Commit 6874dfce authored by Nathan's avatar Nathan
Browse files

[clang-tidy] Fix bugprone-use-after-move when move is in noexcept operator 

Summary: Fixes [[ https://bugs.llvm.org/show_bug.cgi?id=44667 | noexcept operator misinterpreted as being evaluated ]].

Reviewers: aaron.ballman, alexfh, JonasToth, hokein, gribozavr2

Reviewed By: gribozavr2

Subscribers: merge_guards_bot, Quuxplusone, xazax.hun, cfe-commits

Tags: #clang, #clang-tools-extra

Differential Revision: https://reviews.llvm.org/D73441
parent c7c5da6d

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

+23 −1
Original line number Diff line number Diff line
@@ -8,6 +8,10 @@ 


#include "UseAfterMoveCheck.h"



#include "clang/AST/Expr.h"

#include "clang/AST/ExprCXX.h"

#include "clang/AST/ExprConcepts.h"

#include "clang/ASTMatchers/ASTMatchers.h"

#include "clang/Analysis/CFG.h"

#include "clang/Lex/Lexer.h"
@@ -23,6 +27,23 @@ namespace bugprone { 


namespace {



AST_MATCHER(Expr, hasUnevaluatedContext) {

  if (isa<CXXNoexceptExpr>(Node) || isa<RequiresExpr>(Node))

    return true;

  if (const auto *UnaryExpr = dyn_cast<UnaryExprOrTypeTraitExpr>(&Node)) {

    switch (UnaryExpr->getKind()) {

    case UETT_SizeOf:

    case UETT_AlignOf:

      return true;

    default:

      return false;

    }

  }

  if (const auto *TypeIDExpr = dyn_cast<CXXTypeidExpr>(&Node))

    return !TypeIDExpr->isPotentiallyEvaluated();

  return false;

}



/// Contains information about a use-after-move.

struct UseAfterMove {

  // The DeclRefExpr that constituted the use of the object.
@@ -77,7 +98,8 @@ private: 
static StatementMatcher inDecltypeOrTemplateArg() {

  return anyOf(hasAncestor(typeLoc()),

               hasAncestor(declRefExpr(

                   to(functionDecl(ast_matchers::isTemplateInstantiation())))));

                   to(functionDecl(ast_matchers::isTemplateInstantiation())))),

               hasAncestor(expr(hasUnevaluatedContext())));

}



UseAfterMoveFinder::UseAfterMoveFinder(ASTContext *TheContext)

clang-tools-extra/test/clang-tidy/checkers/bugprone-use-after-move.cpp

+28 −0
Original line number Diff line number Diff line
@@ -1270,4 +1270,32 @@ class C : T, B { 
    C c;

  }

};

}
 
} // namespace PR33020



namespace UnevalContext {

struct Foo {};

void noExcept() {

  Foo Bar;

  (void) noexcept(Foo{std::move(Bar)});

  Foo Other{std::move(Bar)};

}

void sizeOf() {

  Foo Bar;

  (void)sizeof(Foo{std::move(Bar)});

  Foo Other{std::move(Bar)};

}

void alignOf() {

  Foo Bar;

#pragma clang diagnostic push

#pragma clang diagnostic ignored "-Wgnu-alignof-expression"

  (void)alignof(Foo{std::move(Bar)});

#pragma clang diagnostic pop

  Foo Other{std::move(Bar)};

}

void typeId() {

  Foo Bar;

  // error: you need to include <typeinfo> before using the 'typeid' operator

  // (void) typeid(Foo{std::move(Bar)}).name();

  Foo Other{std::move(Bar)};

}

} // namespace UnevalContext