tuple containing a possible arrangement of subtree |
| 64 | nodes for a tree with a total of 'n' leaf nodes. |
| 65 | """ |
| 66 | if n == 0: |
| 67 | return |
| 68 | elif n == 1: |
| 69 | yield (0,) |
| 70 | elif n == 2: |
| 71 | yield (1, 1) |
| 72 | else: |
| 73 | for prevt in subtree_sizes(n - 1): |
| 74 | prev = list(prevt) |
| 75 | yield tuple([1] + prev) |
| 76 | for i in range(len(prev)): |
| 77 | prev[i] += 1 |
| 78 | yield tuple(prev) |
| 79 | prev[i] -= 1 |
| 80 | |