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Rework the `timescale directive and cleanup `line a bit. 

This patch reworks the `timescale directive to do a better
job of parsing the line, it refactors some of the code and
should produce better error messages. It also tightens up
parsing the numeric constant, etc. to better match the
Verilog standard.

The parsing of `line has been enhanced to only allow 0, 1 or
2 for the level and a single line comment at the end of the
line is ignored.
This commit is contained in:
Cary R 2009-05-26 14:15:02 -07:00 committed by Stephen Williams
parent 5fc236accc
commit 6297422427
1 changed files with 105 additions and 89 deletions
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@ -983,6 +983,83 @@ static verinum*make_unsized_dec(const char*ptr)
return res;
}
/*
* Convert the string to a time unit or precision.
* Returns true on failure.
*/
static bool get_timescale_const(const char *&cp, int &res, bool is_unit)
{
/* Check for the 1 digit. */
if (*cp != '1') {
if (is_unit) {
VLerror(yylloc, "Invalid `timescale unit constant "
"(1st digit)");
} else {
VLerror(yylloc, "Invalid `timescale precision constant "
"(1st digit)");
}
return true;
}
cp += 1;
/* Check the number of zeros after the 1. */
res = strspn(cp, "0");
if (res > 2) {
if (is_unit) {
VLerror(yylloc, "Invalid `timescale unit constant "
"(number of zeros)");
} else {
VLerror(yylloc, "Invalid `timescale precision constant "
"(number of zeros)");
}
return true;
}
cp += res;
/* Skip any space between the digits and the scaling string. */
cp += strspn(cp, " \t");
/* Now process the scaling string. */
if (strncmp("s", cp, 1) == 0) {
res -= 0;
cp += 1;
return false;
} else if (strncmp("ms", cp, 2) == 0) {
res -= 3;
cp += 2;
return false;
} else if (strncmp("us", cp, 2) == 0) {
res -= 6;
cp += 2;
return false;
} else if (strncmp("ns", cp, 2) == 0) {
res -= 9;
cp += 2;
return false;
} else if (strncmp("ps", cp, 2) == 0) {
res -= 12;
cp += 2;
return false;
} else if (strncmp("fs", cp, 2) == 0) {
res -= 15;
cp += 2;
return false;
}
if (is_unit) {
VLerror(yylloc, "Invalid `timescale unit scale");
} else {
VLerror(yylloc, "Invalid `timescale precision scale");
}
return true;
}
/*
* The timescale parameter has the form:
@ -990,99 +1067,39 @@ static verinum*make_unsized_dec(const char*ptr)
*/
static void process_timescale(const char*txt)
{
unsigned num;
const char*cp = txt + strspn(txt, " \t");
char*tmp;
const char*ctmp;
// Add beetter error detection. Look at `line
/* Skip the space after the `timescale directive. */
if (cp == txt) {
VLerror(yylloc, "Space required after `timescale directive.");
return;
}
int unit = 0;
int prec = 0;
num = strtoul(cp, &tmp, 10);
if (num == 0) {
VLerror(yylloc, "Invalid timescale string.");
return;
}
/* Get the time units. */
if (get_timescale_const(cp, unit, true)) return;
while (num >= 10) {
unit += 1;
num /= 10;
}
if (num != 1) {
VLerror(yylloc, "Invalid timescale unit number.");
return;
}
cp = tmp;
/* Skip any space after the time units, the '/' and any
* space after the '/'. */
cp += strspn(cp, " \t");
ctmp = cp + strcspn(cp, " \t/");
if (strncmp("s", cp, ctmp-cp) == 0) {
unit -= 0;
} else if (strncmp("ms", cp, ctmp-cp) == 0) {
unit -= 3;
} else if (strncmp("us", cp, ctmp-cp) == 0) {
unit -= 6;
} else if (strncmp("ns", cp, ctmp-cp) == 0) {
unit -= 9;
} else if (strncmp("ps", cp, ctmp-cp) == 0) {
unit -= 12;
} else if (strncmp("fs", cp, ctmp-cp) == 0) {
unit -= 15;
} else {
VLerror(yylloc, "Invalid timescale unit of measurement");
if (*cp != '/') {
VLerror(yylloc, "`timescale separator '/' appears to be missing.");
return;
}
cp = ctmp;
cp += strspn(cp, " \t/");
num = strtoul(cp, &tmp, 10);
if (num == 0) {
VLerror(yylloc, "Invalid timescale string.");
return;
}
assert(num);
while (num >= 10) {
prec += 1;
num /= 10;
}
if (num != 1) {
VLerror(yylloc, "Invalid timescale precision number.");
return;
}
cp = tmp;
cp += 1;
cp += strspn(cp, " \t");
ctmp = cp + strcspn(cp, " \t\r");
if (strncmp("s", cp, ctmp-cp) == 0) {
prec -= 0;
/* Get the time precision. */
if (get_timescale_const(cp, prec, false)) return;
} else if (strncmp("ms", cp, ctmp-cp) == 0) {
prec -= 3;
} else if (strncmp("us", cp, ctmp-cp) == 0) {
prec -= 6;
} else if (strncmp("ns", cp, ctmp-cp) == 0) {
prec -= 9;
} else if (strncmp("ps", cp, ctmp-cp) == 0) {
prec -= 12;
} else if (strncmp("fs", cp, ctmp-cp) == 0) {
prec -= 15;
} else {
VLerror(yylloc, "Invalid timescale precision units of measurement");
/* Verify that only space and/or a single line comment is left. */
cp += strspn(cp, " \t");
if (strncmp(cp, "//", 2) != 0 &&
(size_t)(cp-yytext) != strlen(yytext)) {
VLerror(yylloc, "Invalid `timescale directive (extra garbage "
"after precision).");
return;
}
@ -1211,8 +1228,7 @@ static void line_directive2()
}
/* Skip the space after the file name. */
cp = fn_end;
cp += 1;
cp = fn_end + 1;
cpr = cp;
cpr += strspn(cp, " \t");
if (cp == cpr) {
@ -1223,16 +1239,16 @@ static void line_directive2()
cp = cpr;
/* Check that the level is correct, we do not need the level. */
strtoul(cp, &cpr, 10);
if (cp == cpr) {
if (strspn(cp, "012") != 1) {
VLerror(yylloc, "Invalid level for `line directive.");
return;
}
cp = cpr;
cp += 1;
/* Verify that only space is left. */
cpr += strspn(cp, " \t");
if ((size_t)(cpr-yytext) != strlen(yytext)) {
/* Verify that only space and/or a single line comment is left. */
cp += strspn(cp, " \t");
if (strncmp(cp, "//", 2) != 0 &&
(size_t)(cp-yytext) != strlen(yytext)) {
VLerror(yylloc, "Invalid `line directive (extra garbage after "
"level).");
return;