From: Alp Toker <alp@nuanti.com>
Date: Wed, 27 Nov 2013 03:18:17 +0000 (+0000)
Subject: Implement -Wold-style-cast
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=2d07e35a5bc72fac07e015808c4dda20245a18ed;p=clang

Implement -Wold-style-cast

Based on a patch by Ondřej Hošek!

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@195808 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/clang/Basic/DiagnosticGroups.td b/include/clang/Basic/DiagnosticGroups.td
index 38a939faae..6de1a48d9f 100644
--- a/include/clang/Basic/DiagnosticGroups.td
+++ b/include/clang/Basic/DiagnosticGroups.td
@@ -216,7 +216,7 @@ def NonPODVarargs : DiagGroup<"non-pod-varargs">;
 def : DiagGroup<"nonportable-cfstrings">;
 def NonVirtualDtor : DiagGroup<"non-virtual-dtor">;
 def OveralignedType : DiagGroup<"over-aligned">;
-def : DiagGroup<"old-style-cast">;
+def OldStyleCast : DiagGroup<"old-style-cast">;
 def : DiagGroup<"old-style-definition">;
 def OutOfLineDeclaration : DiagGroup<"out-of-line-declaration">;
 def : DiagGroup<"overflow">;
diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td
index b8d99ba52c..a314bf493a 100644
--- a/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/include/clang/Basic/DiagnosticSemaKinds.td
@@ -2299,6 +2299,8 @@ def note_function_to_bool_call : Note<
 def warn_cast_align : Warning<
   "cast from %0 to %1 increases required alignment from %2 to %3">,
   InGroup<CastAlign>, DefaultIgnore;
+def warn_old_style_cast : Warning<
+  "use of old-style cast">, InGroup<OldStyleCast>, DefaultIgnore;
 
 // Separate between casts to void* and non-void* pointers.
 // Some APIs use (abuse) void* for something like a user context,
diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index 55f9d6f8a0..b2bff51cd9 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -5138,6 +5138,10 @@ Sema::ActOnCastExpr(Scope *S, SourceLocation LParenLoc,
     CastExpr = Result.take();
   }
 
+  if (getLangOpts().CPlusPlus && !castType->isVoidType())
+    Diag(CastExpr->getLocStart(), diag::warn_old_style_cast)
+        << SourceRange(LParenLoc, RParenLoc);
+
   return BuildCStyleCastExpr(LParenLoc, castTInfo, RParenLoc, CastExpr);
 }
 
diff --git a/test/SemaCXX/old-style-cast.cpp b/test/SemaCXX/old-style-cast.cpp
new file mode 100644
index 0000000000..d8198fcc56
--- /dev/null
+++ b/test/SemaCXX/old-style-cast.cpp
@@ -0,0 +1,11 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -Wold-style-cast %s
+
+void test1() {
+  long x = (long)12; // expected-warning {{use of old-style cast}}
+  (long)x; // expected-warning {{use of old-style cast}} expected-warning {{expression result unused}}
+  (void**)x; // expected-warning {{use of old-style cast}} expected-warning {{expression result unused}}
+  long y = static_cast<long>(12);
+  (void)y;
+  typedef void VOID;
+  (VOID)y;
+}