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