clang vs gcc 2020

1495742 talks about PGO, not LTO, so which one it is? Visual C++; GNU Compiler Collection (GCC) Clang; Among them, Visual C++ was developed by Microsoft, and they don’t support other platforms like Linux. Sure. Allowing every package to pick their favorite compiler risks running into binary (in)compatibility bugs sooner or later. - Issue close_status updated to: Accepted As for security, -fstack-protector* is another thing not properly implemented in clang, it leaves the stack guards in registers so makes it easier for exploits to store the value back. Firefox can't build on Fedora 33 due to gcc internal bug, reported 18 days ago: I agree that it needs to be reconsidered. ", Honza posted an update to "Firefox 64 built with GCC and Clang" https://hubicka.blogspot.com/2018/12/firefox-64-built-with-gcc-and-clang.html as "Even more fun with building and benchmarking Firefox with GCC and Clang" https://hubicka.blogspot.com/2018/12/even-more-fun-with-building-and.html. From: : no-reply: Subject: : Re: [PATCH v3 0/5] Vs clang-10 and gcc-9 warnings: Date: : Tue, 16 Jun 2020 22:15:50 -0700 (PDT) So why should we allow such an unfair privilege to this package? On the library front, MSVC implements and releases new features at about the same rate as GCC and Clang. As I understand it, the Fedora GCC maintainers are willing to apply any required patches. The aim was to improve the codebase, while I cannot report on that for numerous reasons like I … Ubuntu 19.10 was running on this 32-core / 64-thread high-end system. http://www.fsfla.org/~lxoliva/writeups/gOlogy/gOlogy.html. If you switch to a different compiler (which I think should not be done at all given the negative feedback from the toolchain maintainers), this is a major change that should only be done in Rawhide. 05 February 2019. I don't think we need to swing in the other direction, and assert that gcc must be used, because that's already what the guidelines say, and I don't see a reason to make an empty pronouncement like that. - Issue untagged with: meeting, Metadata Update from @sgallagh: Years later, though, things are obviously a bit different. Thanks. Clang 3.3 and later implement all of the ISO C++ 2011 standard. We also use mozilla crash reported and submit debug symbols to mozilla so we don't depend much on Fedora Abrt. I am not sure this is done when you use an alternative compiler and Figuring out how to handle "mass rebuilds" (and whether full distro rebuilds are even needed for a change to one of the many compilers) would be the main fallout from something like this. 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I think it's pretty clear, but I'll repeat it: the benchmark compared firefox as it was in Fedora then with the upstream binary. then people can run the benchmarks to see if there is ac_add_options --enable-tests Mozilla upstream switches from gcc to clang and we're going to follow upstream here due to clang performance, maintenance costs and compilation speed. various security hardening flags: https://src.fedoraproject.org/rpms/redhat-rpm-config/blob/master/f/buildfla= Please stop repeating that "one such reason that was brought forward turned out to be false" and "this exception was granted based on false premises". with clang and -D_FORTIFY_SOURCE=3D2 isn't implemented properly. FWIW, I'm +1 for a temporary switch as a workaround to be able to ship firefox updates at all. GCC 10 vs. Clang 10 Compiler Performance On AMD Zen 2 + Intel , Ringing In 2020 By Clang'ing The Linux 5.5 Kernel - Benchmarks Of GCC vs. Clang Built Kernels. We can always ask @mjw about debuginfo stuff ;). that for testing. I'd like to have free hands to use the best compiler available and not to be restricted by one of them to produce the best binaries for our users. I have a feeling that Clang is better tested than GCC. ac_add_options MOZ_PGO=1 The comparison is correct for what it compares: Firefox upstream binaries vs. Firefox Fedora binaries. It is a valid comparison. For compiling c++, there are many compilers in the market, but 3 of them are very popular. This is clang-cl.exe. In the spec file I see -fno-delete-null-pointer-checks, has that bug been fixed and can this option be dropped, or has it been just disabled without actually trying to fix the codebase? ", Upstream Firefox is more than welcome to make a different choice around security vs. performance, but I for one would rather Fedora be known as "That one OS that didn't get hit by the latest punny security vulnerability. One of the interesting milestones this year in the compiler world was the ability with LLVM Clang 9.0 to compile Linux 5.3+ for x86_64 without needing any extra patches to either the kernel or the LLVM/Clang compiler. So we might not even know which security hardening features are Thus, this exception has no valid basis and hence ought to be rescinded. CPU: Intel(R) Xeon(R) CPU E5-2680 v3 @ 2.50GHz; ... the Intel compiler is about 50 times slower than gcc and Clang is about 58 times slower than gcc. or the linker flags -z relro, -z defs and -z now. (Typical Microsoft ). We're a place where coders share, stay up-to-date and grow their careers. At least until Mozilla moves the tests from gcc-plugin they need to support it. AFAIK yes, they use it for some memory/sanity testing. This was around the time when I had still worked for Nokia. Then we can talk about gcc performance, I'll happily revert the change and build it with gcc with your setup. And Clang implements many GNU language extensions and enables them by default. We're going to produce testing clang builds after In general, this sounds like a mistake to allow Firefox to transition from GCC to Clang. Clang/LLVM and GCC Community GCC Community Allegedly, the code base is really old, and has only started getting "refreshed" in earnest in the past few years (post C++11). Same thoughts as signed overflow: – Available handling modes need improvement (e.g. For packages build with default toolchain rpmbuild makes sure to add All rights reserved. 0\Apps\android-ndk-r10\ clang vs gcc android emulator still exists and contains the only clang vs gcc android emulator clang. Tom Stellard (clang maintainer) has asked me to file this ticket to comply with Fedora processes. Clang vs GCC vs MSVC - which one is correct? Do you have a src.rpm where you enable the clang LTO and PGO? But it has to be made at the level of the whole distribution (Fedora) and not by every single package (and especially not by the maintainers of one package with a special exception for that one package only). Most (if not all) of the security hardening doesn't work in Clang. What developers Nathan Chancellor and Nathan Huckleberry found were that "GCC always beats LLVM" for 64-bit ARM and x86_64, even when LLVM is compiled with LTO and PGO enabled. Did you have --enable-tests and X server? We're also going to use gcc on second arches platforms where clang is not well supported yet. In addition to that, there are security issues (llvm doesn't implement e.g. in clang were known or not when the decision was made. The guidelines are clear. https://bugzilla.redhat.com/show_bug.cgi?id=1862029, gcc crashes during pgo builds on all Fedoras, reported a month ago: annobin so tools can check all security hardening is done/covers all We just need a bit more input to know. AGREED: The exception for firefox is granted (+6, +1, 0), Metadata Update from @zbyszek: Well, it should be compared to what you can achieve in the distro if you build with clang, not to what Mozilla ships, they might not build with -fstack-protector-strong, -D_FORTIFY_SOURCE=2, -fstack-clash-protection etc. ac_add_options --enable-lto So let's me rephrase a bit the ticket title - "Allow Firefox to use the best compiler available to build Firefox binaries, remove the gcc lock-in to allow use clang if gcc proves to be inefficient.". All trademarks used are properties of their respective owners. One would hope that major clang updates are no more painful than major gcc updates but I have no idea if that's actually true. Clang 3.3 fully supported C++ 11, Clang 3.4 fully supported C++ 14, and Clang 5 fully supported C++ 17, and all were significantly ahead of GCC at that time. Recently, I've been compiling some of the codebases I work on under Clang 3.8 instead of GCC 4.8, to take advantage of better compiler warnings and faster compilation speed (I've seen a 33% speedup, though I haven't tested this rigorously). In my view, the valid considerations that weren't brought forth before voting were the following: Please stop repeating that "one such reason that was brought forward turned out to be false" and "this exception was granted based on false premises". The guidelines don't seem to offer any wiggle room here: "Packages may only build with an alternative compiler to gcc if upstream does not support gcc.". https://bugzilla.redhat.com/show_bug.cgi?id=1849165. linker. But it is not enough to generalize to other programs or the whole distro. I don't see any issues with clang/debuginfo on my test builds, works normally in gdb. Re: [PATCH v3 1/5] fpu/softfloat: Silence 'bitwise negation of boolean expression' warning, Alex Bennée, 2020/06/17 [PATCH v3 2/5] migration: fix xbzrle encoding rate calculation, Richard Henderson, 2020/06/17 Perhaps this should be raised with the Fedora packaging committee instead of FESCo, since they oversee the packaging guidelines. Known issue? This comment has been minimized. Or how Presented at last week's Linux Plumbers Conference 2020 was a look at the kernel compile times with Clang. Since Honza has access to the upstream benchmarking setup now it should be easier to keep the gcc builds smaller and faster than the clang builds. The linked bugzillas have a comment by @stransky that it is OK. CC @tibbs. Please use the Fedora Firefox package and produce faster binaries than the ones which are shipped by Mozilla. That's perhaps something from the past and can be removed. What @stransky is asking for is an exception, which requires FESCo approval. performance claims. Using the top-end AMD EPYC 7742 in a 2P Linux server configuration, here are C/C++ compiler benchmarks looking at the performance when built by the GNU Compiler Collection (GCC), LLVM Clang, and AOCC 2.0. I switched to clang instead of gcc at some point (whenever at least it is possible). The choice of library usually depends on the system being developed for … I formally propose: "Firefox, being a critical component that connects to untrusted data sources, must continue to compile using gcc in order to produce code less vulnerable to attack. faster binaries. but it's also clear that patches are required to actually get a working binary. [PATCH v3 0/5] Vs clang-10 and gcc-9 warnings, Richard Henderson <= [PATCH v3 1/5] fpu/softfloat: Silence 'bitwise negation of boolean expression' warning, Richard Henderson, 2020/06/17. I wonder if gcc team is able to provide gcc fixes needed to build Firefox, that's the main point here. VS produces code that is 1.5-2x slower than gcc and clang windows 10.0 visual studio 2017 version 15.6 preview Patrik Huber reported Feb 07, 2018 at 11:51 AM Honza Hubicka is currently testing if -fno-semantics-interposition (the default behavior of clang, but not of gcc) doesn't affect significantly the non-LTO builds. Login http://web.basemark.com/. - Issue close_status updated to: Invalid Copy link Quote reply Michael has written more than 20,000 articles covering the state of Linux hardware support, Linux performance, graphics drivers, and other topics. strong, -D_GLIBCXX_ASSERTIONS, -fexceptions and -Werror=3Dformat-security= That unfortunately means extra maintenance for us to keep gcc fixes up-to date. Did you have --enable-tests and X server? From what I've gathered so far I need something like: be built with gcc. AFAIK a while ago upstream nginx had a problem that was mitigated by hardened compilation flags in downstream distributions but was not on the upstream distributed builds. But I recommend to take latest nightly and do the tests there as it uses the same flags for gcc/clang and the build/benchmark is easier that with rpm packages. much benchmarking was actually done. ac_add_options MOZ_PGO=1 That's my thinking too. Judging from the evidence gathered so far, there are 2 likely possible outcomes: either the GCC binaries will be approximately the same speed if not slightly faster, or the Clang binaries will only be faster for one reason: missing security features. But I don't know of the We're going to produce testing clang builds after that for testing. clang vs gcc diagnostic flags 28 Jun 2019. with knowledge of the alternative toolchain might know about others in clang were known or not when the decision was made. Jakub works on updated/fixed gcc in Fedora, from my initial testing the builds roughly match the clang performance. RHBZ#1495742 talks about PGO, not LTO, so which one it is? The situation is here again and even in worse state. Provide clear diagnostic messages. For GCC there is extensive documentation how/if certain optimization You can take this package: Then we could see if that speed difference is big enough to You can directly compare fedora firefox builds with binaries provided by mozilla. The main issue encountered when Clang'ing Linux 5.3 was the AMDGPU driver running into build problems. RISC-V code quality issues (GCC vs Clang). I'm building in f28/f29/f30 gcc with those fixes - gcc-8.2.1-6.fc{28,29,30} and once those are built, will try building firefox myself in mock. Clang came out of apple’s stable and became open sourced in 2007. The resolution was to "allow" clang to be used, not to mandate it. That initial support in Linux 5.3 was not without a few issues, but on Linux 5.5 the experience is in great shape with the stable Clang compiler. Command Tips ; 1. From what I've gathered so far I need something like: To be clear here, the next security Firefox update is still going to be built with gcc. This patch makes a change in Clang so that when you use the GCC attribute spelling, the attribute is automatically available in all three spellings by default. Clang's C++11 mode can be used with libc++ or with gcc… I am also inclined to go this direction. Thus Clang is born . It is a valid comparison. - Issue status updated to: Closed (was: Open). Please advise. The one such reason that was brought forward turned out to be false. Intel Compiler vs. GCC. It seems strange that the C/C++ guidelines wouldn't mention this. Compilation time generally increased relative to Clang 4.0. Clang's command-line interface is similar to and shares many flags and options with GCC. But I don't believe those can make so huge performance difference. There are some recommendations in his last blog post on "Communication with maintainers of Firefox packages in individual Linux distros". tables on all architectures (.eh_frame), which impacts generating The guidelines don't seem to offer any wiggle room here: "Packages may only build with an alternative compiler to gcc if upstream does not support gcc." code: https://fedoraproject.org/wiki/Toolchain/Watermark. sources, must continue to compile using gcc in order to produce code I am not aware of something similar for llvm. The clang vs gcc android emulator emulators used to provide a button for this, but such buttons were shown only in a specific skin: Skin with dynamic hardware controls. less vulnerable to attack. #2020 Firefox is switching from gcc to clang/llvm Closed: Invalid 2 months ago by cverna. I get the ebp value using the following code. I would wager that part of it was to avoid the "ooo, shiny" effect (which is closely related to the "-O9 because fasterer" effect. +1 to reverting the exception in this case, Metadata Update from @bowlofeggs: Benchmarks: Is the src.rpm setup to be able to run the tests during build (against Xvfb)? Mozilla uses clang as a default compiler for Firefox so it's expected to work as Mozilla fixes all related bugs there. Also binaries build with the default toolchain get watermarked by But there is no rationale to allow Firefox to do something that no other package in Fedora is allowed to do without a strong reason. In Fedora -fstack-clash-protection is a no-op on clang. In addition to supporting our site through advertisements, you can help by subscribing to Phoronix Premium. For some unknown reason they choose to drop gcc’s front end , and create a new compiler front end from scratch. Can we add it to Monday's agenda? ... 2020. Even if somebody else made a different benchmark with a different version of the compiler with different options, doesn't make the first one "false", "wrong", or anything else, except possibly "outdated". Such a change has no business ending up in a security update to a released distribution, ever. (https://bugzilla.mozilla.org/show_bug.cgi?id=1495742). like -fcf-protection, -fasynchronous-unwind-tables, -fstack-protector- I don't think gcc is inferior to clang. - Issue status updated to: Closed (was: Open), Metadata Update from @zbyszek: @kkofler There's a clear benchmark in this particular case. As pointed out by others at least -fstack-clash-protection is a noop The rule to use GCC is not "vendor lock-in", it is there to ensure that the distribution consistently uses the same compiler-level security features, among other things. If it goes well we don't need to switch to clang at all. - Issue close_status updated to: Rejected No other changes were made to the system besides switching out the kernel built under each compiler. Are there some benchmarks available? Clang vs. GCC - code coverage checking April 2, 2016. The last time I looked into using clang to build stuff in Fedora (two years ago), the debuginfo generated by it was pretty broken (debuginfo stuff was missing enough things that debugsource subpackages would not generate properly). @stransky, does upstream still plan to support gcc? I for one was not aware at how many of the security protections in GCC were not available in clang. All of these tests were done on the AMD EPYC 7742 2P configuration with the Daytona reference server running Ubuntu Linux. Has this been resolved since? We can always ask @mjw about debuginfo stuff ;). http://hubicka.blogspot.com/2018/12/firefox-64-built-with-gcc-and-clang.html Actually we still use gcc for Firefox 64 and I'm going to switch to clang only if it proves to be better for the Fedora builds. Mozilla upstream switches from gcc to clang and we're going to follow upstream here due to clang performance, maintenance costs and compilation speed. I think it is a serious mistake to grant this exception. June 2020: 10.0: In a May 2017 benchmark comparing AOCC v1.0 to Clang 4 and 5, and GCC 6 through 8, Phoronix found AOCC provided significant but modest improvement over Clang 4.0 in several benchmarks and no difference in others. If other programs face the same consideration and would benefit from clang, let's consider them case by case. To me, this looks like clear evidence that this exception was granted based on false premises: The claimed 10% performance gain was the one argument that swayed the decision in favor of granting the exception, but this benchmark shows that GCC-built binaries are actually faster on all benchmarks: one single benchmark (JetStream) is won by the old GCC 6, all the others by GCC 8. I feel that the recent interest of gcc folks in Firefox is driven by the clang competitor and if Firefox is vendor-locked again nothing will be improved. Well, it should be compared to what you can achieve in the distro if you build with clang, not to what Mozilla ships, they might not build with -fstack-protector-strong, -D_FORTIFY_SOURCE=2, -fstack-clash-protection etc. As it stands right now, GCC is faster than Clang at compiling the Linux kernel. This one isn’t technically “undefined behavior”, but it certainly leads to exploitable conditions. https://browserbench.org Do you have a src.rpm where you enable the clang LTO and PGO? unsigned overflow detection -fsanitize=unsigned-integer-overflow – gcc: needed – clang: working! with both the system compiler and the alternative compiler I'd like to get an exception to use clang until gcc is fixed. I don't see any restrictions on using clang in the guidelines - what is the concern that would need FESCo approval? The speed difference is about 10-20%, mainly due to PGO/LTO. With that resolved and no new Clang kernel compatibility problems introduced, it was a pleasant experience building Linux 5.5 with Clang simply by adjusting the CC environment variable. I agree with Kevin here that for such a vital tool that regularly interacts with untrusted content, switching away from a security-hardened compilation environment would be a mistake. As a side note, I've proposed the bugzillas as prioritized bugs. (Clang lags significantly behind GCC on security hardening.) It's not a guideline so I'm not bothered by the wording. Ubuntu 19.10 was running on this 32-core / 64-thread high-end system. Phoronix Premium allows ad-free access to the site, multi-page articles on a single page, and other features while supporting this site's continued operations. actually any speed difference. Ringing In 2020 By Clang'ing The Linux 5.5 Kernel - Benchmarks Of GCC vs. Clang Built Kernels. Apple uses LLVM extensively. I am pretty certain that the decision came from FESCo as FPC wouldn't have undertaken a restriction of that magnitude on its own. qemu is much slower when built with clang vs gcc: Date: Mon, 24 Aug 2020 16:54:01 +0000: We’re seeing significant slowdowns when we build qemu with clang instead of gcc. the past it was often incomplete, or completely disabled because it was Note: You need to compare Firefox 64 binaries and later as this is the first release built by clang by Mozilla. And nobody is being "locked in", nobody forces Fedora to choose GCC, this is a deliberate choice. not all tools could handle what llvm generated. Clang is faster than Gcc uses less memory. Can you be more specific which security features are missing and ideally file a #BZ for that with details? On GCC you and can choose whether to use libc++ or libstdc++ using the compiler option "-stdlib=". 62 Results - 48 Systems Especially in Fedora context. We don't even have gcc in the buildroot by default these days. For example, even though Clang implements atomic intrinsics which correspond exactly with C11 atomics, it also implements GCC's __sync_* intrinsics for … MOZ_PGO should do the trick but I failed to produce anything faster with that - there may be some catch here or maybe the profiling data is not correctly used. Thus, this exception has no valid basis and hence ought to be rescinded. When gcc proves faster on x86_64 or at least matches clang we may switch back to gcc - but recently the performance difference is significant. GitHub Gist: instantly share code, notes, and snippets. Yes, MOZ_PGO enables PGO builds which should bring more significant performance boost. My recall of the history is a bit murky and I'm a bit short on time this morning so I can't provide an easy summary of why we decided to add that language, but it was certainly in the early days of clang being in the distro. Clang Vs Gcc 2020 You also can browse the consolidated DCCCD CE schedule or und bietet zudem zahlreiche innovative. See https://blog.mozilla.org/nfroyd/2018/05/29/when-implementation-monoculture-right-thing/#comment-2809 for details, GCC actually with LTO/PGO creates smaller and faster Firefox. I know this because one of the distributions I help develop uses Clang for the system compiler (OpenMandriva), and I was forced to rollback some of the debuginfo enhancements since they don't work with clang-produced debuginfo (I am co-maintainer of the RPM and DNF stack in OpenMandriva). Debuginfo generation with Clang is broken. to comment on this ticket. warrant giving up some of the features and compatibility with It's just reverting the exception. Legal Disclaimer, Privacy Policy | Contact. It seems that depending on which benchmark The fact is that last time I tried gcc8 + PGO the final binaries crashed and when I removed the problematic parts the final binaries has inferior speed compared to Mozilla ones. On the language front, MSVC does lag behind. https://koji.fedoraproject.org/koji/taskinfo?taskID=31403563 Chip vendors, mainly including Intel, ARM, AMD, and IBM (PowerPC). ac_add_options --enable-lto The system compiler (gcc) makes sure they And it would be good to see the actual benchmarks used for the GCC vs. LLVM Clang Compiler Benchmarks 2019. Closed: Invalid Reopen Issue. +1. He also notes that it is just hard to reproduce the "official builds" whatever compiler you do use. @jlaw Can you comment on the Tools team's position on switching Firefox to clang? We don't throw gcc away (firefox.spec has a single pref to switch compiler) but rather we're going to use the best tool for the actual task. Similar to how GCC supports __attribute__((foo)) as [[gnu::foo]] in C++ mode, it now supports the same spelling in C mode as well. The fact that the upstream binary, built with much fewer security hardening features, is faster (and that compared to the existing Fedora binary that does not yet enable LTO and PGO, not to what seems to be possible to achieve with GCC) is undoubtedly true, but not useful information in the context of the decision to make here. the default system toolchain. Backgrounds: I need to get the register value in the c code, so I found this in gcc usage. On Thu, 2018-12-06 at 20:03 +0000, Kevin Fenzi wrote: It seems strange that the C/C++ guidelines wouldn't mention this. Firefox in Fedora must be built with the distro compiler, so right now clang works better. Nothing from gcc, nothing from clang, nothing from sparse. I think it's pretty clear, but I'll repeat it: the benchmark compared firefox as it was in Fedora then with the upstream binary. Yet it’s a clear violation of C99′s paragraph 7.26.3. qemu is much slower when built with clang vs gcc, Brian Cain, 2020/08/24 qemu is much slower when built with clang vs gcc , Taylor Simpson <= Prev by Date: … I haven't looked recently at the debuginfo that llvm generates, but in Clang for Objective-C cloud be fully used for the production environment in 2009. I don't see why Firefox gets yet another Firefox-only exception. That's sad to hear. Even if somebody else made a different benchmark with a different version of the compiler with different options, doesn't make the first one "false", "wrong", or anything else, except possibly "outdated". GCC 4.9.0 Clang 3.5.0 benchmarks, GCC 4.9.0 Clang 3.5.0 performance data from OpenBenchmarking.org and the Phoronix Test Suite. The mission at Phoronix since 2004 has centered around enriching the Linux hardware experience. None of our gcc plugin based enhancements work with clang, and we have no equivalent for clang. MOZ_PGO should make more difference than LTO, assuming the train run is reasonable. It can store it’s AST on disk then read it. I did the benchmarks on mozilla nightly built directly from mozilla repository, with mozilla default flags without any Fedora specific tweaks, both with clang 7 and gcc 8. Details, gcc 4.9.0 clang 3.5.0 performance data from OpenBenchmarking.org and the Phoronix Test Suite behavior ”, but the... One isn ’ t technically “ undefined behavior ”, but it possible. Isn ’ t technically “ undefined behavior ”, but also the words you use an alternative compiler linker... And became open sourced in 2007 favorite compiler risks running into binary ( in ) compatibility bugs sooner later! To other web engine implementations ( Chromium, QtWebEngine, WebKitGtk, clang vs gcc 2020 ) can browse the consolidated CE...: Firefox upstream binaries vs. Firefox Fedora binaries built with clang, and snippets which is Firefox binaries. As TAKAHIROMIYASHITA an HSA-eligible health insurance policy 2018 Income Tax Returns for example, if a user has a that. It is OK risks running into binary ( in ) compatibility bugs sooner or later file a BZ. Think it is possible ) besides switching out the kernel compile times with clang and is! Works normally in gdb even know which security features are missing are obviously a bit more input know..., but also the words you use are unpleasant on Mon, Dec 10, 2018 at +0000... Certainly consider relaxing that requirement for the debuginfo package generation, as configured in Fedora, from my testing! Security update to a C/C++ compiler we do not support ( i.e note: you to... Not complete enough for the performance claims llvm generated the market, but it expected. Unknown reason they choose to drop gcc ’ s clang vs gcc 2020 on disk then read.. Magnitude on its own NULL object or something similarly undefined out slower than in gcc.! See why Firefox gets yet another Firefox-only exception properties of their respective.. Status updated to: open ( was: Closed ) worse state maintenance for us to keep fixes. Package generation, as configured in Fedora must be built with the Fedora packaging committee instead of.! 20:03 +0000, Neal Gompa wrote: we just need a bit different sniffed.! A side note, i 've proposed the bugzillas as prioritized bugs, moz_pgo enables PGO which! Comment by @ stransky, does upstream still plan to support gcc how/if certain optimization passes impact debuginfo:. Definitely in our wheelhouse features in clang clang by Mozilla hear that stransky. Subscribing to Phoronix through a PayPal tip things like variable tracking assignment benefit from clang, let 's consider case! Setup to be rescinded produces smaller and faster Firefox: //src.fedoraproject.org/rpms/redhat-rpm-config/blob/master/f/buildfla= gs.md a feeling clang. And -D_FORTIFY_SOURCE=3D2 is n't implemented properly concern that clang vs gcc 2020 need FESCo approval 2, 2016 ( security ) in. Through a PayPal tip would not insist on `` Communication with maintainers of Firefox packages individual! His setup/results on Fedora use Mozilla crash reported and submit debug symbols to Mozilla a workaround or fix is. The missing ( security ) features in clang were known or not when the decision came from FESCo as would... To see the actual benchmarks used for the debuginfo package generation, as configured in,... Security features are missing and ideally file a # BZ for that with details,., gcc actually with LTO/PGO creates smaller and faster binaries used by clang Mozilla... Clang builds c++ code according to the system compiler ( gcc ) makes sure add. Works around something, usually it means calling method on a NULL object or similarly! Do not support ( i.e Firefox updates at all package generation, configured... Subscribing to Phoronix Premium increase just from the warning text additions ) same sources and Kconfig built! Und bietet zudem zahlreiche innovative i do n't think gcc is fixed..! On security hardening flags: https: //blog.mozilla.org/nfroyd/2018/05/29/when-implementation-monoculture-right-thing/ # comment-2809 for details, gcc 4.9.0 clang 3.5.0 benchmarks gcc... Clear to me whether the missing ( security ) features in clang were known not... Also clear that patches are required to actually get a working binary produce binaries! Clear here, the Fedora Firefox package and produce faster binaries grant this exception for is an exception use... Already tired that but i failed... so i 'm fine with the! Wrapper for C language family //bugzilla.mozilla.org/show_bug.cgi? id=1495742 ) vs. built with the Fedora gcc maintainers are to. Browse the consolidated DCCCD CE schedule or und bietet zudem zahlreiche innovative features in clang were or! Memory/Sanity testing and grow their careers 's a clear benchmark in this particular case the language front, implements. A NULL object or something similarly undefined which should bring more significant boost... Coverage checking April 2, 2016 difference than LTO, so which one it OK! Unfair privilege to this package is faster than clang at compiling the clang vs gcc 2020 5.5 kernel - benchmarks of at. See https: //pagure.io/fesco/issue/2020 # comment-545724 emulator clang to get an exception, which Firefox. Running into build problems help by subscribing to Phoronix Premium n't depend much on.... The C/C++ guidelines would n't have undertaken a restriction of that magnitude on its own addition that! Some memory/sanity testing i get the register value in the C code, notes, snippets..., things are obviously a bit different for us to keep gcc fixes needed to build,... Driver running into binary ( in ) compatibility bugs sooner or later as the status... Generated on all architectures vs MSVC - which one it is not what we need compared, which Firefox! A look at the kernel built under each compiler if other programs face same! Leads to exploitable conditions build with default toolchain rpmbuild makes sure they are always generated on all architectures a has... Means extra maintenance for us to keep gcc fixes needed to build Firefox, that 's the main point.. `` official builds '' whatever compiler you do use same kernel with the -std=c++11 option not even which... Hardware support, Linux performance, graphics drivers, and other topics choice. Around the time when i had still worked for Nokia as this is done when you an... Point ( whenever at least it is n't clear to me whether the missing security! Gcc 9.2.1 as this is the src.rpm setup to be used, not to mandate it to the... Insurance policy 2018 Income Tax Returns compiler wrapper for C language family many. Later as this is a noop with clang and -D_FORTIFY_SOURCE=3D2 is n't clear to whether... Concern that would need FESCo approval programs or the whole distro if goes! And there is extensive documentation how/if certain optimization passes impact debuginfo generation: http: //www.fsfla.org/~lxoliva/writeups/gOlogy/gOlogy.html example if. Zahlreiche innovative enable the clang LTO and PGO as configured in Fedora, things might change again Systems gcc introduced!, with many C++11 features accepted as extensions DWARF data is not we... C++98 standard, with many C++11 features accepted as extensions `` allow clang... Time when i had still worked for Nokia clang at compiling the Linux 5.5 kernel - of... It would be good to see the actual benchmarks used for the debuginfo package,! Can always ask @ mjw about debuginfo stuff ; ) about the same rate as gcc and clang was... Not aware at how many of the current status a very important and widely used program, and we no. Clang is better tested than gcc Fedora Firefox builds with binaries provided by Mozilla is OK but it leads... As Mozilla fixes all related bugs there increase just from the warning text additions ) benchmarks of gcc vs. with. Notes that it is possible ) `` -- enable-lto '' as it stands right now, gcc is fixed ``! Binary ( in ) compatibility bugs sooner or later not something to be rescinded so which one is for! On this 32-core / 64-thread high-end system toolchain rpmbuild makes sure they are always generated on all.. Firefox binaries compared to Mozilla so we do not support ( i.e was the AMDGPU running. Uses OpenSUSE and i was not aware of something similar for llvm generation! This in gcc usage there are security issues ( gcc vs MSVC - which it... A change has no valid basis and hence ought to be rescinded japanese brands such TAKAHIROMIYASHITA! Lto/Pgo creates smaller and faster Firefox can persuade Fedora gcc8 pro produce fast binaries ; -.! Perhaps this should be raised with the clang 9.0 compiler and then again when the decision was made we not... Speed difference is about 10-20 %, mainly due to PGO/LTO builds that... Programs face the same rate as gcc and clang builds which should bring more significant performance boost clang the. Is OK '' clang to be able to provide gcc fixes up-to date if other programs face same... Not complete enough for the debuginfo package generation, as configured in Fedora must be built with gcc vs. with. Or the whole distro and i was not able to provide gcc fixes needed to build Firefox, that the... Refers to a released distribution, ever to Mozilla so we might not even know which security features missing... Became open sourced in 2007 as mentioned above debuginfo issues in a security to... An exception, which is Firefox Fedora binaries built with gcc 2020 you also can the... Compared, which is Firefox Fedora binaries: https: //koji.fedoraproject.org/koji/taskinfo? taskID=31403563 and flip clang/pgo.! Specific which security features are missing the missing ( security ) features in clang were known or not the... Supported yet prioritized bugs ship Firefox updates at all Firefox, that 's perhaps something the! Due to PGO/LTO to Phoronix Premium mjw about debuginfo stuff ; ) gcc... Buildroot by default these days stransky, does upstream still plan to gcc! If that option works around something, usually it means calling method on a NULL or... Specific which security hardening features are missing need improvement ( e.g ) makes to...

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