Kevin Buettner
3d8efabf21
This change makes gas's notion of the msp430 dwarf2 address size match that of gcc and gdb. This is needed so that the format of addresses generated for DW_LNE_set_address in .debug_line will match the address size for the compilation unit. In gcc/config/msp430/msp430.h, it's set to 4: #define DWARF2_ADDR_SIZE 4 Likewise in gdb/msp430-tdep.c: set_gdbarch_dwarf2_addr_size (gdbarch, 4); (As far as I can tell, however, GDB doesn't use this value when decoding .debug_line. Instead, GDB uses the Pointer Size from the compilation unit.) readelf is able to seamlessly handle mismatches between these various sizes by using the size of the DW_LNE_set_address instruction to determine the address size. Another way to fix this problem is to make GDB behave in a similar manner. In my opinion, GDB should detect and inform the user about these mismatches; it's not clear to me if it's correct for GDB to go ahead and read the address anyway when a size mismatch is detected. Without this change, addresses in .debug_line are encoded in two bytes for some multilibs. When GDB reads the address for DW_LNE_set_address, it uses the pointer size provided by the CU. When these values don't match, GDB reads the wrong number of bytes. In the cases that I've looked at, GDB is reading 4 bytes from a 2 byte container, which results in a garbage address. GDB discards lines which have a bogus address; the end result is that GDB records no line number information for CUs which have a mismatch between the address size (from the CU) and the format of the address used by DW_LNE_set_address. gas/ChangeLog: * config/tc-msp430.h (DWARF2_ADDR_SIZE): Set to 4.
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.