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This article mainly shows you "how to achieve function reference in Tool", the content is easy to understand, clear, hope to help you solve your doubts, the following let the editor lead you to study and learn "how to achieve function reference in Tool" this article.

Recently, some children's shoes have encountered an exception returned by a floating-point function. The code is simplified as follows

Run it in VxWorks

The result of the calculation is obviously wrong. Why?

Look at Workbench's Build Console. There is a Warning:

It turns out that the function aaa () is not declared.

Change the code

Run again.

OK,it works!

Interested children's shoes can disassemble the twice bbb.o files.

Compare it.

The corresponding instructions are indeed different, but I don't know where to go with my undergraduate compilation knowledge.

Next, extend the type you just had.

Let's take a look at the running results.

The internal operation of ccc () and ddd () is normal, but the return value is overflowed; unfortunately, the internal processing of bbb () is messed up, indicating that the input parameter is already wrong.

Print out the length of the return value:

Have become 4Bytes.

It seems that when the compiler can not find the prototype, it is processed according to 32bits.

Add all the statements:

Everything's normal this time.

Of course, it is best to put the function declaration in the header file, and then reference the header file.

In addition, for this typical floating-point operation, we mentioned earlier that you need to include the option VX_FP_TASK when creating a Task

These are all the contents of the article "how to implement function references in Tool". Thank you for reading! I believe we all have a certain understanding, hope to share the content to help you, if you want to learn more knowledge, welcome to follow the industry information channel!

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