#pragma TEST_CODE: Check Generated Code

Function Definition

  #pragma TEST_CODE CompOp <Size> {<HashCode>}   

  CompOp: ==|!=|<|>|<=|>=   

<Size>: Size of the function to be used with compare operation

<HashCode>: Optional value specifying one specific code pattern.

None

This pragma checks the generated code. If the check fails, the Compiler issues message C3601.

This pragma tests the following items:

• Size of the function:

  Compares the compare operator and the size given as arguments with the size of the function.

  This feature checks whether the compiler-generated code is more or less than a given boundary. To check only the hashcode, use a condition which is always TRUE, such as != 0.

• Hashcode:

  The compiler generates a 16-bit hashcode from the code of the next function. This hashcode considers:

  • The code bytes of the generated functions
  • The type, offset, and addend of any fixup.

To get the hashcode of a certain function, compile the function with an active #pragma TEST_CODE (which will fail). Then copy the computed hashcode out of the body of message C3601.

The following listings present two examples of the TEST_CODE pragma.

/* check that an empty function is smaller */
/* than 10 bytes */

#pragma TEST_CODE < 10

void main(void) {

}

You can also use the TEST_CODE pragma to detect when a different code is generated, as shown in the following listing.

/* If the following pragma fails, check the code. */
/* If the code is OK, add the hashcode to the */

/* list of allowed codes : */

#pragma TEST_CODE != 0 25645 37594

/* check code patterns : */

/* 25645 : shift for *2 */

/* 37594 : mult for *2 */

void main(void) {

  f(2*i);

}

Message C3601