diff options
Diffstat (limited to 'libdw/dwarf_getscopevar.c')
| -rw-r--r-- | libdw/dwarf_getscopevar.c | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/libdw/dwarf_getscopevar.c b/libdw/dwarf_getscopevar.c new file mode 100644 index 0000000..6ce214f --- /dev/null +++ b/libdw/dwarf_getscopevar.c @@ -0,0 +1,175 @@ +/* Find a named variable or parameter within given scopes. + Copyright (C) 2005-2009 Red Hat, Inc. + This file is part of Red Hat elfutils. + + Red Hat elfutils 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; version 2 of the License. + + Red Hat elfutils 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 Red Hat elfutils; if not, write to the Free Software Foundation, + Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA. + + In addition, as a special exception, Red Hat, Inc. gives You the + additional right to link the code of Red Hat elfutils with code licensed + under any Open Source Initiative certified open source license + (http://www.opensource.org/licenses/index.php) which requires the + distribution of source code with any binary distribution and to + distribute linked combinations of the two. Non-GPL Code permitted under + this exception must only link to the code of Red Hat elfutils through + those well defined interfaces identified in the file named EXCEPTION + found in the source code files (the "Approved Interfaces"). The files + of Non-GPL Code may instantiate templates or use macros or inline + functions from the Approved Interfaces without causing the resulting + work to be covered by the GNU General Public License. Only Red Hat, + Inc. may make changes or additions to the list of Approved Interfaces. + Red Hat's grant of this exception is conditioned upon your not adding + any new exceptions. If you wish to add a new Approved Interface or + exception, please contact Red Hat. You must obey the GNU General Public + License in all respects for all of the Red Hat elfutils code and other + code used in conjunction with Red Hat elfutils except the Non-GPL Code + covered by this exception. If you modify this file, you may extend this + exception to your version of the file, but you are not obligated to do + so. If you do not wish to provide this exception without modification, + you must delete this exception statement from your version and license + this file solely under the GPL without exception. + + Red Hat elfutils is an included package of the Open Invention Network. + An included package of the Open Invention Network is a package for which + Open Invention Network licensees cross-license their patents. No patent + license is granted, either expressly or impliedly, by designation as an + included package. Should you wish to participate in the Open Invention + Network licensing program, please visit www.openinventionnetwork.com + <http://www.openinventionnetwork.com>. */ + +#ifdef HAVE_CONFIG_H +# include <config.h> +#endif + +#include <stdbool.h> +#include <string.h> +#include "libdwP.h" +#include <dwarf.h> + + +/* Find the containing CU's files. */ +static int +getfiles (Dwarf_Die *die, Dwarf_Files **files) +{ + return INTUSE(dwarf_getsrcfiles) (&CUDIE (die->cu), files, NULL); +} + +/* Fetch an attribute that should have a constant integer form. */ +static int +getattr (Dwarf_Die *die, int search_name, Dwarf_Word *value) +{ + Dwarf_Attribute attr_mem; + return INTUSE(dwarf_formudata) (INTUSE(dwarf_attr) (die, search_name, + &attr_mem), value); +} + +/* Search SCOPES[0..NSCOPES-1] for a variable called NAME. + Ignore the first SKIP_SHADOWS scopes that match the name. + If MATCH_FILE is not null, accept only declaration in that source file; + if MATCH_LINENO or MATCH_LINECOL are also nonzero, accept only declaration + at that line and column. + + If successful, fill in *RESULT with the DIE of the variable found, + and return N where SCOPES[N] is the scope defining the variable. + Return -1 for errors or -2 for no matching variable found. */ + +int +dwarf_getscopevar (Dwarf_Die *scopes, int nscopes, + const char *name, int skip_shadows, + const char *match_file, int match_lineno, int match_linecol, + Dwarf_Die *result) +{ + /* Match against the given file name. */ + size_t match_file_len = match_file == NULL ? 0 : strlen (match_file); + bool lastfile_matches = false; + const char *lastfile = NULL; + inline bool file_matches (Dwarf_Files *files, size_t idx) + { + if (idx >= files->nfiles) + return false; + + const char *file = files->info[idx].name; + if (file != lastfile) + { + size_t len = strlen (file); + lastfile_matches = (len >= match_file_len + && !memcmp (match_file, file, match_file_len) + && (len == match_file_len + || file[len - match_file_len - 1] == '/')); + } + return lastfile_matches; + } + + /* Start with the innermost scope and move out. */ + for (int out = 0; out < nscopes; ++out) + if (INTUSE(dwarf_haschildren) (&scopes[out])) + { + if (INTUSE(dwarf_child) (&scopes[out], result) != 0) + return -1; + do + { + switch (INTUSE(dwarf_tag) (result)) + { + case DW_TAG_variable: + case DW_TAG_formal_parameter: + break; + + default: + continue; + } + + /* Only get here for a variable or parameter. Check the name. */ + const char *diename = INTUSE(dwarf_diename) (result); + if (diename != NULL && !strcmp (name, diename)) + { + /* We have a matching name. */ + + if (skip_shadows > 0) + { + /* Punt this scope for the one it shadows. */ + --skip_shadows; + break; + } + + if (match_file != NULL) + { + /* Check its decl_file. */ + + Dwarf_Word i; + Dwarf_Files *files; + if (getattr (result, DW_AT_decl_file, &i) != 0 + || getfiles (&scopes[out], &files) != 0) + break; + + if (!file_matches (files, i)) + break; + + if (match_lineno > 0 + && (getattr (result, DW_AT_decl_line, &i) != 0 + || (int) i != match_lineno)) + break; + if (match_linecol > 0 + && (getattr (result, DW_AT_decl_column, &i) != 0 + || (int) i != match_linecol)) + break; + } + + /* We have a winner! */ + return out; + } + } + while (INTUSE(dwarf_siblingof) (result, result) == 0); + } + + return -2; +} |