r224268 - Sema: Cleanup and improve string-plus-char checking.

[Daniel Marjamaki]

Author: danielmarjamaki
Date: Mon Dec 15 14:22:33 2014
New Revision: 224268

URL: http://llvm.org/viewvc/llvm-project?rev=224268&view=rev
Log:
Sema: Cleanup and improve string-plus-char checking.

Patch by Anders Rönnholm

Modified:
    cfe/trunk/lib/Sema/SemaExpr.cpp
    cfe/trunk/test/Sema/string-plus-char.c

Modified: cfe/trunk/lib/Sema/SemaExpr.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExpr.cpp?rev=224268&r1=224267&r2=224268&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaExpr.cpp (original)
+++ cfe/trunk/lib/Sema/SemaExpr.cpp Mon Dec 15 14:22:33 2014
@@ -7312,13 +7312,13 @@ static void diagnoseStringPlusInt(Sema &
 /// \brief Emit a warning when adding a char literal to a string.
 static void diagnoseStringPlusChar(Sema &Self, SourceLocation OpLoc,
                                    Expr *LHSExpr, Expr *RHSExpr) {
-  const DeclRefExpr *StringRefExpr =
-      dyn_cast<DeclRefExpr>(LHSExpr->IgnoreImpCasts());
+  const Expr *StringRefExpr = LHSExpr;
   const CharacterLiteral *CharExpr =
       dyn_cast<CharacterLiteral>(RHSExpr->IgnoreImpCasts());
-  if (!StringRefExpr) {
-    StringRefExpr = dyn_cast<DeclRefExpr>(RHSExpr->IgnoreImpCasts());
+
+  if (!CharExpr) {
     CharExpr = dyn_cast<CharacterLiteral>(LHSExpr->IgnoreImpCasts());
+    StringRefExpr = RHSExpr;
   }
 
   if (!CharExpr || !StringRefExpr)

Modified: cfe/trunk/test/Sema/string-plus-char.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/string-plus-char.c?rev=224268&r1=224267&r2=224268&view=diff
==============================================================================
--- cfe/trunk/test/Sema/string-plus-char.c (original)
+++ cfe/trunk/test/Sema/string-plus-char.c Mon Dec 15 14:22:33 2014
@@ -1,5 +1,11 @@
 // RUN: %clang_cc1 -fsyntax-only -verify %s
 
+struct AB{const char *a; const char*b;};
+
+const char *foo(const struct AB *ab) {
+  return ab->a + 'b'; // expected-warning {{adding 'char' to a string pointer does not append to the string}} expected-note {{use array indexing to silence this warning}}
+}
+
 void f(const char *s) {
   char *str = 0;
   char *str2 = str + 'c'; // expected-warning {{adding 'char' to a string pointer does not append to the string}} expected-note {{use array indexing to silence this warning}}
@@ -8,6 +14,15 @@ void f(const char *s) {
 
   str = 'c' + str;// expected-warning {{adding 'char' to a string pointer does not append to the string}} expected-note {{use array indexing to silence this warning}}
 
+  char strArr[] = "foo";
+  str = strArr + 'c'; // expected-warning {{adding 'char' to a string pointer does not append to the string}} expected-note {{use array indexing to silence this warning}}
+  char *strArr2[] = {"ac","dc"};
+  str = strArr2[0] + 'c'; // expected-warning {{adding 'char' to a string pointer does not append to the string}} expected-note {{use array indexing to silence this warning}}
+
+
+  struct AB ab;
+  constStr = foo(&ab) + 'c'; // expected-warning {{adding 'char' to a string pointer does not append to the string}} expected-note {{use array indexing to silence this warning}}
+
   // no-warning
   char c = 'c';
   str = str + c;