1 files changed, 52 insertions, 6 deletions

diff --git a/clang-tools-extra/clang-tidy/misc/SuspiciousMissingCommaCheck.cpp b/clang-tools-extra/clang-tidy/misc/SuspiciousMissingCommaCheck.cpp
index a3a479c89b3..be983aa9233 100644
--- a/clang-tools-extra/clang-tidy/misc/SuspiciousMissingCommaCheck.cpp
+++ b/clang-tools-extra/clang-tidy/misc/SuspiciousMissingCommaCheck.cpp
@@ -19,8 +19,51 @@ namespace misc {
 
 namespace {
 
-AST_MATCHER(StringLiteral, isConcatenatedLiteral) {
-  return Node.getNumConcatenated() > 1;
+bool isConcatenatedLiteralsOnPurpose(ASTContext* Ctx,
+                                     const StringLiteral* Lit) {
+  // String literals surrounded by parentheses are assumed to be on purpose.
+  //    i.e.:  const char* Array[] = { ("a" "b" "c"), "d", [...] };
+  auto Parents = Ctx->getParents(*Lit);
+  if (Parents.size() == 1 && Parents[0].get<ParenExpr>() != nullptr)
+    return true;
+
+  // Appropriately indented string literals are assumed to be on purpose.
+  // The following frequent indentation is accepted:
+  //     const char* Array[] = {
+  //       "first literal"
+  //           "indented literal"
+  //           "indented literal",
+  //       "second literal",
+  //       [...]
+  //     };
+  const SourceManager& SM = Ctx->getSourceManager();
+  bool IndentedCorrectly = true;
+  SourceLocation FirstToken = Lit->getStrTokenLoc(0);
+  FileID BaseFID = SM.getFileID(FirstToken);
+  unsigned int BaseIndent = SM.getSpellingColumnNumber(FirstToken);
+  unsigned int BaseLine = SM.getSpellingLineNumber(FirstToken);
+  for (unsigned int TokNum = 1; TokNum < Lit->getNumConcatenated(); ++ TokNum) {
+    SourceLocation Token = Lit->getStrTokenLoc(TokNum);
+    FileID FID = SM.getFileID(Token);
+    unsigned int Indent = SM.getSpellingColumnNumber(Token);
+    unsigned int Line = SM.getSpellingLineNumber(Token);
+    if (FID != BaseFID || Line != BaseLine + TokNum || Indent <= BaseIndent) {
+      IndentedCorrectly = false;
+      break;
+    }
+  }
+  if (IndentedCorrectly)
+    return true;
+
+  // There is no pattern recognized by the checker, assume it's not on purpose.
+  return false;
+}
+
+AST_MATCHER_P(StringLiteral, isConcatenatedLiteral,
+              unsigned, MaxConcatenatedTokens) {
+  return Node.getNumConcatenated() > 1 &&
+         Node.getNumConcatenated() < MaxConcatenatedTokens &&
+         !isConcatenatedLiteralsOnPurpose(&Finder->getASTContext(), &Node);
 }
 
 }  // namespace
@@ -29,17 +72,19 @@ SuspiciousMissingCommaCheck::SuspiciousMissingCommaCheck(
     StringRef Name, ClangTidyContext *Context)
     : ClangTidyCheck(Name, Context),
       SizeThreshold(Options.get("SizeThreshold", 5U)),
-      RatioThreshold(std::stod(Options.get("RatioThreshold", ".2"))) {}
+      RatioThreshold(std::stod(Options.get("RatioThreshold", ".2"))),
+      MaxConcatenatedTokens(Options.get("MaxConcatenatedTokens", 5U)) {}
 
 void SuspiciousMissingCommaCheck::storeOptions(
     ClangTidyOptions::OptionMap &Opts) {
   Options.store(Opts, "SizeThreshold", SizeThreshold);
   Options.store(Opts, "RatioThreshold", std::to_string(RatioThreshold));
+  Options.store(Opts, "MaxConcatenatedTokens", MaxConcatenatedTokens);
 }
 
 void SuspiciousMissingCommaCheck::registerMatchers(MatchFinder *Finder) {
   const auto ConcatenatedStringLiteral =
-      stringLiteral(isConcatenatedLiteral()).bind("str");
+      stringLiteral(isConcatenatedLiteral(MaxConcatenatedTokens)).bind("str");
 
   const auto StringsInitializerList =
       initListExpr(hasType(constantArrayType()),
@@ -51,9 +96,10 @@ void SuspiciousMissingCommaCheck::registerMatchers(MatchFinder *Finder) {
 void SuspiciousMissingCommaCheck::check(
     const MatchFinder::MatchResult &Result) {
   const auto *InitializerList = Result.Nodes.getNodeAs<InitListExpr>("list");
-  const auto *ConcatenatedLiteral = Result.Nodes.getNodeAs<Expr>("str");
+  const auto *ConcatenatedLiteral =
+      Result.Nodes.getNodeAs<StringLiteral>("str");
   assert(InitializerList && ConcatenatedLiteral);
-
+  
   // Skip small arrays as they often generate false-positive.
   unsigned int Size = InitializerList->getNumInits();
   if (Size < SizeThreshold) return;