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(skip_evaluation): New variable.

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(&&, ||, ?:): Increment it in unevaluated subexpressions.
(/, %, integer_overflow): Suppress diagnostics if skip_evaluation != 0.
(yyerror): Clear skip_evaluation.

From-SVN: r9914
This commit is contained in:
Richard Kenner 1995-06-09 17:58:24 -04:00
parent 17856c497f
commit 245391da4e
1 changed files with 28 additions and 10 deletions
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38
gcc/cexp.y
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@ -86,6 +86,10 @@ static jmp_buf parse_return_error;
/* Nonzero means count most punctuation as part of a name. */
static int keyword_parsing = 0;
/* Nonzero means do not evaluate this expression.
This is a count, since unevaluated expressions can nest. */
static int skip_evaluation;
/* some external tables of character types */
extern unsigned char is_idstart[], is_idchar[], is_hor_space[];
@ -225,7 +229,8 @@ exp : exp '*' exp
| exp '/' exp
{ if ($3.value == 0)
{
error ("division by zero in #if");
if (!skip_evaluation)
error ("division by zero in #if");
$3.value = 1;
}
$$.unsignedp = $1.unsignedp || $3.unsignedp;
@ -240,7 +245,8 @@ exp : exp '*' exp
| exp '%' exp
{ if ($3.value == 0)
{
error ("division by zero in #if");
if (!skip_evaluation)
error ("division by zero in #if");
$3.value = 1;
}
$$.unsignedp = $1.unsignedp || $3.unsignedp;
@ -313,15 +319,26 @@ exp : exp '*' exp
| exp '|' exp
{ $$.value = $1.value | $3.value;
$$.unsignedp = $1.unsignedp || $3.unsignedp; }
| exp AND exp
{ $$.value = ($1.value && $3.value);
| exp AND
{ skip_evaluation += !$1.value; }
exp
{ skip_evaluation -= !$1.value;
$$.value = ($1.value && $4.value);
$$.unsignedp = 0; }
| exp OR exp
{ $$.value = ($1.value || $3.value);
| exp OR
{ skip_evaluation += !!$1.value; }
exp
{ skip_evaluation -= !!$1.value;
$$.value = ($1.value || $4.value);
$$.unsignedp = 0; }
| exp '?' exp ':' exp
{ $$.value = $1.value ? $3.value : $5.value;
$$.unsignedp = $3.unsignedp || $5.unsignedp; }
| exp '?'
{ skip_evaluation += !$1.value; }
exp ':'
{ skip_evaluation += !!$1.value - !$1.value; }
exp
{ skip_evaluation -= !!$1.value;
$$.value = $1.value ? $4.value : $7.value;
$$.unsignedp = $4.unsignedp || $7.unsignedp; }
| INT
{ $$ = yylval.integer; }
| CHAR
@ -865,13 +882,14 @@ yyerror (s)
char *s;
{
error (s);
skip_evaluation = 0;
longjmp (parse_return_error, 1);
}
static void
integer_overflow ()
{
if (pedantic)
if (!skip_evaluation && pedantic)
pedwarn ("integer overflow in preprocessor expression");
}