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Why some functions got WARNING L15, while others not!

Hi,
I have several functions called in T0 isr. The outline of call tree like this:

void T0_isr() interrupt 1 {
    getkey();
}

void getkey() {
    char c;
    c = filterGetKeyCode();
}

char filterGetKeyCode() {
    char c;
    c = getKeyCode();
    return c;
}

char getKeyCode() {
    char c;
    char cd;
    // c be assigned somehow
    cd = encodeFlex(c);
    c = decode(cd);
    return c;
}

char encodeFlex(char c) {
    return encode(c);
}

char encode(char);

char decode(char);

Now linker reports (simplified):
Warning 15: multiple call to segment
segment: getKeyCode
caller1: T0_isr
caller2: c_c51stratup

Warning 15: multiple call to segment
segment: encodeFlex
caller1: T0_isr
caller2: c_c51startup

My question is: why getKeyCode and encodeFlex incur warnings, while others, like decode, passed by linker.
When I disoverlay getKeyCode, and declare encodeFlex with reentrant, the warnings all disappear. But I still worry about other functions called in isr. Is it safe now?

Thanks in advance.

d.curie

Parents

0 Ding Curie over 21 years ago in reply to Drew Davis
When checking the call map, I eventually found where the multiply calls occurred. There are two callers to _getkey, a function implemented in a project-specific way to override the library function with the same name in stdio.lib. I explicitly called _getkey in T0_isr, and again I implicitly called _getkey in scrollDigit since it calls sscanf, which in turn calls getchar, which then call _getkey. All related call branches are listed as follows.

?PR?GETKEYCODE?KEYBOARD_P +--> ?PR?_DECODE38?FUNC +--> ?PR?_ENCODE83FLEX?FUNC ?PR?_ENCODE83FLEX?FUNC +--> ?PR?_ENCODE83?FUNC ?PR?FILTERKEYCODE?KEYBOARD_P +--> ?PR?GETKEYCODE?KEYBOARD_P ?PR?_GETKEY?KEYBOARD_P +--> ?PR?FILTERKEYCODE?KEYBOARD_P +--> ?PR?_TOASCII?KEYBOARD_P +--> ?PR?_LOADKEYQUEUE?KEYBOARD_P ?PR?T0_ISR?T0_ISR +--> ?PR?_GETKEY?KEYBOARD_P ?PR?_SCROLLDIGIT?GUI +--> ?CO?GUI +--> ?PR?PRINTF?PRINTF +--> ?PR?SCANF?SCANF +--> ?PR?_TEXTOUT?GUI ?PR?SCANF?SCANF +--> ?PR?GETCHAR?UNGETCHAR +--> ?PR?_ISSPACE?ISSPACE +--> ?PR?GETCHAR?GETCHAR +--> ?PR??C?ATOF??C?ATOF ?PR?GETCHAR?GETCHAR +--> ?PR?_GETKEY?KEYBOARD_P +--> ?PR?PUTCHAR?PUTCHAR
But my original question is still there! Why encode83flex get warning, whereas decode38 not?
And a new question arises: I invoke sscanf in scrollDigit, but the call map above shows scanf is called instead! In my opinion, sscanf should not call getchar (in turn _getkey) even though scanf does.
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0 Ding Curie over 21 years ago in reply to Drew Davis
When checking the call map, I eventually found where the multiply calls occurred. There are two callers to _getkey, a function implemented in a project-specific way to override the library function with the same name in stdio.lib. I explicitly called _getkey in T0_isr, and again I implicitly called _getkey in scrollDigit since it calls sscanf, which in turn calls getchar, which then call _getkey. All related call branches are listed as follows.

?PR?GETKEYCODE?KEYBOARD_P +--> ?PR?_DECODE38?FUNC +--> ?PR?_ENCODE83FLEX?FUNC ?PR?_ENCODE83FLEX?FUNC +--> ?PR?_ENCODE83?FUNC ?PR?FILTERKEYCODE?KEYBOARD_P +--> ?PR?GETKEYCODE?KEYBOARD_P ?PR?_GETKEY?KEYBOARD_P +--> ?PR?FILTERKEYCODE?KEYBOARD_P +--> ?PR?_TOASCII?KEYBOARD_P +--> ?PR?_LOADKEYQUEUE?KEYBOARD_P ?PR?T0_ISR?T0_ISR +--> ?PR?_GETKEY?KEYBOARD_P ?PR?_SCROLLDIGIT?GUI +--> ?CO?GUI +--> ?PR?PRINTF?PRINTF +--> ?PR?SCANF?SCANF +--> ?PR?_TEXTOUT?GUI ?PR?SCANF?SCANF +--> ?PR?GETCHAR?UNGETCHAR +--> ?PR?_ISSPACE?ISSPACE +--> ?PR?GETCHAR?GETCHAR +--> ?PR??C?ATOF??C?ATOF ?PR?GETCHAR?GETCHAR +--> ?PR?_GETKEY?KEYBOARD_P +--> ?PR?PUTCHAR?PUTCHAR
But my original question is still there! Why encode83flex get warning, whereas decode38 not?
And a new question arises: I invoke sscanf in scrollDigit, but the call map above shows scanf is called instead! In my opinion, sscanf should not call getchar (in turn _getkey) even though scanf does.
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