mirror of
git://gcc.gnu.org/git/gcc.git
synced 2025-04-06 21:41:19 +08:00
3267bd36aa
Unlike bootstrap-debug, bootstrap-debug-lean used to pass compare using the traditional compare command, because it compiled both stage2 and stage3 with options that used to generate identical output (-fcompare-debug= in stage2 vs -fcompare-debug in stage3). Since we started adding relevant command-line flags to DW_AT_producer, this is no longer the case, and stages 2 and 3 object files that differ in nothing but the DW_AT_producer strings. -fcompare-debug is short for -fcompare-debug=-gtoggle, so stage3 compiles twice, once with the normal options, once with toggled -g, to then compare the temporary final dumps. When enabled, both compilations get from the driver an additional -frandom-seed flag (if none is given explicitly). -fcompare-debug= is short for -fno-compare-debug, disabling the second compilation. The difference between the DW_AT_producer lines are the different -fcompare-debug flags, and the presence of the -frandom-seed flag in the stage3 compilation. It is easy and sensible enough to filter the -fcompare-debug flags out of the DW_AT_producer string. This option should never affect the compilation output, it just determines whether or not to perform an additional compilation that should produce the same executable output. However, dropping -frandom-seed is not quite correct, in that it might have other consequences on the compilation. So, it makes little sense to make the effort to drop it when it's implicit; for those comparing compiler output differences, it might even hint at what causes, and could fix, difficult to explain differences, namely, explicitly supplying -frandom-seed options. They don't seem to matter for compiler bootstraps, though, at least for now, so we can safely refrain from issuing -frandom-seed (or maybe we already issue it where needed :-), and then, for bootstrap-debug-lean, use the compare-debug script, that strips out debug information before comparing the object files. for config/ChangeLog * bootstrap-debug-lean.mk (do-compare): Use the contrib/compare-debug script. for gcc/ChangeLog * dwarf2out.c (gen_producer_string): Discard OPT_fcompare_debug. From-SVN: r254750
This directory contains the GNU Compiler Collection (GCC). The GNU Compiler Collection is free software. See the files whose names start with COPYING for copying permission. The manuals, and some of the runtime libraries, are under different terms; see the individual source files for details. The directory INSTALL contains copies of the installation information as HTML and plain text. The source of this information is gcc/doc/install.texi. The installation information includes details of what is included in the GCC sources and what files GCC installs. See the file gcc/doc/gcc.texi (together with other files that it includes) for usage and porting information. An online readable version of the manual is in the files gcc/doc/gcc.info*. See http://gcc.gnu.org/bugs/ for how to report bugs usefully. Copyright years on GCC source files may be listed using range notation, e.g., 1987-2012, indicating that every year in the range, inclusive, is a copyrightable year that could otherwise be listed individually.