xref: /llvm-project/libcxx/utils/libcxx/sym_check/diff.py (revision 7bfaa0f09d0564f315ea778023b34b8a113ec740) 
1# -*- Python -*- vim: set syntax=python tabstop=4 expandtab cc=80:
2# ===----------------------------------------------------------------------===##
3#
4# Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5# See https://llvm.org/LICENSE.txt for license information.
6# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7#
8# ===----------------------------------------------------------------------===##
9"""
10diff - A set of functions for diff-ing two symbol lists.
11"""
12
13from libcxx.sym_check import util
14
15
16def _symbol_difference(lhs, rhs):
17    lhs_names = set(((n["name"], n["type"]) for n in lhs))
18    rhs_names = set(((n["name"], n["type"]) for n in rhs))
19    diff_names = lhs_names - rhs_names
20    return [n for n in lhs if (n["name"], n["type"]) in diff_names]
21
22
23def _find_by_key(sym_list, k):
24    for sym in sym_list:
25        if sym["name"] == k:
26            return sym
27    return None
28
29
30def added_symbols(old, new):
31    return _symbol_difference(new, old)
32
33
34def removed_symbols(old, new):
35    return _symbol_difference(old, new)
36
37
38def changed_symbols(old, new):
39    changed = []
40    for old_sym in old:
41        if old_sym in new:
42            continue
43        new_sym = _find_by_key(new, old_sym["name"])
44        if new_sym is not None and not new_sym in old and old_sym != new_sym:
45            changed += [(old_sym, new_sym)]
46    return changed
47
48
49def diff(old, new):
50    added = added_symbols(old, new)
51    removed = removed_symbols(old, new)
52    changed = changed_symbols(old, new)
53    return added, removed, changed
54
55
56def report_diff(
57    added_syms, removed_syms, changed_syms, names_only=False, demangle=True
58):
59    def maybe_demangle(name):
60        return util.demangle_symbol(name) if demangle else name
61
62    report = ""
63    for sym in added_syms:
64        report += "Symbol added: %s\n" % maybe_demangle(sym["name"])
65        if not names_only:
66            report += "    %s\n\n" % sym
67    if added_syms and names_only:
68        report += "\n"
69    for sym in removed_syms:
70        report += "SYMBOL REMOVED: %s\n" % maybe_demangle(sym["name"])
71        if not names_only:
72            report += "    %s\n\n" % sym
73    if removed_syms and names_only:
74        report += "\n"
75    if not names_only:
76        for sym_pair in changed_syms:
77            old_sym, new_sym = sym_pair
78            old_str = "\n    OLD SYMBOL: %s" % old_sym
79            new_str = "\n    NEW SYMBOL: %s" % new_sym
80            report += "SYMBOL CHANGED: %s%s%s\n\n" % (
81                maybe_demangle(old_sym["name"]),
82                old_str,
83                new_str,
84            )
85
86    added = bool(len(added_syms) != 0)
87    abi_break = bool(len(removed_syms))
88    if not names_only:
89        abi_break = abi_break or len(changed_syms)
90    if added or abi_break:
91        report += "Summary\n"
92        report += "    Added:   %d\n" % len(added_syms)
93        report += "    Removed: %d\n" % len(removed_syms)
94        if not names_only:
95            report += "    Changed: %d\n" % len(changed_syms)
96        if not abi_break:
97            report += "Symbols added."
98        else:
99            report += "ABI BREAKAGE: SYMBOLS ADDED OR REMOVED!"
100    else:
101        report += "Symbols match."
102    is_different = abi_break or bool(len(added_syms)) or bool(len(changed_syms))
103    return report, abi_break, is_different
104