[clang-tidy] Check for suspicious string assignments.

It is possible to assign arbitrary integer types to strings.
Sometimes it is the result of missing to_string call or apostrophes.

Reviewers: alexfh

Differential Revision: http://reviews.llvm.org/D15411

llvm-svn: 255630

1 files changed, 53 insertions, 0 deletions

diff --git a/clang-tools-extra/test/clang-tidy/misc-string-integer-assignment.cpp b/clang-tools-extra/test/clang-tidy/misc-string-integer-assignment.cpp
new file mode 100644
index 00000000000..cb823410777
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/misc-string-integer-assignment.cpp
@@ -0,0 +1,53 @@
+// RUN: %check_clang_tidy %s misc-string-integer-assignment %t
+
+namespace std {
+template<typename T>
+struct basic_string {
+  basic_string& operator=(T);
+  basic_string& operator=(basic_string);
+  basic_string& operator+=(T);
+  basic_string& operator+=(basic_string);
+};
+
+typedef basic_string<char> string;
+typedef basic_string<wchar_t> wstring;
+}
+
+typedef int MyArcaneChar;
+
+int main() {
+  std::string s;
+  std::wstring ws;
+  int x = 5;
+
+  s = 6;
+// CHECK-MESSAGES: :[[@LINE-1]]:7: warning: an integer is interpreted as a character code when assigning {{.*}} [misc-string-integer-assignment]
+// CHECK-FIXES: {{^}}  s = '6';{{$}}
+  s = 66;
+// CHECK-MESSAGES: :[[@LINE-1]]:7: warning: an integer is interpreted as a chara
+// CHECK-FIXES: {{^}}  s = "66";{{$}}
+  s = x;
+// CHECK-MESSAGES: :[[@LINE-1]]:7: warning: an integer is interpreted as a chara
+// CHECK-FIXES: {{^}}  s = std::to_string(x);{{$}}
+  s = 'c';
+  s = static_cast<char>(6);
+
+// +=
+  ws += 6;
+// CHECK-MESSAGES: :[[@LINE-1]]:9: warning: an integer is interpreted as a chara
+// CHECK-FIXES: {{^}}  ws += L'6';{{$}}
+  ws += 66;
+// CHECK-MESSAGES: :[[@LINE-1]]:9: warning: an integer is interpreted as a chara
+// CHECK-FIXES: {{^}}  ws += L"66";{{$}}
+  ws += x;
+// CHECK-MESSAGES: :[[@LINE-1]]:9: warning: an integer is interpreted as a chara
+// CHECK-FIXES: {{^}}  ws += std::to_wstring(x);{{$}}
+  ws += L'c';
+  ws += (wchar_t)6;
+
+  std::basic_string<MyArcaneChar> as;
+  as = 6;
+// CHECK-MESSAGES: :[[@LINE-1]]:8: warning: an integer is interpreted as a chara
+// CHECK-FIXES: {{^}}  as = 6;{{$}}
+
+}