1  /* Test for various situations where a new declaration of an
       2     identifier conflicts with an earlier declaration which isn't in the
       3     same scope.  These are all undefined behavior per C89 sections
       4     6.1.2.2p7, 6.1.2.6p2, and 6.3.2.2p2/footnote 38 (C99 6.2.2p7 and
       5     6.2.7p2 - implicit declarations are invalid in C99).  */
       6  
       7  /* { dg-do compile } */
       8  /* { dg-options "-std=c89 -pedantic -Wall -Wno-unused" } */
       9  
      10  /* Extern at function scope, clashing with extern at file scope */
      11  
      12  extern int foo1;		/* { dg-message "note: previous" } */
      13  extern int bar1(int);		/* { dg-message "note: previous" } */
      14  
      15  void test1(void)
      16  {
      17    extern double foo1;		/* { dg-error "conflict" } */
      18    extern double bar1(double);	/* { dg-error "conflict" } */
      19  }
      20  
      21  /* Extern at file scope, clashing with extern at function scope */
      22  
      23  void test2(void)
      24  {
      25    extern double foo2;		/* { dg-message "note: previous" } */
      26    extern double bar2(double);	/* { dg-message "note: previous" } */
      27  }
      28  
      29  extern int foo2;		/* { dg-error "conflict" } */
      30  extern int bar2(int);		/* { dg-error "conflict" } */
      31  
      32  /* Extern at function scope, clashing with extern at earlier function
      33     scope.  Also, don't be fooled by a typedef at file scope.  */
      34  
      35  typedef float baz3;		/* { dg-bogus } */
      36  
      37  void prime3(void)
      38  {
      39    extern int foo3;		/* { dg-message "note: previous" } */
      40    extern int bar3(int);		/* { dg-message "note: previous" } */
      41    extern int baz3;		/* { dg-message "note: previous" } */
      42  }
      43  
      44  void test3(void)
      45  {
      46    extern double foo3;		/* { dg-error "conflict" } */
      47    extern double bar3(double);	/* { dg-error "conflict" } */
      48    extern double baz3;		/* { dg-error "conflict" } */
      49  }
      50  
      51  /* Extern at function scope, clashing with previous implicit decl.  */
      52  
      53  void prime4(void)
      54  {
      55    bar4(); /* { dg-line implicit_bar4 } */
      56    /* { dg-warning "implicit declaration of function" "implicit" { target *-*-* } implicit_bar4 } */
      57  }
      58  
      59  void test4(void)
      60  {
      61    extern double bar4(double);	/* { dg-error "conflict" } */
      62  /* { dg-message "note: previous implicit declaration" "previous" { target *-*-* } implicit_bar4 } */
      63  }
      64  
      65  /* Implicit decl, clashing with extern at previous function scope.  */
      66  
      67  void prime5(void)
      68  {
      69    extern double bar5(double);	/* { dg-message "note: previous declaration" "previous 1" } */
      70  } /* { dg-message "note: previous implicit declaration" "previous 2" { target *-*-* } .-1 } */
      71  
      72  void test5(void)
      73  {
      74    bar5(1);			/* { dg-warning "implicit declaration of function" } */
      75  } /* { dg-error "incompatible implicit declaration" "" { target *-*-* } .-1 } */
      76  
      77  /* Extern then static, both at file scope.  */
      78  
      79  extern int test6(int);		/* { dg-message "note: previous" } */
      80  static int test6(int x)		/* { dg-error "follows non-static" } */
      81  { return x; }
      82  
      83  
      84  /* Extern then static, extern at previous function scope.  */
      85  
      86  void prime7(void)
      87  {
      88    extern int test7(int);	/* { dg-message "note: previous" } */
      89  }
      90  
      91  static int test7(int x)		/* { dg-error "follows non-static" } */
      92  { return x; }
      93  
      94  /* Implicit decl then static.  */
      95  
      96  void prime8(void)
      97  {
      98    test8();			/* { dg-message "note: previous" } */
      99                                  /* { dg-warning "implicit" "implicit" { target *-*-* } .-1 } */
     100  }
     101  
     102  static int test8(int x)		/* { dg-error "follows non-static" } */
     103  { return x; }