mirror of
https://sourceware.org/git/binutils-gdb.git
synced 2025-01-15 12:34:05 +08:00
71a3c36949
In Rust, virtual tables work a bit differently than they do in C++. In C++, as you know, they are connected to a particular class hierarchy. Rust, instead, can generate a virtual table for potentially any type -- in fact, one such virtual table for each trait (a trait is similar to an abstract class or to a Java interface) that a type implements. Objects that are referenced via a trait can't currently be inspected by gdb. This patch implements the Rust equivalent of "set print object". gdb relies heavily on the C++ ABI to decode virtual tables; primarily to make "set print object" work; but also "info vtbl". However, Rust does not currently have a specified ABI, so this approach seems unwise to emulate. Instead, I've changed the Rust compiler to emit some DWARF that describes trait objects (previously their internal structure was opaque), vtables (currently just a size -- but I hope to expand this in the future), and the concrete type for which a vtable was emitted. The concrete type is expressed as a DW_AT_containing_type on the vtable's type. This is a small extension to DWARF. This patch adds a new entry to quick_symbol_functions to return the symtab that holds a data address. Previously there was no way in gdb to look up a full (only minimal) non-text symbol by address. The psymbol implementation of this method works by lazily filling in a map that is added to the objfile. This avoids slowing down psymbol reading for a feature that is likely to not be used too frequently. I did not update .gdb_index. My thinking here is that the DWARF 5 indices will obsolete .gdb_index soon-ish, meaning that adding a new feature to them is probably wasted work. If necessary I can update the DWARF 5 index code when it lands in gdb. Regression tested on x86-64 Fedora 25. 2017-11-17 Tom Tromey <tom@tromey.com> * symtab.h (struct symbol) <is_rust_vtable>: New member. (struct rust_vtable_symbol): New. (find_symbol_at_address): Declare. * symtab.c (find_symbol_at_address): New function. * symfile.h (struct quick_symbol_functions) <find_compunit_symtab_by_address>: New member. * symfile-debug.c (debug_qf_find_compunit_symtab_by_address): New function. (debug_sym_quick_functions): Link to debug_qf_find_compunit_symtab_by_address. * rust-lang.c (rust_get_trait_object_pointer): New function. (rust_evaluate_subexp) <case UNOP_IND>: New case. Call rust_get_trait_object_pointer. * psymtab.c (psym_relocate): Clear psymbol_map. (psym_fill_psymbol_map, psym_find_compunit_symtab_by_address): New functions. (psym_functions): Link to psym_find_compunit_symtab_by_address. * objfiles.h (struct objfile) <psymbol_map>: New member. * dwarf2read.c (dwarf2_gdb_index_functions): Update. (process_die) <DW_TAG_variable>: New case. Call read_variable. (rust_containing_type, read_variable): New functions. 2017-11-17 Tom Tromey <tom@tromey.com> * gdb.rust/traits.rs: New file. * gdb.rust/traits.exp: New file. |
||
|---|---|---|
| bfd | ||
| binutils | ||
| config | ||
| cpu | ||
| elfcpp | ||
| etc | ||
| gas | ||
| gdb | ||
| gold | ||
| gprof | ||
| include | ||
| intl | ||
| ld | ||
| libdecnumber | ||
| libiberty | ||
| opcodes | ||
| readline | ||
| sim | ||
| texinfo | ||
| zlib | ||
| .cvsignore | ||
| .gitattributes | ||
| .gitignore | ||
| ChangeLog | ||
| compile | ||
| config-ml.in | ||
| config.guess | ||
| config.rpath | ||
| config.sub | ||
| configure | ||
| configure.ac | ||
| COPYING | ||
| COPYING3 | ||
| COPYING3.LIB | ||
| COPYING.LIB | ||
| COPYING.LIBGLOSS | ||
| COPYING.NEWLIB | ||
| depcomp | ||
| djunpack.bat | ||
| install-sh | ||
| libtool.m4 | ||
| lt~obsolete.m4 | ||
| ltgcc.m4 | ||
| ltmain.sh | ||
| ltoptions.m4 | ||
| ltsugar.m4 | ||
| ltversion.m4 | ||
| MAINTAINERS | ||
| Makefile.def | ||
| Makefile.in | ||
| Makefile.tpl | ||
| makefile.vms | ||
| missing | ||
| mkdep | ||
| mkinstalldirs | ||
| move-if-change | ||
| README | ||
| README-maintainer-mode | ||
| setup.com | ||
| src-release.sh | ||
| symlink-tree | ||
| ylwrap | ||
README for GNU development tools This directory contains various GNU compilers, assemblers, linkers, debuggers, etc., plus their support routines, definitions, and documentation. If you are receiving this as part of a GDB release, see the file gdb/README. If with a binutils release, see binutils/README; if with a libg++ release, see libg++/README, etc. That'll give you info about this package -- supported targets, how to use it, how to report bugs, etc. It is now possible to automatically configure and build a variety of tools with one command. To build all of the tools contained herein, run the ``configure'' script here, e.g.: ./configure make To install them (by default in /usr/local/bin, /usr/local/lib, etc), then do: make install (If the configure script can't determine your type of computer, give it the name as an argument, for instance ``./configure sun4''. You can use the script ``config.sub'' to test whether a name is recognized; if it is, config.sub translates it to a triplet specifying CPU, vendor, and OS.) If you have more than one compiler on your system, it is often best to explicitly set CC in the environment before running configure, and to also set CC when running make. For example (assuming sh/bash/ksh): CC=gcc ./configure make A similar example using csh: setenv CC gcc ./configure make Much of the code and documentation enclosed is copyright by the Free Software Foundation, Inc. See the file COPYING or COPYING.LIB in the various directories, for a description of the GNU General Public License terms under which you can copy the files. REPORTING BUGS: Again, see gdb/README, binutils/README, etc., for info on where and how to report problems.