10.26 __declspec(noreturn)

The __declspec(noreturn) attribute asserts that a function never returns.

Note

This attribute has the function equivalent __attribute((noreturn)). However, __attribute((noreturn)) and __declspec(noreturn) differ in that when compiling a function definition, if the function reaches an explicit or implicit return, __attribute((noreturn)) is ignored and the compiler generates a warning. This does not apply to __declspec(noreturn).

Usage

Use this attribute to reduce the cost of calling a function that never returns, such as exit(). If a noreturn function returns to its caller, the behavior is undefined.

Restrictions

The return address is not preserved when calling the noreturn function. This limits the ability of a debugger to display the call stack.

Examples

__declspec(noreturn) void overflow(void); // never return on overflow
int negate(int x) 
{
    if (x == 0x80000000) overflow();
    return -x;
}
Related reference
10.43 __attribute__((noreturn)) function attribute
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