[clang-tidy] - PerformanceUnnecesaryCopyInitialization - only trigger for decl stmts with single VarDecl.
Summary: This fixes bug: https://llvm.org/bugs/show_bug.cgi?id=27325
Reviewers: alexfh
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D19865
llvm-svn: 269389
diff --git a/clang-tools-extra/clang-tidy/performance/UnnecessaryCopyInitialization.cpp b/clang-tools-extra/clang-tidy/performance/UnnecessaryCopyInitialization.cpp
index aa37c65..dfaff82 100644
--- a/clang-tools-extra/clang-tidy/performance/UnnecessaryCopyInitialization.cpp
+++ b/clang-tools-extra/clang-tidy/performance/UnnecessaryCopyInitialization.cpp
@@ -20,10 +20,6 @@
void recordFixes(const VarDecl &Var, ASTContext &Context,
DiagnosticBuilder &Diagnostic) {
- // Do not propose fixes in macros since we cannot place them correctly.
- if (Var.getLocation().isMacroID())
- return;
-
Diagnostic << utils::fixit::changeVarDeclToReference(Var, Context);
if (!Var.getType().isLocalConstQualified())
Diagnostic << utils::fixit::changeVarDeclToConst(Var);
@@ -57,14 +53,16 @@
auto localVarCopiedFrom = [](const internal::Matcher<Expr> &CopyCtorArg) {
return compoundStmt(
forEachDescendant(
- varDecl(hasLocalStorage(),
- hasType(matchers::isExpensiveToCopy()),
- hasInitializer(cxxConstructExpr(
- hasDeclaration(cxxConstructorDecl(
- isCopyConstructor())),
- hasArgument(0, CopyCtorArg))
- .bind("ctorCall")))
- .bind("newVarDecl")))
+ declStmt(
+ has(varDecl(hasLocalStorage(),
+ hasType(matchers::isExpensiveToCopy()),
+ hasInitializer(
+ cxxConstructExpr(
+ hasDeclaration(cxxConstructorDecl(
+ isCopyConstructor())),
+ hasArgument(0, CopyCtorArg))
+ .bind("ctorCall")))
+ .bind("newVarDecl"))).bind("declStmt")))
.bind("blockStmt");
};
@@ -84,6 +82,11 @@
const auto *OldVar = Result.Nodes.getNodeAs<VarDecl>("oldVarDecl");
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 =
+ Result.Nodes.getNodeAs<DeclStmt>("declStmt")->isSingleDecl() &&
+ !NewVar->getLocation().isMacroID();
// A constructor that looks like T(const T& t, bool arg = false) counts as a
// copy only when it is called with default arguments for the arguments after
@@ -93,14 +96,16 @@
return;
if (OldVar == nullptr) {
- handleCopyFromMethodReturn(*NewVar, *BlockStmt, *Result.Context);
+ handleCopyFromMethodReturn(*NewVar, *BlockStmt, IssueFix, *Result.Context);
} else {
- handleCopyFromLocalVar(*NewVar, *OldVar, *BlockStmt, *Result.Context);
+ handleCopyFromLocalVar(*NewVar, *OldVar, *BlockStmt, IssueFix,
+ *Result.Context);
}
}
void UnnecessaryCopyInitialization::handleCopyFromMethodReturn(
- const VarDecl &Var, const Stmt &BlockStmt, ASTContext &Context) {
+ const VarDecl &Var, const Stmt &BlockStmt, bool IssueFix,
+ ASTContext &Context) {
bool IsConstQualified = Var.getType().isConstQualified();
if (!IsConstQualified && !isOnlyUsedAsConst(Var, BlockStmt, Context))
return;
@@ -114,12 +119,13 @@
"const reference but is only used as const "
"reference; consider making it a const reference")
<< &Var;
- recordFixes(Var, Context, Diagnostic);
+ if (IssueFix)
+ recordFixes(Var, Context, Diagnostic);
}
void UnnecessaryCopyInitialization::handleCopyFromLocalVar(
const VarDecl &NewVar, const VarDecl &OldVar, const Stmt &BlockStmt,
- ASTContext &Context) {
+ bool IssueFix, ASTContext &Context) {
if (!isOnlyUsedAsConst(NewVar, BlockStmt, Context) ||
!isOnlyUsedAsConst(OldVar, BlockStmt, Context))
return;
@@ -128,7 +134,8 @@
"local copy %0 of the variable %1 is never modified; "
"consider avoiding the copy")
<< &NewVar << &OldVar;
- recordFixes(NewVar, Context, Diagnostic);
+ if (IssueFix)
+ recordFixes(NewVar, Context, Diagnostic);
}
} // namespace performance