gnupic: some question about the directive GLOBAL in the source code.
Subject:
some question about the directive GLOBAL in the source code.
From:
feqin fan ####@####.####
Date:
14 Aug 2012 10:35:38 -0000
Message-Id: <CAOfAq_oR-SQUA5HOwAeZbutm9Gy3ztYZEr-7FFXfqeSEg0Ji_Q@mail.gmail.com>
Hello, everybody, I'm sorry to trouble you again.
I have read most of the source code of gputils. I have a query about
the implementation of the directive GLOBAL.
for example, Have this code:
global var
udata
var res 1
the assembler deal with the first line "global var",
the calling sequence is like this : yyparse() - do_or_append_insn(char *,
struct pnode *) - do_insn(char *, struct pnode *) - do_global()
the function do_global() source code :
1, if (state.mode == absolute) {
2, gperror(GPE_OBJECT_ONLY, NULL);
3, } else {
4, for (; parms; parms = TAIL(parms)) {
5, p = maybe_evaluate_concat(HEAD(parms)); //p will point to
"var".
6, if (p) {
7, s = get_symbol(state.stTop, p); //s will be NULL
8, if (s == NULL) {
9, snprintf(buf,
10, sizeof(buf),
11 "Symbol not previously defined (%s).",
12, p);
13, gperror(GPE_NOSYM, buf);
the line 4 must be first executed, in line 5 the p will point to "var". and
in line 7, because the source code "global var" is the first line of the
being assembled code.
So. in the function do_global() line 7, the s will be NULL,so the error
will be print..
Please tell what's wring in my analyses..??
:-)
THX, Guys..
