Squashed 'third_party/elfutils/' content from commit 555e15e
Change-Id: I61cde98949e47e5c8c09c33260de17f30921be79
git-subtree-dir: third_party/elfutils
git-subtree-split: 555e15ebe8bf1eb33d00747173cfc80cc65648a4
diff --git a/libdw/dwarf_getscopevar.c b/libdw/dwarf_getscopevar.c
new file mode 100644
index 0000000..7b1416f
--- /dev/null
+++ b/libdw/dwarf_getscopevar.c
@@ -0,0 +1,159 @@
+/* Find a named variable or parameter within given scopes.
+ Copyright (C) 2005-2009 Red Hat, Inc.
+ This file is part of elfutils.
+
+ This file is free software; you can redistribute it and/or modify
+ it under the terms of either
+
+ * the GNU Lesser General Public License as published by the Free
+ Software Foundation; either version 3 of the License, or (at
+ your option) any later version
+
+ or
+
+ * the GNU General Public License as published by the Free
+ Software Foundation; either version 2 of the License, or (at
+ your option) any later version
+
+ or both in parallel, as here.
+
+ 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 copies of the GNU General Public License and
+ the GNU Lesser General Public License along with this program. If
+ not, see <http://www.gnu.org/licenses/>. */
+
+#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);
+}
+
+static inline int
+file_matches (const char *lastfile,
+ size_t match_file_len, const char *match_file,
+ Dwarf_Files *files, size_t idx,
+ bool *lastfile_matches)
+{
+ 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;
+}
+
+/* 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;
+
+ /* 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 (lastfile, match_file_len, match_file,
+ files, i, &lastfile_matches))
+ 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;
+}