# Asserts in F

The F′ framework uses asserts to perform run-time checks for software
errors. They are a method for verifying conditions that should be true
unless there is a software or processor error. Assert.hpp defines macros
to declare an assertion in C++ code. CAssert.hpp defines macros to
declare an assertion in C code.

The definition for the framework assert is found in Fw/Types/Assert.hpp.
The user calls the `FW_ASSERT(cond, arg1, ...)` macro with up to six arguments. The
arguments can consist of any basic types shown below.

  - I8 8-bit signed integer

  - U8 8-bit unsigned integer

  - I16 16-bit signed integer

  - U16 16-bit unsigned integer

  - I32 32-bit signed integer

  - U32 32-bit unsigned integer

  - F32 32-bit IEEE floating point number (float)

  - F64 64-bit floating point number (double)

  - I64 64-bit signed integer

  - U64 64-bit unsigned integer

  - bool C++ Boolean type

These types are used in FPP specifications. Note that not all types are
available on all processor architectures. The types that are available
is a configurable feature of the architecture and is typically set by
compiler arguments.

The assert can be configured in the following ways:

  - FW\_ASSERT\_LEVEL Sets the level or reporting for the asserts.

      - FW\_NO\_ASSERT Shows the asserts turned off. The code to check
        the condition is not compiled. Some developers prefer this once
        the code has been tested to regain some processing performance.

      - FW\_FILEID\_ASSERT Identifies an integer value for the file
        where the assert occurs (as opposed to \_\_FILE\_\_). It saves
        code space since no file name is stored.

      - FW\_FILENAME\_ASSERT Identifies which file the assert occurred
        in. (The \_\_FILE\_\_ macro is used.)

  - FW\_ASSERT\_TEXT\_SIZE Identifies the size of the buffer used to
    store the text of the assert.

## AssertHook

By default, when FW\_ASSERT is called the framework prints a message
(location of and arguments to the macro), and then calls the C assert()
function. The framework also provides a function that allows the
registration of a user-defined handler. The handler is
registerAssertHook and can be found in FwAssert.hpp. The assert hook is
called with a string representing the text of the assert. The user
implements a derived class that implements the reportAssert() pure
virtual method, and does whatever project-specific logic is required.

### reportAssert

When formatting an assert message use the default message line hash or
name, and argument approach.

### printAssert

When outputting the assert message use the default Fw::Logger. Force the
Fw::Logger default to printf for systems with print f.

### doAssert

Actually asserts (action of assert).