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The print_floating routine currently makes a lot of assumptions about host and target floating point formats. This patch cleans up many of those. One problem is that print_floating may currently be called with types that are not actually floating-point types, and it tries hard to output those as floating-point values anyway. However, there is only one single caller of print_floating where this can ever happen: print_scalar_formatted. And in fact, it is much simpler to handle the case where the value to be printed is not already of floating-point type right there. So this patch changes print_scalar_formatted to handle the 'f' format as follows: - If the value to be printed is already of floating-point type, just call print_floating on it. - Otherwise, if there is a standard target floating-point type of the same size as the value, call print_floating using that type. - Otherwise, just print the value as if the 'f' format had not been specified at all. This has the overall effect to printing everything the same way as the old code did, but is overall a lot simpler. (Also, it would allow us to change the above strategy more easily, if that might be a more intuitive user interface. For example, in the third case above, maybe an error would be more appropriate?) Given that change, print_floating can become much simpler. In particular, we now always have a floating-point format that we can consult. This means we can use the floating-point format to programmatically determine the number of digits necessary to print the value. The current code uses a hard-coded value of 9, 17, or 35 digits. Note that this matches the DECIMAL_DIG values for IEEE-32, IEEE-64, and IEEE-128. (Actually, for IEEE-128 the correct value is 36 -- the 35 seems to be an oversight.) The DECIMAL_DIG value is defined to be the smallest number so that any number in the target format, when printed to this number of digits and then scanned back into a binary floating-point number, will result in the original value. Now that we always have a FP format, we can just compute the DECIMAL_DIG value using the formula from the C standard. This will be correct for *all* FP formats, not just the above list, and it will be correct (as opposed to current code) if the target formats differ from the host ones. The patch moves the new logic to a new floatformat_to_string routine (analogous to the existing decimal_to_string). The print_floating routine now calls floatformat_to_string or decimal_to_string, making the separate print_decimal_floating and generic_val_print_decfloat routines unnecessary. gdb/ChangeLog: 2017-10-24 Ulrich Weigand <uweigand@de.ibm.com> * doublest.c (floatformat_precision): New routine. (floatformat_to_string): Likewise. * doublest.c (floatformat_to_string): Add prototype. * printcmd.c (print_scalar_formatted): Only call print_floating on floating-point types. * valprint.c: Do not include "floatformat.h". (generic_val_print_decfloat): Remove. (generic_val_print): Call generic_val_print_float for both TYPE_CODE_FLT and TYPE_CODE_DECFLOAT. (print_floating): Use floatformat_to_string. Handle decimal float. (print_decimal_floating): Remove, merge into floatformat_to_string. * value.h (print_decimal_floating): Remove. * Makefile.in: Do not build doublest.c with -Wformat-nonliteral.
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.