clang/test/Sema/asm-goto.cpp

   1 // RUN: %clang_cc1 %s -triple i386-pc-linux-gnu -verify -fsyntax-only
   2 // RUN: %clang_cc1 %s -triple x86_64-pc-linux-gnu -verify -fsyntax-only
   3
   4 struct S {
   5   ~S();
   6   int f(int);
   7 private:
   8   int k;
   9 };
  10 void test1(int n) {
  11 // expected-error@+1 {{cannot jump from this goto statement to its label}}
  12   goto DirectJump;
  13 // expected-note@+1 {{jump bypasses variable with a non-trivial destructor}}
  14   S s1;
  15
  16 DirectJump:
  17 // expected-error@+1 {{cannot jump from this asm goto statement to one of its possible targets}}
  18   asm goto("jmp %l0;" ::::Later);
  19 // expected-note@+1 {{jump bypasses variable with a non-trivial destructor}}
  20   S s2;
  21 // expected-note@+1 {{possible target of asm goto statement}}
  22 Later:
  23   return;
  24 }
  25
  26 struct T { ~T(); };
  27 void test2(int a) {
  28   if (a) {
  29 FOO:
  30 // expected-note@+2 {{jump exits scope of variable with non-trivial destructor}}
  31 // expected-note@+1 {{jump exits scope of variable with non-trivial destructor}}
  32     T t;
  33     void *p = &&BAR;
  34 // expected-error@+1 {{cannot jump from this asm goto statement to one of its possible targets}}
  35     asm goto("jmp %l0;" ::::BAR);
  36 // expected-error@+1 {{cannot jump from this indirect goto statement to one of its possible targets}}
  37     goto *p;
  38     p = &&FOO;
  39     goto *p;
  40     return;
  41   }
  42 // expected-note@+2 {{possible target of asm goto statement}}
  43 // expected-note@+1 {{possible target of indirect goto statement}}
  44 BAR:
  45   return;
  46 }
  47
  48 int test3(int n)
  49 {
  50   // expected-error@+2 {{cannot jump from this asm goto statement to one of its possible targets}}
  51   // expected-error@+1 {{cannot jump from this asm goto statement to one of its possible targets}}
  52   asm volatile goto("testl %0, %0; jne %l1;" :: "r"(n)::label_true, loop);
  53   // expected-note@+3 {{jump bypasses initialization of variable length array}}
  54   // expected-note@+2 {{possible target of asm goto statement}}
  55   // expected-note@+1 {{jump enters a statement expression}}
  56   return ({int a[n];label_true: 2;});
  57   // expected-note@+1 {{jump bypasses initialization of variable length array}}
  58   int b[n];
  59 // expected-note@+1 {{possible target of asm goto statement}}
  60 loop:
  61   return 0;
  62 }
  63
  64 void test4cleanup(int*);
  65 // No errors expected.
  66 void test4(void) {
  67   asm goto(""::::l0);
  68 l0:;
  69   int x __attribute__((cleanup(test4cleanup)));
  70   asm goto(""::::l1);
  71 l1:;
  72 }
  73
  74 void statement_expressions() {
  75   ({
  76     __label__ label;
  77     asm goto("" : : : : label);
  78     label:;
  79   });
  80
  81   ({
  82     __label__ label;
  83     asm goto("" : : : : label);
  84     label:;
  85   });
  86 }