[Bug c++/19808] miss a warning about uninitialized member usage in member initializer list in constructor

["mpolacek at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=19808

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |mpolacek at gcc dot gnu.org

--- Comment #48 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
I have a patch that for this:

// PR c++/19808
// { dg-do compile { target c++11 } }
// { dg-options "-Wuninitialized" }

struct S {
  int i, j, k, l;
  S() : i(j), // { dg-warning "field .S::j. is uninitialized when used here" }
        j(1),
        k(l + 1), // { dg-warning "field .S::l. is uninitialized when used
here" }
        l(2) { }
};

struct A {
  int a, b, c;
  A() : a(b // { dg-warning "field .A::b. is uninitialized when used here" }
          + c) { } // { dg-warning "field .A::c. is uninitialized when used
here" }
};

struct B {
  int &r;
  int *p;
  int a;
  B() : r(a), p(&a), a(1) { }
};

struct C {
  const int &r1, &r2;
  C () : r1(r2), // { dg-warning "reference .C::r2. is not yet bound to a value
when used here" }
         r2(r1) { }
};

struct D {
  int a = 1;
  int b = 2;
  D() : a(b + 1), b(a + 1) { } // { dg-warning "field .D::b. is uninitialized
when used here" }
};

struct E {
  int a = 1;
  E() : a(a + 1) { } // { dg-warning "field .E::a. is uninitialized when used
here" }
};

struct F {
  int a = 1;
  int b;
  F() : b(a + 1) { }
};

struct bar {
  bar() {}
  bar(bar&) {}
};

class foo {
  bar first;
  bar second;
public:
  foo() : first(second) {} // { dg-warning "field .foo::second. is
uninitialized when used here" }
};

does this:

$ ./cc1plus -quiet  -Wuninitialized  Wuninitialized-12.C
Wuninitialized-12.C: In constructor ‘S::S()’:
Wuninitialized-12.C:7:11: warning: field ‘S::j’ is uninitialized when used here
[-Wuninitialized]
    7 |   S() : i(j), // { dg-warning "field .S::j. is uninitialized when used
here" }
      |           ^
Wuninitialized-12.C:9:11: warning: field ‘S::l’ is uninitialized when used here
[-Wuninitialized]
    9 |         k(l + 1), // { dg-warning "field .S::l. is uninitialized when
used here" }
      |           ^
Wuninitialized-12.C: In constructor ‘A::A()’:
Wuninitialized-12.C:15:11: warning: field ‘A::b’ is uninitialized when used
here [-Wuninitialized]
   15 |   A() : a(b // { dg-warning "field .A::b. is uninitialized when used
here" }
      |           ^
Wuninitialized-12.C:16:13: warning: field ‘A::c’ is uninitialized when used
here [-Wuninitialized]
   16 |           + c) { } // { dg-warning "field .A::c. is uninitialized when
used here" }
      |             ^
Wuninitialized-12.C: In constructor ‘C::C()’:
Wuninitialized-12.C:28:13: warning: reference ‘C::r2’ is not yet bound to a
value when used here [-Wuninitialized]
   28 |   C () : r1(r2), // { dg-warning "reference .C::r2. is not yet bound to
a value when used here" }
      |             ^~
Wuninitialized-12.C: In constructor ‘D::D()’:
Wuninitialized-12.C:35:11: warning: field ‘D::b’ is uninitialized when used
here [-Wuninitialized]
   35 |   D() : a(b + 1), b(a + 1) { } // { dg-warning "field .D::b. is
uninitialized when used here" }
      |           ^
Wuninitialized-12.C: In constructor ‘E::E()’:
Wuninitialized-12.C:40:11: warning: field ‘E::a’ is uninitialized when used
here [-Wuninitialized]
   40 |   E() : a(a + 1) { } // { dg-warning "field .E::a. is uninitialized
when used here" }
      |           ^
Wuninitialized-12.C: In constructor ‘foo::foo()’:
Wuninitialized-12.C:58:17: warning: field ‘foo::second’ is uninitialized when
used here [-Wuninitialized]
   58 |   foo() : first(second) {} // { dg-warning "field .foo::second. is
uninitialized when used here" }
      |                 ^~~~~~