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# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
include <syserr.h>
include "qpoe.h"
# QP_GMSYM -- Lookup the named macro in the symbol table and return a pointer
# to the symstruct describing the macro as the function value. NULL is
# returned if the macro is not defined, or if the named symbol is not a macro.
# Local macros take precedence over global macros. In the case of a local
# macro whose value is stored in the datafile, we have to allocate an internal
# buffer to hold the data after we exit; this data must be used promptly,
# before the routine is again called.
pointer procedure qp_gmsym (qp, macro, textp)
pointer qp #I QPOE descriptor
char macro[ARB] #I macro name
pointer textp #O char pointer to macro text
int sz_textbuf, nchars, fd
pointer st, sm, sym, textbuf
data textbuf /NULL/, sz_textbuf /NULL/
int fm_getfd(), read()
pointer qm_symtab(), strefsbuf(), stfind()
errchk realloc, fm_getfd, seek, read
begin
st = QP_ST(qp)
sm = qm_symtab (QP_QM(qp))
# First look in the datafile local symbol table. Macros are stored
# in the datafile symbol table as string macros of type TY_MACRO.
sym = stfind (st, macro)
if (sym != NULL)
if (S_DTYPE(sym) == TY_MACRO)
if (and (S_FLAGS(sym), SF_DELETED) == 0) {
if (S_LFILE(sym) > 0) {
# Macro value stored as data.
# Make sure the text buffer is large enough.
if (sz_textbuf < S_NELEM(sym)) {
sz_textbuf = S_NELEM(sym)
call realloc (textbuf, sz_textbuf, TY_CHAR)
}
# Read the data.
fd = fm_getfd (QP_FM(qp), S_LFILE(sym), READ_ONLY, 0)
call seek (fd, S_OFFSET(sym))
nchars = max (0, read (fd, Memc[textbuf], S_NELEM(sym)))
Memc[textbuf+nchars] = EOS
textp = textbuf
call fm_retfd (QP_FM(qp), S_LFILE(sym))
} else {
# Macro value stored in symbol table.
textp = strefsbuf (st, S_OFFSET(sym))
}
# Exit if a local symbol was found.
return (sym)
}
# Next look in the global macro symbol table.
sym = stfind (sm, macro)
if (sym != NULL)
if (and (S_FLAGS(sym), SF_DELETED) == 0)
textp = strefsbuf (sm, S_OFFSET(sym))
else
sym = NULL
return (sym)
end
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