Stop collecting when we got two VarDecls from DS1

Author: flovent

clang-tools-extra/clang-tidy/modernize/UseStructuredBindingCheck.cpp

@@ -55,10 +55,9 @@ matchTwoVarDecl(const DeclStmt *DS1, const DeclStmt *DS2,
     return true;
   };
 
-  if (!CollectVarsInDeclStmt(DS1) || !CollectVarsInDeclStmt(DS2))
-    return false;
-
-  if (Vars.size() != 2)
+  // If we already get two VarDecls, then don't need to collect from DS2.
+  if (!CollectVarsInDeclStmt(DS1) ||
+      (Vars.size() != 2 && !CollectVarsInDeclStmt(DS2)) || Vars.size() != 2)
     return false;
 
   if (InnerMatcher1.matches(*Vars[0].first, Finder, Builder) &&

clang-tools-extra/test/clang-tidy/checkers/modernize/use-structured-binding.cpp

@@ -32,6 +32,15 @@ void DecomposeByAssignWarnCases() {
     // CHECK-FIXES-ALL: // REMOVE
   }
 
+  {
+    auto P = getPair<int, int>();
+    // CHECK-MESSAGES-ALL: :[[@LINE-1]]:5: warning: use structured binding to decompose a pair [modernize-use-structured-binding]
+    // CHECK-FIXES-ALL: auto [x, y] = getPair<int, int>();
+    int x = P.first, y = P.second; // REMOVE
+    // CHECK-FIXES-ALL: // REMOVE
+    int z;
+  }
+
   {
     auto P = getPair<int, int>();
     // CHECK-MESSAGES-ALL: :[[@LINE-1]]:5: warning: use structured binding to decompose a pair [modernize-use-structured-binding]
@@ -93,6 +102,14 @@ void forRangeWarnCases() {
     // CHECK-FIXES-ALL: // REMOVE
   }
 
+  for (auto P : Pairs) {
+    // CHECK-MESSAGES-ALL: :[[@LINE-1]]:8: warning: use structured binding to decompose a pair [modernize-use-structured-binding]
+    // CHECK-FIXES-ALL: for (auto [x, y] : Pairs) {
+    int x = P.first, y = P.second; // REMOVE
+    // CHECK-FIXES-ALL: // REMOVE
+    int z;
+  }
+
   for (const auto P : Pairs) {
     // CHECK-MESSAGES-ALL: :[[@LINE-1]]:8: warning: use structured binding to decompose a pair [modernize-use-structured-binding]
     // CHECK-FIXES-ALL: for (const auto [x, y] : Pairs) {