[Sanitizers] Basic Solaris sanitizer support (PR 33274)

[ro]

Summary

This patch (on top of https://reviews.llvm.org/D35755) provides the clang side necessary
to enable the Solaris port of the sanitizers implemented by https://reviews.llvm.org/D40898,
https://reviews.llvm.org/D40899, and https://reviews.llvm.org/D40900).

A few features of note:

• While compiler-rt cmake/base-config-ix.cmake (COMPILER_RT_OS_DIR) places the runtime libs in a tolower(CMAKE_SYSTEM_NAME) directory, clang defaults to the OS part of the target triplet (solaris2.11 in the case at hand). The patch makes them agree on compiler-rt's idea.

• While Solaris ld accepts a considerable number of GNU ld options for compatibility, it only does so for the double-dash forms. clang unfortunately is inconsistent here and sometimes uses the double-dash form, sometimes the single-dash one that confuses the hell out of Solaris ld. I've changed the affected places to use the double-dash form that should always work.

• As described in https://reviews.llvm.org/D40899, Solaris ld doesn't create the start_sancov_guards/__stop___sancov_guards labels gld/gold/lld do, so I'm including additional runtime libs into the link that provide them.

• One test uses -fstack-protector, but unlike other systems libssp hasn't been folded into Solaris libc, but needs to be linked with separately.

• For now, only 32-bit x86 asan is enabled on Solaris. 64-bit x86 should follow, but sparc (which requires additional compiler-rt changes not yet submitted) fails miserably due to a llvmsparc backend limitation:

fatal error: error in backend: Function "_ZN7testing8internal16BoolFromGTestEnvEPKcb": over-aligned dynamic alloca not supported.

However, inside the gcc tree, Solaris/sparc asan works almost as well as x86.

[alekseyshl]

lib/Driver/ToolChains/CommonArgs.cpp

699

If it does not exist on Solaris, why change it then? For the consistency sake?

[ro]

lib/Driver/ToolChains/CommonArgs.cpp

699

Consistency for one. Besides, I'm talking to the Solaris linker
engineers whether to just accept and ignore that option
for GNU ld compatibility.

[alekseyshl]

lib/Driver/ToolChains/CommonArgs.cpp

525

Can you elaborate why Solaris ld does not need dynamic lists? How does it export sanitizer symbols then?

[ro]

lib/Driver/ToolChains/CommonArgs.cpp

525

Solaris ld simply defaults to --export-dynamic.

[alekseyshl]

lib/Driver/ToolChains/CommonArgs.cpp

525

Can we say then that ld "defaults to --export-dynamic behavior" (as --export-dynamic does not exists there) instead of "doesn't need this"?

[ro]

lib/Driver/ToolChains/CommonArgs.cpp

525

Sure, that's certainly clearer. As in the revised patch?

[ro]

Reworded comment.

[ro]

There are two issues before the patch can be commited:

• It depends on https://reviews.llvm.org/D35755 which needs minor changes.

• I'm currently working with an experimental version of Solaris ld that *does* support generation of start_sancov_guards etc. labels. This will most likely go into Solaris 11.4, but somehow older linkers without that support (from Solaris 11.3 or OpenSolaris derivatives) will have to be supported, probably by a cmake test. Not sure yet how best to do this.

[ro]

Could anyone please commit this for me?

Thanks.

Rainer

[alekseyshl]

Rainer, check rC324302 out, you probably want to add test cases for Solaris to test/Driver/sanitizer-ld.c too.

[ro]

In D40903#998474, @alekseyshl wrote:

Rainer, check rC324302 out, you probably want to add test cases for Solaris to test/Driver/sanitizer-ld.c too.

Sorry about that! I certainly will, but it'll be some time because I'm about to leave for an extended vacation, to return only in late march.

include/clang/Driver/ToolChain.h

public:
   const char *getCompilerRTArgString(const llvm::opt::ArgList &Args,
                                      StringRef Component,
                                      bool Shared = false) const;
 
   // Returns <ResourceDir>/lib/<OSName>/<arch>.  This is used by runtimes (such
   // as OpenMP) to find arch-specific libraries.
   std::string getArchSpecificLibPath() const;
 
+  // Returns <OSname> part of above.
+  StringRef getOSLibName() const;
+
   /// needsProfileRT - returns true if instrumentation profile is on.
   static bool needsProfileRT(const llvm::opt::ArgList &Args);
 
   /// IsUnwindTablesDefault - Does this tool chain use -funwind-tables
   /// by default.
   virtual bool IsUnwindTablesDefault(const llvm::opt::ArgList &Args) const;
 
   /// \brief Test whether this toolchain defaults to PIC.

lib/Driver/ToolChain.cpp

static StringRef getArchNameForCompilerRTLib(const ToolChain &TC,
 
   // For historic reasons, Android library is using i686 instead of i386.
   if (TC.getArch() == llvm::Triple::x86 && Triple.isAndroid())
     return "i686";
 
   return llvm::Triple::getArchTypeName(TC.getArch());
 }
 
+StringRef ToolChain::getOSLibName() const {
+  switch (Triple.getOS()) {
+  case llvm::Triple::FreeBSD:
+    return "freebsd";
+  case llvm::Triple::Solaris:
+    return "sunos";
+  default:
+    return getOS();
+  }
+}
+
 std::string ToolChain::getCompilerRTPath() const {
   SmallString<128> Path(getDriver().ResourceDir);
   if (Triple.isOSUnknown()) {
     llvm::sys::path::append(Path, "lib");
   } else {
-    StringRef OSLibName = Triple.isOSFreeBSD() ? "freebsd" : getOS();
-    llvm::sys::path::append(Path, "lib", OSLibName);
+    llvm::sys::path::append(Path, "lib", getOSLibName());
   }
   return Path.str();
 }
 
 std::string ToolChain::getCompilerRT(const ArgList &Args, StringRef Component,
                                      bool Shared) const {
   const llvm::Triple &TT = getTriple();
   const char *Env = TT.isAndroid() ? "-android" : "";

 const char *ToolChain::getCompilerRTArgString(const llvm::opt::ArgList &Args,
                                               StringRef Component,
                                               bool Shared) const {
   return Args.MakeArgString(getCompilerRT(Args, Component, Shared));
 }
 
 std::string ToolChain::getArchSpecificLibPath() const {
   SmallString<128> Path(getDriver().ResourceDir);
-  StringRef OSLibName = getTriple().isOSFreeBSD() ? "freebsd" : getOS();
-  llvm::sys::path::append(Path, "lib", OSLibName,
+  llvm::sys::path::append(Path, "lib", getOSLibName(),
                           llvm::Triple::getArchTypeName(getArch()));
   return Path.str();
 }
 
 bool ToolChain::needsProfileRT(const ArgList &Args) {
   if (Args.hasFlag(options::OPT_fprofile_arcs, options::OPT_fno_profile_arcs,
                    false) ||
       Args.hasArg(options::OPT_fprofile_generate) ||

lib/Driver/ToolChains/CommonArgs.cpp

bool tools::addOpenMPRuntime(ArgStringList &CmdArgs, const ToolChain &TC,
   return true;
 }
 
 static void addSanitizerRuntime(const ToolChain &TC, const ArgList &Args,
                                 ArgStringList &CmdArgs, StringRef Sanitizer,
                                 bool IsShared, bool IsWhole) {
   // Wrap any static runtimes that must be forced into executable in
   // whole-archive.
-  if (IsWhole) CmdArgs.push_back("-whole-archive");
+  if (IsWhole) CmdArgs.push_back("--whole-archive");
   CmdArgs.push_back(TC.getCompilerRTArgString(Args, Sanitizer, IsShared));
-  if (IsWhole) CmdArgs.push_back("-no-whole-archive");
+  if (IsWhole) CmdArgs.push_back("--no-whole-archive");
 
   if (IsShared) {
     addArchSpecificRPath(TC, Args, CmdArgs);
   }
 }
 
 // Tries to use a file with the list of dynamic symbols that need to be exported
 // from the runtime library. Returns true if the file was found.
 static bool addSanitizerDynamicList(const ToolChain &TC, const ArgList &Args,
                                     ArgStringList &CmdArgs,
                                     StringRef Sanitizer) {
+  // Solaris ld defaults to --export-dynamic behaviour but doesn't support
+  // the option, so don't try to pass it.
+  if (TC.getTriple().getOS() == llvm::Triple::Solaris)
+    return true;
   SmallString<128> SanRT(TC.getCompilerRT(Args, Sanitizer));
   if (llvm::sys::fs::exists(SanRT + ".syms")) {
     CmdArgs.push_back(Args.MakeArgString("--dynamic-list=" + SanRT + ".syms"));
     return true;
   }
   return false;
 }
 
bool tools::addSanitizerRuntimes(const ToolChain &TC, const ArgList &Args,
   }
   for (auto S : RequiredSymbols) {
     CmdArgs.push_back("-u");
     CmdArgs.push_back(Args.MakeArgString(S));
   }
   // If there is a static runtime with no dynamic list, force all the symbols
   // to be dynamic to be sure we export sanitizer interface functions.
   if (AddExportDynamic)
-    CmdArgs.push_back("-export-dynamic");
+    CmdArgs.push_back("--export-dynamic");
 
   const SanitizerArgs &SanArgs = TC.getSanitizerArgs();
   if (SanArgs.hasCrossDsoCfi() && !AddExportDynamic)
     CmdArgs.push_back("-export-dynamic-symbol=__cfi_check");
 
   return !StaticRuntimes.empty() || !NonWholeStaticRuntimes.empty();
 }
 

lib/Driver/ToolChains/Solaris.h

public:
   void
   AddClangSystemIncludeArgs(const llvm::opt::ArgList &DriverArgs,
                             llvm::opt::ArgStringList &CC1Args) const override;
 
   void
   addLibStdCxxIncludePaths(const llvm::opt::ArgList &DriverArgs,
                            llvm::opt::ArgStringList &CC1Args) const override;
 
+  SanitizerMask getSupportedSanitizers() const override;
   unsigned GetDefaultDwarfVersion() const override { return 2; }
 
 protected:
   Tool *buildAssembler() const override;
   Tool *buildLinker() const override;
 };
 
 } // end namespace toolchains
 } // end namespace driver
 } // end namespace clang
 
 #endif // LLVM_CLANG_LIB_DRIVER_TOOLCHAINS_SOLARIS_H

lib/Driver/ToolChains/Solaris.cpp

if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nostartfiles)) {
 
     CmdArgs.push_back(Args.MakeArgString(getToolChain().GetFilePath("crti.o")));
     CmdArgs.push_back(
         Args.MakeArgString(getToolChain().GetFilePath("values-Xa.o")));
     CmdArgs.push_back(
         Args.MakeArgString(getToolChain().GetFilePath("crtbegin.o")));
   }
 
+  // Provide __start___sancov_guards.  Solaris ld doesn't automatically create
+  // __start_SECNAME labels.
+  CmdArgs.push_back("--whole-archive");
+  CmdArgs.push_back(
+      getToolChain().getCompilerRTArgString(Args, "sancov_begin", false));
+  CmdArgs.push_back("--no-whole-archive");
+
   getToolChain().AddFilePathLibArgs(Args, CmdArgs);
 
   Args.AddAllArgs(CmdArgs, {options::OPT_L, options::OPT_T_Group,
                             options::OPT_e, options::OPT_r});
 
+  bool NeedsSanitizerDeps = addSanitizerRuntimes(getToolChain(), Args, CmdArgs);
   AddLinkerInputs(getToolChain(), Inputs, Args, CmdArgs, JA);
 
   if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs)) {
     if (getToolChain().ShouldLinkCXXStdlib(Args))
       getToolChain().AddCXXStdlibLibArgs(Args, CmdArgs);
+    if (Args.hasArg(options::OPT_fstack_protector) ||
+        Args.hasArg(options::OPT_fstack_protector_strong) ||
+        Args.hasArg(options::OPT_fstack_protector_all)) {
+      // Explicitly link ssp libraries, not folded into Solaris libc.
+      CmdArgs.push_back("-lssp_nonshared");
+      CmdArgs.push_back("-lssp");
+    }
     CmdArgs.push_back("-lgcc_s");
     CmdArgs.push_back("-lc");
     if (!Args.hasArg(options::OPT_shared)) {
       CmdArgs.push_back("-lgcc");
       CmdArgs.push_back("-lm");
     }
+    if (NeedsSanitizerDeps)
+      linkSanitizerRuntimeDeps(getToolChain(), CmdArgs);
   }
 
+  // Provide __stop___sancov_guards.  Solaris ld doesn't automatically create
+  // __stop_SECNAME labels.
+  CmdArgs.push_back("--whole-archive");
+  CmdArgs.push_back(
+      getToolChain().getCompilerRTArgString(Args, "sancov_end", false));
+  CmdArgs.push_back("--no-whole-archive");
+
   if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nostartfiles)) {
     CmdArgs.push_back(
         Args.MakeArgString(getToolChain().GetFilePath("crtend.o")));
   }
   CmdArgs.push_back(Args.MakeArgString(getToolChain().GetFilePath("crtn.o")));
 
   getToolChain().addProfileRTLibs(Args, CmdArgs);
 
Solaris::Solaris(const Driver &D, const llvm::Triple &Triple,
   // If we are currently running Clang inside of the requested system root,
   // add its parent library path to those searched.
   if (StringRef(D.Dir).startswith(D.SysRoot))
     addPathIfExists(D, D.Dir + "/../lib", Paths);
 
   addPathIfExists(D, D.SysRoot + "/usr/lib" + LibSuffix, Paths);
 }
 
+SanitizerMask Solaris::getSupportedSanitizers() const {
+  const bool IsX86 = getTriple().getArch() == llvm::Triple::x86;
+  SanitizerMask Res = ToolChain::getSupportedSanitizers();
+  // FIXME: Omit X86_64 until 64-bit support is figured out.
+  if (IsX86) {
+    Res |= SanitizerKind::Address;
+  }
+  Res |= SanitizerKind::Vptr;
+  return Res;
+}
+
 Tool *Solaris::buildAssembler() const {
   return new tools::solaris::Assembler(*this);
 }
 
 Tool *Solaris::buildLinker() const { return new tools::solaris::Linker(*this); }
 
 void Solaris::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
                                         ArgStringList &CC1Args) const {