clang/test/Sema/extern-redecl.c

   1 // RUN: %clang_cc1 -fsyntax-only -verify -Wno-strict-prototypes %s
   2
   3 static int a16[];  // expected-warning {{tentative array definition assumed to have one element}}
   4
   5 void f16(void) {
   6     extern int a16[];
   7 }
   8
   9
  10 // PR10013: Scope of extern declarations extend past enclosing block
  11 extern int PR10013_x;
  12 int PR10013(void) {
  13   int *PR10013_x = 0;
  14   {
  15     extern int PR10013_x;
  16     extern int PR10013_x;
  17   }
  18
  19   return PR10013_x; // expected-error{{incompatible pointer to integer conversion}}
  20 }
  21
  22 static int test1_a[]; // expected-warning {{tentative array definition assumed to have one element}}
  23 extern int test1_a[];
  24
  25 void test2declarer(void) { extern int test2_array[100]; }
  26 extern int test2_array[];
  27 int test2v = sizeof(test2_array); // expected-error {{invalid application of 'sizeof' to an incomplete type 'int[]'}}
  28
  29 void test3declarer(void) {
  30   { extern int test3_array[100]; }
  31   extern int test3_array[];
  32   int x = sizeof(test3_array); // expected-error {{invalid application of 'sizeof' to an incomplete type 'int[]'}}
  33 }
  34
  35 void test4(void) {
  36   extern int test4_array[];
  37   {
  38     extern int test4_array[100];
  39     int x = sizeof(test4_array); // fine
  40   }
  41   int x = sizeof(test4_array); // expected-error {{invalid application of 'sizeof' to an incomplete type 'int[]'}}
  42 }
  43
  44 // Test that invalid local extern declarations of library
  45 // builtins behave reasonably.
  46 extern void abort(void); // expected-note 2 {{previous declaration is here}}
  47 extern float *calloc(void); // expected-warning {{incompatible redeclaration of library function}} expected-note {{is a builtin}} expected-note 2 {{previous declaration is here}}
  48 void test5a(void) {
  49   int abort(void); // expected-error {{conflicting types}}
  50   float *malloc(void); // expected-warning {{incompatible redeclaration of library function}} expected-note 2 {{is a builtin}}
  51   int *calloc(void); // expected-error {{conflicting types}}
  52 }
  53 void test5b(void) {
  54   int abort(void); // expected-error {{conflicting types}}
  55   float *malloc(void); // expected-warning {{incompatible redeclaration of library function}}
  56   int *calloc(void); // expected-error {{conflicting types}}
  57 }
  58 void test5c(void) {
  59   void (*_abort)(void) = &abort;
  60   void *(*_malloc)() = &malloc;
  61   float *(*_calloc)() = &calloc;
  62 }
  63
  64 void test6(void) {
  65   extern int test6_array1[100];
  66   extern int test6_array2[100];
  67   void test6_fn1(int*);
  68   void test6_fn2(int*);
  69   {
  70     // Types are only merged from visible declarations.
  71     char test6_array2;
  72     char test6_fn2;
  73     {
  74       extern int test6_array1[];
  75       extern int test6_array2[];
  76       (void)sizeof(test6_array1); // ok
  77       (void)sizeof(test6_array2); // expected-error {{incomplete type}}
  78
  79       void test6_fn1();
  80       void test6_fn2();
  81       test6_fn1(1.2); // expected-error {{passing 'double' to parameter of incompatible type 'int *'}}
  82       // FIXME: This is valid, but we should warn on it.
  83       test6_fn2(1.2);
  84     }
  85   }
  86 }