[clang-tidy] Fix an abseil-redundant-strcat-calls crash on 0-parameter StrCat().

Differential Revision: https://reviews.llvm.org/D91601

diff --git a/clang-tools-extra/clang-tidy/abseil/RedundantStrcatCallsCheck.cpp b/clang-tools-extra/clang-tidy/abseil/RedundantStrcatCallsCheck.cpp
index e7d0377..be3fa9a 100644 (file)
--- a/clang-tools-extra/clang-tidy/abseil/RedundantStrcatCallsCheck.cpp
+++ b/clang-tools-extra/clang-tidy/abseil/RedundantStrcatCallsCheck.cpp
@@ -47,6 +47,8 @@ struct StrCatCheckResult {
 };
 
 void RemoveCallLeaveArgs(const CallExpr* Call, StrCatCheckResult* CheckResult) {
+  if (Call->getNumArgs() == 0)
+    return;
   // Remove 'Foo('
   CheckResult->Hints.push_back(
       FixItHint::CreateRemoval(CharSourceRange::getCharRange(

diff --git a/clang-tools-extra/test/clang-tidy/checkers/abseil-redundant-strcat-calls.cpp b/clang-tools-extra/test/clang-tidy/checkers/abseil-redundant-strcat-calls.cpp
index 3afbac5..dad8ef8 100644 (file)
--- a/clang-tools-extra/test/clang-tidy/checkers/abseil-redundant-strcat-calls.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/abseil-redundant-strcat-calls.cpp
@@ -121,6 +121,7 @@ struct AlphaNum {
   AlphaNum &operator=(const AlphaNum &);
 };
 
+string StrCat();
 string StrCat(const AlphaNum &A);
 string StrCat(const AlphaNum &A, const AlphaNum &B);
 string StrCat(const AlphaNum &A, const AlphaNum &B, const AlphaNum &C);
@@ -182,6 +183,9 @@ void Positives() {
   StrAppend(&S, StrCat(1, 2, 3, 4, 5), StrCat(6, 7, 8, 9, 10));
   // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: multiple calls to 'absl::StrCat' can be flattened into a single call
   // CHECK-FIXES: StrAppend(&S, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
+
+  StrCat(1, StrCat());
+  // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: multiple calls to 'absl::StrCat' can be flattened into a single call
 }
 
 void Negatives() {