104 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 "MultipleStatementMacroCheck.h"10#include "clang/AST/ASTContext.h"11#include "clang/ASTMatchers/ASTMatchFinder.h"12 13using namespace clang::ast_matchers;14 15namespace clang::tidy::bugprone {16 17namespace {18 19AST_MATCHER(Expr, isInMacro) { return Node.getBeginLoc().isMacroID(); }20 21} // namespace22 23/// Find the next statement after `S`.24static const Stmt *nextStmt(const MatchFinder::MatchResult &Result,25 const Stmt *S) {26 auto Parents = Result.Context->getParents(*S);27 if (Parents.empty())28 return nullptr;29 const auto *Parent = Parents[0].get<Stmt>();30 if (!Parent)31 return nullptr;32 const Stmt *Prev = nullptr;33 for (const Stmt *Child : Parent->children()) {34 if (Prev == S)35 return Child;36 Prev = Child;37 }38 return nextStmt(Result, Parent);39}40 41using ExpansionRanges = std::vector<SourceRange>;42 43/// \brief Get all the macro expansion ranges related to `Loc`.44///45/// The result is ordered from most inner to most outer.46static ExpansionRanges47getExpansionRanges(SourceLocation Loc, const MatchFinder::MatchResult &Result) {48 ExpansionRanges Locs;49 while (Loc.isMacroID()) {50 Locs.push_back(51 Result.SourceManager->getImmediateExpansionRange(Loc).getAsRange());52 Loc = Locs.back().getBegin();53 }54 return Locs;55}56 57void MultipleStatementMacroCheck::registerMatchers(MatchFinder *Finder) {58 const auto Inner = expr(isInMacro(), unless(compoundStmt())).bind("inner");59 Finder->addMatcher(60 stmt(anyOf(ifStmt(hasThen(Inner)), ifStmt(hasElse(Inner)).bind("else"),61 whileStmt(hasBody(Inner)), forStmt(hasBody(Inner))))62 .bind("outer"),63 this);64}65 66void MultipleStatementMacroCheck::check(67 const MatchFinder::MatchResult &Result) {68 const auto *Inner = Result.Nodes.getNodeAs<Expr>("inner");69 const auto *Outer = Result.Nodes.getNodeAs<Stmt>("outer");70 const auto *Next = nextStmt(Result, Outer);71 if (!Next)72 return;73 74 SourceLocation OuterLoc = Outer->getBeginLoc();75 if (Result.Nodes.getNodeAs<Stmt>("else"))76 OuterLoc = cast<IfStmt>(Outer)->getElseLoc();77 78 auto InnerRanges = getExpansionRanges(Inner->getBeginLoc(), Result);79 auto OuterRanges = getExpansionRanges(OuterLoc, Result);80 auto NextRanges = getExpansionRanges(Next->getBeginLoc(), Result);81 82 // Remove all the common ranges, starting from the top (the last ones in the83 // list).84 while (!InnerRanges.empty() && !OuterRanges.empty() && !NextRanges.empty() &&85 InnerRanges.back() == OuterRanges.back() &&86 InnerRanges.back() == NextRanges.back()) {87 InnerRanges.pop_back();88 OuterRanges.pop_back();89 NextRanges.pop_back();90 }91 92 // Inner and Next must have at least one more macro that Outer doesn't have,93 // and that range must be common to both.94 if (InnerRanges.empty() || NextRanges.empty() ||95 InnerRanges.back() != NextRanges.back())96 return;97 98 diag(InnerRanges.back().getBegin(), "multiple statement macro used without "99 "braces; some statements will be "100 "unconditionally executed");101}102 103} // namespace clang::tidy::bugprone104