[clang] [RISCV][FMV] Support target_version (PR #99040)

[Craig Topper via cfe-commits]

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@@ -3056,6 +3056,45 @@ bool Sema::checkTargetVersionAttr(SourceLocation LiteralLoc, Decl *D,
   enum SecondParam { None };
   enum ThirdParam { Target, TargetClones, TargetVersion };
   llvm::SmallVector<StringRef, 8> Features;
+  if (Context.getTargetInfo().getTriple().isRISCV()) {
+
+    llvm::SmallVector<StringRef, 8> AttrStrs;
+    AttrStr.split(AttrStrs, ';');
+
+    bool IsPriority = false;
+    bool IsDefault = false;
+    for (auto &AttrStr : AttrStrs) {
+      // Only support arch=+ext,... syntax.
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topperc wrote:

What if someone writes `arch=rv64gc;default;` do we error for that?

https://github.com/llvm/llvm-project/pull/99040