From 1f317d6c052daaa8c3dfcf64d114a95e003b2592 Mon Sep 17 00:00:00 2001
From: Alexander Kornienko <alexfh@google.com>
Date: Wed, 16 Jul 2014 13:38:48 +0000
Subject: [PATCH] Avoid adding redundant parens.

Reviewers: bkramer

Reviewed By: bkramer

Subscribers: cfe-commits, sbenza

Differential Revision: http://reviews.llvm.org/D4534

llvm-svn: 213149
---
 .../clang-tidy/google/AvoidCStyleCastsCheck.cpp    | 22 +++++++++++++---------
 .../test/clang-tidy/avoid-c-style-casts.cpp        | 16 +++++++++++++++-
 2 files changed, 28 insertions(+), 10 deletions(-)

diff --git a/clang-tools-extra/clang-tidy/google/AvoidCStyleCastsCheck.cpp b/clang-tools-extra/clang-tidy/google/AvoidCStyleCastsCheck.cpp
index 7f8a965..4b8bf14 100644
--- a/clang-tools-extra/clang-tidy/google/AvoidCStyleCastsCheck.cpp
+++ b/clang-tools-extra/clang-tidy/google/AvoidCStyleCastsCheck.cpp
@@ -56,6 +56,7 @@ bool pointedTypesAreEqual(QualType SourceType, QualType DestType) {
   }
   return SourceType.getUnqualifiedType() == DestType.getUnqualifiedType();
 }
+
 void AvoidCStyleCastsCheck::check(const MatchFinder::MatchResult &Result) {
   const auto *CastExpr = Result.Nodes.getNodeAs<CStyleCastExpr>("cast");
 
@@ -85,15 +86,18 @@ void AvoidCStyleCastsCheck::check(const MatchFinder::MatchResult &Result) {
     diag_builder << ("Use " + CastType + ".").str();
     if (ParenRange.getBegin().isMacroID() || ParenRange.getEnd().isMacroID())
       return;
-    diag_builder << FixItHint::CreateReplacement(
-                        ParenRange,
-                        (CastType + "<" + DestTypeString + ">(").str())
-                 << FixItHint::CreateInsertion(
-                        Lexer::getLocForEndOfToken(
-                            CastExpr->getSubExprAsWritten()->getLocEnd(), 0,
-                            *Result.SourceManager,
-                            Result.Context->getLangOpts()),
-                        ")");
+
+    const Expr *SubExpr = CastExpr->getSubExprAsWritten()->IgnoreImpCasts();
+    std::string CastText = (CastType + "<" + DestTypeString + ">").str();
+    if (!isa<ParenExpr>(SubExpr)) {
+      CastText.push_back('(');
+      diag_builder << FixItHint::CreateInsertion(
+          Lexer::getLocForEndOfToken(SubExpr->getLocEnd(), 0,
+                                     *Result.SourceManager,
+                                     Result.Context->getLangOpts()),
+          ")");
+    }
+    diag_builder << FixItHint::CreateReplacement(ParenRange, CastText);
   };
   // Suggest appropriate C++ cast. See [expr.cast] for cast notation semantics.
   switch (CastExpr->getCastKind()) {
diff --git a/clang-tools-extra/test/clang-tidy/avoid-c-style-casts.cpp b/clang-tools-extra/test/clang-tidy/avoid-c-style-casts.cpp
index a81c262..9ae6320 100644
--- a/clang-tools-extra/test/clang-tidy/avoid-c-style-casts.cpp
+++ b/clang-tools-extra/test/clang-tidy/avoid-c-style-casts.cpp
@@ -17,7 +17,7 @@ void f(int a, double b, const char *cpc, const void *cpv, X *pX) {
 
   char *pc2 = (char*)(cpc + 33);
   // CHECK-MESSAGES: :[[@LINE-1]]:15: warning: C-style casts are discouraged. Use const_cast. {{.*}}
-  // CHECK-FIXES: char *pc2 = const_cast<char *>((cpc + 33));
+  // CHECK-FIXES: char *pc2 = const_cast<char *>(cpc + 33);
 
   const char &crc = *cpc;
   char &rc = (char&)crc;
@@ -33,6 +33,20 @@ void f(int a, double b, const char *cpc, const void *cpv, X *pX) {
   // CHECK-MESSAGES: :[[@LINE-1]]:20: warning: C-style casts are discouraged. Use const_cast. {{.*}}
   // CHECK-FIXES: char ****ppppc = const_cast<char ****>(ppcpcpc);
 
+  char ***pppc = (char***)*(ppcpcpc);
+  // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: C-style casts are discouraged. Use const_cast. {{.*}}
+  // CHECK-FIXES: char ***pppc = const_cast<char ***>(*(ppcpcpc));
+
+  char ***pppc2 = (char***)(*ppcpcpc);
+  // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: C-style casts are discouraged. Use const_cast. {{.*}}
+  // CHECK-FIXES: char ***pppc2 = const_cast<char ***>(*ppcpcpc);
+
+  char *pc5 = (char*)(const char*)(cpv);
+  // CHECK-MESSAGES: :[[@LINE-1]]:15: warning: C-style casts are discouraged. Use const_cast. {{.*}}
+  // CHECK-MESSAGES: :[[@LINE-2]]:22: warning: C-style casts are discouraged. Use reinterpret_cast. {{.*}}
+  // CHECK-FIXES: char *pc5 = const_cast<char *>(reinterpret_cast<const char *>(cpv));
+
+
   int b1 = (int)b;
   // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: C-style casts are discouraged. Use static_cast. [google-readability-casting]
   // CHECK-FIXES: int b1 = static_cast<int>(b);
-- 
2.7.4