[LLVM][Clang][AArch64] Implement AArch64 build attributes

llvm/lib/Support/AArch64BuildAttributes.cpp

@@ -39,7 +39,6 @@ StringRef getOptionalStr(unsigned Optional) {
   case OPTIONAL:
     return "optional";
   case OPTIONAL_NOT_FOUND:
-    LLVM_FALLTHROUGH;
   default:
     return "";
   }
@@ -62,17 +61,14 @@ StringRef getTypeStr(unsigned Type) {
   case NTBS:
     return "ntbs";
   case TYPE_NOT_FOUND:
-    LLVM_FALLTHROUGH;
   default:
     return "";
   }
 }
 SubsectionType getTypeID(StringRef Type) {
   return StringSwitch<SubsectionType>(Type)
-      .Case("uleb128", ULEB128)
-      .Case("ULEB128", ULEB128)
-      .Case("NTBS", NTBS)
-      .Case("ntbs", NTBS)
+      .Cases("uleb128", "ULEB128", ULEB128)
+      .Cases("ntbs", "NTBS", NTBS)
       .Default(TYPE_NOT_FOUND);
 }
 StringRef getSubsectionTypeUnknownError() {
@@ -86,7 +82,6 @@ StringRef getPauthABITagsStr(unsigned PauthABITag) {
   case TAG_PAUTH_SCHEMA:
     return "Tag_PAuth_Schema";
   case PAUTHABI_TAG_NOT_FOUND:
-    LLVM_FALLTHROUGH;
   default:
     return "";
   }
@@ -107,7 +102,6 @@ StringRef getFeatureAndBitsTagsStr(unsigned FeatureAndBitsTag) {
   case TAG_FEATURE_GCS:
     return "Tag_Feature_GCS";
   case FEATURE_AND_BITS_TAG_NOT_FOUND:
-    LLVM_FALLTHROUGH;
   default:
     return "";
   }

llvm/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp

@@ -7821,13 +7821,6 @@ bool AArch64AsmParser::parseDirectiveAeabiSubSectionHeader(SMLoc L) {
   // (3)uleb128 separated by 2 commas.
   MCAsmParser &Parser = getParser();
 
-  bool HasActiveSubsection = true;
-  std::unique_ptr<MCELFStreamer::AttributeSubSection> ActiveSubsection =
-      getTargetStreamer().getActiveAtributesSubsection();
-  if (nullptr == ActiveSubsection) {
-    HasActiveSubsection = false;
-  }
-
   // Consume the name (subsection name)
   StringRef SubsectionName;
   AArch64BuildAttributes::VendorID SubsectionNameID;
@@ -7846,6 +7839,13 @@ bool AArch64AsmParser::parseDirectiveAeabiSubSectionHeader(SMLoc L) {
     return true;
   }
 
+  bool SubsectionExists = true;
+  std::unique_ptr<MCELFStreamer::AttributeSubSection> ExistingSubsection =
+      getTargetStreamer().getActiveSubsectionByName(SubsectionName);
+  if (nullptr == ExistingSubsection) {
+    SubsectionExists = false;
+  }
+
   // Consume the first parameter (optionality parameter)
   AArch64BuildAttributes::SubsectionOptional IsOptional;
   // options: optional/required
@@ -7858,20 +7858,19 @@ bool AArch64AsmParser::parseDirectiveAeabiSubSectionHeader(SMLoc L) {
                 Optionality);
       return true;
     }
-    if (HasActiveSubsection &&
-        (SubsectionName == ActiveSubsection->VendorName)) {
-      if (IsOptional != ActiveSubsection->IsOptional) {
+    if (SubsectionExists) {
+      if (IsOptional != ExistingSubsection->IsOptional) {
         Error(Parser.getTok().getLoc(),
               "optionality mismatch! subsection '" + SubsectionName +
                   "' already exists with optionality defined as '" +
-                  Twine(ActiveSubsection->IsOptional) + "' and not '" +
+                  Twine(ExistingSubsection->IsOptional) + "' and not '" +
                   Twine(IsOptional) + "' (0: required, 1: optional)");
         return true;
       }
     }
   } else {
     Error(Parser.getTok().getLoc(),
-          "optionality parameter not found, expected required|optinal");
+          "optionality parameter not found, expected required|optional");
     return true;
   }
   // Check for possible IsOptional unaccepted values for known subsections
@@ -7906,13 +7905,12 @@ bool AArch64AsmParser::parseDirectiveAeabiSubSectionHeader(SMLoc L) {
                 Name);
       return true;
     }
-    if (HasActiveSubsection &&
-        (SubsectionName == ActiveSubsection->VendorName)) {
-      if (Type != ActiveSubsection->ParameterType) {
+    if (SubsectionExists) {
+      if (Type != ExistingSubsection->ParameterType) {
         Error(Parser.getTok().getLoc(),
               "type mismatch! subsection '" + SubsectionName +
                   "' already exists with type defined as '" +
-                  Twine(ActiveSubsection->ParameterType) + "' and not '" +
+                  Twine(ExistingSubsection->ParameterType) + "' and not '" +
                   Twine(Type) + "' (0: uleb128, 1: ntbs)");
         return true;
       }

llvm/lib/Target/AArch64/MCTargetDesc/AArch64ELFStreamer.cpp

@@ -189,9 +189,7 @@ class AArch64TargetAsmStreamer : public AArch64TargetStreamer {
                                              Override);
         break;
       case AArch64BuildAttributes::TAG_FEATURE_BTI:
-        LLVM_FALLTHROUGH;
       case AArch64BuildAttributes::TAG_FEATURE_GCS:
-        LLVM_FALLTHROUGH;
       case AArch64BuildAttributes::TAG_FEATURE_PAC:
         OS << "\t.aeabi_attribute" << "\t"
            << AArch64BuildAttributes::getFeatureAndBitsTagsStr(Tag) << ", "
@@ -212,7 +210,6 @@ class AArch64TargetAsmStreamer : public AArch64TargetStreamer {
                                              Override);
         break;
       case AArch64BuildAttributes::TAG_PAUTH_PLATFORM:
-        LLVM_FALLTHROUGH;
       case AArch64BuildAttributes::TAG_PAUTH_SCHEMA:
         OS << "\t.aeabi_attribute" << "\t"
            << AArch64BuildAttributes::getPauthABITagsStr(Tag) << ", " << Value;
@@ -246,16 +243,7 @@ class AArch64TargetAsmStreamer : public AArch64TargetStreamer {
 
     switch (SubsectionID) {
     default: {
-      assert(0 && "Subsection error");
-      break;
-    }
-    case AArch64BuildAttributes::VENDOR_UNKNOWN: {
-      // Keep the data structure consistent with the case of ELF emission
-      // (important for llvm-mc asm parsing)
-      OS << "\t" << SubsectionTag << "\t" << SubsectionName << ", "
-         << OptionalStr << ", " << ParameterStr;
-      AArch64TargetStreamer::emitAtributesSubsection(SubsectionName, Optional,
-                                                     ParameterType);
+      // Treated as a private subsection
       break;
     }
     case AArch64BuildAttributes::AEABI_PAUTHABI: {
@@ -265,10 +253,6 @@ class AArch64TargetAsmStreamer : public AArch64TargetStreamer {
       assert(AArch64BuildAttributes::ULEB128 == ParameterType &&
              "subsection .aeabi-pauthabi should be "
              "marked as uleb128 and not as ntbs");
-      OS << "\t" << SubsectionTag << "\t" << SubsectionName << ", "
-         << OptionalStr << ", " << ParameterStr;
-      AArch64TargetStreamer::emitAtributesSubsection(SubsectionName, Optional,
-                                                     ParameterType);
       break;
     }
     case AArch64BuildAttributes::AEABI_FEATURE_AND_BITS: {
@@ -278,13 +262,15 @@ class AArch64TargetAsmStreamer : public AArch64TargetStreamer {
       assert(AArch64BuildAttributes::ULEB128 == ParameterType &&
              "subsection .aeabi_feature_and_bits should "
              "be marked as uleb128 and not as ntbs");
-      OS << "\t" << SubsectionTag << "\t" << SubsectionName << ", "
-         << OptionalStr << ", " << ParameterStr;
-      AArch64TargetStreamer::emitAtributesSubsection(SubsectionName, Optional,
-                                                     ParameterType);
       break;
     }
     }
+    OS << "\t" << SubsectionTag << "\t" << SubsectionName << ", " << OptionalStr
+       << ", " << ParameterStr;
+    // Keep the data structure consistent with the case of ELF emission
+    // (important for llvm-mc asm parsing)
+    AArch64TargetStreamer::emitAtributesSubsection(SubsectionName, Optional,
+                                                   ParameterType);
     OS << "\n";
   }
 

llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.cpp

@@ -182,6 +182,16 @@ AArch64TargetStreamer::getActiveAtributesSubsection() {
   return nullptr;
 }
 
+std::unique_ptr<MCELFStreamer::AttributeSubSection>
+AArch64TargetStreamer::getActiveSubsectionByName(StringRef name) {
+  for (MCELFStreamer::AttributeSubSection &SubSection : AttributeSubSections) {
+    if (name == SubSection.VendorName) {
+      return std::make_unique<MCELFStreamer::AttributeSubSection>(SubSection);
+    }
+  }
+  return nullptr;
+}
+
 void AArch64TargetStreamer::emitAttribute(StringRef VendorName, unsigned Tag,
                                           unsigned Value, std::string String,
                                           bool Override) {

llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.h

@@ -104,6 +104,8 @@ class AArch64TargetStreamer : public MCTargetStreamer {
   void activateAtributesSubsection(StringRef VendorName);
   std::unique_ptr<MCELFStreamer::AttributeSubSection>
   getActiveAtributesSubsection();
+  std::unique_ptr<MCELFStreamer::AttributeSubSection>
+  getActiveSubsectionByName(StringRef name);
   void
   insertAttributeInPlace(const MCELFStreamer::AttributeItem &Attr,
                          MCELFStreamer::AttributeSubSection &AttSubSection);

llvm/test/MC/AArch64/aarch64-build-attributes-asm-err-headers.s

@@ -33,11 +33,11 @@
 // ERR-NEXT: .aeabi_subsection aeabi_pauthabi, a, uleb128
 
 .aeabi_subsection aeabi_pauthabi, 1, uleb128
-// ERR: error: optionality parameter not found, expected required|optinal
+// ERR: error: optionality parameter not found, expected required|optional
 // ERR-NEXT: .aeabi_subsection aeabi_pauthabi, 1, uleb128
 
 .aeabi_subsection aeabi_pauthabi, ,uleb128
-// ERR: error: optionality parameter not found, expected required|optinal
+// ERR: error: optionality parameter not found, expected required|optional
 // ERR-NEXT: .aeabi_subsection aeabi_pauthabi, ,uleb128
 
 .aeabi_subsection aeabi_pauthabi,uleb128
@@ -59,4 +59,3 @@
 .aeabi_subsection aeabi_pauthabi, required, a
 // ERR: error: unknown AArch64 build attributes type, expected uleb128|ntbs: a
 // ERR-NEXT: .aeabi_subsection aeabi_pauthabi, required, a
-

llvm/test/MC/AArch64/aarch64-build-attributes-asm-private-subsections-err.s

@@ -13,4 +13,16 @@
 .aeabi_subsection private_subsection_1, optional, ntbs
 .aeabi_attribute 324, 1
 // ERR: error: active subsection type is NTBS (string), found ULEB128 (unsigned)
-// ERR-NEXT: .aeabi_attribute 324, 1
+// ERR-NEXT: .aeabi_attribute 324, 1
+
+.aeabi_subsection foo, optional, uleb128
+.aeabi_subsection bar, optional, uleb128
+.aeabi_subsection foo, required, uleb128
+// ERR: error: optionality mismatch! subsection 'foo' already exists with optionality defined as '1' and not '0' (0: required, 1: optional)
+// ERR-NEXT: .aeabi_subsection foo, required, uleb128
+
+.aeabi_subsection goo, optional, ntbs
+.aeabi_subsection zar, optional, ntbs
+.aeabi_subsection goo, optional, uleb128
+// ERR: error: type mismatch! subsection 'goo' already exists with type defined as '1' and not '0' (0: uleb128, 1: ntbs)
+// ERR-NEXT: .aeabi_subsection goo, optional, uleb128