Better diagnostics for string initialization.

This commit improves Clang's diagnostics for string initialization.
Where it would previously say:

  /tmp/a.c:3:9: error: array initializer must be an initializer list
  wchar_t s[] = "Hi";
          ^
  /tmp/a.c:4:6: error: array initializer must be an initializer list or string literal
  char t[] = L"Hi";
       ^

It will now say

  /tmp/a.c:3:9: error: initializing wide char array with non-wide string literal
  wchar_t s[] = "Hi";
          ^
  /tmp/a.c:4:6: error: initializing char array with wide string literal
  char t[] = L"Hi";
       ^

As a bonus, it also fixes the fact that Clang would previously reject
this valid C11 code:

  char16_t s[] = u"hi";
  char32_t t[] = U"hi";

because it would only recognize the built-in types for char16_t and
char32_t, which do not exist in C.

llvm-svn: 181880

1 files changed, 40 insertions, 0 deletions

diff --git a/clang/test/SemaCXX/string-init.cpp b/clang/test/SemaCXX/string-init.cpp
new file mode 100644
index 00000000000..7e62d1855ac
--- /dev/null
+++ b/clang/test/SemaCXX/string-init.cpp
@@ -0,0 +1,40 @@
+// RUN: %clang_cc1 -std=c++11 -fsyntax-only -verify %s
+
+void f() {
+  char a1[] = "a"; // No error.
+  char a2[] = u8"a"; // No error.
+  char a3[] = u"a"; // expected-error{{initializing char array with wide string literal}}
+  char a4[] = U"a"; // expected-error{{initializing char array with wide string literal}}
+  char a5[] = L"a"; // expected-error{{initializing char array with wide string literal}}
+
+  wchar_t b1[] = "a"; // expected-error{{initializing wide char array with non-wide string literal}}
+  wchar_t b2[] = u8"a"; // expected-error{{initializing wide char array with non-wide string literal}}
+  wchar_t b3[] = u"a"; // expected-error{{initializing wide char array with incompatible wide string literal}}
+  wchar_t b4[] = U"a"; // expected-error{{initializing wide char array with incompatible wide string literal}}
+  wchar_t b5[] = L"a"; // No error.
+
+  char16_t c1[] = "a"; // expected-error{{initializing wide char array with non-wide string literal}}
+  char16_t c2[] = u8"a"; // expected-error{{initializing wide char array with non-wide string literal}}
+  char16_t c3[] = u"a"; // No error.
+  char16_t c4[] = U"a"; // expected-error{{initializing wide char array with incompatible wide string literal}}
+  char16_t c5[] = L"a"; // expected-error{{initializing wide char array with incompatible wide string literal}}
+
+  char32_t d1[] = "a"; // expected-error{{initializing wide char array with non-wide string literal}}
+  char32_t d2[] = u8"a"; // expected-error{{initializing wide char array with non-wide string literal}}
+  char32_t d3[] = u"a"; // expected-error{{initializing wide char array with incompatible wide string literal}}
+  char32_t d4[] = U"a"; // No error.
+  char32_t d5[] = L"a"; // expected-error{{initializing wide char array with incompatible wide string literal}}
+
+  int e1[] = "a"; // expected-error{{array initializer must be an initializer list}}
+  int e2[] = u8"a"; // expected-error{{array initializer must be an initializer list}}
+  int e3[] = u"a"; // expected-error{{array initializer must be an initializer list}}
+  int e4[] = U"a"; // expected-error{{array initializer must be an initializer list}}
+  int e5[] = L"a"; // expected-error{{array initializer must be an initializer list}}
+}
+
+void g() {
+  char a[] = 1; // expected-error{{array initializer must be an initializer list or string literal}}
+  wchar_t b[] = 1; // expected-error{{array initializer must be an initializer list or wide string literal}}
+  char16_t c[] = 1; // expected-error{{array initializer must be an initializer list or wide string literal}}
+  char32_t d[] = 1; // expected-error{{array initializer must be an initializer list or wide string literal}}
+}