<div dir="ltr">Sorry I was being stupid and had the static sanitizer libraries after some dynamic ones which caused some linker errors.<div>Do they need to be wrapped in -whole-archive/-no-whole-archive? Do I also need to pass the '--dynamic-list' flags?</div><div><br></div><div>Although I got the tests working, getting the CMake build to add the proper libraries is going to be a lot more difficult.</div><div>I would implore you to consider a solution that shifts the work onto the compiler.</div><div><br></div><div>/Eric</div></div><div class="gmail_extra"><br><div class="gmail_quote">On Mon, Oct 20, 2014 at 5:31 PM, Alexey Samsonov <span dir="ltr"><<a href="mailto:vonosmas@gmail.com" target="_blank">vonosmas@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div class="gmail_extra"><br><div class="gmail_quote"><span class="">On Mon, Oct 20, 2014 at 2:43 PM, Eric Fiselier <span dir="ltr"><<a href="mailto:eric@efcs.ca" target="_blank">eric@efcs.ca</a>></span> wrote:<br></span><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Hi All,<div><br></div><span class=""><div>I've spent some time trying to work around this. I probe clang to find the libclang_rt libraries but I cant seem to link them correctly.<br></div><div>Would anybody be able to offer advice as to how to properly link the static sanitizer libraries?</div></span></div></blockquote><div><br></div><div>What do you mean? If you know the location of sanitizer runtimes, you can just add them to linker invocation, possibly wrapped in -whole-archive/-no-whole-archive.</div><div>Or are you talking about adding one more flag to force linking in sanitizer runtimes?</div><div><div class="h5"><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><span><font color="#888888"><div><br></div><div>/Eric</div></font></span></div><div><div><div class="gmail_extra"><br><div class="gmail_quote">On Sat, Oct 18, 2014 at 12:06 PM, Eric Fiselier <span dir="ltr"><<a href="mailto:eric@efcs.ca" target="_blank">eric@efcs.ca</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><span><span style="font-family:arial,sans-serif;font-size:13px">> Would it help if we teach the Clang driver to print the path to sanitizer runtime libraries (smth. like GCC's -print-libgcc-file-name flag)?<div><br></div></span></span><div style="font-family:arial,sans-serif;font-size:13px">That would be one way to solve the problem and probably a good approach.</div><div style="font-family:arial,sans-serif;font-size:13px">I would rather have flags that force the libraries to be linked even in the presence of '-nodefaultlibs'. </div><div style="font-family:arial,sans-serif;font-size:13px">It seems somewhat odd that GCC ignores -static-libgcc with -nodefaultlibs.</div><div style="font-family:arial,sans-serif;font-size:13px"><br></div><div style="font-family:arial,sans-serif;font-size:13px"><font face="arial, sans-serif">Either way, with this new behavior there are going to be some growing pains, but that is our problem.</font></div></div><div><div><div class="gmail_extra"><br><div class="gmail_quote">On Fri, Oct 17, 2014 at 5:38 PM, Alexey Samsonov <span dir="ltr"><<a href="mailto:vonosmas@gmail.com" target="_blank">vonosmas@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div class="gmail_extra"><br><div class="gmail_quote"><span>On Fri, Oct 17, 2014 at 2:53 PM, Eric Fiselier <span dir="ltr"><<a href="mailto:eric@efcs.ca" target="_blank">eric@efcs.ca</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><span><span style="font-size:13px;font-family:arial,sans-serif">> If I understand correctly, when you pass -fsanitize=undefined (or whatever) to the linker job, all it does is add the library. If this is correct, then it makes no sense to have -nodefaultlibs remove it: it's not a default lib and it was explicitly added by passing -fsanitize to the link job.</span><br><div><br></div></span><div>I agree. It seems to me your asking for the library to be linked in explicitly. However I think the current behavior is acceptable as well. A couple of salient points.</div><div>1. As mentioned repeatedly, it isn't always possible to configure c++ projects so they only use -fsanitize when compiling and not linking.</div><div>2. There is a need for a way to remove the default sanitizer libraries.</div><div>3. GCC also removes the sanitizer libraries when -fsanitize and -nodefaultlibs are given.</div><span><div><br></div><div>> <span style="font-family:arial,sans-serif;font-size:13px">Why can't we link with libc++ using -stdlib=libc++ flag? Linking against libc++abi instead of (not "in addition to") libsupc++ (or whatever) might be challenging, though.</span></div><div style="font-family:arial,sans-serif;font-size:13px">However, I think it would really make sense to add support for this configuration to Clang driver. It would make your LIT configs simpler (you'll just invoke the Clang with</div><div style="font-family:arial,sans-serif;font-size:13px">some arguments, instead of linking with libc++ and libc++abi manually), and make usage of libc++/libc++abi easier for end user.</div><div style="font-family:arial,sans-serif;font-size:13px"><br></div></span><div style="font-family:arial,sans-serif;font-size:13px">I'm currently working on patching the clang driver to better handle linking against libc++ and its many ABI libraries. </div><div style="font-family:arial,sans-serif;font-size:13px">It will take some work before this approach is viable for testing libc++, and even when it is viable older compilers and GCC will still have to be supported separately. </div><div style="font-family:arial,sans-serif;font-size:13px"><br></div><div style="font-family:arial,sans-serif;font-size:13px">Currently the libc++ test suite handles linking the required libraries works with both GCC and Clang. It is generic and flexible across a wide range of compilers, platforms and ABI library combinations.</div><div style="font-family:arial,sans-serif;font-size:13px">Changing the way we set up the tests to deal with this will require a fair amount of work and a ton of special cases. I'll look into what we can do to make the change.</div></div></blockquote><div><br></div></span><div>Would it help if we teach the Clang driver to print the path to sanitizer runtime libraries (smth. like GCC's -print-libgcc-file-name flag)?</div><div><div><div><br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div style="font-family:arial,sans-serif;font-size:13px"><br></div><div style="font-family:arial,sans-serif;font-size:13px"><br></div><div>Thanks for your time</div><span><font color="#888888"><div>/Eric</div><div><br></div></font></span></div><div><div><div class="gmail_extra"><br><div class="gmail_quote">On Fri, Oct 17, 2014 at 3:24 PM, Alexey Samsonov <span dir="ltr"><<a href="mailto:vonosmas@gmail.com" target="_blank">vonosmas@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div class="gmail_extra"><br><div class="gmail_quote"><span>On Fri, Oct 17, 2014 at 1:11 PM, Filipe Cabecinhas <span dir="ltr"><<a href="mailto:filcab@filcab.net" target="_blank">filcab@filcab.net</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">I don't know anything about the go compiler, but it seems to me this patch shouldn't be done like this.<div><br></div><div>If I understand correctly, when you pass -fsanitize=undefined (or whatever) to the linker job, all it does is add the library. If this is correct, then it makes no sense to have -nodefaultlibs remove it: it's not a default lib and it was explicitly added by passing -fsanitize to the link job.</div></blockquote><div><br></div></span><div>-fsanitize=whatever not only adds the static sanitizer runtime library, but also pulls in its dependencies on system libraries (-lc, -ldl, -lpthread, -lrt). It would be weird to add these libraries if the user explicitly specified -nodefaultlibs. Generally, it's ok to make this flag win other flags, adding libraries explicitly. For example, GCC manual specifies that "-static-libgcc" is ignored in presence of "-nodefaultlibs".</div><span><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div> </div></blockquote><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div><span></span></div><div><br></div><div>From what's in the bug report, isn't it possible to change go's behaviour by passing it -fsanitize=blah in CFLAGS but now passing it in LDFLAGS, since it will add it by itself?</div></blockquote><div><br></div></span><div>Not really, it's hard to fix the build system in your project if it builds 10 binaries with LDFLAGS, and 10 more targets with "LDFLAGS + -nodefaultlibs + ...".It's nice if the driver is able to handle it automatically and discard the irrelevant flags in the second case.</div><span><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div><br></div><div>Regards,</div><div><br></div><div> Filipe<div><div><br><br>On Friday, October 17, 2014, Eric Fiselier <<a href="mailto:eric@efcs.ca" target="_blank">eric@efcs.ca</a>> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Hi All,<div><br></div><div>The libc++ LIT test driver uses -nodefaultlibs so that it can properly link against libc++ and the ABI library.</div></div></blockquote></div></div></div></blockquote><div><br></div></span><div>Why can't we link with libc++ using -stdlib=libc++ flag? Linking against libc++abi instead of (not "in addition to") libsupc++ (or whatever) might be challenging, though.</div><div>However, I think it would really make sense to add support for this configuration to Clang driver. It would make your LIT configs simpler (you'll just invoke the Clang with</div><div>some arguments, instead of linking with libc++ and libc++abi manually), and make usage of libc++/libc++abi easier for end user.</div><div><div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div><div><div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div>Since this patch we can no longer use sanitizers when running our test suite since it's quite difficult to mimic the driver's behavior and manually link in the sanitizer runtimes.</div><div><br></div><div>I agree with the rational behind your change. </div><div>However, since it's difficult to manually link the sanitizer runtimes, it would be nice to have a way to force the front end to do it even when -nodefaultlibs is present.</div><div>I think we should consider adding '-static-lib*san' flags similar to the ones provided by GCC.<br></div><div><br></div><div>I'm not very knowledgeable about the clang linker driver so any input is welcome. </div><div><br></div><div>/Eric</div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Fri, Sep 26, 2014 at 3:22 PM, Alexey Samsonov <span dir="ltr"><<a>vonosmas@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Author: samsonov<br>
Date: Fri Sep 26 16:22:08 2014<br>
New Revision: 218541<br>
<br>
URL: <a href="http://llvm.org/viewvc/llvm-project?rev=218541&view=rev" target="_blank">http://llvm.org/viewvc/llvm-project?rev=218541&view=rev</a><br>
Log:<br>
Don't link in sanitizer runtimes if -nostdlib/-nodefaultlibs is provided.<br>
<br>
It makes no sense to link in sanitizer runtimes in this case: the user<br>
probably doesn't want to see any system/toolchain libs in his link if he<br>
provides these flags, and the link will most likely fail anyway - as sanitizer<br>
runtimes depend on libpthread, libdl, libc etc.<br>
<br>
Also, see discussion in <a href="https://code.google.com/p/address-sanitizer/issues/detail?id=344" target="_blank">https://code.google.com/p/address-sanitizer/issues/detail?id=344</a><br>
<br>
Modified:<br>
cfe/trunk/lib/Driver/Tools.cpp<br>
cfe/trunk/test/Driver/sanitizer-ld.c<br>
<br>
Modified: cfe/trunk/lib/Driver/Tools.cpp<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Driver/Tools.cpp?rev=218541&r1=218540&r2=218541&view=diff" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Driver/Tools.cpp?rev=218541&r1=218540&r2=218541&view=diff</a><br>
==============================================================================<br>
--- cfe/trunk/lib/Driver/Tools.cpp (original)<br>
+++ cfe/trunk/lib/Driver/Tools.cpp Fri Sep 26 16:22:08 2014<br>
@@ -2243,6 +2243,10 @@ collectSanitizerRuntimes(const ToolChain<br>
// C runtime, etc). Returns true if sanitizer system deps need to be linked in.<br>
static bool addSanitizerRuntimes(const ToolChain &TC, const ArgList &Args,<br>
ArgStringList &CmdArgs) {<br>
+ // Don't link in any sanitizer runtimes if we have no system libraries.<br>
+ if (Args.hasArg(options::OPT_nostdlib) ||<br>
+ Args.hasArg(options::OPT_nodefaultlibs))<br>
+ return false;<br>
SmallVector<StringRef, 4> SharedRuntimes, StaticRuntimes,<br>
HelperStaticRuntimes;<br>
collectSanitizerRuntimes(TC, Args, SharedRuntimes, StaticRuntimes,<br>
<br>
Modified: cfe/trunk/test/Driver/sanitizer-ld.c<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Driver/sanitizer-ld.c?rev=218541&r1=218540&r2=218541&view=diff" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Driver/sanitizer-ld.c?rev=218541&r1=218540&r2=218541&view=diff</a><br>
==============================================================================<br>
--- cfe/trunk/test/Driver/sanitizer-ld.c (original)<br>
+++ cfe/trunk/test/Driver/sanitizer-ld.c Fri Sep 26 16:22:08 2014<br>
@@ -301,3 +301,10 @@<br>
// CHECK-LSAN-ASAN-LINUX-NOT: libclang_rt.lsan<br>
// CHECK-LSAN-ASAN-LINUX: libclang_rt.asan-x86_64<br>
// CHECK-LSAN-ASAN-LINUX-NOT: libclang_rt.lsan<br>
+<br>
+// RUN: %clang -nostdlib -fsanitize=address %s -### -o %t.o 2>&1 \<br>
+// RUN: -target x86_64-unknown-linux \<br>
+// RUN: --sysroot=%S/Inputs/basic_linux_tree \<br>
+// RUN: | FileCheck --check-prefix=CHECK-NOSTDLIB %s<br>
+// CHECK-NOSTDLIB: "{{.*}}ld{{(.exe)?}}"<br>
+// CHECK-NOSTDLIB-NOT: libclang_rt.asan<br>
<br>
<br>
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</blockquote></div><br></div>
</blockquote></div></div></div>
</blockquote></div></div></div><span><font color="#888888"><br><br clear="all"><div><br></div>-- <br><div dir="ltr">Alexey Samsonov<br><a href="mailto:vonosmas@gmail.com" target="_blank">vonosmas@gmail.com</a></div>
</font></span></div></div>
</blockquote></div><br></div>
</div></div></blockquote></div></div></div><span><font color="#888888"><br><br clear="all"><div><br></div>-- <br><div dir="ltr">Alexey Samsonov<br><a href="mailto:vonosmas@gmail.com" target="_blank">vonosmas@gmail.com</a></div>
</font></span></div></div>
</blockquote></div><br></div>
</div></div></blockquote></div><br></div>
</div></div></blockquote></div></div></div><span class="HOEnZb"><font color="#888888"><br><br clear="all"><div><br></div>-- <br><div dir="ltr">Alexey Samsonov<br><a href="mailto:vonosmas@gmail.com" target="_blank">vonosmas@gmail.com</a></div>
</font></span></div></div>
</blockquote></div><br></div>