gdb/macroexp.h

   1 /* Interface to C preprocessor macro expansion for GDB.
   2    Copyright (C) 2002 Free Software Foundation, Inc.
   3    Contributed by Red Hat, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 2 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, write to the Free Software
  19    Foundation, Inc., 51 Franklin Street, Fifth Floor,
  20    Boston, MA 02110-1301, USA.  */
  21
  22
  23 #ifndef MACROEXP_H
  24 #define MACROEXP_H
  25
  26 /* A function for looking up preprocessor macro definitions.  Return
  27    the preprocessor definition of NAME in scope according to BATON, or
  28    zero if NAME is not defined as a preprocessor macro.
  29
  30    The caller must not free or modify the definition returned.  It is
  31    probably unwise for the caller to hold pointers to it for very
  32    long; it probably lives in some objfile's obstacks.  */
  33 typedef struct macro_definition *(macro_lookup_ftype) (const char *name,
  34                                                        void *baton);
  35
  36
  37 /* Expand any preprocessor macros in SOURCE, and return the expanded
  38    text.  Use LOOKUP_FUNC and LOOKUP_FUNC_BATON to find identifiers'
  39    preprocessor definitions.  SOURCE is a null-terminated string.  The
  40    result is a null-terminated string, allocated using xmalloc; it is
  41    the caller's responsibility to free it.  */
  42 char *macro_expand (const char *source,
  43                     macro_lookup_ftype *lookup_func,
  44                     void *lookup_func_baton);
  45
  46
  47 /* Expand all preprocessor macro references that appear explicitly in
  48    SOURCE, but do not expand any new macro references introduced by
  49    that first level of expansion.  Use LOOKUP_FUNC and
  50    LOOKUP_FUNC_BATON to find identifiers' preprocessor definitions.
  51    SOURCE is a null-terminated string.  The result is a
  52    null-terminated string, allocated using xmalloc; it is the caller's
  53    responsibility to free it.  */
  54 char *macro_expand_once (const char *source,
  55                          macro_lookup_ftype *lookup_func,
  56                          void *lookup_func_baton);
  57
  58
  59 /* If the null-terminated string pointed to by *LEXPTR begins with a
  60    macro invocation, return the result of expanding that invocation as
  61    a null-terminated string, and set *LEXPTR to the next character
  62    after the invocation.  The result is completely expanded; it
  63    contains no further macro invocations.
  64
  65    Otherwise, if *LEXPTR does not start with a macro invocation,
  66    return zero, and leave *LEXPTR unchanged.
  67
  68    Use LOOKUP_FUNC and LOOKUP_BATON to find macro definitions.
  69
  70    If this function returns a string, the caller is responsible for
  71    freeing it, using xfree.
  72
  73    We need this expand-one-token-at-a-time interface in order to
  74    accomodate GDB's C expression parser, which may not consume the
  75    entire string.  When the user enters a command like
  76
  77       (gdb) break *func+20 if x == 5
  78
  79    the parser is expected to consume `func+20', and then stop when it
  80    sees the "if".  But of course, "if" appearing in a character string
  81    or as part of a larger identifier doesn't count.  So you pretty
  82    much have to do tokenization to find the end of the string that
  83    needs to be macro-expanded.  Our C/C++ tokenizer isn't really
  84    designed to be called by anything but the yacc parser engine.  */
  85 char *macro_expand_next (char **lexptr,
  86                          macro_lookup_ftype *lookup_func,
  87                          void *lookup_baton);
  88
  89
  90 #endif /* MACROEXP_H */