[clang] [CIR] Upstream func args alloca handling (PR #129167)

[Andy Kaylor via cfe-commits]

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@@ -149,16 +153,49 @@ mlir::LogicalResult CIRGenFunction::declare(Address addr, const Decl *var,
 
 void CIRGenFunction::startFunction(GlobalDecl gd, QualType returnType,
                                    cir::FuncOp fn, cir::FuncType funcType,
-                                   SourceLocation loc,
+                                   FunctionArgList args, SourceLocation loc,
                                    SourceLocation startLoc) {
   assert(!curFn &&
          "CIRGenFunction can only be used for one function at a time");
 
   fnRetTy = returnType;
   curFn = fn;
 
+  const auto *fd = dyn_cast_or_null<FunctionDecl>(gd.getDecl());
+
   mlir::Block *entryBB = &fn.getBlocks().front();
   builder.setInsertionPointToStart(entryBB);
+
+  // TODO(cir): this should live in `emitFunctionProlog
+  // Declare all the function arguments in the symbol table.
+  for (const auto nameValue : llvm::zip(args, entryBB->getArguments())) {
+    auto *paramVar = std::get<0>(nameValue);
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andykaylor wrote:

Yeah, I know this. I don't know how I missed these. I'll probably do this a few more times before it completely sinks in.

https://github.com/llvm/llvm-project/pull/129167