diff options
7 files changed, 195 insertions, 0 deletions
diff --git a/clang-tools-extra/clang-tidy/misc/CMakeLists.txt b/clang-tools-extra/clang-tidy/misc/CMakeLists.txt index 1c200953e00..fdfa26e6d05 100644 --- a/clang-tools-extra/clang-tidy/misc/CMakeLists.txt +++ b/clang-tools-extra/clang-tidy/misc/CMakeLists.txt @@ -23,6 +23,7 @@ add_clang_library(clangTidyMiscModule SizeofContainerCheck.cpp StaticAssertCheck.cpp StringIntegerAssignmentCheck.cpp + SuspiciousMissingCommaCheck.cpp SuspiciousSemicolonCheck.cpp SwappedArgumentsCheck.cpp ThrowByValueCatchByReferenceCheck.cpp diff --git a/clang-tools-extra/clang-tidy/misc/MiscTidyModule.cpp b/clang-tools-extra/clang-tidy/misc/MiscTidyModule.cpp index 2da30b7c58e..7dc8a217389 100644 --- a/clang-tools-extra/clang-tidy/misc/MiscTidyModule.cpp +++ b/clang-tools-extra/clang-tidy/misc/MiscTidyModule.cpp @@ -31,6 +31,7 @@ #include "SizeofContainerCheck.h" #include "StaticAssertCheck.h" #include "StringIntegerAssignmentCheck.h" +#include "SuspiciousMissingCommaCheck.h" #include "SuspiciousSemicolonCheck.h" #include "SwappedArgumentsCheck.h" #include "ThrowByValueCatchByReferenceCheck.h" @@ -88,6 +89,8 @@ public: "misc-static-assert"); CheckFactories.registerCheck<StringIntegerAssignmentCheck>( "misc-string-integer-assignment"); + CheckFactories.registerCheck<SuspiciousMissingCommaCheck>( + "misc-suspicious-missing-comma"); CheckFactories.registerCheck<SuspiciousSemicolonCheck>( "misc-suspicious-semicolon"); CheckFactories.registerCheck<SwappedArgumentsCheck>( diff --git a/clang-tools-extra/clang-tidy/misc/SuspiciousMissingCommaCheck.cpp b/clang-tools-extra/clang-tidy/misc/SuspiciousMissingCommaCheck.cpp new file mode 100644 index 00000000000..a3a479c89b3 --- /dev/null +++ b/clang-tools-extra/clang-tidy/misc/SuspiciousMissingCommaCheck.cpp @@ -0,0 +1,80 @@ +//===--- SuspiciousMissingCommaCheck.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 "SuspiciousMissingCommaCheck.h" +#include "clang/AST/ASTContext.h" +#include "clang/ASTMatchers/ASTMatchFinder.h" + +using namespace clang::ast_matchers; + +namespace clang { +namespace tidy { +namespace misc { + +namespace { + +AST_MATCHER(StringLiteral, isConcatenatedLiteral) { + return Node.getNumConcatenated() > 1; +} + +} // namespace + +SuspiciousMissingCommaCheck::SuspiciousMissingCommaCheck( + StringRef Name, ClangTidyContext *Context) + : ClangTidyCheck(Name, Context), + SizeThreshold(Options.get("SizeThreshold", 5U)), + RatioThreshold(std::stod(Options.get("RatioThreshold", ".2"))) {} + +void SuspiciousMissingCommaCheck::storeOptions( + ClangTidyOptions::OptionMap &Opts) { + Options.store(Opts, "SizeThreshold", SizeThreshold); + Options.store(Opts, "RatioThreshold", std::to_string(RatioThreshold)); +} + +void SuspiciousMissingCommaCheck::registerMatchers(MatchFinder *Finder) { + const auto ConcatenatedStringLiteral = + stringLiteral(isConcatenatedLiteral()).bind("str"); + + const auto StringsInitializerList = + initListExpr(hasType(constantArrayType()), + has(expr(ignoringImpCasts(ConcatenatedStringLiteral)))); + + Finder->addMatcher(StringsInitializerList.bind("list"), this); +} + +void SuspiciousMissingCommaCheck::check( + const MatchFinder::MatchResult &Result) { + const auto *InitializerList = Result.Nodes.getNodeAs<InitListExpr>("list"); + const auto *ConcatenatedLiteral = Result.Nodes.getNodeAs<Expr>("str"); + assert(InitializerList && ConcatenatedLiteral); + + // Skip small arrays as they often generate false-positive. + unsigned int Size = InitializerList->getNumInits(); + if (Size < SizeThreshold) return; + + // Count the number of occurence of concatenated string literal. + unsigned int Count = 0; + for (unsigned int i = 0; i < Size; ++i) { + const Expr *Child = InitializerList->getInit(i)->IgnoreImpCasts(); + if (const auto *Literal = dyn_cast<StringLiteral>(Child)) { + if (Literal->getNumConcatenated() > 1) ++Count; + } + } + + // Warn only when concatenation is not common in this initializer list. + // The current threshold is set to less than 1/5 of the string literals. + if (double(Count) / Size > RatioThreshold) return; + + diag(ConcatenatedLiteral->getLocStart(), + "suspicious string literal, probably missing a comma"); +} + +} // namespace misc +} // namespace tidy +} // namespace clang diff --git a/clang-tools-extra/clang-tidy/misc/SuspiciousMissingCommaCheck.h b/clang-tools-extra/clang-tidy/misc/SuspiciousMissingCommaCheck.h new file mode 100644 index 00000000000..209d7fb2bf5 --- /dev/null +++ b/clang-tools-extra/clang-tidy/misc/SuspiciousMissingCommaCheck.h @@ -0,0 +1,41 @@ +//===--- SuspiciousMissingCommaCheck.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_SUSPICIOUS_MISSING_COMMA_H +#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MISC_SUSPICIOUS_MISSING_COMMA_H + +#include "../ClangTidy.h" + +namespace clang { +namespace tidy { +namespace misc { + +/// This check finds string literals which are probably concatenated accidentally. +/// +/// For the user-facing documentation see: +/// http://clang.llvm.org/extra/clang-tidy/checks/misc-suspicious-missing-comma.html +class SuspiciousMissingCommaCheck : public ClangTidyCheck { +public: + SuspiciousMissingCommaCheck(StringRef Name, ClangTidyContext *Context); + void storeOptions(ClangTidyOptions::OptionMap &Opts) override; + void registerMatchers(ast_matchers::MatchFinder *Finder) override; + void check(const ast_matchers::MatchFinder::MatchResult &Result) override; + +private: + // Minimal size of a string literals array to be considered by the checker. + const unsigned SizeThreshold; + // Maximal threshold ratio of suspicious string literals to be considered. + const double RatioThreshold; +}; + +} // namespace misc +} // namespace tidy +} // namespace clang + +#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MISC_SUSPICIOUS_MISSING_COMMA_H diff --git a/clang-tools-extra/docs/clang-tidy/checks/list.rst b/clang-tools-extra/docs/clang-tidy/checks/list.rst index 912b04ae6f3..c80ea50f072 100644 --- a/clang-tools-extra/docs/clang-tidy/checks/list.rst +++ b/clang-tools-extra/docs/clang-tidy/checks/list.rst @@ -66,6 +66,7 @@ Clang-Tidy Checks misc-sizeof-container misc-static-assert misc-string-integer-assignment + misc-suspicious-missing-comma misc-suspicious-semicolon misc-swapped-arguments misc-throw-by-value-catch-by-reference diff --git a/clang-tools-extra/docs/clang-tidy/checks/misc-suspicious-missing-comma.rst b/clang-tools-extra/docs/clang-tidy/checks/misc-suspicious-missing-comma.rst new file mode 100644 index 00000000000..e46566a3491 --- /dev/null +++ b/clang-tools-extra/docs/clang-tidy/checks/misc-suspicious-missing-comma.rst @@ -0,0 +1,35 @@ +.. title:: clang-tidy - misc-suspicious-missing-comma + +misc-suspicious-missing-comma +============================= + +String literals placed side-by-side are concatenated at translation phase 6 +(after the preprocessor). This feature is used to represent long string +literal on multiple lines. + +For instance, these declarations are equivalent: + const char* A[] = "This is a test"; + const char* B[] = "This" " is a " + "test"; + +A common mistake done by programmers is to forget a comma between two string +literals in an array initializer list. + + const char* Test[] = { + "line 1", + "line 2" // Missing comma! + "line 3", + "line 4", + "line 5" + }; + +The array contains the string "line 2line3" at offset 1 (i.e. Test[1]). Clang +won't generate warnings at compile time. + +This checker may warn incorrectly on cases like: + + const char* SupportedFormat[] = { + "Error %s", + "Code " PRIu64, // May warn here. + "Warning %s", + }; diff --git a/clang-tools-extra/test/clang-tidy/misc-suspicious-missing-comma.cpp b/clang-tools-extra/test/clang-tidy/misc-suspicious-missing-comma.cpp new file mode 100644 index 00000000000..7b64fab45e8 --- /dev/null +++ b/clang-tools-extra/test/clang-tidy/misc-suspicious-missing-comma.cpp @@ -0,0 +1,34 @@ +// RUN: %check_clang_tidy %s misc-suspicious-missing-comma %t + +const char* Cartoons[] = { + "Bugs Bunny", + "Homer Simpson", + "Mickey Mouse", + "Bart Simpson", + "Charlie Brown" // There is a missing comma here. + "Fred Flintstone", + "Popeye", +}; +// CHECK-MESSAGES: :[[@LINE-4]]:3: warning: suspicious string literal, probably missing a comma [misc-suspicious-missing-comma] + +const wchar_t* Colors[] = { + L"Red", L"Yellow", L"Blue", L"Green", L"Purple", L"Rose", L"White", L"Black" +}; + +// The following array should not trigger any warnings. +const char* HttpCommands[] = { + "GET / HTTP/1.0\r\n" + "\r\n", + + "GET /index.html HTTP/1.0\r\n" + "\r\n", + + "GET /favicon.ico HTTP/1.0\r\n" + "header: dummy" + "\r\n", +}; + +// This array is too small to trigger a warning. +const char* SmallArray[] = { + "a" "b", "c" +}; |
