test/Sema/stmtexprs.c

// RUN: %clang_cc1 %s -verify -pedantic -fsyntax-only -Wno-gnu-statement-expression

int stmtexpr_fn(void);
void stmtexprs(int i) {
  __builtin_assume( ({ 1; }) ); // no warning about "side effects"
  __builtin_assume( ({ if (i) { (void)0; }; 42; }) ); // no warning about "side effects"
  // expected-warning@+1 {{the argument to '__builtin_assume' has side effects that will be discarded}}
  __builtin_assume( ({ if (i) ({ stmtexpr_fn(); }); 1; }) );
}