91 lines · cpp
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-exception6//7//===----------------------------------------------------------------------===//8 9#include "ComparisonInTempFailureRetryCheck.h"10#include "clang/AST/ASTContext.h"11#include "clang/ASTMatchers/ASTMatchFinder.h"12#include "clang/Lex/Lexer.h"13 14using namespace clang::ast_matchers;15 16namespace clang::tidy::android {17 18ComparisonInTempFailureRetryCheck::ComparisonInTempFailureRetryCheck(19 StringRef Name, ClangTidyContext *Context)20 : ClangTidyCheck(Name, Context),21 RawRetryList(Options.get("RetryMacros", "TEMP_FAILURE_RETRY")) {22 RawRetryList.split(RetryMacros, ",", -1, false);23}24 25void ComparisonInTempFailureRetryCheck::storeOptions(26 ClangTidyOptions::OptionMap &Opts) {27 Options.store(Opts, "RetryMacros", RawRetryList);28}29 30void ComparisonInTempFailureRetryCheck::registerMatchers(MatchFinder *Finder) {31 // Both glibc's and Bionic's TEMP_FAILURE_RETRY macros structurally look like:32 //33 // #define TEMP_FAILURE_RETRY(x) ({ \34 // typeof(x) y; \35 // do y = (x); \36 // while (y == -1 && errno == EINTR); \37 // y; \38 // })39 //40 // (glibc uses `long int` instead of `typeof(x)` for the type of y).41 //42 // It's unclear how to walk up the AST from inside the expansion of `x`, and43 // we need to not complain about things like TEMP_FAILURE_RETRY(foo(x == 1)),44 // so we just match the assignment of `y = (x)` and inspect `x` from there.45 Finder->addMatcher(46 binaryOperator(hasOperatorName("="),47 hasRHS(ignoringParenCasts(48 binaryOperator(isComparisonOperator()).bind("inner"))))49 .bind("outer"),50 this);51}52 53void ComparisonInTempFailureRetryCheck::check(54 const MatchFinder::MatchResult &Result) {55 StringRef RetryMacroName;56 const auto &Node = *Result.Nodes.getNodeAs<BinaryOperator>("outer");57 if (!Node.getBeginLoc().isMacroID())58 return;59 60 const SourceManager &SM = *Result.SourceManager;61 if (!SM.isMacroArgExpansion(Node.getRHS()->IgnoreParenCasts()->getBeginLoc()))62 return;63 64 const LangOptions &Opts = Result.Context->getLangOpts();65 SourceLocation LocStart = Node.getBeginLoc();66 while (LocStart.isMacroID()) {67 const SourceLocation Invocation = SM.getImmediateMacroCallerLoc(LocStart);68 Token Tok;69 if (!Lexer::getRawToken(SM.getSpellingLoc(Invocation), Tok, SM, Opts,70 /*IgnoreWhiteSpace=*/true)) {71 if (Tok.getKind() == tok::raw_identifier &&72 llvm::is_contained(RetryMacros, Tok.getRawIdentifier())) {73 RetryMacroName = Tok.getRawIdentifier();74 break;75 }76 }77 78 LocStart = Invocation;79 }80 if (RetryMacroName.empty())81 return;82 83 const auto &Inner = *Result.Nodes.getNodeAs<BinaryOperator>("inner");84 diag(Inner.getOperatorLoc(), "top-level comparison in %0") << RetryMacroName;85 86 // FIXME: FixIts would be nice, but potentially nontrivial when nested macros87 // happen, e.g. `TEMP_FAILURE_RETRY(IS_ZERO(foo()))`88}89 90} // namespace clang::tidy::android91