clang/test/Sema/extern-redecl.c

   1 // RUN: %clang_cc1 -fsyntax-only -verify -Wno-strict-prototypes %s
   2
   3 // rdar: // 8125274
   4 static int a16[];  // expected-warning {{tentative array definition assumed to have one element}}
   5
   6 void f16(void) {
   7     extern int a16[];
   8 }
   9
  10
  11 // PR10013: Scope of extern declarations extend past enclosing block
  12 extern int PR10013_x;
  13 int PR10013(void) {
  14   int *PR10013_x = 0;
  15   {
  16     extern int PR10013_x;
  17     extern int PR10013_x;
  18   }
  19
  20   return PR10013_x; // expected-error{{incompatible pointer to integer conversion}}
  21 }
  22
  23 static int test1_a[]; // expected-warning {{tentative array definition assumed to have one element}}
  24 extern int test1_a[];
  25
  26 // rdar://13535367
  27 void test2declarer(void) { extern int test2_array[100]; }
  28 extern int test2_array[];
  29 int test2v = sizeof(test2_array); // expected-error {{invalid application of 'sizeof' to an incomplete type 'int[]'}}
  30
  31 void test3declarer(void) {
  32   { extern int test3_array[100]; }
  33   extern int test3_array[];
  34   int x = sizeof(test3_array); // expected-error {{invalid application of 'sizeof' to an incomplete type 'int[]'}}
  35 }
  36
  37 void test4(void) {
  38   extern int test4_array[];
  39   {
  40     extern int test4_array[100];
  41     int x = sizeof(test4_array); // fine
  42   }
  43   int x = sizeof(test4_array); // expected-error {{invalid application of 'sizeof' to an incomplete type 'int[]'}}
  44 }
  45
  46 // Test that invalid local extern declarations of library
  47 // builtins behave reasonably.
  48 extern void abort(void); // expected-note 2 {{previous declaration is here}}
  49 extern float *calloc(void); // expected-warning {{incompatible redeclaration of library function}} expected-note {{is a builtin}} expected-note 2 {{previous declaration is here}}
  50 void test5a(void) {
  51   int abort(void); // expected-error {{conflicting types}}
  52   float *malloc(void); // expected-warning {{incompatible redeclaration of library function}} expected-note 2 {{is a builtin}}
  53   int *calloc(void); // expected-error {{conflicting types}}
  54 }
  55 void test5b(void) {
  56   int abort(void); // expected-error {{conflicting types}}
  57   float *malloc(void); // expected-warning {{incompatible redeclaration of library function}}
  58   int *calloc(void); // expected-error {{conflicting types}}
  59 }
  60 void test5c(void) {
  61   void (*_abort)(void) = &abort;
  62   void *(*_malloc)() = &malloc;
  63   float *(*_calloc)() = &calloc;
  64 }
  65
  66 void test6(void) {
  67   extern int test6_array1[100];
  68   extern int test6_array2[100];
  69   void test6_fn1(int*);
  70   void test6_fn2(int*);
  71   {
  72     // Types are only merged from visible declarations.
  73     char test6_array2;
  74     char test6_fn2;
  75     {
  76       extern int test6_array1[];
  77       extern int test6_array2[];
  78       (void)sizeof(test6_array1); // ok
  79       (void)sizeof(test6_array2); // expected-error {{incomplete type}}
  80
  81       void test6_fn1();
  82       void test6_fn2();
  83       test6_fn1(1.2); // expected-error {{passing 'double' to parameter of incompatible type 'int *'}}
  84       // FIXME: This is valid, but we should warn on it.
  85       test6_fn2(1.2);
  86     }
  87   }
  88 }