Add a new check, readability-simplify-subscript-expr, that diagnoses array subscript expressions that can be simplified.
Currently, diagnoses code that calls container.data()[some_index] when the container exposes a suitable operator[]() method that can be used directly.
Patch by Shuai Wang.
llvm-svn: 332519
diff --git a/clang-tools-extra/clang-tidy/readability/CMakeLists.txt b/clang-tools-extra/clang-tidy/readability/CMakeLists.txt
index 95769ee..961ad88 100644
--- a/clang-tools-extra/clang-tidy/readability/CMakeLists.txt
+++ b/clang-tools-extra/clang-tidy/readability/CMakeLists.txt
@@ -25,6 +25,7 @@
RedundantSmartptrGetCheck.cpp
RedundantStringInitCheck.cpp
SimplifyBooleanExprCheck.cpp
+ SimplifySubscriptExprCheck.cpp
StaticAccessedThroughInstanceCheck.cpp
StaticDefinitionInAnonymousNamespaceCheck.cpp
StringCompareCheck.cpp
diff --git a/clang-tools-extra/clang-tidy/readability/ReadabilityTidyModule.cpp b/clang-tools-extra/clang-tidy/readability/ReadabilityTidyModule.cpp
index f39e4a1..be1ae43 100644
--- a/clang-tools-extra/clang-tidy/readability/ReadabilityTidyModule.cpp
+++ b/clang-tools-extra/clang-tidy/readability/ReadabilityTidyModule.cpp
@@ -32,6 +32,7 @@
#include "RedundantStringCStrCheck.h"
#include "RedundantStringInitCheck.h"
#include "SimplifyBooleanExprCheck.h"
+#include "SimplifySubscriptExprCheck.h"
#include "StaticAccessedThroughInstanceCheck.h"
#include "StaticDefinitionInAnonymousNamespaceCheck.h"
#include "StringCompareCheck.h"
@@ -72,6 +73,8 @@
"readability-redundant-function-ptr-dereference");
CheckFactories.registerCheck<RedundantMemberInitCheck>(
"readability-redundant-member-init");
+ CheckFactories.registerCheck<SimplifySubscriptExprCheck>(
+ "readability-simplify-subscript-expr");
CheckFactories.registerCheck<StaticAccessedThroughInstanceCheck>(
"readability-static-accessed-through-instance");
CheckFactories.registerCheck<StaticDefinitionInAnonymousNamespaceCheck>(
diff --git a/clang-tools-extra/clang-tidy/readability/SimplifySubscriptExprCheck.cpp b/clang-tools-extra/clang-tidy/readability/SimplifySubscriptExprCheck.cpp
new file mode 100644
index 0000000..28cc576
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/readability/SimplifySubscriptExprCheck.cpp
@@ -0,0 +1,76 @@
+//===--- SimplifySubscriptExprCheck.cpp - clang-tidy-----------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "SimplifySubscriptExprCheck.h"
+#include "../utils/OptionsUtils.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang {
+namespace tidy {
+namespace readability {
+
+static const char kDefaultTypes[] =
+ "::std::basic_string;::std::basic_string_view;::std::vector;::std::array";
+
+SimplifySubscriptExprCheck::SimplifySubscriptExprCheck(
+ StringRef Name, ClangTidyContext *Context)
+ : ClangTidyCheck(Name, Context), Types(utils::options::parseStringList(
+ Options.get("Types", kDefaultTypes))) {
+}
+
+void SimplifySubscriptExprCheck::registerMatchers(MatchFinder *Finder) {
+ if (!getLangOpts().CPlusPlus)
+ return;
+
+ const auto TypesMatcher = hasUnqualifiedDesugaredType(
+ recordType(hasDeclaration(cxxRecordDecl(hasAnyName(
+ llvm::SmallVector<StringRef, 8>(Types.begin(), Types.end()))))));
+
+ Finder->addMatcher(
+ arraySubscriptExpr(hasBase(ignoringParenImpCasts(
+ cxxMemberCallExpr(
+ has(memberExpr().bind("member")),
+ on(hasType(qualType(
+ unless(anyOf(substTemplateTypeParmType(),
+ hasDescendant(substTemplateTypeParmType()))),
+ anyOf(TypesMatcher, pointerType(pointee(TypesMatcher)))))),
+ callee(namedDecl(hasName("data"))))
+ .bind("call")))),
+ this);
+}
+
+void SimplifySubscriptExprCheck::check(const MatchFinder::MatchResult &Result) {
+ const auto *Call = Result.Nodes.getNodeAs<CXXMemberCallExpr>("call");
+ if (Result.Context->getSourceManager().isMacroBodyExpansion(
+ Call->getExprLoc()))
+ return;
+
+ const auto *Member = Result.Nodes.getNodeAs<MemberExpr>("member");
+ auto DiagBuilder =
+ diag(Member->getMemberLoc(),
+ "accessing an element of the container does not require a call to "
+ "'data()'; did you mean to use 'operator[]'?");
+ if (Member->isArrow())
+ DiagBuilder << FixItHint::CreateInsertion(Member->getLocStart(), "(*")
+ << FixItHint::CreateInsertion(Member->getOperatorLoc(), ")");
+ DiagBuilder << FixItHint::CreateRemoval(
+ {Member->getOperatorLoc(), Call->getLocEnd()});
+}
+
+void SimplifySubscriptExprCheck::storeOptions(
+ ClangTidyOptions::OptionMap &Opts) {
+ Options.store(Opts, "Types", utils::options::serializeStringList(Types));
+}
+
+} // namespace readability
+} // namespace tidy
+} // namespace clang
diff --git a/clang-tools-extra/clang-tidy/readability/SimplifySubscriptExprCheck.h b/clang-tools-extra/clang-tidy/readability/SimplifySubscriptExprCheck.h
new file mode 100644
index 0000000..86a21b9
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/readability/SimplifySubscriptExprCheck.h
@@ -0,0 +1,38 @@
+//===--- SimplifySubscriptExprCheck.h - clang-tidy---------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_SIMPLIFYSUBSCRIPTEXPRCHECK_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_SIMPLIFYSUBSCRIPTEXPRCHECK_H
+
+#include "../ClangTidy.h"
+
+namespace clang {
+namespace tidy {
+namespace readability {
+
+/// Simplifies subscript expressions.
+///
+/// For the user-facing documentation see:
+/// http://clang.llvm.org/extra/clang-tidy/checks/readability-simplify-subscript-expr.html
+class SimplifySubscriptExprCheck : public ClangTidyCheck {
+public:
+ SimplifySubscriptExprCheck(StringRef Name, ClangTidyContext *Context);
+ void registerMatchers(ast_matchers::MatchFinder *Finder) override;
+ void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+ void storeOptions(ClangTidyOptions::OptionMap& Opts) override;
+
+private:
+ const std::vector<std::string> Types;
+};
+
+} // namespace readability
+} // namespace tidy
+} // namespace clang
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_SIMPLIFYSUBSCRIPTEXPRCHECK_H