binutils-gdb/gdb/macroexp.h

/* Interface to C preprocessor macro expansion for GDB.
   Copyright (C) 2002, 2007, 2008, 2009 Free Software Foundation, Inc.
   Contributed by Red Hat, Inc.

   This file is part of GDB.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */


#ifndef MACROEXP_H
#define MACROEXP_H

/* A function for looking up preprocessor macro definitions.  Return
   the preprocessor definition of NAME in scope according to BATON, or
   zero if NAME is not defined as a preprocessor macro.

   The caller must not free or modify the definition returned.  It is
   probably unwise for the caller to hold pointers to it for very
   long; it probably lives in some objfile's obstacks.  */
typedef struct macro_definition *(macro_lookup_ftype) (const char *name,
                                                       void *baton);


/* Expand any preprocessor macros in SOURCE, and return the expanded
   text.  Use LOOKUP_FUNC and LOOKUP_FUNC_BATON to find identifiers'
   preprocessor definitions.  SOURCE is a null-terminated string.  The
   result is a null-terminated string, allocated using xmalloc; it is
   the caller's responsibility to free it.  */
char *macro_expand (const char *source,
                    macro_lookup_ftype *lookup_func,
                    void *lookup_func_baton);


/* Expand all preprocessor macro references that appear explicitly in
   SOURCE, but do not expand any new macro references introduced by
   that first level of expansion.  Use LOOKUP_FUNC and
   LOOKUP_FUNC_BATON to find identifiers' preprocessor definitions.
   SOURCE is a null-terminated string.  The result is a
   null-terminated string, allocated using xmalloc; it is the caller's
   responsibility to free it.  */
char *macro_expand_once (const char *source,
                         macro_lookup_ftype *lookup_func,
                         void *lookup_func_baton);


/* If the null-terminated string pointed to by *LEXPTR begins with a
   macro invocation, return the result of expanding that invocation as
   a null-terminated string, and set *LEXPTR to the next character
   after the invocation.  The result is completely expanded; it
   contains no further macro invocations.

   Otherwise, if *LEXPTR does not start with a macro invocation,
   return zero, and leave *LEXPTR unchanged.

   Use LOOKUP_FUNC and LOOKUP_BATON to find macro definitions.

   If this function returns a string, the caller is responsible for
   freeing it, using xfree.

   We need this expand-one-token-at-a-time interface in order to
   accomodate GDB's C expression parser, which may not consume the
   entire string.  When the user enters a command like

      (gdb) break *func+20 if x == 5

   the parser is expected to consume `func+20', and then stop when it
   sees the "if".  But of course, "if" appearing in a character string
   or as part of a larger identifier doesn't count.  So you pretty
   much have to do tokenization to find the end of the string that
   needs to be macro-expanded.  Our C/C++ tokenizer isn't really
   designed to be called by anything but the yacc parser engine.  */
char *macro_expand_next (char **lexptr,
                         macro_lookup_ftype *lookup_func,
                         void *lookup_baton);

/* Functions to classify characters according to cpp rules.  */

int macro_is_whitespace (int c);
int macro_is_identifier_nondigit (int c);
int macro_is_digit (int c);


#endif /* MACROEXP_H */