AN3350 datasheet(153/185 Pages) STMICROELECTRONICS

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AN3350

Pragmas for diagnostic messages

Doc ID 018512 Rev 2

153/185

19.30

warn_ptr_int_conv

Controls the recognition the conversion of pointer values to incorrectly-sized integral values.

Syntax

#pragma warn_ptr_int_conv on | off | reset

Remarks

If you enable this pragma, the compiler issues a warning message if an expression attempts

to convert a pointer value to an integral type that is not large enough to hold the pointer

value.

Example 104 Example for #pragma warn_ptr_int_conv

#pragma warn_ptr_int_conv on

char *my_ptr;

char too_small = (char)my_ptr; /* WARNING: char is too small. */

See also Section 19.11: warn_any_ptr_int_conv.

By default, this pragma is off.

19.31

warn_resultnotused

Controls the issuing of warning messages when function results are ignored.

Syntax

#pragma warn_resultnotused on | off | reset

Remarks

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

statement that calls a function without using its result. To prevent this, cast the statement

with (void).Example 105 provides an example.

Example 105 Example of function calls with unused results

#pragma warn_resultnotused on

extern int bar();

void func()

{

bar(); /* WARNING: result of function call is not used. */

void(bar()); /* OK: void cast suppresses warning. */

}

This pragma does not correspond to any panel setting. By default, this pragma is off.

19.32

warn_undefmacro

Controls the detection of undefined macros in #if and #elif directives.

AN3350 Datasheet(PDF) 153 Page - STMicroelectronics