[AArch64] Make the memtag sanitizer require the memtag extension

[chill]

Summary

... or otherwise we get an ICE.

[vitalybuka]

clang/lib/Driver/ToolChains/Clang.cpp

1561 ↗

(On Diff #212558)

Please move back Driver closer to the first use

1624 ↗

(On Diff #212558)

maybe better place is somewhere near llvm/tools/clang/lib/Driver/SanitizerArgs.cpp:1020

clang/test/Driver/fsanitize.c

194

Can you also add command line where driver accepts flags?

[chill]

clang/lib/Driver/ToolChains/Clang.cpp

1624 ↗

(On Diff #212558)

The check is target specific, I prefer to keep it in a function that's already target specific anyway.

[chill]

clang/lib/Driver/ToolChains/Clang.cpp

1632 ↗

(On Diff #213597)

I've already fixed the line length here.

[vitalybuka]

clang/lib/Driver/ToolChains/Clang.cpp

1624 ↗

(On Diff #212558)

My thoughts here are that the check is both sanitizer specific and platform specific. However it's going to be always sanitizers specific, but in theory we may get more platforms supporting "mte".

Also right now err_stack_tagging_requires_hardware_feature is very platform specific.
Something less specific?

'-fsanitize=memtag' requires hardware support (+memtag)

[eugenis]

clang/lib/Driver/SanitizerArgs.cpp

1054

I'm a bit worried that this check can be satisfied by, say, a source file or a relative include path of "+mte".

[chill]

clang/lib/Driver/SanitizerArgs.cpp

1054

Fair enough, I've updated the patch.

[eugenis]

LGTM

clang/include/clang/Basic/DiagnosticDriverKinds.td

def warn_slash_u_filename : Warning<"'/U%0' treated as the '/U' option">,
   InGroup<DiagGroup<"slash-u-filename">>;
 def note_use_dashdash : Note<"Use '--' to treat subsequent arguments as filenames">;
 
 def err_drv_ropi_rwpi_incompatible_with_pic : Error<
   "embedded and GOT-based position independence are incompatible">;
 def err_drv_ropi_incompatible_with_cxx : Error<
   "ROPI is not compatible with c++">;
 
+def err_stack_tagging_requires_hardware_feature : Error<
+  "'-fsanitize=memtag' requires hardware support (+memtag)">;
+
 def warn_target_unsupported_nan2008 : Warning<
   "ignoring '-mnan=2008' option because the '%0' architecture does not support it">,
   InGroup<UnsupportedNan>;
 def warn_target_unsupported_nanlegacy : Warning<
   "ignoring '-mnan=legacy' option because the '%0' architecture does not support it">,
   InGroup<UnsupportedNan>;
 def warn_target_unsupported_abslegacy : Warning<
   "ignoring '-mabs=legacy' option because the '%0' architecture does not support it">,

clang/lib/Driver/SanitizerArgs.cpp

static void addIncludeLinkerOption(const ToolChain &TC,
   if (TC.getTriple().getArch() == llvm::Triple::x86) {
     // Win32 mangles C function names with a '_' prefix.
     LinkerOptionFlag += '_';
   }
   LinkerOptionFlag += SymbolName;
   CmdArgs.push_back(Args.MakeArgString(LinkerOptionFlag));
 }
 
+static bool hasTargetFeatureMTE(const llvm::opt::ArgStringList &CmdArgs) {
+  for (auto Start = CmdArgs.begin(), End = CmdArgs.end(); Start != End; ++Start) {
+    auto It = std::find(Start, End, StringRef("+mte"));
+    if (It == End)
+      break;
+    if (It > Start && *std::prev(It) == StringRef("-target-feature"))
+      return true;
+    Start = It;
+  }
+  return false;
+}
+
 void SanitizerArgs::addArgs(const ToolChain &TC, const llvm::opt::ArgList &Args,
                             llvm::opt::ArgStringList &CmdArgs,
                             types::ID InputType) const {
   // NVPTX doesn't currently support sanitizers.  Bailing out here means that
   // e.g. -fsanitize=address applies only to host code, which is what we want
   // for now.
   if (TC.getTriple().isNVPTX())
     return;
void SanitizerArgs::addArgs(const ToolChain &TC, const llvm::opt::ArgList &Args,
   // enabled.
   if (Sanitizers.hasOneOf(CFIClasses) && !TC.getTriple().isOSWindows() &&
       !Args.hasArg(options::OPT_fvisibility_EQ)) {
     TC.getDriver().Diag(clang::diag::err_drv_argument_only_allowed_with)
         << lastArgumentForMask(TC.getDriver(), Args,
                                Sanitizers.Mask & CFIClasses)
         << "-fvisibility=";
   }
+
+  if (Sanitizers.has(SanitizerKind::MemTag) && !hasTargetFeatureMTE(CmdArgs))
+    TC.getDriver().Diag(diag::err_stack_tagging_requires_hardware_feature);
 }
 
 SanitizerMask parseArgValues(const Driver &D, const llvm::opt::Arg *A,
                              bool DiagnoseErrors) {
   assert((A->getOption().matches(options::OPT_fsanitize_EQ) ||
           A->getOption().matches(options::OPT_fno_sanitize_EQ) ||
           A->getOption().matches(options::OPT_fsanitize_recover_EQ) ||
           A->getOption().matches(options::OPT_fno_sanitize_recover_EQ) ||
           A->getOption().matches(options::OPT_fsanitize_trap_EQ) ||

clang/test/Driver/fsanitize.c

 
 // RUN: %clang -target aarch64-linux-android -fsanitize=memtag,hwaddress -fno-rtti %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-SANMT-SANHA
 // CHECK-SANMT-SANHA: '-fsanitize=memtag' not allowed with '-fsanitize=hwaddress'
 
 // RUN: %clang -target i386-linux-android -fsanitize=memtag -fno-rtti %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-SANMT-BAD-ARCH
 // RUN: %clang -target x86_64-linux-android -fsanitize=memtag -fno-rtti %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-SANMT-BAD-ARCH
 // CHECK-SANMT-BAD-ARCH: unsupported option '-fsanitize=memtag' for target
 
+// RUN: %clang -target aarch64-linux -fsanitize=memtag -march=armv8-a+memtag %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-SANMT-MT
+// CHECK-SANMT-MT: "-target-feature" "+mte"
+// CHECK-SANMT-MT-SAME: "-fsanitize=memtag"
+
+// RUN: %clang -target aarch64-linux -fsanitize=memtag %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-SANMT-NOMT-0
+// CHECK-SANMT-NOMT-0: '-fsanitize=memtag' requires hardware support (+memtag)
+
+// RUN: %clang -target aarch64-linux -fsanitize=memtag -I +mte %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-SANMT-NOMT-1
+// CHECK-SANMT-NOMT-1: '-fsanitize=memtag' requires hardware support (+memtag)
+
 // RUN: %clang -target x86_64-linux-gnu -fsanitize=address -fsanitize-address-use-after-scope %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-USE-AFTER-SCOPE
 // RUN: %clang_cl --target=x86_64-windows -fsanitize=address -fsanitize-address-use-after-scope -### -- %s 2>&1 | FileCheck %s --check-prefix=CHECK-USE-AFTER-SCOPE
 // CHECK-USE-AFTER-SCOPE: -cc1{{.*}}-fsanitize-address-use-after-scope
 
 // RUN: %clang -target x86_64-linux-gnu -fsanitize=address -fno-sanitize-address-use-after-scope %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-USE-AFTER-SCOPE-OFF
 // RUN: %clang_cl --target=x86_64-windows -fsanitize=address -fno-sanitize-address-use-after-scope -### -- %s 2>&1 | FileCheck %s --check-prefix=CHECK-USE-AFTER-SCOPE-OFF
 // CHECK-USE-AFTER-SCOPE-OFF-NOT: -cc1{{.*}}address-use-after-scope