1 //===--- NoEscapeCheck.cpp - clang-tidy -----------------------------------===//
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 "NoEscapeCheck.h"
10 #include "clang/AST/ASTContext.h"
11 #include "clang/ASTMatchers/ASTMatchFinder.h"
12
13 using namespace clang::ast_matchers;
14
15 namespace clang {
16 namespace tidy {
17 namespace bugprone {
18
registerMatchers(MatchFinder * Finder)19 void NoEscapeCheck::registerMatchers(MatchFinder *Finder) {
20 Finder->addMatcher(callExpr(callee(functionDecl(hasName("::dispatch_async"))),
21 argumentCountIs(2),
22 hasArgument(1, blockExpr().bind("arg-block"))),
23 this);
24 Finder->addMatcher(callExpr(callee(functionDecl(hasName("::dispatch_after"))),
25 argumentCountIs(3),
26 hasArgument(2, blockExpr().bind("arg-block"))),
27 this);
28 }
29
check(const MatchFinder::MatchResult & Result)30 void NoEscapeCheck::check(const MatchFinder::MatchResult &Result) {
31 const auto *MatchedEscapingBlock =
32 Result.Nodes.getNodeAs<BlockExpr>("arg-block");
33 const BlockDecl *EscapingBlockDecl = MatchedEscapingBlock->getBlockDecl();
34 for (const BlockDecl::Capture &CapturedVar : EscapingBlockDecl->captures()) {
35 const VarDecl *Var = CapturedVar.getVariable();
36 if (Var && Var->hasAttr<NoEscapeAttr>()) {
37 // FIXME: Add a method to get the location of the use of a CapturedVar so
38 // that we can diagnose the use of the pointer instead of the block.
39 diag(MatchedEscapingBlock->getBeginLoc(),
40 "pointer %0 with attribute 'noescape' is captured by an "
41 "asynchronously-executed block")
42 << Var;
43 diag(Var->getBeginLoc(), "the 'noescape' attribute is declared here.",
44 DiagnosticIDs::Note);
45 }
46 }
47 }
48
49 } // namespace bugprone
50 } // namespace tidy
51 } // namespace clang
52