This patch fixes PR c++/16117.
gdb has an extension so that users can use expressions like FILE::NAME
to choose a variable of the given name from the given file. The bug
is that this extension takes precedence over ordinary C++ expressions
of the same form. You might think this is merely hypothetical, but
now that C++ headers commonly do not use an extension, it is more
common.
This patch fixes the bug by making two related changes. First, it
changes gdb to prefer the ordinary C++ meaning of a symbol over the
extended meaning. Second, it arranges for single-quoting of the
symbol to indicate a preference for the extension.
Built and regtested on x86-64 Fedora 18.
New test case included.
2013-11-15 Tom Tromey <tromey@redhat.com>
PR c++/16117:
* c-exp.y (lex_one_token): Add "is_quoted_name" argument.
(classify_name): Likewise. Prefer a field of "this" over a
filename.
(classify_inner_name, yylex): Update.
2013-11-15 Tom Tromey <tromey@redhat.com>
* gdb.texinfo (Variables): Note gdb rules for ambiguous cases.
Add example.
2013-11-15 Tom Tromey <tromey@redhat.com>
* gdb.cp/includefile: New file.
* gdb.cp/filename.exp: New file.
* gdb.cp/filename.cc: New file.
+2013-11-15 Tom Tromey <tromey@redhat.com>
+
+ PR c++/16117:
+ * c-exp.y (lex_one_token): Add "is_quoted_name" argument.
+ (classify_name): Likewise. Prefer a field of "this" over a
+ filename.
+ (classify_inner_name, yylex): Update.
+
2013-11-15 Joel Brobecker <brobecker@adacore.com>
* dwarf2expr.h (struct dwarf_expr_context_funcs) <read_reg>:
/* Read one token, getting characters through lexptr. */
static int
-lex_one_token (void)
+lex_one_token (int *is_quoted_name)
{
int c;
int namelen;
char *copy;
last_was_structop = 0;
+ *is_quoted_name = 0;
retry:
{
++tokstart;
namelen = lexptr - tokstart - 1;
+ *is_quoted_name = 1;
+
goto tryname;
}
else if (host_len > 1)
/* Classify a NAME token. The contents of the token are in `yylval'.
Updates yylval and returns the new token type. BLOCK is the block
- in which lookups start; this can be NULL to mean the global
- scope. */
+ in which lookups start; this can be NULL to mean the global scope.
+ IS_QUOTED_NAME is non-zero if the name token was originally quoted
+ in single quotes. */
static int
-classify_name (const struct block *block)
+classify_name (const struct block *block, int is_quoted_name)
{
struct symbol *sym;
char *copy;
}
else if (!sym)
{
- /* See if it's a file name. */
- struct symtab *symtab;
-
- symtab = lookup_symtab (copy);
- if (symtab)
- {
- yylval.bval = BLOCKVECTOR_BLOCK (BLOCKVECTOR (symtab), STATIC_BLOCK);
- return FILENAME;
- }
-
/* If we found a field of 'this', we might have erroneously
found a constructor where we wanted a type name. Handle this
case by noticing that we found a constructor and then look up
return TYPENAME;
}
}
+
+ /* If we found a field, then we want to prefer it over a
+ filename. However, if the name was quoted, then it is better
+ to check for a filename or a block, since this is the only
+ way the user has of requiring the extension to be used. */
+ if (is_a_field_of_this.type == NULL || is_quoted_name)
+ {
+ /* See if it's a file name. */
+ struct symtab *symtab;
+
+ symtab = lookup_symtab (copy);
+ if (symtab)
+ {
+ yylval.bval = BLOCKVECTOR_BLOCK (BLOCKVECTOR (symtab),
+ STATIC_BLOCK);
+ return FILENAME;
+ }
+ }
}
if (sym && SYMBOL_CLASS (sym) == LOC_TYPEDEF)
char *copy;
if (context == NULL)
- return classify_name (block);
+ return classify_name (block, 0);
type = check_typedef (context);
if (TYPE_CODE (type) != TYPE_CODE_STRUCT
struct type *context_type = NULL;
int last_to_examine, next_to_examine, checkpoint;
const struct block *search_block;
+ int is_quoted_name;
if (popping && !VEC_empty (token_and_value, token_fifo))
goto do_pop;
/* Read the first token and decide what to do. Most of the
subsequent code is C++-only; but also depends on seeing a "::" or
name-like token. */
- current.token = lex_one_token ();
+ current.token = lex_one_token (&is_quoted_name);
if (current.token == NAME)
- current.token = classify_name (expression_context_block);
+ current.token = classify_name (expression_context_block, is_quoted_name);
if (parse_language->la_language != language_cplus
|| (current.token != TYPENAME && current.token != COLONCOLON
&& current.token != FILENAME))
last_was_coloncolon = current.token == COLONCOLON;
while (1)
{
- current.token = lex_one_token ();
+ int ignore;
+
+ /* We ignore quoted names other than the very first one.
+ Subsequent ones do not have any special meaning. */
+ current.token = lex_one_token (&ignore);
current.value = yylval;
VEC_safe_push (token_and_value, token_fifo, ¤t);
+2013-11-15 Tom Tromey <tromey@redhat.com>
+
+ * gdb.texinfo (Variables): Note gdb rules for ambiguous cases.
+ Add example.
+
2013-11-14 Tom Tromey <tromey@redhat.com>
* gdb.texinfo (Breakpoints In Python): Replace "as" with "in".
@end smallexample
@cindex C@t{++} scope resolution
-These uses of @samp{::} are very rarely in conflict with the very similar
-use of the same notation in C@t{++}. @value{GDBN} also supports use of the C@t{++}
-scope resolution operator in @value{GDBN} expressions.
-@c FIXME: Um, so what happens in one of those rare cases where it's in
-@c conflict?? --mew
+These uses of @samp{::} are very rarely in conflict with the very
+similar use of the same notation in C@t{++}. When they are in
+conflict, the C@t{++} meaning takes precedence; however, this can be
+overridden by quoting the file or function name with single quotes.
+
+For example, suppose the program is stopped in a method of a class
+that has a field named @code{includefile}, and there is also an
+include file named @file{includefile} that defines a variable,
+@code{some_global}.
+
+@smallexample
+(@value{GDBP}) p includefile
+$1 = 23
+(@value{GDBP}) p includefile::some_global
+A syntax error in expression, near `'.
+(@value{GDBP}) p 'includefile'::some_global
+$2 = 27
+@end smallexample
@cindex wrong values
@cindex variable values, wrong
+2013-11-15 Tom Tromey <tromey@redhat.com>
+
+ * gdb.cp/includefile: New file.
+ * gdb.cp/filename.exp: New file.
+ * gdb.cp/filename.cc: New file.
+
2013-11-15 Doug Evans <xdje42@gmail.com>
* gdb.python/py-breakpoint.exp: Make tests have unique names.
--- /dev/null
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 2013 Free Software Foundation, Inc.
+
+ 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 "includefile"
+
+class C {
+public:
+ int includefile[1];
+
+ C() {
+ includefile[0] = 23;
+ }
+
+ void m() {
+ /* stop here */
+ }
+};
+
+int main() {
+ C c;
+ c.m();
+}
--- /dev/null
+# Copyright 2013 Free Software Foundation, Inc.
+
+# 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/>.
+
+if { [skip_cplus_tests] } { continue }
+
+standard_testfile .cc
+
+if {[prepare_for_testing $testfile.exp $testfile $srcfile {debug c++}]} {
+ return -1
+}
+
+if ![runto_main] then {
+ perror "couldn't run to main"
+ continue
+}
+
+gdb_breakpoint [gdb_get_line_number "stop here"]
+gdb_continue_to_breakpoint "stop here"
+
+gdb_test "print includefile\[0\]" " = 23"
+gdb_test "print 'includefile'::some_global" " = 27"
--- /dev/null
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 2013 Free Software Foundation, Inc.
+
+ 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/>. */
+
+int some_global = 27;