Chris Bieneman <be...@apple.com> writes: > beanz created this revision. > beanz added reviewers: zaks.anna, kubabrecka, bogner. > beanz added a subscriber: cfe-commits. > > The -nodefaultlibs and -nostdlib flags suppress all the runtime > libraries that the driver puts on the link line. This feels wrong. If > a user specifies "-fsanitize=<blah>" I think it is expected that the > sanitizer library would be included on the link line.
In terms of user expectations, either (a) you pass -nodefaultlibs and expect -fsanitize to still add the (non-default) libs it needs, or (b) you pass -fsanitize but want to disable all of the libs with -nodefaultlibs. This patch implements (a), and I think that makes sense, since it means that "clang -nodefaultlibs -fsanitize=... foo.c" is sufficient to build a standalone thing that's still sanitized. The problem with (b) is that a command like that would have to be invalid - you're required to also link a particular sanitizer lib at that point, so you'd constantly need to say "no default libs, except for the ones I need for this to even compile". In any case, what do similar flags that need to pull in runtimes to work do, like PGO/coverage instrumentation? Whatever we end up doing should be consistent across all of these. > > https://reviews.llvm.org/D24048 > > Files: > lib/Driver/ToolChains.cpp > lib/Driver/ToolChains.h > lib/Driver/Tools.cpp > > Index: lib/Driver/Tools.cpp > =================================================================== > --- lib/Driver/Tools.cpp > +++ lib/Driver/Tools.cpp > @@ -8032,6 +8032,8 @@ > > // Let the tool chain choose which runtime library to link. > getMachOToolChain().AddLinkRuntimeLibArgs(Args, CmdArgs); > + } else { > + getMachOToolChain().AddLinkSanitizerLibArgs(Args, CmdArgs); > } > > if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nostartfiles)) { > Index: lib/Driver/ToolChains.h > =================================================================== > --- lib/Driver/ToolChains.h > +++ lib/Driver/ToolChains.h > @@ -282,6 +282,10 @@ > virtual void AddLinkRuntimeLibArgs(const llvm::opt::ArgList &Args, > llvm::opt::ArgStringList &CmdArgs) > const; > > + virtual void > + AddLinkSanitizerLibArgs(const llvm::opt::ArgList &Args, > + llvm::opt::ArgStringList &CmdArgs) const {} > + > virtual void addStartObjectFileArgs(const llvm::opt::ArgList &Args, > llvm::opt::ArgStringList &CmdArgs) > const { > } > @@ -571,6 +575,10 @@ > > RuntimeLibType GetRuntimeLibType(const llvm::opt::ArgList &Args) const > override; > > + void > + AddLinkSanitizerLibArgs(const llvm::opt::ArgList &Args, > + llvm::opt::ArgStringList &CmdArgs) const override; > + > void AddLinkRuntimeLibArgs(const llvm::opt::ArgList &Args, > llvm::opt::ArgStringList &CmdArgs) const > override; > > Index: lib/Driver/ToolChains.cpp > =================================================================== > --- lib/Driver/ToolChains.cpp > +++ lib/Driver/ToolChains.cpp > @@ -425,22 +425,7 @@ > return; > } > > - const SanitizerArgs &Sanitize = getSanitizerArgs(); > - if (Sanitize.needsAsanRt()) > - AddLinkSanitizerLibArgs(Args, CmdArgs, "asan"); > - if (Sanitize.needsUbsanRt()) > - AddLinkSanitizerLibArgs(Args, CmdArgs, "ubsan"); > - if (Sanitize.needsTsanRt()) > - AddLinkSanitizerLibArgs(Args, CmdArgs, "tsan"); > - if (Sanitize.needsStatsRt()) { > - StringRef OS = isTargetMacOS() ? "osx" : "iossim"; > - AddLinkRuntimeLib(Args, CmdArgs, > - (Twine("libclang_rt.stats_client_") + OS + ".a").str(), > - /*AlwaysLink=*/true); > - AddLinkSanitizerLibArgs(Args, CmdArgs, "stats"); > - } > - if (Sanitize.needsEsanRt()) > - AddLinkSanitizerLibArgs(Args, CmdArgs, "esan"); > + AddLinkSanitizerLibArgs(Args, CmdArgs); > > // Otherwise link libSystem, then the dynamic runtime library, and finally > any > // target specific static runtime library. > @@ -495,6 +480,26 @@ > } > } > > +void DarwinClang::AddLinkSanitizerLibArgs( > + const llvm::opt::ArgList &Args, llvm::opt::ArgStringList &CmdArgs) const > { > + const SanitizerArgs &Sanitize = getSanitizerArgs(); > + if (Sanitize.needsAsanRt()) > + AddLinkSanitizerLibArgs(Args, CmdArgs, "asan"); > + if (Sanitize.needsUbsanRt()) > + AddLinkSanitizerLibArgs(Args, CmdArgs, "ubsan"); > + if (Sanitize.needsTsanRt()) > + AddLinkSanitizerLibArgs(Args, CmdArgs, "tsan"); > + if (Sanitize.needsStatsRt()) { > + StringRef OS = isTargetMacOS() ? "osx" : "iossim"; > + AddLinkRuntimeLib(Args, CmdArgs, > + (Twine("libclang_rt.stats_client_") + OS + ".a").str(), > + /*AlwaysLink=*/true); > + AddLinkSanitizerLibArgs(Args, CmdArgs, "stats"); > + } > + if (Sanitize.needsEsanRt()) > + AddLinkSanitizerLibArgs(Args, CmdArgs, "esan"); > +} > + > void Darwin::AddDeploymentTarget(DerivedArgList &Args) const { > const OptTable &Opts = getDriver().getOpts(); > _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
