[llvm] [Xtensa] Implement base CallConvention. (PR #83280)

[Sergei Barannikov via llvm-commits]

================
@@ -686,6 +763,57 @@ bool XtensaAsmParser::ParseInstruction(ParseInstructionInfo &Info,
   return false;
 }
 
+bool XtensaAsmParser::parseLiteralDirective(SMLoc L) {
+  MCAsmParser &Parser = getParser();
+  const MCExpr *Value;
+  SMLoc LiteralLoc = getLexer().getLoc();
+  XtensaTargetStreamer &TS = this->getTargetStreamer();
+
+  if (Parser.parseExpression(Value))
+    return true;
+
+  const MCSymbolRefExpr *SE = dyn_cast<MCSymbolRefExpr>(Value);
+
+  if (!SE)
+    return Error(LiteralLoc, "literal label must be a symbol");
+
+  if (Parser.parseToken(AsmToken::Comma, "expected comma"))
+    return true;
+
+  SMLoc OpcodeLoc = getLexer().getLoc();
+  if (parseOptionalToken(AsmToken::EndOfStatement))
+    return Error(OpcodeLoc, "expected value");
+
+  if (Parser.parseExpression(Value))
+    return true;
+
+  MCSymbol *Sym = getContext().getOrCreateSymbol(SE->getSymbol().getName());
+
+  TS.emitLiteral(Sym, Value, LiteralLoc);
+
+  return false;
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s-barannikov wrote:

The method should consume the terminating newline.

https://github.com/llvm/llvm-project/pull/83280