From 5565941effbe6e4d255f7a1b35c04ab5c106db41 Mon Sep 17 00:00:00 2001
From: Jordan Rose <jordan_rose@apple.com>
Date: Fri, 25 Oct 2013 16:52:00 +0000
Subject: Add -Wstring-plus-char, which warns when adding char literals to C
 strings.
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Specifically, this warns when a character literal is added (using '+') to a
variable with type 'char *' (or any other pointer to character type). Like
-Wstring-plus-int, there is a fix-it to change "foo + 'a'" to "&foo['a']"
iff the character literal is on the right side of the string.

Patch by Anders Rönnholm!

llvm-svn: 193418
---
 clang/test/SemaCXX/string-plus-char.cpp | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)
 create mode 100644 clang/test/SemaCXX/string-plus-char.cpp

(limited to 'clang/test/SemaCXX/string-plus-char.cpp')

diff --git a/clang/test/SemaCXX/string-plus-char.cpp b/clang/test/SemaCXX/string-plus-char.cpp
new file mode 100644
index 00000000000..00a2c4550dc
--- /dev/null
+++ b/clang/test/SemaCXX/string-plus-char.cpp
@@ -0,0 +1,32 @@
+// RUN: %clang_cc1 -fsyntax-only -std=c++11 -verify %s
+
+class A {
+public:
+  A(): str() { }
+  A(const char *p) { }
+  A(char *p) : str(p + 'a') { } // expected-warning {{adding 'char' to a string pointer does not append to the string}} expected-note {{use array indexing to silence this warning}}
+  A& operator+(const char *p) { return *this; }
+  A& operator+(char ch) { return *this; }
+  char * str;
+};
+
+void f(const char *s) {
+  A a = s + 'a'; // // expected-warning {{adding 'char' to a string pointer does not append to the string}} expected-note {{use array indexing to silence this warning}}
+  a = a + s + 'b'; // no-warning
+
+  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}}
+
+  const char *constStr = s + 'c'; // expected-warning {{adding 'char' to a string pointer does not append to the string}} expected-note {{use array indexing to silence this warning}}
+
+  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}}
+
+  wchar_t *wstr;
+  wstr = wstr + L'c'; // expected-warning {{adding 'wchar_t' to a string pointer does not append to the string}} expected-note {{use array indexing to silence this warning}}
+  str2 = str + u'a'; // expected-warning {{adding 'char16_t' 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;
+  str = c + str;
+}
-- 
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