[clang-tidy] White List Option for performance-unnecessary-value-param, performance-unnecessary-copy-initialization and performance-for-range-copy

New option added to these three checks to be able to silence false positives on
types that are intentionally passed by value or copied. Such types are e.g.
intrusive reference counting pointer types like llvm::IntrusiveRefCntPtr. The
new option is named WhiteListTypes and can contain a semicolon-separated list of
names of these types. Regular expressions are allowed. Default is empty.

Differential Revision: https://reviews.llvm.org/D52727

llvm-svn: 344340

6 files changed, 51 insertions, 11 deletions

diff --git a/clang-tools-extra/clang-tidy/performance/ForRangeCopyCheck.cpp b/clang-tools-extra/clang-tidy/performance/ForRangeCopyCheck.cpp
index d60a2f349f6..4b90df43aed 100644
--- a/clang-tools-extra/clang-tidy/performance/ForRangeCopyCheck.cpp
+++ b/clang-tools-extra/clang-tidy/performance/ForRangeCopyCheck.cpp
@@ -10,6 +10,8 @@
 #include "ForRangeCopyCheck.h"
 #include "../utils/DeclRefExprUtils.h"
 #include "../utils/FixItHintUtils.h"
+#include "../utils/Matchers.h"
+#include "../utils/OptionsUtils.h"
 #include "../utils/TypeTraits.h"
 #include "clang/Analysis/Analyses/ExprMutationAnalyzer.h"
 
@@ -21,10 +23,14 @@ namespace performance {
 
 ForRangeCopyCheck::ForRangeCopyCheck(StringRef Name, ClangTidyContext *Context)
     : ClangTidyCheck(Name, Context),
-      WarnOnAllAutoCopies(Options.get("WarnOnAllAutoCopies", 0)) {}
+      WarnOnAllAutoCopies(Options.get("WarnOnAllAutoCopies", 0)),
+      AllowedTypes(
+          utils::options::parseStringList(Options.get("AllowedTypes", ""))) {}
 
 void ForRangeCopyCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
   Options.store(Opts, "WarnOnAllAutoCopies", WarnOnAllAutoCopies);
+  Options.store(Opts, "AllowedTypes",
+                utils::options::serializeStringList(AllowedTypes));
 }
 
 void ForRangeCopyCheck::registerMatchers(MatchFinder *Finder) {
@@ -32,7 +38,10 @@ void ForRangeCopyCheck::registerMatchers(MatchFinder *Finder) {
   // initialized through MaterializeTemporaryExpr which indicates a type
   // conversion.
   auto LoopVar = varDecl(
-      hasType(hasCanonicalType(unless(anyOf(referenceType(), pointerType())))),
+      hasType(qualType(
+          unless(anyOf(hasCanonicalType(anyOf(referenceType(), pointerType())),
+                       hasDeclaration(namedDecl(
+                           matchers::matchesAnyListedName(AllowedTypes))))))),
       unless(hasInitializer(expr(hasDescendant(materializeTemporaryExpr())))));
   Finder->addMatcher(cxxForRangeStmt(hasLoopVariable(LoopVar.bind("loopVar")))
                          .bind("forRange"),
@@ -41,6 +50,7 @@ void ForRangeCopyCheck::registerMatchers(MatchFinder *Finder) {
 
 void ForRangeCopyCheck::check(const MatchFinder::MatchResult &Result) {
   const auto *Var = Result.Nodes.getNodeAs<VarDecl>("loopVar");
+
   // Ignore code in macros since we can't place the fixes correctly.
   if (Var->getBeginLoc().isMacroID())
     return;
diff --git a/clang-tools-extra/clang-tidy/performance/ForRangeCopyCheck.h b/clang-tools-extra/clang-tidy/performance/ForRangeCopyCheck.h
index f88a126e5d7..de8b2c911db 100644
--- a/clang-tools-extra/clang-tidy/performance/ForRangeCopyCheck.h
+++ b/clang-tools-extra/clang-tidy/performance/ForRangeCopyCheck.h
@@ -40,6 +40,7 @@ private:
                                        ASTContext &Context);
 
   const bool WarnOnAllAutoCopies;
+  const std::vector<std::string> AllowedTypes;
 };
 
 } // namespace performance
diff --git a/clang-tools-extra/clang-tidy/performance/UnnecessaryCopyInitialization.cpp b/clang-tools-extra/clang-tidy/performance/UnnecessaryCopyInitialization.cpp
index 177497c41b8..ef6bcd6f649 100644
--- a/clang-tools-extra/clang-tidy/performance/UnnecessaryCopyInitialization.cpp
+++ b/clang-tools-extra/clang-tidy/performance/UnnecessaryCopyInitialization.cpp
@@ -12,6 +12,7 @@
 #include "../utils/DeclRefExprUtils.h"
 #include "../utils/FixItHintUtils.h"
 #include "../utils/Matchers.h"
+#include "../utils/OptionsUtils.h"
 
 namespace clang {
 namespace tidy {
@@ -30,6 +31,12 @@ void recordFixes(const VarDecl &Var, ASTContext &Context,
 using namespace ::clang::ast_matchers;
 using utils::decl_ref_expr::isOnlyUsedAsConst;
 
+UnnecessaryCopyInitialization::UnnecessaryCopyInitialization(
+    StringRef Name, ClangTidyContext *Context)
+    : ClangTidyCheck(Name, Context),
+      AllowedTypes(
+          utils::options::parseStringList(Options.get("AllowedTypes", ""))) {}
+
 void UnnecessaryCopyInitialization::registerMatchers(MatchFinder *Finder) {
   auto ConstReference = referenceType(pointee(qualType(isConstQualified())));
   auto ConstOrConstReference =
@@ -50,12 +57,17 @@ void UnnecessaryCopyInitialization::registerMatchers(MatchFinder *Finder) {
       callExpr(callee(functionDecl(returns(ConstReference))),
                unless(callee(cxxMethodDecl())));
 
-  auto localVarCopiedFrom = [](const internal::Matcher<Expr> &CopyCtorArg) {
+  auto localVarCopiedFrom = [this](const internal::Matcher<Expr> &CopyCtorArg) {
     return compoundStmt(
                forEachDescendant(
                    declStmt(
                        has(varDecl(hasLocalStorage(),
-                                   hasType(matchers::isExpensiveToCopy()),
+                                   hasType(qualType(
+                                       allOf(hasCanonicalType(
+                                                 matchers::isExpensiveToCopy()),
+                                             unless(hasDeclaration(namedDecl(
+                                                 matchers::matchesAnyListedName(
+                                                     AllowedTypes))))))),
                                    unless(isImplicit()),
                                    hasInitializer(
                                        cxxConstructExpr(
@@ -84,6 +96,7 @@ void UnnecessaryCopyInitialization::check(
   const auto *ObjectArg = Result.Nodes.getNodeAs<VarDecl>("objectArg");
   const auto *BlockStmt = Result.Nodes.getNodeAs<Stmt>("blockStmt");
   const auto *CtorCall = Result.Nodes.getNodeAs<CXXConstructExpr>("ctorCall");
+
   // Do not propose fixes if the DeclStmt has multiple VarDecls or in macros
   // since we cannot place them correctly.
   bool IssueFix =
@@ -144,6 +157,12 @@ void UnnecessaryCopyInitialization::handleCopyFromLocalVar(
     recordFixes(NewVar, Context, Diagnostic);
 }
 
+void UnnecessaryCopyInitialization::storeOptions(
+    ClangTidyOptions::OptionMap &Opts) {
+  Options.store(Opts, "AllowedTypes",
+                utils::options::serializeStringList(AllowedTypes));
+}
+
 } // namespace performance
 } // namespace tidy
 } // namespace clang
diff --git a/clang-tools-extra/clang-tidy/performance/UnnecessaryCopyInitialization.h b/clang-tools-extra/clang-tidy/performance/UnnecessaryCopyInitialization.h
index 8ed4142731c..1844aa4bf29 100644
--- a/clang-tools-extra/clang-tidy/performance/UnnecessaryCopyInitialization.h
+++ b/clang-tools-extra/clang-tidy/performance/UnnecessaryCopyInitialization.h
@@ -26,10 +26,10 @@ namespace performance {
 // const references, and const pointers to const.
 class UnnecessaryCopyInitialization : public ClangTidyCheck {
 public:
-  UnnecessaryCopyInitialization(StringRef Name, ClangTidyContext *Context)
-      : ClangTidyCheck(Name, Context) {}
+  UnnecessaryCopyInitialization(StringRef Name, ClangTidyContext *Context);
   void registerMatchers(ast_matchers::MatchFinder *Finder) override;
   void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+  void storeOptions(ClangTidyOptions::OptionMap &Opts) override;
 
 private:
   void handleCopyFromMethodReturn(const VarDecl &Var, const Stmt &BlockStmt,
@@ -38,6 +38,7 @@ private:
   void handleCopyFromLocalVar(const VarDecl &NewVar, const VarDecl &OldVar,
                               const Stmt &BlockStmt, bool IssueFix,
                               ASTContext &Context);
+  const std::vector<std::string> AllowedTypes;
 };
 
 } // namespace performance
diff --git a/clang-tools-extra/clang-tidy/performance/UnnecessaryValueParamCheck.cpp b/clang-tools-extra/clang-tidy/performance/UnnecessaryValueParamCheck.cpp
index db5a12f9b12..ac76cea3603 100644
--- a/clang-tools-extra/clang-tidy/performance/UnnecessaryValueParamCheck.cpp
+++ b/clang-tools-extra/clang-tidy/performance/UnnecessaryValueParamCheck.cpp
@@ -12,6 +12,7 @@
 #include "../utils/DeclRefExprUtils.h"
 #include "../utils/FixItHintUtils.h"
 #include "../utils/Matchers.h"
+#include "../utils/OptionsUtils.h"
 #include "../utils/TypeTraits.h"
 #include "clang/Frontend/CompilerInstance.h"
 #include "clang/Lex/Lexer.h"
@@ -68,17 +69,22 @@ UnnecessaryValueParamCheck::UnnecessaryValueParamCheck(
     StringRef Name, ClangTidyContext *Context)
     : ClangTidyCheck(Name, Context),
       IncludeStyle(utils::IncludeSorter::parseIncludeStyle(
-          Options.getLocalOrGlobal("IncludeStyle", "llvm"))) {}
+          Options.getLocalOrGlobal("IncludeStyle", "llvm"))),
+      AllowedTypes(
+          utils::options::parseStringList(Options.get("AllowedTypes", ""))) {}
 
 void UnnecessaryValueParamCheck::registerMatchers(MatchFinder *Finder) {
   // This check is specific to C++ and doesn't apply to languages like
   // Objective-C.
   if (!getLangOpts().CPlusPlus)
     return;
-  const auto ExpensiveValueParamDecl =
-      parmVarDecl(hasType(hasCanonicalType(allOf(
-                      unless(referenceType()), matchers::isExpensiveToCopy()))),
-                  decl().bind("param"));
+  const auto ExpensiveValueParamDecl = parmVarDecl(
+      hasType(qualType(allOf(
+          hasCanonicalType(matchers::isExpensiveToCopy()),
+          unless(anyOf(hasCanonicalType(referenceType()),
+                       hasDeclaration(namedDecl(
+                           matchers::matchesAnyListedName(AllowedTypes)))))))),
+      decl().bind("param"));
   Finder->addMatcher(
       functionDecl(hasBody(stmt()), isDefinition(), unless(isImplicit()),
                    unless(cxxMethodDecl(anyOf(isOverride(), isFinal()))),
@@ -173,6 +179,8 @@ void UnnecessaryValueParamCheck::storeOptions(
     ClangTidyOptions::OptionMap &Opts) {
   Options.store(Opts, "IncludeStyle",
                 utils::IncludeSorter::toString(IncludeStyle));
+  Options.store(Opts, "AllowedTypes",
+                utils::options::serializeStringList(AllowedTypes));
 }
 
 void UnnecessaryValueParamCheck::onEndOfTranslationUnit() {
diff --git a/clang-tools-extra/clang-tidy/performance/UnnecessaryValueParamCheck.h b/clang-tools-extra/clang-tidy/performance/UnnecessaryValueParamCheck.h
index ae5ef7e9631..a1d6586931e 100644
--- a/clang-tools-extra/clang-tidy/performance/UnnecessaryValueParamCheck.h
+++ b/clang-tools-extra/clang-tidy/performance/UnnecessaryValueParamCheck.h
@@ -40,6 +40,7 @@ private:
       MutationAnalyzers;
   std::unique_ptr<utils::IncludeInserter> Inserter;
   const utils::IncludeSorter::IncludeStyle IncludeStyle;
+  const std::vector<std::string> AllowedTypes;
 };
 
 } // namespace performance