[Bug middle-end/69234] recent GCC trunk compilers miscompile the V8 JavaScript interpreter/JITC
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69234 --- Comment #1 from Abe --- The file "incremental-marking.o" is compiled from the source code at "/src/heap/incremental-marking.cc".
[Bug middle-end/69234] recent GCC trunk compilers miscompile the V8 JavaScript interpreter/JITC
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69234 --- Comment #6 from Andrew Pinski --- (In reply to Markus Trippelsdorf from comment #5) > BTW, Honza promised to implement a -fnull-this-pointer switch for this issue, > because Firefox, Kdevelop, QT5, etc. are also affected. Sounds like so many folks depends on this undefined behavior. It is sad it was not until GCC 6 people are finding this undefined behavior. I rather have people fix their code rather than changing GCC. Since -fsantize=undefined will find it. There is no reason to have another flag to disable the optimization.
[Bug middle-end/69234] recent GCC trunk compilers miscompile the V8 JavaScript interpreter/JITC
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69234 --- Comment #13 from Andrew Pinski --- (In reply to Markus Trippelsdorf from comment #12) > They are actually aware of the issue for over a year: > > https://bugs.chromium.org/p/v8/issues/detail?id=3782 That is sad and just means they don't care about their code being correct.
[Bug middle-end/69234] recent GCC trunk compilers miscompile the V8 JavaScript interpreter/JITC
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69234 Andrew Pinski changed: What|Removed |Added Status|UNCONFIRMED |RESOLVED Resolution|--- |DUPLICATE --- Comment #10 from Andrew Pinski --- . *** This bug has been marked as a duplicate of bug 68853 ***
[Bug middle-end/69234] recent GCC trunk compilers miscompile the V8 JavaScript interpreter/JITC
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69234 --- Comment #11 from Andrew Pinski --- (In reply to Abe from comment #9) > Created attachment 37309 [details] > preprocessed part of V8 > > I will attach a compressed form of the relevant file -- > "incremental-marking.cc" from V8, preprocessed on AMD64 Ubuntu 14.04.3 LTS > using GCC built from trunk revision 226861; analysis showed that > preprocessing the same source on the same machine using GCC built from trunk > revision 226860 produced the same preprocessor output modulo lines starting > in '#'. Yes this was the same bug. I had forgot I had already debugged this and reported what was wrong with the code. Can you or someone please report this back to google about their broken code.
[Bug middle-end/69234] recent GCC trunk compilers miscompile the V8 JavaScript interpreter/JITC
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69234 --- Comment #12 from Markus Trippelsdorf --- (In reply to Andrew Pinski from comment #11) > (In reply to Abe from comment #9) > > Created attachment 37309 [details] > > preprocessed part of V8 > > > > I will attach a compressed form of the relevant file -- > > "incremental-marking.cc" from V8, preprocessed on AMD64 Ubuntu 14.04.3 LTS > > using GCC built from trunk revision 226861; analysis showed that > > preprocessing the same source on the same machine using GCC built from trunk > > revision 226860 produced the same preprocessor output modulo lines starting > > in '#'. > > Yes this was the same bug. I had forgot I had already debugged this and > reported what was wrong with the code. Can you or someone please report > this back to google about their broken code. They are actually aware of the issue for over a year: https://bugs.chromium.org/p/v8/issues/detail?id=3782
[Bug middle-end/69234] recent GCC trunk compilers miscompile the V8 JavaScript interpreter/JITC
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69234 Markus Trippelsdorf changed: What|Removed |Added Status|UNCONFIRMED |RESOLVED CC||trippels at gcc dot gnu.org Resolution|--- |DUPLICATE --- Comment #4 from Markus Trippelsdorf --- dup. *** This bug has been marked as a duplicate of bug 68853 ***
[Bug middle-end/69234] recent GCC trunk compilers miscompile the V8 JavaScript interpreter/JITC
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69234 --- Comment #2 from Andrew Pinski --- This sounds like maybe a bug in the V8 sources. Can you try -fno-delete-null-pointer-checks ? Also can you provide the preprocessed source which is being miscompiled?
[Bug middle-end/69234] recent GCC trunk compilers miscompile the V8 JavaScript interpreter/JITC
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69234 --- Comment #5 from Markus Trippelsdorf --- BTW, Honza promised to implement a -fnull-this-pointer switch for this issue, because Firefox, Kdevelop, QT5, etc. are also affected.
[Bug middle-end/69234] recent GCC trunk compilers miscompile the V8 JavaScript interpreter/JITC
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69234 --- Comment #9 from Abe --- Created attachment 37309 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=37309=edit preprocessed part of V8 I will attach a compressed form of the relevant file -- "incremental-marking.cc" from V8, preprocessed on AMD64 Ubuntu 14.04.3 LTS using GCC built from trunk revision 226861; analysis showed that preprocessing the same source on the same machine using GCC built from trunk revision 226860 produced the same preprocessor output modulo lines starting in '#'.
[Bug middle-end/69234] recent GCC trunk compilers miscompile the V8 JavaScript interpreter/JITC
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69234 --- Comment #3 from Jakub Jelinek --- In that case, I guess the questions are: 1) does -fno-delete-null-pointer-checks cure the crash? 2) do any of the functions/methods defined in the problematic file have nonnull attribute? 3) can you try to compile it with -fsanitize=undefined and see if errors are reported on it?
[Bug middle-end/69234] recent GCC trunk compilers miscompile the V8 JavaScript interpreter/JITC
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69234 Abe changed: What|Removed |Added Status|RESOLVED|UNCONFIRMED Resolution|DUPLICATE |--- --- Comment #8 from Abe --- Attaching the preprocessed source, compressed b/c it`s big... FYI, I _did_ try searching for "V8" before submitting the bug. The search engine found nothing relevant. It did _not_, for example, find bug #68853 :-(
[Bug middle-end/69234] recent GCC trunk compilers miscompile the V8 JavaScript interpreter/JITC
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69234 --- Comment #7 from Markus Trippelsdorf --- At least the issue should be mentioned either in changes.html or porting_to.html.
