mirror of https://github.com/flysand7/ciabatta.git
79 lines
1.6 KiB
Markdown
79 lines
1.6 KiB
Markdown
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# assert.h - debug assertions
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Macro definitions:
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- [`assert(expr)`](#assert)
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- [`static_assert`](#static-assert)
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## [assert](#assert)
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Assert a given condition is true, otherwise abort execution of a program.
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The macro checks whether `expr` is true, and if not, prints the
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diagnostic information and then aborts execution in a way equivalent to calling
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abort() function (See SIGABRT).
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If `_DEBUG` macro is defined, assert does not print a diagnostic message, and
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instead simply causes a debug break.
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If NDEBUG macro is defined assert expands to an empty statement. If both NDEBUG
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and `_DEBUG` are defined, then `_DEBUG` macro is ignored.
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```c
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#if defined(NDEBUG)
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#define assert(expr) ((void)0)
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#elif defined(`_DEBUG`)
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#define assert(expr) /* debug break */
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#else
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#define assert(expr) /* print diagnostic, then abort */
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#endif
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```
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<details>
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<summary>Example</summary>
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```c
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// Uncomment to disable assert
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//#define NDEBUG
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#include <assert.h>
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int factorial(int n) {
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assert(n >= 0);
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if(n == 0) return 1;
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return n*factorial(n-1);
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}
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int main() {
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printf("Factorial of %d is %d\n", 10, factorial(10));
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printf("Factorial of %d is %d\n", -1, factorial(-1));
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return 0;
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}
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```
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The first function would print 3628800, the second would trigger an assert.
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Output:
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```
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Factorial of 10 is 3628800
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Assertion failed: n >= 0
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Function: factorial
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File: test\test_assert.c
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Line: 4
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Trace:
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4: factorial
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3: main
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2: mainCRTStartup
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1: BaseThreadInitThunk
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0: RtlUserThreadStart
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```
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</details>
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## [static_assert](#static-assert)
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Keyword macro that expands to C11 keyword `_Static_assert`.
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```c
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#define static_assert _Static_assert
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```
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