llvm-project/clang/test/Sema/exprs.c

// RUN: clang %s -verify -pedantic -fsyntax-only

// PR1966
_Complex double test1() {
  return __extension__ 1.0if;
}

_Complex double test2() {
  return 1.0if;    // expected-warning {{imaginary constants are an extension}}
}

// rdar://6097308
void test3() {
  int x;
  (__extension__ x) = 10;
}

// rdar://6162726
void test4() {
      static int var;
      var =+ 5;  // expected-warning {{use of unary operator that may be intended as compound assignment (+=)}}
      var =- 5;  // expected-warning {{use of unary operator that may be intended as compound assignment (-=)}}
      var = +5;
      var = -5;
}