[clang-tools-extra] r304570 - [clang-tidy] check for __func__/__FUNCTION__ in lambdas
Alexander Kornienko via cfe-commits
cfe-commits at lists.llvm.org
Fri Jun 2 10:36:33 PDT 2017
Author: alexfh
Date: Fri Jun 2 12:36:32 2017
New Revision: 304570
URL: http://llvm.org/viewvc/llvm-project?rev=304570&view=rev
Log:
[clang-tidy] check for __func__/__FUNCTION__ in lambdas
Add a clang-tidy check for using func__/FUNCTION__ inside lambdas. This
evaluates to the string operator(), which is almost never useful and almost
certainly not what the author intended.
Patch by Bryce Liu!
Differential Revision: https://reviews.llvm.org/D33497
Added:
clang-tools-extra/trunk/clang-tidy/misc/LambdaFunctionNameCheck.cpp
clang-tools-extra/trunk/clang-tidy/misc/LambdaFunctionNameCheck.h
clang-tools-extra/trunk/docs/clang-tidy/checks/misc-lambda-function-name.rst
clang-tools-extra/trunk/test/clang-tidy/misc-lambda-function-name.cpp
Modified:
clang-tools-extra/trunk/clang-tidy/misc/CMakeLists.txt
clang-tools-extra/trunk/clang-tidy/misc/MiscTidyModule.cpp
clang-tools-extra/trunk/docs/ReleaseNotes.rst
clang-tools-extra/trunk/docs/clang-tidy/checks/list.rst
Modified: clang-tools-extra/trunk/clang-tidy/misc/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/clang-tidy/misc/CMakeLists.txt?rev=304570&r1=304569&r2=304570&view=diff
==============================================================================
--- clang-tools-extra/trunk/clang-tidy/misc/CMakeLists.txt (original)
+++ clang-tools-extra/trunk/clang-tidy/misc/CMakeLists.txt Fri Jun 2 12:36:32 2017
@@ -4,6 +4,7 @@ add_clang_library(clangTidyMiscModule
ArgumentCommentCheck.cpp
AssertSideEffectCheck.cpp
ForwardingReferenceOverloadCheck.cpp
+ LambdaFunctionNameCheck.cpp
MisplacedConstCheck.cpp
UnconventionalAssignOperatorCheck.cpp
BoolPointerImplicitConversionCheck.cpp
Added: clang-tools-extra/trunk/clang-tidy/misc/LambdaFunctionNameCheck.cpp
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/clang-tidy/misc/LambdaFunctionNameCheck.cpp?rev=304570&view=auto
==============================================================================
--- clang-tools-extra/trunk/clang-tidy/misc/LambdaFunctionNameCheck.cpp (added)
+++ clang-tools-extra/trunk/clang-tidy/misc/LambdaFunctionNameCheck.cpp Fri Jun 2 12:36:32 2017
@@ -0,0 +1,99 @@
+//===--- LambdaFunctionNameCheck.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 "LambdaFunctionNameCheck.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/Frontend/CompilerInstance.h"
+#include "clang/Lex/MacroInfo.h"
+#include "clang/Lex/Preprocessor.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang {
+namespace tidy {
+namespace misc {
+
+namespace {
+
+// Keep track of macro expansions that contain both __FILE__ and __LINE__. If
+// such a macro also uses __func__ or __FUNCTION__, we don't want to issue a
+// warning because __FILE__ and __LINE__ may be useful even if __func__ or
+// __FUNCTION__ is not, especially if the macro could be used in the context of
+// either a function body or a lambda body.
+class MacroExpansionsWithFileAndLine : public PPCallbacks {
+public:
+ explicit MacroExpansionsWithFileAndLine(
+ LambdaFunctionNameCheck::SourceRangeSet *SME)
+ : SuppressMacroExpansions(SME) {}
+
+ void MacroExpands(const Token &MacroNameTok,
+ const MacroDefinition &MD, SourceRange Range,
+ const MacroArgs *Args) override {
+ bool has_file = false;
+ bool has_line = false;
+ for (const auto& T : MD.getMacroInfo()->tokens()) {
+ if (T.is(tok::identifier)) {
+ StringRef IdentName = T.getIdentifierInfo()->getName();
+ if (IdentName == "__FILE__") {
+ has_file = true;
+ } else if (IdentName == "__LINE__") {
+ has_line = true;
+ }
+ }
+ }
+ if (has_file && has_line) {
+ SuppressMacroExpansions->insert(Range);
+ }
+ }
+
+private:
+ LambdaFunctionNameCheck::SourceRangeSet* SuppressMacroExpansions;
+};
+
+} // namespace
+
+void LambdaFunctionNameCheck::registerMatchers(MatchFinder *Finder) {
+ // Match on PredefinedExprs inside a lambda.
+ Finder->addMatcher(predefinedExpr(hasAncestor(lambdaExpr())).bind("E"),
+ this);
+}
+
+void LambdaFunctionNameCheck::registerPPCallbacks(CompilerInstance &Compiler) {
+ Compiler.getPreprocessor().addPPCallbacks(
+ llvm::make_unique<MacroExpansionsWithFileAndLine>(
+ &SuppressMacroExpansions));
+}
+
+void LambdaFunctionNameCheck::check(const MatchFinder::MatchResult &Result) {
+ const auto *E = Result.Nodes.getNodeAs<PredefinedExpr>("E");
+ if (E->getIdentType() != PredefinedExpr::Func &&
+ E->getIdentType() != PredefinedExpr::Function) {
+ // We don't care about other PredefinedExprs.
+ return;
+ }
+ if (E->getLocation().isMacroID()) {
+ auto ER =
+ Result.SourceManager->getImmediateExpansionRange(E->getLocation());
+ if (SuppressMacroExpansions.find(SourceRange(ER.first, ER.second)) !=
+ SuppressMacroExpansions.end()) {
+ // This is a macro expansion for which we should not warn.
+ return;
+ }
+ }
+ diag(E->getLocation(),
+ "inside a lambda, '%0' expands to the name of the function call "
+ "operator; consider capturing the name of the enclosing function "
+ "explicitly")
+ << PredefinedExpr::getIdentTypeName(E->getIdentType());
+}
+
+} // namespace misc
+} // namespace tidy
+} // namespace clang
Added: clang-tools-extra/trunk/clang-tidy/misc/LambdaFunctionNameCheck.h
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/clang-tidy/misc/LambdaFunctionNameCheck.h?rev=304570&view=auto
==============================================================================
--- clang-tools-extra/trunk/clang-tidy/misc/LambdaFunctionNameCheck.h (added)
+++ clang-tools-extra/trunk/clang-tidy/misc/LambdaFunctionNameCheck.h Fri Jun 2 12:36:32 2017
@@ -0,0 +1,51 @@
+//===--- LambdaFunctionNameCheck.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_MISC_LAMBDA_FUNCTION_NAME_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MISC_LAMBDA_FUNCTION_NAME_H
+
+#include "../ClangTidy.h"
+
+namespace clang {
+namespace tidy {
+namespace misc {
+
+/// Detect when __func__ or __FUNCTION__ is being used from within a lambda. In
+/// that context, those expressions expand to the name of the call operator
+/// (i.e., `operator()`).
+///
+/// For the user-facing documentation see:
+/// http://clang.llvm.org/extra/clang-tidy/checks/misc-lambda-function-name.html
+class LambdaFunctionNameCheck : public ClangTidyCheck {
+public:
+ struct SourceRangeLessThan {
+ bool operator()(const SourceRange &L, const SourceRange &R) {
+ if (L.getBegin() == R.getBegin()) {
+ return L.getEnd() < R.getEnd();
+ }
+ return L.getBegin() < R.getBegin();
+ }
+ };
+ using SourceRangeSet = std::set<SourceRange, SourceRangeLessThan>;
+
+ LambdaFunctionNameCheck(StringRef Name, ClangTidyContext *Context)
+ : ClangTidyCheck(Name, Context) {}
+ void registerMatchers(ast_matchers::MatchFinder *Finder) override;
+ void registerPPCallbacks(CompilerInstance &Compiler) override;
+ void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+
+private:
+ SourceRangeSet SuppressMacroExpansions;
+};
+
+} // namespace misc
+} // namespace tidy
+} // namespace clang
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MISC_LAMBDA_FUNCTION_NAME_H
Modified: clang-tools-extra/trunk/clang-tidy/misc/MiscTidyModule.cpp
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/clang-tidy/misc/MiscTidyModule.cpp?rev=304570&r1=304569&r2=304570&view=diff
==============================================================================
--- clang-tools-extra/trunk/clang-tidy/misc/MiscTidyModule.cpp (original)
+++ clang-tools-extra/trunk/clang-tidy/misc/MiscTidyModule.cpp Fri Jun 2 12:36:32 2017
@@ -21,6 +21,7 @@
#include "InaccurateEraseCheck.h"
#include "IncorrectRoundings.h"
#include "InefficientAlgorithmCheck.h"
+#include "LambdaFunctionNameCheck.h"
#include "MacroParenthesesCheck.h"
#include "MacroRepeatedSideEffectsCheck.h"
#include "MisplacedConstCheck.h"
@@ -68,6 +69,8 @@ public:
"misc-assert-side-effect");
CheckFactories.registerCheck<ForwardingReferenceOverloadCheck>(
"misc-forwarding-reference-overload");
+ CheckFactories.registerCheck<LambdaFunctionNameCheck>(
+ "misc-lambda-function-name");
CheckFactories.registerCheck<MisplacedConstCheck>("misc-misplaced-const");
CheckFactories.registerCheck<UnconventionalAssignOperatorCheck>(
"misc-unconventional-assign-operator");
Modified: clang-tools-extra/trunk/docs/ReleaseNotes.rst
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/docs/ReleaseNotes.rst?rev=304570&r1=304569&r2=304570&view=diff
==============================================================================
--- clang-tools-extra/trunk/docs/ReleaseNotes.rst (original)
+++ clang-tools-extra/trunk/docs/ReleaseNotes.rst Fri Jun 2 12:36:32 2017
@@ -77,6 +77,11 @@ Improvements to clang-tidy
Finds perfect forwarding constructors that can unintentionally hide copy or move constructors.
+- New `misc-lambda-function-name
+ <http://clang.llvm.org/extra/clang-tidy/checks/misc-lambda-function-name.html>`_ check
+
+ Finds uses of ``__func__`` or ``__FUNCTION__`` inside lambdas.
+
- New `modernize-replace-random-shuffle
<http://clang.llvm.org/extra/clang-tidy/checks/modernize-replace-random-shuffle.html>`_ check
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=304570&r1=304569&r2=304570&view=diff
==============================================================================
--- clang-tools-extra/trunk/docs/clang-tidy/checks/list.rst (original)
+++ clang-tools-extra/trunk/docs/clang-tidy/checks/list.rst Fri Jun 2 12:36:32 2017
@@ -82,6 +82,7 @@ Clang-Tidy Checks
misc-inaccurate-erase
misc-incorrect-roundings
misc-inefficient-algorithm
+ misc-lambda-function-name
misc-macro-parentheses
misc-macro-repeated-side-effects
misc-misplaced-const
Added: clang-tools-extra/trunk/docs/clang-tidy/checks/misc-lambda-function-name.rst
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/docs/clang-tidy/checks/misc-lambda-function-name.rst?rev=304570&view=auto
==============================================================================
--- clang-tools-extra/trunk/docs/clang-tidy/checks/misc-lambda-function-name.rst (added)
+++ clang-tools-extra/trunk/docs/clang-tidy/checks/misc-lambda-function-name.rst Fri Jun 2 12:36:32 2017
@@ -0,0 +1,27 @@
+.. title:: clang-tidy - misc-lambda-function-name
+
+misc-lambda-function-name
+=========================
+
+Checks for attempts to get the name of a function from within a lambda
+expression. The name of a lambda is always something like ``operator()``, which
+is almost never what was intended.
+
+Example:
+
+.. code-block:: c++
+
+ void FancyFunction() {
+ [] { printf("Called from %s\n", __func__); }();
+ [] { printf("Now called from %s\n", __FUNCTION__); }();
+ }
+
+Output::
+
+ Called from operator()
+ Now called from operator()
+
+Likely intended output::
+
+ Called from FancyFunction
+ Now called from FancyFunction
Added: clang-tools-extra/trunk/test/clang-tidy/misc-lambda-function-name.cpp
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/test/clang-tidy/misc-lambda-function-name.cpp?rev=304570&view=auto
==============================================================================
--- clang-tools-extra/trunk/test/clang-tidy/misc-lambda-function-name.cpp (added)
+++ clang-tools-extra/trunk/test/clang-tidy/misc-lambda-function-name.cpp Fri Jun 2 12:36:32 2017
@@ -0,0 +1,41 @@
+// RUN: %check_clang_tidy %s misc-lambda-function-name %t
+
+void Foo(const char* a, const char* b, int c) {}
+
+#define FUNC_MACRO Foo(__func__, "", 0)
+#define FUNCTION_MACRO Foo(__FUNCTION__, "", 0)
+#define EMBED_IN_ANOTHER_MACRO1 FUNC_MACRO
+
+void Positives() {
+ [] { __func__; }();
+ // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: inside a lambda, '__func__' expands to the name of the function call operator; consider capturing the name of the enclosing function explicitly [misc-lambda-function-name]
+ [] { __FUNCTION__; }();
+ // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: inside a lambda, '__FUNCTION__' expands to the name of the function call operator; consider capturing the name of the enclosing function explicitly [misc-lambda-function-name]
+ [] { FUNC_MACRO; }();
+ // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: inside a lambda, '__func__' expands to the name of the function call operator; consider capturing the name of the enclosing function explicitly [misc-lambda-function-name]
+ [] { FUNCTION_MACRO; }();
+ // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: inside a lambda, '__FUNCTION__' expands to the name of the function call operator; consider capturing the name of the enclosing function explicitly [misc-lambda-function-name]
+ [] { EMBED_IN_ANOTHER_MACRO1; }();
+ // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: inside a lambda, '__func__' expands to the name of the function call operator; consider capturing the name of the enclosing function explicitly [misc-lambda-function-name]
+}
+
+#define FUNC_MACRO_WITH_FILE_AND_LINE Foo(__func__, __FILE__, __LINE__)
+#define FUNCTION_MACRO_WITH_FILE_AND_LINE Foo(__FUNCTION__, __FILE__, __LINE__)
+#define EMBED_IN_ANOTHER_MACRO2 FUNC_MACRO_WITH_FILE_AND_LINE
+
+void Negatives() {
+ __func__;
+ __FUNCTION__;
+
+ // __PRETTY_FUNCTION__ should not trigger a warning because its value is
+ // actually potentially useful.
+ __PRETTY_FUNCTION__;
+ [] { __PRETTY_FUNCTION__; }();
+
+ // Don't warn if __func__/__FUNCTION is used inside a macro that also uses
+ // __FILE__ and __LINE__, on the assumption that __FILE__ and __LINE__ will
+ // be useful even if __func__/__FUNCTION__ is not.
+ [] { FUNC_MACRO_WITH_FILE_AND_LINE; }();
+ [] { FUNCTION_MACRO_WITH_FILE_AND_LINE; }();
+ [] { EMBED_IN_ANOTHER_MACRO2; }();
+}
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