loplugin:unnecessaryparen

look for  statements like

return (function());

Change-Id: I906cf2183489f87225b99b987caca67e39b26cc3
Reviewed-on: https://gerrit.libreoffice.org/41260
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>
Tested-by: Noel Grandin <noel.grandin@collabora.co.uk>

1 files changed, 32 insertions, 0 deletions

diff --git a/compilerplugins/clang/unnecessaryparen.cxx b/compilerplugins/clang/unnecessaryparen.cxx
index 4abfd69e3b7c..1e01c41d5893 100644
--- a/compilerplugins/clang/unnecessaryparen.cxx
+++ b/compilerplugins/clang/unnecessaryparen.cxx
@@ -55,6 +55,7 @@ public:
     bool VisitDoStmt(const DoStmt *);
     bool VisitWhileStmt(const WhileStmt *);
     bool VisitSwitchStmt(const SwitchStmt *);
+    bool VisitReturnStmt(const ReturnStmt* );
     bool VisitCallExpr(const CallExpr *);
     bool TraverseUnaryExprOrTypeTraitExpr(UnaryExprOrTypeTraitExpr *);
     bool TraverseCaseStmt(CaseStmt *);
@@ -162,6 +163,37 @@ bool UnnecessaryParen::VisitSwitchStmt(const SwitchStmt* switchStmt)
     return true;
 }
 
+bool UnnecessaryParen::VisitReturnStmt(const ReturnStmt* returnStmt)
+{
+    if (ignoreLocation(returnStmt))
+        return true;
+    if (returnStmt->getLocStart().isMacroID())
+        return true;
+
+    if (!returnStmt->getRetValue())
+        return true;
+    auto parenExpr = dyn_cast<ParenExpr>(returnStmt->getRetValue()->IgnoreImpCasts());
+    if (!parenExpr)
+        return true;
+    if (parenExpr->getLocStart().isMacroID())
+        return true;
+    // assignments need extra parentheses or they generate a compiler warning
+    auto binaryOp = dyn_cast<BinaryOperator>(parenExpr->getSubExpr());
+    if (binaryOp && binaryOp->getOpcode() == BO_Assign)
+        return true;
+
+    // only non-operator-calls for now
+    auto subExpr = parenExpr->getSubExpr();
+    if (isa<CallExpr>(subExpr) && !isa<CXXOperatorCallExpr>(subExpr))
+    {
+        report(
+            DiagnosticsEngine::Warning, "parentheses immediately inside return statement",
+            parenExpr->getLocStart())
+            << parenExpr->getSourceRange();
+    }
+    return true;
+}
+
 void UnnecessaryParen::VisitSomeStmt(const Stmt *parent, const Expr* cond, StringRef stmtName)
 {
     if (ignoreLocation(parent))