[Clang][RISCV] Recognize unsupport feature by supporting isValidFeatureName

Author: BeMg

clang/lib/Basic/Targets/RISCV.cpp

@@ -478,3 +478,10 @@ bool RISCVTargetInfo::validateCpuSupports(StringRef Feature) const {
   // __riscv_feature_bits structure.
   return -1 != llvm::RISCVISAInfo::getRISCVFeaturesBitsInfo(Feature).second;
 }
+
+bool RISCVTargetInfo::isValidFeatureName(StringRef Name) const {
+  if (Name == "__RISCV_TargetAttrNeedOverride")
+    return true;
+
+  return llvm::RISCVISAInfo::isSupportedExtensionFeature(Name);
+}

clang/lib/Basic/Targets/RISCV.h

@@ -130,6 +130,7 @@ class RISCVTargetInfo : public TargetInfo {
   bool supportsCpuSupports() const override { return getTriple().isOSLinux(); }
   bool supportsCpuInit() const override { return getTriple().isOSLinux(); }
   bool validateCpuSupports(StringRef Feature) const override;
+  bool isValidFeatureName(StringRef Name) const override;
 };
 class LLVM_LIBRARY_VISIBILITY RISCV32TargetInfo : public RISCVTargetInfo {
 public:

clang/lib/Sema/SemaDeclAttr.cpp

@@ -2993,10 +2993,17 @@ bool Sema::checkTargetAttr(SourceLocation LiteralLoc, StringRef AttrStr) {
     return Diag(LiteralLoc, diag::warn_unsupported_target_attribute)
            << Unknown << Tune << ParsedAttrs.Tune << Target;
 
-  if (Context.getTargetInfo().getTriple().isRISCV() &&
-      ParsedAttrs.Duplicate != "")
-    return Diag(LiteralLoc, diag::err_duplicate_target_attribute)
-           << Duplicate << None << ParsedAttrs.Duplicate << Target;
+  if (Context.getTargetInfo().getTriple().isRISCV()) {
+    if (ParsedAttrs.Duplicate != "")
+      return Diag(LiteralLoc, diag::err_duplicate_target_attribute)
+             << Duplicate << None << ParsedAttrs.Duplicate << Target;
+    for (const auto &Feature : ParsedAttrs.Features) {
+      auto CurFeature = StringRef(Feature);
+      if (!CurFeature.starts_with("+") && !CurFeature.starts_with("-"))
+        return Diag(LiteralLoc, diag::warn_unsupported_target_attribute)
+               << Unsupported << None << AttrStr << Target;
+    }
+  }
 
   if (ParsedAttrs.Duplicate != "")
     return Diag(LiteralLoc, diag::warn_unsupported_target_attribute)

clang/test/Sema/attr-target-riscv.c

@@ -4,3 +4,12 @@
 int __attribute__((target("arch=rv64g"))) foo(void) { return 0; }
 //expected-error@+1 {{redefinition of 'foo'}}
 int __attribute__((target("arch=rv64gc"))) foo(void) { return 0; }
+
+//expected-warning@+1 {{unsupported 'notafeature' in the 'target' attribute string; 'target' attribute ignored}}
+int __attribute__((target("arch=+notafeature"))) UnsupportFeature(void) { return 0; }
+
+//expected-warning@+1 {{unsupported 'arch=+zba,zbb' in the 'target' attribute string; 'target' attribute ignored}}
+int __attribute__((target("arch=+zba,zbb"))) WithoutAddSigned(void) { return 0; }
+
+//expected-warning@+1 {{unsupported 'arch=zba' in the 'target' attribute string; 'target' attribute ignored}}
+int __attribute__((target("arch=zba"))) WithoutAddSigned2(void) { return 0; }