1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8
9 #include "clang-tidy/ClangTidyCheck.h"
10 #include "clang-tidy/ClangTidyModuleRegistry.h"
11
12 #include "hide_from_abi.hpp"
13
14 namespace {
AST_MATCHER(clang::ClassTemplateDecl,hasFullSpecializations)15 AST_MATCHER(clang::ClassTemplateDecl, hasFullSpecializations) { return !Node.specializations().empty(); }
AST_MATCHER(clang::CXXRecordDecl,isTrivial)16 AST_MATCHER(clang::CXXRecordDecl, isTrivial) { return Node.isTrivial(); }
17 } // namespace
18
19 namespace libcpp {
hide_from_abi(llvm::StringRef name,clang::tidy::ClangTidyContext * context)20 hide_from_abi::hide_from_abi(llvm::StringRef name, clang::tidy::ClangTidyContext* context)
21 : clang::tidy::ClangTidyCheck(name, context) {}
22
registerMatchers(clang::ast_matchers::MatchFinder * finder)23 void hide_from_abi::registerMatchers(clang::ast_matchers::MatchFinder* finder) {
24 using namespace clang::ast_matchers;
25
26 auto has_hide_from_abi_attr = anyOf(hasAttr(clang::attr::Visibility), hasAttr(clang::attr::AbiTag));
27
28 finder->addMatcher(
29 functionDecl(
30 unless(anyOf(
31 // These functions can't be marked `[[gnu::always_inline]]` for various reasons,
32 // so we can't mark them `_LIBCPP_HIDE_FROM_ABI`. These functions are ignored in
33 // all namespaces. Checking the qualified name is a lot harder and these names
34 // should result in very few (if any) false-negatives. This is also just a
35 // temporary work-around until we can mark functions as HIDE_FROM_ABI without
36 // having to add `[[gnu::always_inline]]` with GCC.
37 hasAnyName("__introsort",
38 "__inplace_merge",
39 "__libcpp_snprintf_l",
40 "__libcpp_asprintf_l",
41 "__libcpp_sscanf_l",
42 "__tree_sub_invariant",
43 "__stable_sort_move",
44 "__stable_sort",
45 "__stable_partition",
46 "__lock_first",
47 "__stable_partition_impl"),
48 has_hide_from_abi_attr,
49 cxxMethodDecl(), // We have explicitly instantiated classes and some of their methods don't have these attributes
50 isDeleted(),
51 isConsteval())),
52 isDefinition())
53 .bind("hide_from_abi_on_free_function"),
54 this);
55
56 auto on_trivial = allOf(
57 unless(isImplicit()), isDefaulted(), unless(ofClass(hasAncestor(classTemplateDecl()))), ofClass(isTrivial()));
58
59 // TODO: find a better way to check for explicit instantiations. Currently, every template that has a full
60 // specialization is ignored. For example, vector is ignored because we instantiate vector<double>
61 // in discrete_distribution.
62 finder->addMatcher(
63 cxxMethodDecl(
64 unless(anyOf(
65 has_hide_from_abi_attr,
66 isDeleted(),
67 isImplicit(),
68 hasAncestor(cxxRecordDecl(isLambda())),
69 ofClass(anyOf(hasAncestor(classTemplateDecl(hasFullSpecializations())),
70 hasAnyName("basic_filebuf",
71 "basic_ifstream",
72 "basic_ofstream", // These are in the dylib in ABIv2
73 // TODO: fix the matcher to catch `sentry` instantiation.
74 "sentry"))),
75 isConsteval(),
76 hasParent(classTemplateSpecializationDecl()),
77 on_trivial)),
78 isDefinition())
79 .bind("hide_from_abi_on_member_function"),
80 this);
81
82 finder->addMatcher(
83 cxxMethodDecl(has_hide_from_abi_attr, on_trivial).bind("hide_from_abi_on_defaulted_smf_in_trivial_class"), this);
84 }
85
check(const clang::ast_matchers::MatchFinder::MatchResult & result)86 void hide_from_abi::check(const clang::ast_matchers::MatchFinder::MatchResult& result) {
87 if (const auto* call = result.Nodes.getNodeAs<clang::FunctionDecl>("hide_from_abi_on_free_function");
88 call != nullptr) {
89 diag(call->getBeginLoc(), "_LIBCPP_HIDE_FROM_ABI is missing");
90 }
91
92 // The rest gets ignored in C++03 because it is subtly different in some cases.
93 // e.g. we change the definition of default constructors in some cases
94 // TODO: check whether we can remove thse differences
95 if (!result.Context->getLangOpts().CPlusPlus11)
96 return;
97
98 if (const auto* call = result.Nodes.getNodeAs<clang::CXXMethodDecl>("hide_from_abi_on_member_function");
99 call != nullptr) {
100 diag(call->getLocation(), "_LIBCPP_HIDE_FROM_ABI or _LIBCPP_HIDE_FROM_ABI_VIRTUAL is missing");
101 }
102
103 if (const auto* call =
104 result.Nodes.getNodeAs<clang::CXXMethodDecl>("hide_from_abi_on_defaulted_smf_in_trivial_class");
105 call != nullptr) {
106 diag(call->getLocation(),
107 "_LIBCPP_HIDE_FROM_ABI should not be used for special member functions in trivial classes");
108 }
109 }
110 } // namespace libcpp
111