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preproc: implement %substr() and %tok() preprocessor functions

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Implement preprocessor functions equivalent to the %substr and %deftok
directive.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
This commit is contained in:
H. Peter Anvin 2022-11-11 19:02:41 -08:00
parent 913901e529
commit 4150848a7d
1 changed files with 107 additions and 69 deletions
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176
asm/preproc.c
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@ -3586,6 +3586,8 @@ static Token *pp_strcat(Token *tline, const char *dname)
break;
case TOKEN_STR:
unquote_token(t);
/* fall through */
case TOKEN_INTERNAL_STR:
len += t->len;
break;
default:
@ -3608,6 +3610,78 @@ static Token *pp_strcat(Token *tline, const char *dname)
return t;
}
/*
* Implement substring extraction as used by the %substr directive
* and function.
*/
static Token *pp_substr(Token *tline, const char *dname)
{
int64_t start, count;
const char *txt;
size_t len;
struct ppscan pps;
Token *t;
expr *evalresult;
struct tokenval tokval;
t = skip_white(tline);
if (!tok_is(t, TOKEN_STR)) {
nasm_nonfatal("`%s' requires a string as parameter", dname);
return NULL;
}
pps.tptr = skip_white(t->next);
if (tok_is(pps.tptr, TOKEN_COMMA))
pps.tptr = skip_white(pps.tptr->next);
if (!pps.tptr) {
nasm_nonfatal("`%s' requires a starting index", dname);
return NULL;
}
pps.ntokens = -1;
tokval.t_type = TOKEN_INVALID;
evalresult = evaluate(ppscan, &pps, &tokval, NULL, true, NULL);
if (!evalresult) {
return NULL;
} else if (!is_simple(evalresult)) {
nasm_nonfatal("non-constant value given to `%s'", dname);
return NULL;
}
start = evalresult->value - 1;
pps.tptr = skip_white(pps.tptr);
if (!pps.tptr) {
count = 1; /* Backwards compatibility: one character */
} else {
tokval.t_type = TOKEN_INVALID;
evalresult = evaluate(ppscan, &pps, &tokval, NULL, true, NULL);
if (!evalresult) {
return NULL;
} else if (!is_simple(evalresult)) {
nasm_nonfatal("non-constant value given to `%s'", dname);
return NULL;
}
count = evalresult->value;
}
unquote_token(t);
len = t->len;
/* make start and count being in range */
if (start < 0)
start = 0;
if (count < 0)
count = len + count + 1 - start;
if (start + count > (int64_t)len)
count = len - start;
if (!len || count < 0 || start >=(int64_t)len)
start = -1, count = 0; /* empty string */
txt = (start < 0) ? "" : tok_text(t) + start;
return make_tok_qstr_len(NULL, txt, count);
}
/**
* find and process preprocessor directive in passed line
* Find out if a line contains a preprocessor directive, and deal
@ -4666,9 +4740,7 @@ issue_error:
}
/*
* Convert the string to a token stream. Note that smacros
* are stored with the token stream reversed, so we have to
* reverse the output of tokenize().
* Convert the string to a token stream.
*/
macro_start = tokenize(unquote_token_cstr(t));
@ -4763,16 +4835,12 @@ issue_error:
* zero, and a string token to use as an expansion. Create
* and store an SMacro.
*/
define_smacro(mname, casesense, macro_start, NULL);
if (macro_start)
define_smacro(mname, casesense, macro_start, NULL);
free_tlist(tline);
break;
case PP_SUBSTR:
{
int64_t start, count;
const char *txt;
size_t len;
if (!(mname = get_id(&tline, dname)))
goto done;
@ -4780,72 +4848,16 @@ issue_error:
tline = expand_smacro(tline->next);
last->next = NULL;
t = skip_white(tline);
/* t should now point to the string */
if (!tok_is(t, TOKEN_STR)) {
nasm_nonfatal("`%s' requires string as second parameter", dname);
free_tlist(tline);
goto done;
}
pps.tptr = t->next;
pps.ntokens = -1;
tokval.t_type = TOKEN_INVALID;
evalresult = evaluate(ppscan, &pps, &tokval, NULL, true, NULL);
if (!evalresult) {
free_tlist(tline);
goto done;
} else if (!is_simple(evalresult)) {
nasm_nonfatal("non-constant value given to `%s'", dname);
free_tlist(tline);
goto done;
}
start = evalresult->value - 1;
pps.tptr = skip_white(pps.tptr);
if (!pps.tptr) {
count = 1; /* Backwards compatibility: one character */
} else {
tokval.t_type = TOKEN_INVALID;
evalresult = evaluate(ppscan, &pps, &tokval, NULL, true, NULL);
if (!evalresult) {
free_tlist(tline);
goto done;
} else if (!is_simple(evalresult)) {
nasm_nonfatal("non-constant value given to `%s'", dname);
free_tlist(tline);
goto done;
}
count = evalresult->value;
}
unquote_token(t);
len = t->len;
/* make start and count being in range */
if (start < 0)
start = 0;
if (count < 0)
count = len + count + 1 - start;
if (start + count > (int64_t)len)
count = len - start;
if (!len || count < 0 || start >=(int64_t)len)
start = -1, count = 0; /* empty string */
txt = (start < 0) ? "" : tok_text(t) + start;
len = count;
macro_start = make_tok_qstr_len(NULL, txt, len);
macro_start = pp_substr(tline, dname);
/*
* We now have a macro name, an implicit parameter count of
* zero, and a numeric token to use as an expansion. Create
* zero, and a string token to use as an expansion. Create
* and store an SMacro.
*/
define_smacro(mname, casesense, macro_start, NULL);
if (macro_start)
define_smacro(mname, casesense, macro_start, NULL);
free_tlist(tline);
break;
}
case PP_ASSIGN:
if (!(mname = get_id(&tline, dname)))
@ -6887,6 +6899,30 @@ stdmac_strcat(const SMacro *s, Token **params, int nparams)
return pp_strcat(expand_smacro_noreset(params[0]), s->name);
}
/* %substr() function */
static Token *
stdmac_substr(const SMacro *s, Token **params, int nparams)
{
nasm_assert(nparams == 1);
return pp_substr(expand_smacro_noreset(params[0]), s->name);
}
/* %tok() function */
static Token *
stdmac_tok(const SMacro *s, Token **params, int nparams)
{
Token *t = expand_smacro_noreset(params[0]);
(void)nparams;
if (!tok_is(t, TOKEN_STR)) {
nasm_nonfatal("`%s' requires string as parameter", s->name);
return NULL;
}
return reverse_tokens(tokenize(unquote_token_cstr(t)));
}
/* Add magic standard macros */
struct magic_macros {
const char *name;
@ -6905,6 +6941,8 @@ static void pp_add_magic_stdmac(void)
{ "%eval", false, 1, SPARM_EVAL|SPARM_VARADIC, stdmac_join },
{ "%str", false, 1, SPARM_GREEDY|SPARM_STR, stdmac_join },
{ "%strcat", false, 1, SPARM_GREEDY, stdmac_strcat },
{ "%substr", false, 1, SPARM_GREEDY, stdmac_substr },
{ "%tok", false, 1, 0, stdmac_tok },
{ NULL, false, 0, 0, NULL }
};
const struct magic_macros *m;