Enable LLVM asan support for NetBSD/amd64

Summary:
Enable LLVM asan sanitizer for NetBSD/amd64.

Don't generate -ldl for dlopen(3)-like functions on NetBSD.
These features are available in libc on NetBSD.

Sponsored by <The NetBSD Foundation>

Reviewers: joerg, eugenis, kcc, dim

Reviewed By: dim

Subscribers: #clang, #sanitizers

Tags: #clang, #sanitizers

Differential Revision: https://reviews.llvm.org/D34960

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@307104 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Driver/ToolChains/CommonArgs.cpp

@@ -524,6 +524,7 @@ void tools::linkSanitizerRuntimeDeps(const ToolChain &TC,
   CmdArgs.push_back("-lm");
   // There's no libdl on FreeBSD or RTEMS.
   if (TC.getTriple().getOS() != llvm::Triple::FreeBSD &&
+      TC.getTriple().getOS() != llvm::Triple::NetBSD &&
       TC.getTriple().getOS() != llvm::Triple::RTEMS)
     CmdArgs.push_back("-ldl");
 }

lib/Driver/ToolChains/NetBSD.cpp

@@ -15,6 +15,7 @@
 #include "clang/Driver/Compilation.h"
 #include "clang/Driver/Driver.h"
 #include "clang/Driver/Options.h"
+#include "clang/Driver/SanitizerArgs.h"
 #include "llvm/Option/ArgList.h"
 
 using namespace clang::driver;
@@ -246,6 +247,7 @@ void netbsd::Linker::ConstructJob(Compilation &C, const JobAction &JA,
   Args.AddAllArgs(CmdArgs, options::OPT_Z_Flag);
   Args.AddAllArgs(CmdArgs, options::OPT_r);
 
+  bool NeedsSanitizerDeps = addSanitizerRuntimes(getToolChain(), Args, CmdArgs);
   AddLinkerInputs(getToolChain(), Inputs, Args, CmdArgs, JA);
 
   unsigned Major, Minor, Micro;
@@ -279,6 +281,8 @@ void netbsd::Linker::ConstructJob(Compilation &C, const JobAction &JA,
       getToolChain().AddCXXStdlibLibArgs(Args, CmdArgs);
       CmdArgs.push_back("-lm");
     }
+    if (NeedsSanitizerDeps)
+      linkSanitizerRuntimeDeps(getToolChain(), CmdArgs);
     if (Args.hasArg(options::OPT_pthread))
       CmdArgs.push_back("-lpthread");
     CmdArgs.push_back("-lc");
@@ -410,3 +414,12 @@ void NetBSD::addLibStdCxxIncludePaths(const llvm::opt::ArgList &DriverArgs,
   addLibStdCXXIncludePaths(getDriver().SysRoot, "/usr/include/g++", "", "", "",
                            "", DriverArgs, CC1Args);
 }
+
+SanitizerMask NetBSD::getSupportedSanitizers() const {
+  const bool IsX86_64 = getTriple().getArch() == llvm::Triple::x86_64;
+  SanitizerMask Res = ToolChain::getSupportedSanitizers();
+  if (IsX86_64) {
+    Res |= SanitizerKind::Address;
+  }
+  return Res;
+}

lib/Driver/ToolChains/NetBSD.h

@@ -66,6 +66,7 @@ class LLVM_LIBRARY_VISIBILITY NetBSD : public Generic_ELF {
       llvm::opt::ArgStringList &CC1Args) const override;
 
   bool IsUnwindTablesDefault() const override { return true; }
+  SanitizerMask getSupportedSanitizers() const override;
 
 protected:
   Tool *buildAssembler() const override;