[nasm:nasm-2.16.xx] preproc: add options for a base prefix to %num(), add %hex()
nasm-bot for H. Peter Anvin
hpa at zytor.com
Fri Oct 13 17:54:04 PDT 2023
Commit-ID: dcac46d973ad6ecc47ca9b6ad96ece087fd82613
Gitweb: http://repo.or.cz/w/nasm.git?a=commitdiff;h=dcac46d973ad6ecc47ca9b6ad96ece087fd82613
Author: H. Peter Anvin <hpa at zytor.com>
AuthorDate: Fri, 13 Oct 2023 17:50:55 -0700
Committer: H. Peter Anvin <hpa at zytor.com>
CommitDate: Fri, 13 Oct 2023 17:50:55 -0700
preproc: add options for a base prefix to %num(), add %hex()
Make it possible to add a base prefix to %num().
Add the %hex() function, producing hexadecimal values that are
nevertheless valid NASM numeric constants.
Signed-off-by: H. Peter Anvin <hpa at zytor.com>
---
asm/preproc.c | 79 ++++++++++++++++++++++++++++++++++++++++++++++++---------
doc/nasmdoc.src | 26 ++++++++++++++-----
2 files changed, 87 insertions(+), 18 deletions(-)
diff --git a/asm/preproc.c b/asm/preproc.c
index 0e0195ee..85c19890 100644
--- a/asm/preproc.c
+++ b/asm/preproc.c
@@ -206,14 +206,15 @@ typedef Token *(*ExpandSMacro)(const SMacro *s, Token **params, int nparams);
* if SPARM_GREEDY is set.
*/
enum sparmflags {
- SPARM_PLAIN = 0,
- SPARM_EVAL = 1, /* Evaluate as a numeric expression (=) */
- SPARM_STR = 2, /* Convert to quoted string ($) */
- SPARM_NOSTRIP = 4, /* Don't strip braces (!) */
- SPARM_GREEDY = 8, /* Greedy final parameter (+) */
- SPARM_VARADIC = 16, /* Any number of separate arguments */
- SPARM_OPTIONAL = 32, /* Optional argument */
- SPARM_CONDQUOTE = 64 /* With SPARM_STR, don't re-quote a string */
+ SPARM_PLAIN = 0,
+ SPARM_EVAL = 1, /* Evaluate as a numeric expression (=) */
+ SPARM_STR = 2, /* Convert to quoted string ($) */
+ SPARM_NOSTRIP = 4, /* Don't strip braces (!) */
+ SPARM_GREEDY = 8, /* Greedy final parameter (+) */
+ SPARM_VARADIC = 16, /* Any number of separate arguments */
+ SPARM_OPTIONAL = 32, /* Optional argument */
+ SPARM_CONDQUOTE = 64, /* With SPARM_STR, don't re-quote a string */
+ SPARM_HEX = 128 /* With SPARM_EVAL, generate hexadecimal numbers */
};
struct smac_param {
@@ -650,6 +651,7 @@ static Token *expand_smacro(Token * tline);
static Token *expand_id(Token * tline);
static Context *get_ctx(const char *name, const char **namep);
static Token *make_tok_num(Token *next, int64_t val);
+static Token *make_tok_hex(Token *next, int64_t val);
static int64_t get_tok_num(const Token *t, bool *err);
static Token *make_tok_qstr(Token *next, const char *str);
static Token *make_tok_qstr_len(Token *next, const char *str, size_t len);
@@ -5924,7 +5926,11 @@ static SMacro *expand_one_smacro(Token ***tpp)
nasm_nonfatal("non-constant expression in parameter %d of %s `%s'",
i+1, mtype, m->name);
} else {
- params[i] = make_tok_num(NULL, reloc_value(evalresult));
+ int64_t v = reloc_value(evalresult);
+ if (flags & SPARM_HEX)
+ params[i] = make_tok_hex(NULL, v);
+ else
+ params[i] = make_tok_num(NULL, v);
}
}
@@ -7215,12 +7221,13 @@ stdmac_num(const SMacro *s, Token **params, int nparam)
unsigned int i;
int nd;
unsigned int base;
- char numstr[256];
+ char numstr[262];
char * const endstr = numstr + sizeof numstr - 1;
- const int maxlen = sizeof numstr - 3;
+ const int maxlen = sizeof numstr - 5;
const int maxbase = sizeof num_digits - 1;
char *p;
bool moredigits;
+ char decorate;
(void)nparam;
@@ -7231,6 +7238,28 @@ stdmac_num(const SMacro *s, Token **params, int nparam)
dparm = parm[1];
bparm = parm[2];
+ decorate = 0;
+ if (bparm < 0) {
+ bparm = -bparm;
+ switch (bparm) {
+ case 2:
+ decorate = 'b';
+ break;
+ case 8:
+ decorate = 'q';
+ break;
+ case 10:
+ decorate = 'd';
+ break;
+ case 16:
+ decorate = 'x';
+ break;
+ default:
+ bparm = -bparm; /* Error out below */
+ break;
+ }
+ }
+
if (bparm < 2 || bparm > maxbase) {
nasm_nonfatal("invalid base %"PRId64" given to %s()",
bparm, s->name);
@@ -7252,14 +7281,26 @@ stdmac_num(const SMacro *s, Token **params, int nparam)
nd = dparm;
}
+ /* Are we supposed to generate an empty string for zero? */
+ if (!nd && !n)
+ decorate = 0;
+
p = endstr;
*p = '\0';
*--p = '\'';
+ /*
+ * Note that the actual maximum number of digits can never exceed 64,
+ * so even if moredigits is set it cannot cause string overrun.
+ */
while (nd-- > 0 || (moredigits && n)) {
*--p = num_digits[n % base];
n /= base;
}
+ if (decorate) {
+ *--p = decorate;
+ *--p = '0';
+ }
*--p = '\'';
return new_Token(NULL, TOKEN_STR, p, endstr - p);
@@ -7307,6 +7348,7 @@ static void pp_add_magic_stdmac(void)
{ "%abs", false, 1, SPARM_EVAL, stdmac_abs },
{ "%count", false, 1, SPARM_VARADIC, stdmac_count },
{ "%eval", false, 1, SPARM_EVAL|SPARM_VARADIC, stdmac_join },
+ { "%hex", false, 1, SPARM_EVAL|SPARM_HEX|SPARM_VARADIC, stdmac_join },
{ "%str", false, 1, SPARM_GREEDY|SPARM_STR, stdmac_join },
{ "%strcat", false, 1, SPARM_STR|SPARM_CONDQUOTE|SPARM_VARADIC, stdmac_strcat },
{ "%strlen", false, 1, SPARM_STR|SPARM_CONDQUOTE, stdmac_strlen },
@@ -8002,9 +8044,22 @@ static Token *make_tok_num(Token *next, int64_t val)
return next;
}
+/* Create a numeric token as unsigned hexadecimal */
+static Token *make_tok_hex(Token *next, int64_t val)
+{
+ char numbuf[32];
+ int len;
+ uint64_t uval = val;
+
+ len = snprintf(numbuf, sizeof numbuf, "%#"PRIx64, uval);
+ next = new_Token(next, TOKEN_NUM, numbuf, len);
+
+ return next;
+}
+
/*
* Do the inverse of make_tok_num(). This only needs to be able
- * to parse the output of make_tok_num().
+ * to parse the output of make_tok_num() or make_tok_hex().
*/
static int64_t get_tok_num(const Token *t, bool *err)
{
diff --git a/doc/nasmdoc.src b/doc/nasmdoc.src
index ddf8b630..3b5ea462 100644
--- a/doc/nasmdoc.src
+++ b/doc/nasmdoc.src
@@ -2919,6 +2919,14 @@ The expressions passed to \c{%eval()} are \i{critical expressions},
see \k{crit}.
+\C{f_hex} \i\c{%hex()} Function
+
+Equivalent to \i\c\{%eval()}, except that the results generated are
+given as hexadecimal. A \c{0x} prefix is added unless the value is
+zero, equivalent to the C \c{printf("%#x")} format. See also the
+\c{%num()} function, (\k{f_num}).
+
+
\S{f_is} \i\c{%is()} Family Functions
Each \i\c{%if} family directive (see \k{condasm}) has an equivalent
@@ -2948,16 +2956,23 @@ argument to the conditional using \c{\{\}}:
The \c{%num()} function evaluates its arguments as expressions, and
then produces a quoted string encoding the first argument as an
-\e{unsigned} integer. The second argument is the desired number of
-digits (max 253, default -1), and the second argument is the encoding
-base (from 2 to 64, default 10.)
+\e{unsigned} 64-bit integer.
+
+The second argument is the desired number of digits (max 255, default
+-1).
+
+The third argument is the encoding base (from 2 to 64, default 10); if
+the base is given as -2, -8, -10, or -16, then \c{0b}, \c{0q}, \c{0d}
+or \c{0x} is prepended, respectively; all other negative values are
+disallowed.
Only the first argument is required.
If the number of digits is negative, NASM will add additional digits
-if needed, if positive the string is truncated to the number of digits
+if needed; if positive the string is truncated to the number of digits
specified. 0 is treated as -1, except that the input number 0
-generates an empty string (thus, the first digit will never be zero.)
+always generates an empty string (thus, the first digit will never be
+zero), even if the base given is negative.
The full 64-symbol set used is, in order:
@@ -2967,7 +2982,6 @@ If a \e{signed} number needs to be converted to a string, use
\c{%abs()}, \c{%cond()}, and \c{%strcat()} to format the signed number
string to your specific output requirements.
-
\S{f_sel} \i\c{%sel()} Function
The \c{%sel()} function evaluates its first argument as an
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