fixup! [AArch64] Add ability to list extensions enabled for a target

Author: pratlucas

clang/include/clang/Driver/Options.td

@@ -5709,7 +5709,7 @@ def print_supported_extensions : Flag<["-", "--"], "print-supported-extensions">
   MarshallingInfoFlag<FrontendOpts<"PrintSupportedExtensions">>;
 def print_enabled_extensions : Flag<["-", "--"], "print-enabled-extensions">,
   Visibility<[ClangOption, CC1Option, CLOption]>,
-  HelpText<"Print the -march/-mcpu extensions enabled for the given target"
+  HelpText<"Print the extensions enabled by the given target and -march/-mcpu options."
            " (AArch64 only)">,
   MarshallingInfoFlag<FrontendOpts<"PrintEnabledExtensions">>;
 def : Flag<["-"], "mcpu=help">, Alias<print_supported_cpus>;

clang/lib/Driver/ToolChain.cpp

@@ -195,7 +195,7 @@ static void getAArch64MultilibFlags(const Driver &D,
                                        UnifiedFeatures.end());
   std::vector<std::string> MArch;
   for (const auto &Ext : AArch64::Extensions)
-    if (FeatureSet.contains(Ext.TargetFeature))
+    if (FeatureSet.contains(Ext.PosTargetFeature))
       MArch.push_back(Ext.UserVisibleName.str());
   for (const auto &Ext : AArch64::Extensions)
     if (FeatureSet.contains(Ext.NegTargetFeature))

clang/lib/Driver/ToolChains/Clang.cpp

@@ -1523,7 +1523,7 @@ static void CollectARMPACBTIOptions(const ToolChain &TC, const ArgList &Args,
       auto isPAuthLR = [](const char *member) {
         llvm::AArch64::ExtensionInfo pauthlr_extension =
             llvm::AArch64::getExtensionByID(llvm::AArch64::AEK_PAUTHLR);
-        return pauthlr_extension.TargetFeature == member;
+        return pauthlr_extension.PosTargetFeature == member;
       };
 
       if (std::any_of(CmdArgs.begin(), CmdArgs.end(), isPAuthLR))

llvm/include/llvm/TargetParser/AArch64TargetParser.h

@@ -114,14 +114,18 @@ using ExtensionBitset = Bitset<AEK_NUM_EXTENSIONS>;
 // SubtargetFeature which may represent either an actual extension or some
 // internal LLVM property.
 struct ExtensionInfo {
-  StringRef UserVisibleName;      // Human readable name used in -march/-cpu, e.g. "profile"
+  StringRef UserVisibleName;      // Human readable name used in -march, -cpu
+                                  // and target func attribute, e.g. "profile".
   std::optional<StringRef> Alias; // An alias for this extension, if one exists.
   ArchExtKind ID;                 // Corresponding to the ArchExtKind, this
                                   // extensions representation in the bitfield.
-  StringRef ArchFeatureName;      // The feature name defined by the Architecture
-  StringRef Description;          // The textual description of the extension
-  StringRef TargetFeature;        // -target-feature/-mattr enable string, e.g. "+spe"
-  StringRef NegTargetFeature;     // -target-feature/-mattr disable string, e.g. "-spe"
+  StringRef ArchFeatureName;      // The feature name defined by the
+                                  // Architecture, e.g. FEAT_AdvSIMD.
+  StringRef Description;          // The textual description of the extension.
+  StringRef PosTargetFeature;     // -target-feature/-mattr enable string,
+                                  // e.g. "+spe".
+  StringRef NegTargetFeature;     // -target-feature/-mattr disable string,
+                                  // e.g. "-spe".
   CPUFeatures CPUFeature;      // Function Multi Versioning (FMV) bitfield value
                                // set in __aarch64_cpu_features
   StringRef DependentFeatures; // FMV enabled features string,
@@ -275,10 +279,10 @@ struct ExtensionSet {
       Features.emplace_back(T(BaseArch->ArchFeature));
 
     for (const auto &E : Extensions) {
-      if (E.TargetFeature.empty() || !Touched.test(E.ID))
+      if (E.PosTargetFeature.empty() || !Touched.test(E.ID))
         continue;
       if (Enabled.test(E.ID))
-        Features.emplace_back(T(E.TargetFeature));
+        Features.emplace_back(T(E.PosTargetFeature));
       else
         Features.emplace_back(T(E.NegTargetFeature));
     }

llvm/lib/TargetParser/AArch64TargetParser.cpp

@@ -58,8 +58,8 @@ bool AArch64::getExtensionFeatures(
     std::vector<StringRef> &Features) {
   for (const auto &E : Extensions)
     /* INVALID and NONE have no feature name. */
-    if (InputExts.test(E.ID) && !E.TargetFeature.empty())
-      Features.push_back(E.TargetFeature);
+    if (InputExts.test(E.ID) && !E.PosTargetFeature.empty())
+      Features.push_back(E.PosTargetFeature);
 
   return true;
 }
@@ -77,7 +77,7 @@ StringRef AArch64::getArchExtFeature(StringRef ArchExt) {
 
   if (auto AE = parseArchExtension(ArchExtBase)) {
     // Note: the returned string can be empty.
-    return IsNegated ? AE->NegTargetFeature : AE->TargetFeature;
+    return IsNegated ? AE->NegTargetFeature : AE->PosTargetFeature;
   }
 
   return StringRef();
@@ -112,9 +112,9 @@ const AArch64::ArchInfo *AArch64::parseArch(StringRef Arch) {
 
 std::optional<AArch64::ExtensionInfo>
 AArch64::parseArchExtension(StringRef ArchExt) {
+  if (ArchExt.empty())
+    return {};
   for (const auto &A : Extensions) {
-    if (A.UserVisibleName.empty() && !A.Alias)
-      continue;
     if (ArchExt == A.UserVisibleName || ArchExt == A.Alias)
       return A;
   }
@@ -124,7 +124,7 @@ AArch64::parseArchExtension(StringRef ArchExt) {
 std::optional<AArch64::ExtensionInfo>
 AArch64::targetFeatureToExtension(StringRef TargetFeature) {
   for (const auto &E : Extensions)
-    if (TargetFeature == E.TargetFeature)
+    if (TargetFeature == E.PosTargetFeature)
       return E;
   return {};
 }
@@ -148,7 +148,7 @@ void AArch64::PrintSupportedExtensions() {
          << "Description\n";
   for (const auto &Ext : Extensions) {
     // Extensions without a feature cannot be used with -march.
-    if (!Ext.UserVisibleName.empty() && !Ext.TargetFeature.empty()) {
+    if (!Ext.UserVisibleName.empty() && !Ext.PosTargetFeature.empty()) {
       outs() << "    "
              << format(Ext.Description.empty() ? "%-20s%s\n" : "%-20s%-55s%s\n",
                        Ext.UserVisibleName.str().c_str(),
@@ -164,7 +164,7 @@ AArch64::printEnabledExtensions(std::vector<StringRef> EnabledFeatureNames) {
          << "    " << left_justify("Architecture Feature(s)", 55)
          << "Description\n";
   auto IsEnabled = [&](const ExtensionInfo &Ext) {
-    StringRef FeatureName = Ext.TargetFeature.drop_front(); // drop '+' before comparing
+    StringRef FeatureName = Ext.PosTargetFeature.drop_front(); // drop '+' before comparing
     return std::find(EnabledFeatureNames.begin(), EnabledFeatureNames.end(),
                      FeatureName) != EnabledFeatureNames.end();
   };
@@ -275,7 +275,7 @@ bool AArch64::ExtensionSet::parseModifier(StringRef Modifier,
   StringRef ArchExt = Modifier.drop_front(NChars);
 
   if (auto AE = parseArchExtension(ArchExt)) {
-    if (AE->TargetFeature.empty() || AE->NegTargetFeature.empty())
+    if (AE->PosTargetFeature.empty() || AE->NegTargetFeature.empty())
       return false;
     if (IsNegated)
       disable(AE->ID);