AN3350 datasheet(154/185 Pages) STMICROELECTRONICS

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Pragmas for diagnostic messages

AN3350

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Doc ID 018512 Rev 2

Syntax

#pragma warn_undefmacro on | off | reset

Remarks

Example 106 provides an example.

Example 106 Example of undefined macro

#if BADMACRO == 4 /* WARNING: undefined macro. */

Use this pragma to detect the use of undefined macros (especially expressions) where the

default value 0 is used. To suppress this warning message, check if defined first.

Note:

A warning message is only issued when a macro is evaluated. A short-circuited “&&” or “||”

test or unevaluated “?:” will not produce a warning message.

By default, this pragma is off.

19.33

warn_uninitializedvar

Controls the compiler to perform some dataflow analysis and emits warning messages

whenever local variables are initialized before being used.

Syntax

#pragma warn_uninitializedvar on | off | reset

Remarks

By default, this pragma is on.

19.34

warn_unusedarg

Controls the recognition of unreferenced arguments.

Syntax

#pragma warn_unusedarg on | off | reset

Remarks

If you enable this pragma, the compiler issues a warning message when it encounters an

argument you declare but do not use.

This check helps you find arguments that you either misspelled or did not use in your

program.Example 107 shows an example.

Example 107 Warning about unused function arguments

void func(int temp, int error);

{

error = do_something(); /* WARNING: temp is unused. */

}

AN3350 데이터시트(PDF) 154 Page - STMicroelectronics