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The "val_print_type_code_flags ()" function is responsible for
extraction of fields for "flags" data type. These data types are
used when describing a custom register type in a target description
XML. The logic used for the extraction though is not sound:
unsigned field_len = TYPE_FIELD_BITSIZE (type, field);
ULONGEST field_val
= val >> (TYPE_FIELD_BITPOS (type, field) - field_len + 1);
TYPE_FIELD_BITSIZE: The bit length of the field to be extracted.
TYPE_FIELD_BITPOS: The starting position of the field; 0 is LSB.
val: The register value.
Imagine you have a field that starts at position 1 and its length
is 4 bits. According to the third line of the code snippet the
shifting right would become "val >> -2", or "val >> 0xfff...fe"
to be precise. That will result in a "field_val" of 0.
The correct extraction should be:
ULONGEST field_val = val >> TYPE_FIELD_BITPOS (type, field);
The rest of the algorithm that masks out the higher bits is OK.
Co-Authored-By: Simon Marchi <simon.marchi@efficios.com>
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.