loplugin:unnecessaryparen include c++ casts

Change-Id: I132d3c66f0562e2c37a02eaf4c168d06c2b473eb
Reviewed-on: https://gerrit.libreoffice.org/41874
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

2 files changed, 19 insertions, 4 deletions

diff --git a/compilerplugins/clang/test/unnecessaryparen.cxx b/compilerplugins/clang/test/unnecessaryparen.cxx
index 85be13848b22..1ea22288673e 100644
--- a/compilerplugins/clang/test/unnecessaryparen.cxx
+++ b/compilerplugins/clang/test/unnecessaryparen.cxx
@@ -32,6 +32,9 @@ int main()
     // lots of our code uses this style, which I'm loathe to bulk-fix as yet
     int z = (y) ? 1 : 0;
     (void)z;
+
+    int v1 = (static_cast<short>(1)) + 1; // expected-error {{unnecessary parentheses around cast [loplugin:unnecessaryparen]}}
+    (void)v1;
 };
 
 /* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */
diff --git a/compilerplugins/clang/unnecessaryparen.cxx b/compilerplugins/clang/unnecessaryparen.cxx
index 1e01c41d5893..7f0e532585c1 100644
--- a/compilerplugins/clang/unnecessaryparen.cxx
+++ b/compilerplugins/clang/unnecessaryparen.cxx
@@ -109,8 +109,10 @@ bool UnnecessaryParen::VisitParenExpr(const ParenExpr* parenExpr)
     if (insideConditionalOperator && parenExpr == insideConditionalOperator)
         return true;
 
-    auto subParenExpr = dyn_cast<ParenExpr>(parenExpr->getSubExpr()->IgnoreImpCasts());
-    if (subParenExpr) {
+    auto subExpr = parenExpr->getSubExpr()->IgnoreImpCasts();
+
+    if (auto subParenExpr = dyn_cast<ParenExpr>(subExpr))
+    {
         if (subParenExpr->getLocStart().isMacroID())
             return true;
         report(
@@ -119,8 +121,7 @@ bool UnnecessaryParen::VisitParenExpr(const ParenExpr* parenExpr)
             << parenExpr->getSourceRange();
     }
 
-    auto declRefExpr = dyn_cast<DeclRefExpr>(parenExpr->getSubExpr()->IgnoreImpCasts());
-    if (declRefExpr) {
+    if (auto declRefExpr = dyn_cast<DeclRefExpr>(subExpr)) {
         if (declRefExpr->getLocStart().isMacroID())
             return true;
 
@@ -136,6 +137,17 @@ bool UnnecessaryParen::VisitParenExpr(const ParenExpr* parenExpr)
             parenExpr->getLocStart())
             << parenExpr->getSourceRange();
     }
+
+
+    if (auto cxxNamedCastExpr = dyn_cast<CXXNamedCastExpr>(subExpr)) {
+        if (cxxNamedCastExpr->getLocStart().isMacroID())
+            return true;
+        report(
+            DiagnosticsEngine::Warning, "unnecessary parentheses around cast",
+            parenExpr->getLocStart())
+            << parenExpr->getSourceRange();
+    }
+
     return true;
 }