1 files changed, 83 insertions, 0 deletions
diff --git a/clang-tools-extra/test/clang-tidy/cppcoreguidelines-narrowing-conversions-unsigned-char.cpp b/clang-tools-extra/test/clang-tidy/cppcoreguidelines-narrowing-conversions-unsigned-char.cpp
new file mode 100644
index 00000000000..6bd437f98d4
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/cppcoreguidelines-narrowing-conversions-unsigned-char.cpp
@@ -0,0 +1,83 @@
+// RUN: %check_clang_tidy %s cppcoreguidelines-narrowing-conversions %t \
+// RUN: -- -- -target x86_64-unknown-linux -funsigned-char
+
+void narrow_integer_to_unsigned_integer_is_ok() {
+  signed char sc;
+  short s;
+  int i;
+  long l;
+  long long ll;
+
+  char c;
+  unsigned short us;
+  unsigned int ui;
+  unsigned long ul;
+  unsigned long long ull;
+
+  ui = sc;
+  c = s;
+  c = i;
+  c = l;
+  c = ll;
+
+  c = c;
+  c = us;
+  c = ui;
+  c = ul;
+  c = ull;
+}
+
+void narrow_integer_to_signed_integer_is_not_ok() {
+  signed char sc;
+  short s;
+  int i;
+  long l;
+  long long ll;
+
+  char c;
+  unsigned short us;
+  unsigned int ui;
+  unsigned long ul;
+  unsigned long long ull;
+
+  sc = sc;
+  sc = s;
+  // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: narrowing conversion from 'short' to signed type 'signed char' is implementation-defined [cppcoreguidelines-narrowing-conversions]
+  sc = i;
+  // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: narrowing conversion from 'int' to signed type 'signed char' is implementation-defined [cppcoreguidelines-narrowing-conversions]
+  sc = l;
+  // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: narrowing conversion from 'long' to signed type 'signed char' is implementation-defined [cppcoreguidelines-narrowing-conversions]
+  sc = ll;
+  // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: narrowing conversion from 'long long' to signed type 'signed char' is implementation-defined [cppcoreguidelines-narrowing-conversions]
+
+  sc = c;
+  // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: narrowing conversion from 'char' to signed type 'signed char' is implementation-defined [cppcoreguidelines-narrowing-conversions]
+  sc = us;
+  // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: narrowing conversion from 'unsigned short' to signed type 'signed char' is implementation-defined [cppcoreguidelines-narrowing-conversions]
+  sc = ui;
+  // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: narrowing conversion from 'unsigned int' to signed type 'signed char' is implementation-defined [cppcoreguidelines-narrowing-conversions]
+  sc = ul;
+  // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: narrowing conversion from 'unsigned long' to signed type 'signed char' is implementation-defined [cppcoreguidelines-narrowing-conversions]
+  sc = ull;
+  // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: narrowing conversion from 'unsigned long long' to signed type 'signed char' is implementation-defined [cppcoreguidelines-narrowing-conversions]
+}
+
+void narrow_constant_to_unsigned_integer_is_ok() {
+  char c1 = -128; // unsigned dst type is well defined.
+  char c2 = 127;  // unsigned dst type is well defined.
+  char c3 = -129; // unsigned dst type is well defined.
+  char c4 = 128;  // unsigned dst type is well defined.
+  unsigned char uc1 = 0;
+  unsigned char uc2 = 255;
+  unsigned char uc3 = -1;  // unsigned dst type is well defined.
+  unsigned char uc4 = 256; // unsigned dst type is well defined.
+  signed char sc = 128;
+  // CHECK-MESSAGES: :[[@LINE-1]]:20: warning: narrowing conversion from constant value 128 (0x00000080) of type 'int' to signed type 'signed char' is implementation-defined [cppcoreguidelines-narrowing-conversions]
+}
+
+void narrow_conditional_operator_contant_to_unsigned_is_ok(bool b) {
+  // conversion to unsigned char type is well defined.
+  char c1 = b ? 1 : 0;
+  char c2 = b ? 1 : 256;
+  char c3 = b ? -1 : 0;
+}