[PATCH] D73843: [clang-tidy] Fix false positive for cppcoreguidelines-init-variables

[Nathan James via Phabricator via cfe-commits]

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njames93 retitled this revision from "[clang-tidt] Fix false positive for cppcoreguidelines-init-variables" to "[clang-tidy] Fix false positive for cppcoreguidelines-init-variables".
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================
Comment at: clang-tools-extra/clang-tidy/cppcoreguidelines/InitVariablesCheck.cpp:37
+              optionally(hasParent(declStmt(hasParent(
+                  cxxForRangeStmt(hasLoopVariable(varDecl().bind(BadDecl))))))),
+              unless(equalsBoundNode(BadDecl)))
----------------
No point checking if its a template definition or not. According to the standard it's not possible to have a for range statement where the loop variable isn't initialized.


Fixes False positive for cppcoreguidelines-init-variables in range based for loop in template function <https://bugs.llvm.org/show_bug.cgi?id=44746>


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D73843

Files:
  clang-tools-extra/clang-tidy/cppcoreguidelines/InitVariablesCheck.cpp
  clang-tools-extra/test/clang-tidy/checkers/cppcoreguidelines-init-variables.cpp


Index: clang-tools-extra/test/clang-tidy/checkers/cppcoreguidelines-init-variables.cpp
===================================================================
--- clang-tools-extra/test/clang-tidy/checkers/cppcoreguidelines-init-variables.cpp
+++ clang-tools-extra/test/clang-tidy/checkers/cppcoreguidelines-init-variables.cpp
@@ -78,3 +78,9 @@
   int parens(42);
   int braces{42};
 }
+
+template <typename RANGE>
+void f(RANGE r) {
+  for (char c : r) {
+  }
+}
Index: clang-tools-extra/clang-tidy/cppcoreguidelines/InitVariablesCheck.cpp
===================================================================
--- clang-tools-extra/clang-tidy/cppcoreguidelines/InitVariablesCheck.cpp
+++ clang-tools-extra/clang-tidy/cppcoreguidelines/InitVariablesCheck.cpp
@@ -29,11 +29,15 @@
       MathHeader(Options.get("MathHeader", "math.h")) {}
 
 void InitVariablesCheck::registerMatchers(MatchFinder *Finder) {
-  Finder->addMatcher(varDecl(unless(hasInitializer(anything())),
-                             unless(isInstantiated()), isLocalVarDecl(),
-                             unless(isStaticLocal()), isDefinition())
-                         .bind("vardecl"),
-                     this);
+  std::string BadDecl = "badDecl";
+  Finder->addMatcher(
+      varDecl(unless(hasInitializer(anything())), unless(isInstantiated()),
+              isLocalVarDecl(), unless(isStaticLocal()), isDefinition(),
+              optionally(hasParent(declStmt(hasParent(
+                  cxxForRangeStmt(hasLoopVariable(varDecl().bind(BadDecl))))))),
+              unless(equalsBoundNode(BadDecl)))
+          .bind("vardecl"),
+      this);
 }
 
 void InitVariablesCheck::registerPPCallbacks(const SourceManager &SM,


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