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While doing some powerpc Linux tests on a ppc 476 board using GCC 5.2, i noticed inline-bt.exp, inline-cmds.exp and inline-locals.exp failing. FAIL: gdb.opt/inline-bt.exp: continue to bar (1) FAIL: gdb.opt/inline-bt.exp: backtrace from bar (1) FAIL: gdb.opt/inline-bt.exp: continue to bar (2) FAIL: gdb.opt/inline-bt.exp: backtrace from bar (2) FAIL: gdb.opt/inline-bt.exp: continue to bar (3) FAIL: gdb.opt/inline-bt.exp: backtrace from bar (3) FAIL: gdb.opt/inline-cmds.exp: continue to bar (1) FAIL: gdb.opt/inline-cmds.exp: backtrace from bar (1) FAIL: gdb.opt/inline-cmds.exp: continue to bar (2) FAIL: gdb.opt/inline-cmds.exp: backtrace from bar (2) FAIL: gdb.opt/inline-cmds.exp: continue to marker FAIL: gdb.opt/inline-cmds.exp: backtrace from marker FAIL: gdb.opt/inline-cmds.exp: step into finish marker FAIL: gdb.opt/inline-locals.exp: continue to bar (1) FAIL: gdb.opt/inline-locals.exp: continue to bar (2) FAIL: gdb.opt/inline-locals.exp: backtrace from bar (2) FAIL: gdb.opt/inline-locals.exp: continue to bar (3) FAIL: gdb.opt/inline-locals.exp: backtrace from bar (3) They failed because the breakpoint supposedly inserted at bar was actually inserted at noinline. (gdb) break inline-markers.c:20^M Breakpoint 2 at 0x1000079c: file gdb/testsuite/gdb.opt/inline-markers.c, line 20.^M (gdb) continue^M Continuing.^M ^M Breakpoint 2, noinline () at gdb/testsuite/gdb.opt/inline-markers.c:35^M 35 inlined_fn (); /* inlined */^M As we can see, line 20 is really inside bar, not noinline: 18 void bar(void) 19 { 20 x += y; /* set breakpoint 1 here */ 21 } Further investigation shows that this is really due to GCC 5's new ICF pass (-fipa-icf), now enabled by default at -O2, which folds bar and marker into noinline, where the call to inlined_fn was inlined. This breaks the testcase since it expects to stop at specific spots. I thought about two possible fixes for this issue. - Disable the ICF pass manually when building the binary (-fno-ipa-icf). This has the advantage of not having to touch the testcase sources themselves, but the disadvantage of having to add conditional blocks to test the GCC version. If we ever change GCC's default, we will have to adjust the conditional block again to match GCC's behavior. - Modify the testcase sources to make the identical functions unique. This solution doesn't touch the testcase itself, but changes the source code slightly in order to make bar, marker and inlined_fn unique. This causes GCC's ICF pass to ignore these functions and not fold them into a common identical function. I'm good with either of them, but i'm more inclined to go with the second one. The attached patch implements this by adding the new global variable z, set to 0, that gets added in different ways to marker and inlined_fn. Since it is 0, it doesn't affect any possible value checks that we may wish to do in the future (we currently only check for values changed by bar). Ok? ps: I also noticed GDB doesn't do a great job at stating that the breakpoint was actually inserted at a different source line than previously requested, so this sounds like a bug that should be fixed, if it is not just wrong DWARF information (did not investigate it further). gdb/testsuite/ChangeLog: 2015-08-24 Luis Machado <lgustavo@codesourcery.com> * gdb.opt/inline-bt.c: New volatile global z. * gdb.opt/inline-cmds.c: Likewise. * gdb.opt/inline-locals.c: Likewise. * gdb.opt/inline-markers.c: New extern global z. (marker): Use z. (inline_fn): Likewise. |
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binutils | ||
config | ||
cpu | ||
elfcpp | ||
etc | ||
gas | ||
gdb | ||
gold | ||
gprof | ||
include | ||
intl | ||
ld | ||
libdecnumber | ||
libiberty | ||
opcodes | ||
readline | ||
sim | ||
texinfo | ||
zlib | ||
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compile | ||
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config.guess | ||
config.rpath | ||
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configure | ||
configure.ac | ||
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COPYING.LIBGLOSS | ||
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depcomp | ||
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libtool.m4 | ||
lt~obsolete.m4 | ||
ltgcc.m4 | ||
ltmain.sh | ||
ltoptions.m4 | ||
ltsugar.m4 | ||
ltversion.m4 | ||
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makefile.vms | ||
missing | ||
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README | ||
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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.