clang-tools-extra/clang-tidy/bugprone/NoEscapeCheck.cpp

   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
  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
  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