On Tue, Jan 21, 2014 at 1:06 PM, Chandler Carruth <[email protected]> wrote: > On Tue, Jan 21, 2014 at 12:06 AM, Evgeniy Stepanov > <[email protected]> wrote: >> >> I don't this adding builddir/lib to linker search path would be right. > > > Why not?
Because at the moment it contains a bunch of host libraries, and libc++ we are trying to link is a target library. Of course, at the moment it is being built with the host compiler, but it is a target library in spirit. > >> >> Would it make sense to move libc++.so to lib/clang/3.5/lib/linux/? > > > This is a good question. > > Historically, GCC has considered libstdc++ to be "part of" the compiler or > toolchain, and distributed them together. We lookup libstdc++ out of GCC's > installation tree for example. > > Also historically, libc++ has *not* been distributed as "part of" the > compiler or toolchain. On OS X it is actually more part of the OS than the > toolchain. Even on Linux, some care has been taken to try to make it > effective to use libc++ with a GCC host just as much as with a Clang host. > > I'm not trying to endorse either of these approaches, but that's what they > have been historically. To my mind, that makes lib/clang/<version> > inapropriate for libc++. If we want to switch to shipping libc++ as merely > an implementation detail of Clang itself, then I would suggest installing > *both* headers and libraries under lib/clang/<version>. But that would be a > reasonably radical departure from current trends etc. I see, lib/clang is not a good choice then. > >> >> >> On Mon, Jan 20, 2014 at 7:23 PM, Alexey Samsonov <[email protected]> >> wrote: >> > Hi Chandler, >> > >> > Fixing include paths is not enough - you should also fix library >> > lookup paths for dynamic linker in Clang driver. Currently if the >> > build tree has both Clang binary and built libc++ like this: >> > <...>/bin/clang++ >> > <...>/lib/libc++.so >> > >> > Clang binary is not able to locate libc++.so with -stdlib=libc++ >> > provided. Therefore the following brute-force bootstrap process >> > wouldn't work: >> > (1) configure a new build tree with default options and build Clang and >> > libc++ >> > (2) configure a new build tree with just-built Clang as c/c++ compiler >> > and specify LLVM_ENABLE_LIBCXX=ON >> > >> > I'll try to take a closer look at this (and potentially fix the >> > driver) tomorrow, unless someone who has more understanding picks it >> > up from here. >> > >> > >> > >> > On Mon, Jan 20, 2014 at 1:42 PM, Chandler Carruth <[email protected]> >> > wrote: >> >> Author: chandlerc >> >> Date: Mon Jan 20 03:42:24 2014 >> >> New Revision: 199632 >> >> >> >> URL: http://llvm.org/viewvc/llvm-project?rev=199632&view=rev >> >> Log: >> >> Make the Linux support for finding libc++ somewhat less braindead. >> >> >> >> Now instead of just looking in the system root for it, we also look >> >> relative to the clang binary's directory. This should "just work" in >> >> almost all cases. I've added test cases accordingly. >> >> >> >> This is probably *very* worthwhile to backport to the 3.4 branch so >> >> that >> >> folks can check it out, build it, and use that as their host compiler >> >> going forward. >> >> >> >> Modified: >> >> cfe/trunk/lib/Driver/ToolChains.cpp >> >> cfe/trunk/test/Driver/linux-header-search.cpp >> >> >> >> Modified: cfe/trunk/lib/Driver/ToolChains.cpp >> >> URL: >> >> http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Driver/ToolChains.cpp?rev=199632&r1=199631&r2=199632&view=diff >> >> >> >> ============================================================================== >> >> --- cfe/trunk/lib/Driver/ToolChains.cpp (original) >> >> +++ cfe/trunk/lib/Driver/ToolChains.cpp Mon Jan 20 03:42:24 2014 >> >> @@ -2945,9 +2945,24 @@ void Linux::AddClangCXXStdlibIncludeArgs >> >> >> >> // Check if libc++ has been enabled and provide its include paths if >> >> so. >> >> if (GetCXXStdlibType(DriverArgs) == ToolChain::CST_Libcxx) { >> >> - // libc++ is always installed at a fixed path on Linux currently. >> >> - addSystemInclude(DriverArgs, CC1Args, >> >> - getDriver().SysRoot + "/usr/include/c++/v1"); >> >> + const std::string LibCXXIncludePathCandidates[] = { >> >> + // The primary location is within the Clang installation. >> >> + // FIXME: We shouldn't hard code 'v1' here to make Clang future >> >> proof to >> >> + // newer ABI versions. >> >> + getDriver().Dir + "/../include/c++/v1", >> >> + >> >> + // We also check the system as for a long time this is the only >> >> place Clang looked. >> >> + // FIXME: We should really remove this. It doesn't make any >> >> sense. >> >> + getDriver().SysRoot + "/usr/include/c++/v1" >> >> + }; >> >> + for (unsigned i = 0; i < >> >> llvm::array_lengthof(LibCXXIncludePathCandidates); >> >> + ++i) { >> >> + if (!llvm::sys::fs::exists(LibCXXIncludePathCandidates[i])) >> >> + continue; >> >> + // Add the first candidate that exists. >> >> + addSystemInclude(DriverArgs, CC1Args, >> >> LibCXXIncludePathCandidates[i]); >> >> + break; >> >> + } >> >> return; >> >> } >> >> >> >> @@ -2971,7 +2986,7 @@ void Linux::AddClangCXXStdlibIncludeArgs >> >> MIPSABIDirSuffix, DriverArgs, CC1Args)) >> >> return; >> >> >> >> - const std::string IncludePathCandidates[] = { >> >> + const std::string LibStdCXXIncludePathCandidates[] = { >> >> // Gentoo is weird and places its headers inside the GCC install, >> >> so if the >> >> // first attempt to find the headers fails, try these patterns. >> >> InstallDir.str() + "/include/g++-v" + Version.MajorStr + "." + >> >> @@ -2984,8 +2999,9 @@ void Linux::AddClangCXXStdlibIncludeArgs >> >> LibDir.str() + "/../include/c++", >> >> }; >> >> >> >> - for (unsigned i = 0; i < >> >> llvm::array_lengthof(IncludePathCandidates); ++i) { >> >> - if (addLibStdCXXIncludePaths(IncludePathCandidates[i], >> >> + for (unsigned i = 0; i < >> >> llvm::array_lengthof(LibStdCXXIncludePathCandidates); >> >> + ++i) { >> >> + if (addLibStdCXXIncludePaths(LibStdCXXIncludePathCandidates[i], >> >> TripleStr + MIPSABIDirSuffix + >> >> BiarchSuffix, >> >> DriverArgs, CC1Args)) >> >> break; >> >> >> >> Modified: cfe/trunk/test/Driver/linux-header-search.cpp >> >> URL: >> >> http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Driver/linux-header-search.cpp?rev=199632&r1=199631&r2=199632&view=diff >> >> >> >> ============================================================================== >> >> --- cfe/trunk/test/Driver/linux-header-search.cpp (original) >> >> +++ cfe/trunk/test/Driver/linux-header-search.cpp Mon Jan 20 03:42:24 >> >> 2014 >> >> @@ -1,6 +1,29 @@ >> >> // General tests that the header search paths detected by the driver >> >> and passed >> >> // to CC1 are sane. >> >> // >> >> +// Test a simulated installation of libc++ on Linux, both through >> >> sysroot and >> >> +// the installation path of Clang. >> >> +// RUN: %clang -no-canonical-prefixes %s -### -fsyntax-only 2>&1 \ >> >> +// RUN: -target x86_64-unknown-linux-gnu \ >> >> +// RUN: -stdlib=libc++ \ >> >> +// RUN: -ccc-install-dir %S/Inputs/basic_linux_tree/usr/bin \ >> >> +// RUN: --sysroot=%S/Inputs/basic_linux_libcxx_tree \ >> >> +// RUN: | FileCheck --check-prefix=CHECK-BASIC-LIBCXX-SYSROOT %s >> >> +// CHECK-BASIC-LIBCXX-SYSROOT: "{{[^"]*}}clang{{[^"]*}}" "-cc1" >> >> +// CHECK-BASIC-LIBCXX-SYSROOT: "-isysroot" "[[SYSROOT:[^"]+]]" >> >> +// CHECK-BASIC-LIBCXX-SYSROOT: "-internal-isystem" >> >> "[[SYSROOT]]/usr/include/c++/v1" >> >> +// CHECK-BASIC-LIBCXX-SYSROOT: "-internal-isystem" >> >> "[[SYSROOT]]/usr/local/include" >> >> +// RUN: %clang -no-canonical-prefixes %s -### -fsyntax-only 2>&1 \ >> >> +// RUN: -target x86_64-unknown-linux-gnu \ >> >> +// RUN: -stdlib=libc++ \ >> >> +// RUN: -ccc-install-dir %S/Inputs/basic_linux_libcxx_tree/usr/bin >> >> \ >> >> +// RUN: --sysroot=%S/Inputs/basic_linux_libcxx_tree \ >> >> +// RUN: | FileCheck --check-prefix=CHECK-BASIC-LIBCXX-INSTALL %s >> >> +// CHECK-BASIC-LIBCXX-INSTALL: "{{[^"]*}}clang{{[^"]*}}" "-cc1" >> >> +// CHECK-BASIC-LIBCXX-INSTALL: "-isysroot" "[[SYSROOT:[^"]+]]" >> >> +// CHECK-BASIC-LIBCXX-INSTALL: "-internal-isystem" >> >> "[[SYSROOT]]/usr/bin/../include/c++/v1" >> >> +// CHECK-BASIC-LIBCXX-INSTALL: "-internal-isystem" >> >> "[[SYSROOT]]/usr/local/include" >> >> +// >> >> // Test a very broken version of multiarch that shipped in Ubuntu >> >> 11.04. >> >> // RUN: %clang -no-canonical-prefixes %s -### -fsyntax-only 2>&1 \ >> >> // RUN: -target i386-unknown-linux \ >> >> >> >> >> >> _______________________________________________ >> >> cfe-commits mailing list >> >> [email protected] >> >> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits >> > >> > >> > >> > -- >> > Alexey Samsonov, MSK >> > _______________________________________________ >> > cfe-commits mailing list >> > [email protected] >> > http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits >> _______________________________________________ >> cfe-commits mailing list >> [email protected] >> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits > > _______________________________________________ cfe-commits mailing list [email protected] http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
