[Sanitizers] Basic Solaris sanitizer support (PR 33274)

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.

Reviewers: rsmith, alekseyshl

Reviewed By: alekseyshl

Subscribers: jyknight, fedor.sergeev, cfe-commits

Tags: #sanitizers

Differential Revision: https://reviews.llvm.org/D40903

llvm-svn: 324296

clang/include/clang/Driver/ToolChain.h

@@ -355,6 +355,9 @@ class ToolChain {
   // 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);
 

clang/lib/Driver/ToolChain.cpp

@@ -323,13 +323,23 @@ static StringRef getArchNameForCompilerRTLib(const ToolChain &TC,
   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();
 }
@@ -360,8 +370,7 @@ const char *ToolChain::getCompilerRTArgString(const llvm::opt::ArgList &Args,
 
 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();
 }

clang/lib/Driver/ToolChains/CommonArgs.cpp

@@ -508,9 +508,9 @@ static void addSanitizerRuntime(const ToolChain &TC, const ArgList &Args,
                                 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);
@@ -522,6 +522,10 @@ static void addSanitizerRuntime(const ToolChain &TC, const ArgList &Args,
 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"));
@@ -692,7 +696,7 @@ bool tools::addSanitizerRuntimes(const ToolChain &TC, const ArgList &Args,
   // 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)

clang/lib/Driver/ToolChains/Solaris.cpp

@@ -92,24 +92,48 @@ void solaris::Linker::ConstructJob(Compilation &C, const JobAction &JA,
         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")));
@@ -165,6 +189,17 @@ Solaris::Solaris(const Driver &D, const llvm::Triple &Triple,
   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);
 }

clang/lib/Driver/ToolChains/Solaris.h

@@ -65,6 +65,7 @@ class LLVM_LIBRARY_VISIBILITY Solaris : public Generic_ELF {
   addLibStdCxxIncludePaths(const llvm::opt::ArgList &DriverArgs,
                            llvm::opt::ArgStringList &CC1Args) const override;
 
+  SanitizerMask getSupportedSanitizers() const override;
   unsigned GetDefaultDwarfVersion() const override { return 2; }
 
 protected: