diff options
Diffstat (limited to 'clang-tools-extra/clang-tidy/llvm')
4 files changed, 203 insertions, 0 deletions
diff --git a/clang-tools-extra/clang-tidy/llvm/CMakeLists.txt b/clang-tools-extra/clang-tidy/llvm/CMakeLists.txt index ce69c05f349..085fb856496 100644 --- a/clang-tools-extra/clang-tidy/llvm/CMakeLists.txt +++ b/clang-tools-extra/clang-tidy/llvm/CMakeLists.txt @@ -4,6 +4,7 @@ add_clang_library(clangTidyLLVMModule HeaderGuardCheck.cpp IncludeOrderCheck.cpp LLVMTidyModule.cpp + PreferIsaOrDynCastInConditionalsCheck.cpp TwineLocalCheck.cpp LINK_LIBS diff --git a/clang-tools-extra/clang-tidy/llvm/LLVMTidyModule.cpp b/clang-tools-extra/clang-tidy/llvm/LLVMTidyModule.cpp index f5242685c06..fb7b52a3815 100644 --- a/clang-tools-extra/clang-tidy/llvm/LLVMTidyModule.cpp +++ b/clang-tools-extra/clang-tidy/llvm/LLVMTidyModule.cpp @@ -12,6 +12,7 @@ #include "../readability/NamespaceCommentCheck.h" #include "HeaderGuardCheck.h" #include "IncludeOrderCheck.h" +#include "PreferIsaOrDynCastInConditionalsCheck.h" #include "TwineLocalCheck.h" namespace clang { @@ -25,6 +26,8 @@ public: CheckFactories.registerCheck<IncludeOrderCheck>("llvm-include-order"); CheckFactories.registerCheck<readability::NamespaceCommentCheck>( "llvm-namespace-comment"); + CheckFactories.registerCheck<PreferIsaOrDynCastInConditionalsCheck>( + "llvm-prefer-isa-or-dyn-cast-in-conditionals"); CheckFactories.registerCheck<TwineLocalCheck>("llvm-twine-local"); } }; diff --git a/clang-tools-extra/clang-tidy/llvm/PreferIsaOrDynCastInConditionalsCheck.cpp b/clang-tools-extra/clang-tidy/llvm/PreferIsaOrDynCastInConditionalsCheck.cpp new file mode 100644 index 00000000000..252ef3bf217 --- /dev/null +++ b/clang-tools-extra/clang-tidy/llvm/PreferIsaOrDynCastInConditionalsCheck.cpp @@ -0,0 +1,135 @@ +//===--- PreferIsaOrDynCastInConditionalsCheck.cpp - clang-tidy +//---------------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// + +#include "PreferIsaOrDynCastInConditionalsCheck.h" +#include "clang/AST/ASTContext.h" +#include "clang/ASTMatchers/ASTMatchFinder.h" + +using namespace clang::ast_matchers; + +namespace clang { +namespace ast_matchers { +AST_MATCHER(Expr, isMacroID) { return Node.getExprLoc().isMacroID(); } +} // namespace ast_matchers + +namespace tidy { +namespace llvm { + +void PreferIsaOrDynCastInConditionalsCheck::registerMatchers( + MatchFinder *Finder) { + if (!getLangOpts().CPlusPlus) + return; + + auto Condition = hasCondition(implicitCastExpr(has( + callExpr( + allOf(unless(isMacroID()), unless(cxxMemberCallExpr()), + anyOf(callee(namedDecl(hasName("cast"))), + callee(namedDecl(hasName("dyn_cast")).bind("dyn_cast"))))) + .bind("call")))); + + auto Any = anyOf( + has(declStmt(containsDeclaration( + 0, + varDecl(hasInitializer( + callExpr(allOf(unless(isMacroID()), unless(cxxMemberCallExpr()), + callee(namedDecl(hasName("cast"))))) + .bind("assign")))))), + Condition); + + auto CallExpression = + callExpr( + allOf(unless(isMacroID()), unless(cxxMemberCallExpr()), + allOf(callee(namedDecl(anyOf(hasName("isa"), hasName("cast"), + hasName("cast_or_null"), + hasName("dyn_cast"), + hasName("dyn_cast_or_null"))) + .bind("func")), + hasArgument(0, anyOf(declRefExpr().bind("arg"), + cxxMemberCallExpr().bind("arg")))))) + .bind("rhs"); + + Finder->addMatcher( + stmt(anyOf(ifStmt(Any), whileStmt(Any), doStmt(Condition), + binaryOperator( + allOf(unless(isExpansionInFileMatching( + "llvm/include/llvm/Support/Casting.h")), + hasOperatorName("&&"), + hasLHS(implicitCastExpr().bind("lhs")), + hasRHS(anyOf(implicitCastExpr(has(CallExpression)), + CallExpression)))) + .bind("and"))), + this); +} + +void PreferIsaOrDynCastInConditionalsCheck::check( + const MatchFinder::MatchResult &Result) { + if (const auto *MatchedDecl = Result.Nodes.getNodeAs<CallExpr>("assign")) { + SourceLocation StartLoc = MatchedDecl->getCallee()->getExprLoc(); + SourceLocation EndLoc = + StartLoc.getLocWithOffset(StringRef("cast").size() - 1); + + diag(MatchedDecl->getBeginLoc(), + "cast<> in conditional will assert rather than return a null pointer") + << FixItHint::CreateReplacement(SourceRange(StartLoc, EndLoc), + "dyn_cast"); + } else if (const auto *MatchedDecl = + Result.Nodes.getNodeAs<CallExpr>("call")) { + SourceLocation StartLoc = MatchedDecl->getCallee()->getExprLoc(); + SourceLocation EndLoc = + StartLoc.getLocWithOffset(StringRef("cast").size() - 1); + + StringRef Message = + "cast<> in conditional will assert rather than return a null pointer"; + if (Result.Nodes.getNodeAs<NamedDecl>("dyn_cast")) + Message = "return value from dyn_cast<> not used"; + + diag(MatchedDecl->getBeginLoc(), Message) + << FixItHint::CreateReplacement(SourceRange(StartLoc, EndLoc), "isa"); + } else if (const auto *MatchedDecl = + Result.Nodes.getNodeAs<BinaryOperator>("and")) { + const auto *LHS = Result.Nodes.getNodeAs<ImplicitCastExpr>("lhs"); + const auto *RHS = Result.Nodes.getNodeAs<CallExpr>("rhs"); + const auto *Arg = Result.Nodes.getNodeAs<Expr>("arg"); + const auto *Func = Result.Nodes.getNodeAs<NamedDecl>("func"); + + assert(LHS && "LHS is null"); + assert(RHS && "RHS is null"); + assert(Arg && "Arg is null"); + assert(Func && "Func is null"); + + StringRef LHSString(Lexer::getSourceText( + CharSourceRange::getTokenRange(LHS->getSourceRange()), + *Result.SourceManager, getLangOpts())); + + StringRef ArgString(Lexer::getSourceText( + CharSourceRange::getTokenRange(Arg->getSourceRange()), + *Result.SourceManager, getLangOpts())); + + if (ArgString != LHSString) + return; + + StringRef RHSString(Lexer::getSourceText( + CharSourceRange::getTokenRange(RHS->getSourceRange()), + *Result.SourceManager, getLangOpts())); + + std::string Replacement("isa_and_nonnull"); + Replacement += RHSString.substr(Func->getName().size()); + + diag(MatchedDecl->getBeginLoc(), + "isa_and_nonnull<> is preferred over an explicit test for null " + "followed by calling isa<>") + << FixItHint::CreateReplacement(SourceRange(MatchedDecl->getBeginLoc(), + MatchedDecl->getEndLoc()), + Replacement); + } +} + +} // namespace llvm +} // namespace tidy +} // namespace clang diff --git a/clang-tools-extra/clang-tidy/llvm/PreferIsaOrDynCastInConditionalsCheck.h b/clang-tools-extra/clang-tidy/llvm/PreferIsaOrDynCastInConditionalsCheck.h new file mode 100644 index 00000000000..354693c1f69 --- /dev/null +++ b/clang-tools-extra/clang-tidy/llvm/PreferIsaOrDynCastInConditionalsCheck.h @@ -0,0 +1,64 @@ +//===--- PreferIsaOrDynCastInConditionalsCheck.h - clang-tidy ---*- C++ -*-===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// + +#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_LLVM_AVOIDCASTINCONDITIONALCHECK_H +#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_LLVM_AVOIDCASTINCONDITIONALCHECK_H + +#include "../ClangTidyCheck.h" + +namespace clang { +namespace tidy { +namespace llvm { + +/// \brief Looks at conditionals and finds and replaces cases of ``cast<>``, which will +/// assert rather than return a null pointer, and ``dyn_cast<>`` where +/// the return value is not captured. Additionally, finds and replaces cases that match the +/// pattern ``var && isa<X>(var)``, where ``var`` is evaluated twice. +/// +/// Finds cases like these: +/// \code +/// if (auto x = cast<X>(y)) {} +/// // is replaced by: +/// if (auto x = dyn_cast<X>(y)) {} +/// +/// if (cast<X>(y)) {} +/// // is replaced by: +/// if (isa<X>(y)) {} +/// +/// if (dyn_cast<X>(y)) {} +/// // is replaced by: +/// if (isa<X>(y)) {} +/// +/// if (var && isa<T>(var)) {} +/// // is replaced by: +/// if (isa_and_nonnull<T>(var.foo())) {} +/// \endcode +/// +/// // Other cases are ignored, e.g.: +/// \code +/// if (auto f = cast<Z>(y)->foo()) {} +/// if (cast<Z>(y)->foo()) {} +/// if (X.cast(y)) {} +/// \endcode +/// +/// For the user-facing documentation see: +/// http://clang.llvm.org/extra/clang-tidy/checks/llvm-prefer-isa-or-dyn-cast-in-conditionals.html +class PreferIsaOrDynCastInConditionalsCheck : public ClangTidyCheck { +public: + PreferIsaOrDynCastInConditionalsCheck(StringRef Name, + ClangTidyContext *Context) + : ClangTidyCheck(Name, Context) {} + void registerMatchers(ast_matchers::MatchFinder *Finder) override; + void check(const ast_matchers::MatchFinder::MatchResult &Result) override; +}; + +} // namespace llvm +} // namespace tidy +} // namespace clang + +#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_LLVM_AVOIDCASTINCONDITIONALCHECK_H |
