Improve and fix documentation for error code combination

Improve documentation by:

- Fixing off by one errors in binary representations of error codes.
- Clarifying combinations of zero.
- Linking references to variables/macros via doxygen.

Signed-off-by: Chris Jones <christopher.jones@arm.com>
This commit is contained in:
Chris Jones 2021-04-12 15:44:47 +01:00
parent b7d02e0f15
commit abded0ed39
2 changed files with 9 additions and 5 deletions

View file

@ -133,10 +133,14 @@ extern void (*mbedtls_test_hook_error_add)( int, int, const char *, int );
* \brief Combines a high-level and low-level error code together.
*
* This function can be called directly however it is usually
* called via the mbedtls_error_add macro.
* called via the #MBEDTLS_ERROR_ADD macro.
*
* \note When invasive testing is enabled via MBEDTLS_TEST_HOOKS also try to
* call mbedtls_test_hook_error_add.
* While a value of zero is not a negative error code, it is still an
* error code (that denotes success) and can be combined with both a
* negative error code or another value of zero.
*
* \note When invasive testing is enabled via #MBEDTLS_TEST_HOOKS, also try to
* call \link mbedtls_test_hook_error_add \endlink.
*
* \param high high-level error code. See error.h for more details.
* \param low low-level error code. See error.h for more details.

View file

@ -292,7 +292,7 @@ void mbedtls_test_err_add_check( int high, int low,
* examples given in comments have been made positive for ease of
* understanding. The structure of an error code is such:
*
* shhhhhhhllllllll
* shhhhhhhhlllllll
*
* s = sign bit.
* h = high level error code (includes high and module error codes).
@ -308,7 +308,7 @@ void mbedtls_test_err_add_check( int high, int low,
mbedtls_test_fail( "'high' error code is greater than 15 bits",
line, file );
}
else if ( ( high & 0x7F ) != 0 ) // high & 0000000011111111
else if ( ( high & 0x7F ) != 0 ) // high & 0000000001111111
{
mbedtls_test_fail( "'high' contains a low-level error code",
line, file );