[clang-tools-extra] r179103 - Fix UseNullptr fails to replace c-style explicit cast in a return statement

[Ariel J. Bernal]

Author: ajbernal
Date: Tue Apr  9 11:54:56 2013
New Revision: 179103

URL: http://llvm.org/viewvc/llvm-project?rev=179103&view=rev
Log:
Fix UseNullptr fails to replace c-style explicit cast in a return statement

This happens whenever there is a c-style explicit cast to nullptr not
surrounded by parentheses following a return statement.

- Added a white space before nullptr if the character before is alphanumeric
  when replacing the null pointer expression.
- Simplified visitor
- Addes tests

Modified:
    clang-tools-extra/trunk/cpp11-migrate/UseNullptr/NullptrActions.cpp
    clang-tools-extra/trunk/test/cpp11-migrate/UseNullptr/basic.cpp

Modified: clang-tools-extra/trunk/cpp11-migrate/UseNullptr/NullptrActions.cpp
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/cpp11-migrate/UseNullptr/NullptrActions.cpp?rev=179103&r1=179102&r2=179103&view=diff
==============================================================================
--- clang-tools-extra/trunk/cpp11-migrate/UseNullptr/NullptrActions.cpp (original)
+++ clang-tools-extra/trunk/cpp11-migrate/UseNullptr/NullptrActions.cpp Tue Apr  9 11:54:56 2013
@@ -20,6 +20,7 @@
 #include "clang/AST/ASTContext.h"
 #include "clang/AST/RecursiveASTVisitor.h"
 
+#include "clang/Basic/CharInfo.h"
 #include "clang/Lex/Lexer.h"
 
 using namespace clang::ast_matchers;
@@ -42,7 +43,14 @@ bool ReplaceWithNullptr(tooling::Replace
                         SourceLocation StartLoc, SourceLocation EndLoc) {
   if (SM.isFromSameFile(StartLoc, EndLoc) && SM.isFromMainFile(StartLoc)) {
     CharSourceRange Range(SourceRange(StartLoc, EndLoc), true);
-    Replace.insert(tooling::Replacement(SM, Range, "nullptr"));
+    // Add a space if nullptr follows an alphanumeric character. This happens
+    // whenever there is an c-style explicit cast to nullptr not surrounded by
+    // parentheses and right beside a return statement.
+    SourceLocation PreviousLocation = StartLoc.getLocWithOffset(-1);
+    if (isAlphanumeric(*FullSourceLoc(PreviousLocation, SM).getCharacterData()))
+      Replace.insert(tooling::Replacement(SM, Range, " nullptr"));
+    else
+      Replace.insert(tooling::Replacement(SM, Range, "nullptr"));
     return true;
   } else
     return false;
@@ -93,19 +101,11 @@ public:
   // within a cast expression.
   bool VisitStmt(Stmt *S) {
     CastExpr *C = dyn_cast<CastExpr>(S);
-
     if (!C) {
       ResetFirstSubExpr();
       return true;
     } else if (!FirstSubExpr) {
-      // Keep parentheses for implicit casts to avoid cases where an implicit
-      // cast within a parentheses expression is right next to a return
-      // statement otherwise get the subexpression of the outermost explicit
-      // cast.
-      if (C->getStmtClass() == Stmt::ImplicitCastExprClass)
-        FirstSubExpr = C->IgnoreParenImpCasts();
-      else
-        FirstSubExpr = C->getSubExpr();
+        FirstSubExpr = C->getSubExpr()->IgnoreParens();
     }
 
     if (C->getCastKind() == CK_NullToPointer ||

Modified: clang-tools-extra/trunk/test/cpp11-migrate/UseNullptr/basic.cpp
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/test/cpp11-migrate/UseNullptr/basic.cpp?rev=179103&r1=179102&r2=179103&view=diff
==============================================================================
--- clang-tools-extra/trunk/test/cpp11-migrate/UseNullptr/basic.cpp (original)
+++ clang-tools-extra/trunk/test/cpp11-migrate/UseNullptr/basic.cpp Tue Apr  9 11:54:56 2013
@@ -180,6 +180,18 @@ int test_function_return6() {
   // CHECK: return g_null;
 }
 
+int *test_function_return_cast1() {
+  return(int)0;
+  // CHECK: return nullptr;
+}
+
+int *test_function_return_cast2() {
+  #define RET return
+  RET(int)0;
+  // CHECK: RET nullptr;
+  #undef RET
+}
+
 // Test parentheses expressions resulting in a nullptr.
 int *test_parentheses_expression1() {
   return(0);