[llvm] [RISCV] Generate RISCVISAInfo table from RISCVFeatures.td. (PR #89955)

[Pengcheng Wang via llvm-commits]

================
@@ -17,6 +17,102 @@
 
 using namespace llvm;
 
+static StringRef getExtensionName(const Record *R) {
+  StringRef Name = R->getValueAsString("Name");
+  Name.consume_front("experimental-");
+  return Name;
+}
+
+namespace {
+
+struct LessRecordExtensionName {
+  bool operator()(const Record *Rec1, const Record *Rec2) const {
+    return getExtensionName(Rec1) < getExtensionName(Rec2);
+  }
+};
+
+} // end anonymous namespace
+
+static void printExtensionTable(raw_ostream &OS,
+                                const std::vector<Record *> &Extensions,
+                                bool Experimental) {
+  OS << "static const RISCVSupportedExtension Supported";
+  if (Experimental)
+    OS << "Experimental";
+  OS << "Extensions[] = {\n";
+
+  for (Record *R : Extensions) {
+    if (R->getValueAsBit("Experimental") != Experimental)
+      continue;
+
+    OS << "    {\"" << getExtensionName(R) << "\", {"
+       << R->getValueAsInt("MajorVersion") << ", "
+       << R->getValueAsInt("MinorVersion") << "}},\n";
+  }
+
+  OS << "};\n\n";
+}
+
+// Get the extension name from the Record name. This gives the canonical
+// capitalization.
+static StringRef getExtensionNameFromRecordName(const Record *R) {
+  StringRef Name = R->getName();
+  if (!Name.consume_front("FeatureStdExt"))
+    Name.consume_front("FeatureVendor");
+
+  return Name;
+}
+
+static void emitRISCVExtensions(RecordKeeper &Records, raw_ostream &OS) {
+  OS << "#ifdef GET_SUPPORTED_EXTENSIONS\n";
+  OS << "#undef GET_SUPPORTED_EXTENSIONS\n\n";
+
+  std::vector<Record *> Extensions =
+      Records.getAllDerivedDefinitions("RISCVExtension");
+  llvm::sort(Extensions, LessRecordExtensionName());
----------------
wangpc-pp wrote:

Use lambda?

https://github.com/llvm/llvm-project/pull/89955