binutils-gdb/gdb/macroscope.c

163 lines
5.3 KiB
C

/* Functions for deciding which macros are currently in scope.
Copyright (C) 2002-2018 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/>. */
#include "defs.h"
#include "macroscope.h"
#include "symtab.h"
#include "source.h"
#include "target.h"
#include "frame.h"
#include "inferior.h"
#include "complaints.h"
/* A table of user-defined macros. Unlike the macro tables used for
symtabs, this one uses xmalloc for all its allocation, not an
obstack, and it doesn't bcache anything; it just xmallocs things. So
it's perfectly possible to remove things from this, or redefine
things. */
struct macro_table *macro_user_macros;
gdb::unique_xmalloc_ptr<struct macro_scope>
sal_macro_scope (struct symtab_and_line sal)
{
struct macro_source_file *main_file, *inclusion;
struct compunit_symtab *cust;
if (sal.symtab == NULL)
return NULL;
cust = SYMTAB_COMPUNIT (sal.symtab);
if (COMPUNIT_MACRO_TABLE (cust) == NULL)
return NULL;
gdb::unique_xmalloc_ptr<struct macro_scope> ms (XNEW (struct macro_scope));
main_file = macro_main (COMPUNIT_MACRO_TABLE (cust));
inclusion = macro_lookup_inclusion (main_file, sal.symtab->filename);
if (inclusion)
{
ms->file = inclusion;
ms->line = sal.line;
}
else
{
/* There are, unfortunately, cases where a compilation unit can
have a symtab for a source file that doesn't appear in the
macro table. For example, at the moment, Dwarf doesn't have
any way in the .debug_macinfo section to describe the effect
of #line directives, so if you debug a YACC parser you'll get
a macro table which only mentions the .c files generated by
YACC, but symtabs that mention the .y files consumed by YACC.
In the long run, we should extend the Dwarf macro info
representation to handle #line directives, and get GCC to
emit it.
For the time being, though, we'll just treat these as
occurring at the end of the main source file. */
ms->file = main_file;
ms->line = -1;
complaint (&symfile_complaints,
_("symtab found for `%s', but that file\n"
"is not covered in the compilation unit's macro information"),
symtab_to_filename_for_display (sal.symtab));
}
return ms;
}
gdb::unique_xmalloc_ptr<struct macro_scope>
user_macro_scope (void)
{
gdb::unique_xmalloc_ptr<struct macro_scope> ms (XNEW (struct macro_scope));
ms->file = macro_main (macro_user_macros);
ms->line = -1;
return ms;
}
gdb::unique_xmalloc_ptr<struct macro_scope>
default_macro_scope (void)
{
struct symtab_and_line sal;
gdb::unique_xmalloc_ptr<struct macro_scope> ms;
struct frame_info *frame;
CORE_ADDR pc;
/* If there's a selected frame, use its PC. */
frame = deprecated_safe_get_selected_frame ();
if (frame && get_frame_pc_if_available (frame, &pc))
sal = find_pc_line (pc, 0);
/* Fall back to the current listing position. */
else
{
/* Don't call select_source_symtab here. That can raise an
error if symbols aren't loaded, but GDB calls the expression
evaluator in all sorts of contexts.
For example, commands like `set width' call the expression
evaluator to evaluate their numeric arguments. If the
current language is C, then that may call this function to
choose a scope for macro expansion. If you don't have any
symbol files loaded, then get_current_or_default would raise an
error. But `set width' shouldn't raise an error just because
it can't decide which scope to macro-expand its argument in. */
struct symtab_and_line cursal =
get_current_source_symtab_and_line ();
sal.symtab = cursal.symtab;
sal.line = cursal.line;
}
ms = sal_macro_scope (sal);
if (! ms)
ms = user_macro_scope ();
return ms;
}
/* Look up the definition of the macro named NAME in scope at the source
location given by BATON, which must be a pointer to a `struct
macro_scope' structure. */
struct macro_definition *
standard_macro_lookup (const char *name, void *baton)
{
struct macro_scope *ms = (struct macro_scope *) baton;
struct macro_definition *result;
/* Give user-defined macros priority over all others. */
result = macro_lookup_definition (macro_main (macro_user_macros), -1, name);
if (! result)
result = macro_lookup_definition (ms->file, ms->line, name);
return result;
}
void
_initialize_macroscope (void)
{
macro_user_macros = new_macro_table (NULL, NULL, NULL);
macro_set_main (macro_user_macros, "<user-defined>");
macro_allow_redefinitions (macro_user_macros);
}