gcc/testsuite/gcc.dg/redecl-1.c

   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; }