procyberian/nasm
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Don't confuse suffixed hexadecimal with floating-point

Browse source 
1e30 is a floating-point constant, but 1e30h is not.  The scanner
won't know that until it sees the "h", so make sure we keep enough
state to be able to distinguish "1e30" (a possible hex constant) from
"1.e30", "1e+30" or "1.0" (unabiguously floating-point.)
This commit is contained in:
H. Peter Anvin 2007-10-19 14:10:35 -07:00
parent f5f3d70d6d
commit 37d88e4125
2 changed files with 24 additions and 3 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

23
stdscan.c
View file

@ -118,6 +118,8 @@ int stdscan(void *private_data, struct tokenval *tv)
bool rn_error;
bool is_hex = false;
bool is_float = false;
bool has_e = false;
bool has_h = false;
char c;
r = stdscan_bufptr++;
@ -128,8 +130,17 @@ int stdscan(void *private_data, struct tokenval *tv)
for (;;) {
c = *stdscan_bufptr++;
if ((!is_hex && (c == 'e' || c == 'E')) ||
(c == 'P' || c == 'p')) {
if (!is_hex && (c == 'e' || c == 'E')) {
has_e = true;
if (*stdscan_bufptr == '+' || *stdscan_bufptr == '-') {
/* e can only be followed by +/- if it is either a
prefixed hex number or a floating-point number */
is_float = true;
stdscan_bufptr++;
}
} else if (c == 'H' || c == 'h') {
has_h = true;
} else if (c == 'P' || c == 'p') {
is_float = true;
if (*stdscan_bufptr == '+' || *stdscan_bufptr == '-')
stdscan_bufptr++;
@ -142,6 +153,11 @@ int stdscan(void *private_data, struct tokenval *tv)
}
stdscan_bufptr--; /* Point to first character beyond number */
if (has_e && !has_h) {
/* 1e13 is floating-point, but 1e13h is not */
is_float = true;
}
if (is_float) {
tv->t_charptr = stdscan_copy(r, stdscan_bufptr - r);
return tv->t_type = TOKEN_FLOAT;
@ -154,7 +170,8 @@ int stdscan(void *private_data, struct tokenval *tv)
tv->t_charptr = NULL;
return tv->t_type = TOKEN_NUM;
}
} else if (*stdscan_bufptr == '\'' || *stdscan_bufptr == '"') { /* a char constant */
} else if (*stdscan_bufptr == '\'' || *stdscan_bufptr == '"') {
/* a char constant */
char quote = *stdscan_bufptr++, *r;
bool rn_warn;
r = tv->t_charptr = stdscan_bufptr;

4
test/uscore.asm
View file

@ -1,6 +1,10 @@
dd 0x1234_5678
dd 305_419_896 ; Same number as above it
dd 0x1e16 ; NOT a floating-point number!
dd 1e16h ; NOT a floating-point number!
dd 1e16_h ; NOT a floating-point number!
dd $1e16 ; NOT a floating-point number!
dd $1e16 ; NOT a floating-point number!
dd 1e16 ; THIS is a floating-point number!
dd 1e+16
dd 1.e+16