[clang-tools-extra] r264856 - [clang-tidy] readability check for const params in declarations
Alexander Kornienko via cfe-commits
cfe-commits at lists.llvm.org
Wed Mar 30 04:31:40 PDT 2016
Author: alexfh
Date: Wed Mar 30 06:31:33 2016
New Revision: 264856
URL: http://llvm.org/viewvc/llvm-project?rev=264856&view=rev
Log:
[clang-tidy] readability check for const params in declarations
Summary: Adds a clang-tidy warning for top-level consts in function declarations.
Reviewers: hokein, sbenza, alexfh
Subscribers: cfe-commits
Patch by Matt Kulukundis!
Differential Revision: http://reviews.llvm.org/D18408
Added:
clang-tools-extra/trunk/clang-tidy/readability/AvoidConstParamsInDecls.cpp
clang-tools-extra/trunk/clang-tidy/readability/AvoidConstParamsInDecls.h
clang-tools-extra/trunk/docs/clang-tidy/checks/readability-avoid-const-params-in-decls.rst
clang-tools-extra/trunk/test/clang-tidy/readability-avoid-const-params-in-decls.cpp
Modified:
clang-tools-extra/trunk/clang-tidy/readability/CMakeLists.txt
clang-tools-extra/trunk/clang-tidy/readability/ReadabilityTidyModule.cpp
clang-tools-extra/trunk/docs/clang-tidy/checks/list.rst
Added: clang-tools-extra/trunk/clang-tidy/readability/AvoidConstParamsInDecls.cpp
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/clang-tidy/readability/AvoidConstParamsInDecls.cpp?rev=264856&view=auto
==============================================================================
--- clang-tools-extra/trunk/clang-tidy/readability/AvoidConstParamsInDecls.cpp (added)
+++ clang-tools-extra/trunk/clang-tidy/readability/AvoidConstParamsInDecls.cpp Wed Mar 30 06:31:33 2016
@@ -0,0 +1,71 @@
+//===--- AvoidConstParamsInDecls.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 "AvoidConstParamsInDecls.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/ASTMatchers/ASTMatchers.h"
+#include "clang/Lex/Lexer.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang {
+namespace tidy {
+namespace readability {
+namespace {
+
+SourceRange getTypeRange(const ParmVarDecl &Param) {
+ if (Param.getIdentifier() != nullptr)
+ return SourceRange(Param.getLocStart(),
+ Param.getLocEnd().getLocWithOffset(-1));
+ return Param.getSourceRange();
+}
+
+} // namespace
+
+
+void AvoidConstParamsInDecls::registerMatchers(MatchFinder *Finder) {
+ const auto ConstParamDecl =
+ parmVarDecl(hasType(qualType(isConstQualified()))).bind("param");
+ Finder->addMatcher(functionDecl(unless(isDefinition()),
+ has(typeLoc(forEach(ConstParamDecl))))
+ .bind("func"),
+ this);
+}
+
+void AvoidConstParamsInDecls::check(const MatchFinder::MatchResult &Result) {
+ const auto *Func = Result.Nodes.getNodeAs<FunctionDecl>("func");
+ const auto *Param = Result.Nodes.getNodeAs<ParmVarDecl>("param");
+
+ QualType Type = Param->getType();
+ if (!Type.isLocalConstQualified())
+ return;
+
+ Type.removeLocalConst();
+
+ auto Diag = diag(Param->getLocStart(),
+ "parameter %0 is const-qualified in the function "
+ "declaration; const-qualification of parameters only has an "
+ "effect in function definitions");
+ if (Param->getName().empty()) {
+ for (unsigned int i = 0; i < Func->getNumParams(); ++i) {
+ if (Param == Func->getParamDecl(i)) {
+ Diag << (i + 1);
+ break;
+ }
+ }
+ } else {
+ Diag << Param;
+ }
+ Diag << FixItHint::CreateReplacement(getTypeRange(*Param),
+ Type.getAsString());
+}
+
+} // namespace readability
+} // namespace tidy
+} // namespace clang
Added: clang-tools-extra/trunk/clang-tidy/readability/AvoidConstParamsInDecls.h
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/clang-tidy/readability/AvoidConstParamsInDecls.h?rev=264856&view=auto
==============================================================================
--- clang-tools-extra/trunk/clang-tidy/readability/AvoidConstParamsInDecls.h (added)
+++ clang-tools-extra/trunk/clang-tidy/readability/AvoidConstParamsInDecls.h Wed Mar 30 06:31:33 2016
@@ -0,0 +1,33 @@
+//===--- AvoidConstParamsInDecls.h - clang-tidy----------------------------===//
+//
+// 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_AVOID_CONST_PARAMS_IN_DECLS_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_AVOID_CONST_PARAMS_IN_DECLS_H
+
+#include "../ClangTidy.h"
+
+namespace clang {
+namespace tidy {
+namespace readability {
+
+// Detect function declarations that have const value parameters and discourage
+// them.
+class AvoidConstParamsInDecls : public ClangTidyCheck {
+public:
+ using ClangTidyCheck::ClangTidyCheck;
+
+ void registerMatchers(ast_matchers::MatchFinder *Finder) override;
+ void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+};
+
+} // namespace readability
+} // namespace tidy
+} // namespace clang
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_AVOID_CONST_PARAMS_IN_DECLS_H
Modified: clang-tools-extra/trunk/clang-tidy/readability/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/clang-tidy/readability/CMakeLists.txt?rev=264856&r1=264855&r2=264856&view=diff
==============================================================================
--- clang-tools-extra/trunk/clang-tidy/readability/CMakeLists.txt (original)
+++ clang-tools-extra/trunk/clang-tidy/readability/CMakeLists.txt Wed Mar 30 06:31:33 2016
@@ -1,6 +1,7 @@
set(LLVM_LINK_COMPONENTS support)
add_clang_library(clangTidyReadabilityModule
+ AvoidConstParamsInDecls.cpp
BracesAroundStatementsCheck.cpp
ContainerSizeEmptyCheck.cpp
ElseAfterReturnCheck.cpp
Modified: clang-tools-extra/trunk/clang-tidy/readability/ReadabilityTidyModule.cpp
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/clang-tidy/readability/ReadabilityTidyModule.cpp?rev=264856&r1=264855&r2=264856&view=diff
==============================================================================
--- clang-tools-extra/trunk/clang-tidy/readability/ReadabilityTidyModule.cpp (original)
+++ clang-tools-extra/trunk/clang-tidy/readability/ReadabilityTidyModule.cpp Wed Mar 30 06:31:33 2016
@@ -10,6 +10,7 @@
#include "../ClangTidy.h"
#include "../ClangTidyModule.h"
#include "../ClangTidyModuleRegistry.h"
+#include "AvoidConstParamsInDecls.h"
#include "BracesAroundStatementsCheck.h"
#include "ContainerSizeEmptyCheck.h"
#include "ElseAfterReturnCheck.h"
@@ -32,6 +33,8 @@ namespace readability {
class ReadabilityModule : public ClangTidyModule {
public:
void addCheckFactories(ClangTidyCheckFactories &CheckFactories) override {
+ CheckFactories.registerCheck<AvoidConstParamsInDecls>(
+ "readability-avoid-const-params-in-decls");
CheckFactories.registerCheck<BracesAroundStatementsCheck>(
"readability-braces-around-statements");
CheckFactories.registerCheck<ContainerSizeEmptyCheck>(
Modified: clang-tools-extra/trunk/docs/clang-tidy/checks/list.rst
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/docs/clang-tidy/checks/list.rst?rev=264856&r1=264855&r2=264856&view=diff
==============================================================================
--- clang-tools-extra/trunk/docs/clang-tidy/checks/list.rst (original)
+++ clang-tools-extra/trunk/docs/clang-tidy/checks/list.rst Wed Mar 30 06:31:33 2016
@@ -90,8 +90,9 @@ Clang-Tidy Checks
performance-faster-string-find
performance-for-range-copy
performance-implicit-cast-in-loop
- performance-unnecessary-value-param
performance-unnecessary-copy-initialization
+ performance-unnecessary-value-param
+ readability-avoid-const-params-in-decls
readability-braces-around-statements
readability-container-size-empty
readability-else-after-return
Added: clang-tools-extra/trunk/docs/clang-tidy/checks/readability-avoid-const-params-in-decls.rst
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/docs/clang-tidy/checks/readability-avoid-const-params-in-decls.rst?rev=264856&view=auto
==============================================================================
--- clang-tools-extra/trunk/docs/clang-tidy/checks/readability-avoid-const-params-in-decls.rst (added)
+++ clang-tools-extra/trunk/docs/clang-tidy/checks/readability-avoid-const-params-in-decls.rst Wed Mar 30 06:31:33 2016
@@ -0,0 +1,17 @@
+.. title:: clang-tidy - readability-avoid-const-params-in-decls
+
+readability-avoid-const-params-in-decls
+=======================================
+
+Checks whether a function declaration has parameters that are top level const.
+
+`const` values in declarations do not affect the signature of a function, so
+they should not be put there. For example:
+
+Examples:
+
+.. code:: c++
+
+ void f(const string); // Bad: const is top level.
+ void f(const string&); // Good: const is not top level.
+
Added: clang-tools-extra/trunk/test/clang-tidy/readability-avoid-const-params-in-decls.cpp
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/test/clang-tidy/readability-avoid-const-params-in-decls.cpp?rev=264856&view=auto
==============================================================================
--- clang-tools-extra/trunk/test/clang-tidy/readability-avoid-const-params-in-decls.cpp (added)
+++ clang-tools-extra/trunk/test/clang-tidy/readability-avoid-const-params-in-decls.cpp Wed Mar 30 06:31:33 2016
@@ -0,0 +1,78 @@
+// RUN: %check_clang_tidy %s readability-avoid-const-params-in-decls %t
+
+using alias_type = bool;
+using alias_const_type = const bool;
+
+
+void F1(const int i);
+// CHECK-MESSAGES: :[[@LINE-1]]:9: warning: parameter 'i' is const-qualified in the function declaration; const-qualification of parameters only has an effect in function definitions [readability-avoid-const-params-in-decls]
+// CHECK-FIXES: void F1(int i);
+
+void F2(const int *const i);
+// CHECK-MESSAGES: :[[@LINE-1]]:9: warning: parameter 'i' is const-qualified
+// CHECK-FIXES: void F2(const int * i);
+
+void F3(int const i);
+// CHECK-MESSAGES: :[[@LINE-1]]:9: warning: parameter 'i' is const-qualified
+// CHECK-FIXES: void F3(int i);
+
+void F4(alias_type const i);
+// CHECK-MESSAGES: :[[@LINE-1]]:9: warning: parameter 'i' is const-qualified
+// CHECK-FIXES: void F4(alias_type i);
+
+void F5(const int);
+// CHECK-MESSAGES: :[[@LINE-1]]:9: warning: parameter 1 is const-qualified
+// CHECK-FIXES: void F5(int);
+
+void F6(const int *const);
+// CHECK-MESSAGES: :[[@LINE-1]]:9: warning: parameter 1 is const-qualified
+// BUG(b/27584482): void F6(const int *); should be produced
+
+void F7(int, const int);
+// CHECK-MESSAGES: :[[@LINE-1]]:14: warning: parameter 2 is const-qualified
+// CHECK-FIXES: void F7(int, int);
+
+void F8(const int, const int);
+// CHECK-MESSAGES: :[[@LINE-1]]:9: warning: parameter 1 is const-qualified
+// CHECK-MESSAGES: :[[@LINE-2]]:20: warning: parameter 2 is const-qualified
+// CHECK-FIXES: void F8(int, int);
+
+void F9(const int long_name);
+// CHECK-MESSAGES: :[[@LINE-1]]:9: warning: parameter 'long_name'
+// CHECK-FIXES: void F9(int long_name);
+
+void F10(const int *const *const long_name);
+// CHECK-MESSAGES: :[[@LINE-1]]:10: warning: parameter 'long_name'
+// CHECK-FIXES: void F10(const int *const * long_name);
+
+
+struct Foo {
+ Foo(const int i);
+ // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: parameter 'i'
+ // CHECK-FIXES: Foo(int i);
+
+ void operator()(const int i);
+ // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: parameter 'i'
+ // CHECK-FIXES: void operator()(int i);
+};
+
+// Do not match on definitions
+void NF1(const int i) {}
+void NF2(const int *const i) {}
+void NF3(int const i) {}
+void NF4(alias_type const i) {}
+void NF5(const int) {}
+void NF6(const int *const) {}
+void NF7(int, const int) {}
+void NF8(const int, const int) {}
+
+// Do not match on other stuff
+void NF(const alias_type& i);
+void NF(const int &i);
+void NF(const int *i);
+void NF(alias_const_type i);
+void NF(const alias_type&);
+void NF(const int&);
+void NF(const int*);
+void NF(const int* const*);
+void NF(alias_const_type);
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